1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/bitmap.h> 3 #include <linux/kernel.h> 4 #include <linux/module.h> 5 #include <linux/interrupt.h> 6 #include <linux/irq.h> 7 #include <linux/spinlock.h> 8 #include <linux/list.h> 9 #include <linux/device.h> 10 #include <linux/err.h> 11 #include <linux/debugfs.h> 12 #include <linux/seq_file.h> 13 #include <linux/gpio.h> 14 #include <linux/of_gpio.h> 15 #include <linux/idr.h> 16 #include <linux/slab.h> 17 #include <linux/acpi.h> 18 #include <linux/gpio/driver.h> 19 #include <linux/gpio/machine.h> 20 #include <linux/pinctrl/consumer.h> 21 #include <linux/cdev.h> 22 #include <linux/fs.h> 23 #include <linux/uaccess.h> 24 #include <linux/compat.h> 25 #include <linux/anon_inodes.h> 26 #include <linux/file.h> 27 #include <linux/kfifo.h> 28 #include <linux/poll.h> 29 #include <linux/timekeeping.h> 30 #include <uapi/linux/gpio.h> 31 32 #include "gpiolib.h" 33 34 #define CREATE_TRACE_POINTS 35 #include <trace/events/gpio.h> 36 37 /* Implementation infrastructure for GPIO interfaces. 38 * 39 * The GPIO programming interface allows for inlining speed-critical 40 * get/set operations for common cases, so that access to SOC-integrated 41 * GPIOs can sometimes cost only an instruction or two per bit. 42 */ 43 44 45 /* When debugging, extend minimal trust to callers and platform code. 46 * Also emit diagnostic messages that may help initial bringup, when 47 * board setup or driver bugs are most common. 48 * 49 * Otherwise, minimize overhead in what may be bitbanging codepaths. 50 */ 51 #ifdef DEBUG 52 #define extra_checks 1 53 #else 54 #define extra_checks 0 55 #endif 56 57 /* Device and char device-related information */ 58 static DEFINE_IDA(gpio_ida); 59 static dev_t gpio_devt; 60 #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ 61 static struct bus_type gpio_bus_type = { 62 .name = "gpio", 63 }; 64 65 /* 66 * Number of GPIOs to use for the fast path in set array 67 */ 68 #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT 69 70 /* gpio_lock prevents conflicts during gpio_desc[] table updates. 71 * While any GPIO is requested, its gpio_chip is not removable; 72 * each GPIO's "requested" flag serves as a lock and refcount. 73 */ 74 DEFINE_SPINLOCK(gpio_lock); 75 76 static DEFINE_MUTEX(gpio_lookup_lock); 77 static LIST_HEAD(gpio_lookup_list); 78 LIST_HEAD(gpio_devices); 79 80 static DEFINE_MUTEX(gpio_machine_hogs_mutex); 81 static LIST_HEAD(gpio_machine_hogs); 82 83 static void gpiochip_free_hogs(struct gpio_chip *chip); 84 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, 85 struct lock_class_key *lock_key, 86 struct lock_class_key *request_key); 87 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip); 88 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip); 89 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip); 90 91 static bool gpiolib_initialized; 92 93 static inline void desc_set_label(struct gpio_desc *d, const char *label) 94 { 95 d->label = label; 96 } 97 98 /** 99 * gpio_to_desc - Convert a GPIO number to its descriptor 100 * @gpio: global GPIO number 101 * 102 * Returns: 103 * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO 104 * with the given number exists in the system. 105 */ 106 struct gpio_desc *gpio_to_desc(unsigned gpio) 107 { 108 struct gpio_device *gdev; 109 unsigned long flags; 110 111 spin_lock_irqsave(&gpio_lock, flags); 112 113 list_for_each_entry(gdev, &gpio_devices, list) { 114 if (gdev->base <= gpio && 115 gdev->base + gdev->ngpio > gpio) { 116 spin_unlock_irqrestore(&gpio_lock, flags); 117 return &gdev->descs[gpio - gdev->base]; 118 } 119 } 120 121 spin_unlock_irqrestore(&gpio_lock, flags); 122 123 if (!gpio_is_valid(gpio)) 124 WARN(1, "invalid GPIO %d\n", gpio); 125 126 return NULL; 127 } 128 EXPORT_SYMBOL_GPL(gpio_to_desc); 129 130 /** 131 * gpiochip_get_desc - get the GPIO descriptor corresponding to the given 132 * hardware number for this chip 133 * @chip: GPIO chip 134 * @hwnum: hardware number of the GPIO for this chip 135 * 136 * Returns: 137 * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists 138 * in the given chip for the specified hardware number. 139 */ 140 struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip, 141 u16 hwnum) 142 { 143 struct gpio_device *gdev = chip->gpiodev; 144 145 if (hwnum >= gdev->ngpio) 146 return ERR_PTR(-EINVAL); 147 148 return &gdev->descs[hwnum]; 149 } 150 151 /** 152 * desc_to_gpio - convert a GPIO descriptor to the integer namespace 153 * @desc: GPIO descriptor 154 * 155 * This should disappear in the future but is needed since we still 156 * use GPIO numbers for error messages and sysfs nodes. 157 * 158 * Returns: 159 * The global GPIO number for the GPIO specified by its descriptor. 160 */ 161 int desc_to_gpio(const struct gpio_desc *desc) 162 { 163 return desc->gdev->base + (desc - &desc->gdev->descs[0]); 164 } 165 EXPORT_SYMBOL_GPL(desc_to_gpio); 166 167 168 /** 169 * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs 170 * @desc: descriptor to return the chip of 171 */ 172 struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) 173 { 174 if (!desc || !desc->gdev) 175 return NULL; 176 return desc->gdev->chip; 177 } 178 EXPORT_SYMBOL_GPL(gpiod_to_chip); 179 180 /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ 181 static int gpiochip_find_base(int ngpio) 182 { 183 struct gpio_device *gdev; 184 int base = ARCH_NR_GPIOS - ngpio; 185 186 list_for_each_entry_reverse(gdev, &gpio_devices, list) { 187 /* found a free space? */ 188 if (gdev->base + gdev->ngpio <= base) 189 break; 190 else 191 /* nope, check the space right before the chip */ 192 base = gdev->base - ngpio; 193 } 194 195 if (gpio_is_valid(base)) { 196 pr_debug("%s: found new base at %d\n", __func__, base); 197 return base; 198 } else { 199 pr_err("%s: cannot find free range\n", __func__); 200 return -ENOSPC; 201 } 202 } 203 204 /** 205 * gpiod_get_direction - return the current direction of a GPIO 206 * @desc: GPIO to get the direction of 207 * 208 * Returns 0 for output, 1 for input, or an error code in case of error. 209 * 210 * This function may sleep if gpiod_cansleep() is true. 211 */ 212 int gpiod_get_direction(struct gpio_desc *desc) 213 { 214 struct gpio_chip *chip; 215 unsigned offset; 216 int status; 217 218 chip = gpiod_to_chip(desc); 219 offset = gpio_chip_hwgpio(desc); 220 221 if (!chip->get_direction) 222 return -ENOTSUPP; 223 224 status = chip->get_direction(chip, offset); 225 if (status > 0) { 226 /* GPIOF_DIR_IN, or other positive */ 227 status = 1; 228 clear_bit(FLAG_IS_OUT, &desc->flags); 229 } 230 if (status == 0) { 231 /* GPIOF_DIR_OUT */ 232 set_bit(FLAG_IS_OUT, &desc->flags); 233 } 234 return status; 235 } 236 EXPORT_SYMBOL_GPL(gpiod_get_direction); 237 238 /* 239 * Add a new chip to the global chips list, keeping the list of chips sorted 240 * by range(means [base, base + ngpio - 1]) order. 241 * 242 * Return -EBUSY if the new chip overlaps with some other chip's integer 243 * space. 244 */ 245 static int gpiodev_add_to_list(struct gpio_device *gdev) 246 { 247 struct gpio_device *prev, *next; 248 249 if (list_empty(&gpio_devices)) { 250 /* initial entry in list */ 251 list_add_tail(&gdev->list, &gpio_devices); 252 return 0; 253 } 254 255 next = list_entry(gpio_devices.next, struct gpio_device, list); 256 if (gdev->base + gdev->ngpio <= next->base) { 257 /* add before first entry */ 258 list_add(&gdev->list, &gpio_devices); 259 return 0; 260 } 261 262 prev = list_entry(gpio_devices.prev, struct gpio_device, list); 263 if (prev->base + prev->ngpio <= gdev->base) { 264 /* add behind last entry */ 265 list_add_tail(&gdev->list, &gpio_devices); 266 return 0; 267 } 268 269 list_for_each_entry_safe(prev, next, &gpio_devices, list) { 270 /* at the end of the list */ 271 if (&next->list == &gpio_devices) 272 break; 273 274 /* add between prev and next */ 275 if (prev->base + prev->ngpio <= gdev->base 276 && gdev->base + gdev->ngpio <= next->base) { 277 list_add(&gdev->list, &prev->list); 278 return 0; 279 } 280 } 281 282 dev_err(&gdev->dev, "GPIO integer space overlap, cannot add chip\n"); 283 return -EBUSY; 284 } 285 286 /* 287 * Convert a GPIO name to its descriptor 288 */ 289 static struct gpio_desc *gpio_name_to_desc(const char * const name) 290 { 291 struct gpio_device *gdev; 292 unsigned long flags; 293 294 spin_lock_irqsave(&gpio_lock, flags); 295 296 list_for_each_entry(gdev, &gpio_devices, list) { 297 int i; 298 299 for (i = 0; i != gdev->ngpio; ++i) { 300 struct gpio_desc *desc = &gdev->descs[i]; 301 302 if (!desc->name || !name) 303 continue; 304 305 if (!strcmp(desc->name, name)) { 306 spin_unlock_irqrestore(&gpio_lock, flags); 307 return desc; 308 } 309 } 310 } 311 312 spin_unlock_irqrestore(&gpio_lock, flags); 313 314 return NULL; 315 } 316 317 /* 318 * Takes the names from gc->names and checks if they are all unique. If they 319 * are, they are assigned to their gpio descriptors. 320 * 321 * Warning if one of the names is already used for a different GPIO. 322 */ 323 static int gpiochip_set_desc_names(struct gpio_chip *gc) 324 { 325 struct gpio_device *gdev = gc->gpiodev; 326 int i; 327 328 if (!gc->names) 329 return 0; 330 331 /* First check all names if they are unique */ 332 for (i = 0; i != gc->ngpio; ++i) { 333 struct gpio_desc *gpio; 334 335 gpio = gpio_name_to_desc(gc->names[i]); 336 if (gpio) 337 dev_warn(&gdev->dev, 338 "Detected name collision for GPIO name '%s'\n", 339 gc->names[i]); 340 } 341 342 /* Then add all names to the GPIO descriptors */ 343 for (i = 0; i != gc->ngpio; ++i) 344 gdev->descs[i].name = gc->names[i]; 345 346 return 0; 347 } 348 349 static unsigned long *gpiochip_allocate_mask(struct gpio_chip *chip) 350 { 351 unsigned long *p; 352 353 p = kmalloc_array(BITS_TO_LONGS(chip->ngpio), sizeof(*p), GFP_KERNEL); 354 if (!p) 355 return NULL; 356 357 /* Assume by default all GPIOs are valid */ 358 bitmap_fill(p, chip->ngpio); 359 360 return p; 361 } 362 363 static int gpiochip_alloc_valid_mask(struct gpio_chip *gpiochip) 364 { 365 #ifdef CONFIG_OF_GPIO 366 int size; 367 struct device_node *np = gpiochip->of_node; 368 369 size = of_property_count_u32_elems(np, "gpio-reserved-ranges"); 370 if (size > 0 && size % 2 == 0) 371 gpiochip->need_valid_mask = true; 372 #endif 373 374 if (!gpiochip->need_valid_mask) 375 return 0; 376 377 gpiochip->valid_mask = gpiochip_allocate_mask(gpiochip); 378 if (!gpiochip->valid_mask) 379 return -ENOMEM; 380 381 return 0; 382 } 383 384 static int gpiochip_init_valid_mask(struct gpio_chip *gpiochip) 385 { 386 if (gpiochip->init_valid_mask) 387 return gpiochip->init_valid_mask(gpiochip); 388 389 return 0; 390 } 391 392 static void gpiochip_free_valid_mask(struct gpio_chip *gpiochip) 393 { 394 kfree(gpiochip->valid_mask); 395 gpiochip->valid_mask = NULL; 396 } 397 398 bool gpiochip_line_is_valid(const struct gpio_chip *gpiochip, 399 unsigned int offset) 400 { 401 /* No mask means all valid */ 402 if (likely(!gpiochip->valid_mask)) 403 return true; 404 return test_bit(offset, gpiochip->valid_mask); 405 } 406 EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); 407 408 /* 409 * GPIO line handle management 410 */ 411 412 /** 413 * struct linehandle_state - contains the state of a userspace handle 414 * @gdev: the GPIO device the handle pertains to 415 * @label: consumer label used to tag descriptors 416 * @descs: the GPIO descriptors held by this handle 417 * @numdescs: the number of descriptors held in the descs array 418 */ 419 struct linehandle_state { 420 struct gpio_device *gdev; 421 const char *label; 422 struct gpio_desc *descs[GPIOHANDLES_MAX]; 423 u32 numdescs; 424 }; 425 426 #define GPIOHANDLE_REQUEST_VALID_FLAGS \ 427 (GPIOHANDLE_REQUEST_INPUT | \ 428 GPIOHANDLE_REQUEST_OUTPUT | \ 429 GPIOHANDLE_REQUEST_ACTIVE_LOW | \ 430 GPIOHANDLE_REQUEST_OPEN_DRAIN | \ 431 GPIOHANDLE_REQUEST_OPEN_SOURCE) 432 433 static long linehandle_ioctl(struct file *filep, unsigned int cmd, 434 unsigned long arg) 435 { 436 struct linehandle_state *lh = filep->private_data; 437 void __user *ip = (void __user *)arg; 438 struct gpiohandle_data ghd; 439 DECLARE_BITMAP(vals, GPIOHANDLES_MAX); 440 int i; 441 442 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { 443 /* NOTE: It's ok to read values of output lines. */ 444 int ret = gpiod_get_array_value_complex(false, 445 true, 446 lh->numdescs, 447 lh->descs, 448 NULL, 449 vals); 450 if (ret) 451 return ret; 452 453 memset(&ghd, 0, sizeof(ghd)); 454 for (i = 0; i < lh->numdescs; i++) 455 ghd.values[i] = test_bit(i, vals); 456 457 if (copy_to_user(ip, &ghd, sizeof(ghd))) 458 return -EFAULT; 459 460 return 0; 461 } else if (cmd == GPIOHANDLE_SET_LINE_VALUES_IOCTL) { 462 /* 463 * All line descriptors were created at once with the same 464 * flags so just check if the first one is really output. 465 */ 466 if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) 467 return -EPERM; 468 469 if (copy_from_user(&ghd, ip, sizeof(ghd))) 470 return -EFAULT; 471 472 /* Clamp all values to [0,1] */ 473 for (i = 0; i < lh->numdescs; i++) 474 __assign_bit(i, vals, ghd.values[i]); 475 476 /* Reuse the array setting function */ 477 return gpiod_set_array_value_complex(false, 478 true, 479 lh->numdescs, 480 lh->descs, 481 NULL, 482 vals); 483 } 484 return -EINVAL; 485 } 486 487 #ifdef CONFIG_COMPAT 488 static long linehandle_ioctl_compat(struct file *filep, unsigned int cmd, 489 unsigned long arg) 490 { 491 return linehandle_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); 492 } 493 #endif 494 495 static int linehandle_release(struct inode *inode, struct file *filep) 496 { 497 struct linehandle_state *lh = filep->private_data; 498 struct gpio_device *gdev = lh->gdev; 499 int i; 500 501 for (i = 0; i < lh->numdescs; i++) 502 gpiod_free(lh->descs[i]); 503 kfree(lh->label); 504 kfree(lh); 505 put_device(&gdev->dev); 506 return 0; 507 } 508 509 static const struct file_operations linehandle_fileops = { 510 .release = linehandle_release, 511 .owner = THIS_MODULE, 512 .llseek = noop_llseek, 513 .unlocked_ioctl = linehandle_ioctl, 514 #ifdef CONFIG_COMPAT 515 .compat_ioctl = linehandle_ioctl_compat, 516 #endif 517 }; 518 519 static int linehandle_create(struct gpio_device *gdev, void __user *ip) 520 { 521 struct gpiohandle_request handlereq; 522 struct linehandle_state *lh; 523 struct file *file; 524 int fd, i, count = 0, ret; 525 u32 lflags; 526 527 if (copy_from_user(&handlereq, ip, sizeof(handlereq))) 528 return -EFAULT; 529 if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) 530 return -EINVAL; 531 532 lflags = handlereq.flags; 533 534 /* Return an error if an unknown flag is set */ 535 if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) 536 return -EINVAL; 537 538 /* 539 * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If 540 * the hardware actually supports enabling both at the same time the 541 * electrical result would be disastrous. 542 */ 543 if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && 544 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) 545 return -EINVAL; 546 547 /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ 548 if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) && 549 ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || 550 (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) 551 return -EINVAL; 552 553 lh = kzalloc(sizeof(*lh), GFP_KERNEL); 554 if (!lh) 555 return -ENOMEM; 556 lh->gdev = gdev; 557 get_device(&gdev->dev); 558 559 /* Make sure this is terminated */ 560 handlereq.consumer_label[sizeof(handlereq.consumer_label)-1] = '\0'; 561 if (strlen(handlereq.consumer_label)) { 562 lh->label = kstrdup(handlereq.consumer_label, 563 GFP_KERNEL); 564 if (!lh->label) { 565 ret = -ENOMEM; 566 goto out_free_lh; 567 } 568 } 569 570 /* Request each GPIO */ 571 for (i = 0; i < handlereq.lines; i++) { 572 u32 offset = handlereq.lineoffsets[i]; 573 struct gpio_desc *desc; 574 575 if (offset >= gdev->ngpio) { 576 ret = -EINVAL; 577 goto out_free_descs; 578 } 579 580 desc = &gdev->descs[offset]; 581 ret = gpiod_request(desc, lh->label); 582 if (ret) 583 goto out_free_descs; 584 lh->descs[i] = desc; 585 count = i + 1; 586 587 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) 588 set_bit(FLAG_ACTIVE_LOW, &desc->flags); 589 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) 590 set_bit(FLAG_OPEN_DRAIN, &desc->flags); 591 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) 592 set_bit(FLAG_OPEN_SOURCE, &desc->flags); 593 594 ret = gpiod_set_transitory(desc, false); 595 if (ret < 0) 596 goto out_free_descs; 597 598 /* 599 * Lines have to be requested explicitly for input 600 * or output, else the line will be treated "as is". 601 */ 602 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { 603 int val = !!handlereq.default_values[i]; 604 605 ret = gpiod_direction_output(desc, val); 606 if (ret) 607 goto out_free_descs; 608 } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { 609 ret = gpiod_direction_input(desc); 610 if (ret) 611 goto out_free_descs; 612 } 613 dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", 614 offset); 615 } 616 /* Let i point at the last handle */ 617 i--; 618 lh->numdescs = handlereq.lines; 619 620 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); 621 if (fd < 0) { 622 ret = fd; 623 goto out_free_descs; 624 } 625 626 file = anon_inode_getfile("gpio-linehandle", 627 &linehandle_fileops, 628 lh, 629 O_RDONLY | O_CLOEXEC); 630 if (IS_ERR(file)) { 631 ret = PTR_ERR(file); 632 goto out_put_unused_fd; 633 } 634 635 handlereq.fd = fd; 636 if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { 637 /* 638 * fput() will trigger the release() callback, so do not go onto 639 * the regular error cleanup path here. 640 */ 641 fput(file); 642 put_unused_fd(fd); 643 return -EFAULT; 644 } 645 646 fd_install(fd, file); 647 648 dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", 649 lh->numdescs); 650 651 return 0; 652 653 out_put_unused_fd: 654 put_unused_fd(fd); 655 out_free_descs: 656 for (i = 0; i < count; i++) 657 gpiod_free(lh->descs[i]); 658 kfree(lh->label); 659 out_free_lh: 660 kfree(lh); 661 put_device(&gdev->dev); 662 return ret; 663 } 664 665 /* 666 * GPIO line event management 667 */ 668 669 /** 670 * struct lineevent_state - contains the state of a userspace event 671 * @gdev: the GPIO device the event pertains to 672 * @label: consumer label used to tag descriptors 673 * @desc: the GPIO descriptor held by this event 674 * @eflags: the event flags this line was requested with 675 * @irq: the interrupt that trigger in response to events on this GPIO 676 * @wait: wait queue that handles blocking reads of events 677 * @events: KFIFO for the GPIO events 678 * @read_lock: mutex lock to protect reads from colliding with adding 679 * new events to the FIFO 680 * @timestamp: cache for the timestamp storing it between hardirq 681 * and IRQ thread, used to bring the timestamp close to the actual 682 * event 683 */ 684 struct lineevent_state { 685 struct gpio_device *gdev; 686 const char *label; 687 struct gpio_desc *desc; 688 u32 eflags; 689 int irq; 690 wait_queue_head_t wait; 691 DECLARE_KFIFO(events, struct gpioevent_data, 16); 692 struct mutex read_lock; 693 u64 timestamp; 694 }; 695 696 #define GPIOEVENT_REQUEST_VALID_FLAGS \ 697 (GPIOEVENT_REQUEST_RISING_EDGE | \ 698 GPIOEVENT_REQUEST_FALLING_EDGE) 699 700 static __poll_t lineevent_poll(struct file *filep, 701 struct poll_table_struct *wait) 702 { 703 struct lineevent_state *le = filep->private_data; 704 __poll_t events = 0; 705 706 poll_wait(filep, &le->wait, wait); 707 708 if (!kfifo_is_empty(&le->events)) 709 events = EPOLLIN | EPOLLRDNORM; 710 711 return events; 712 } 713 714 715 static ssize_t lineevent_read(struct file *filep, 716 char __user *buf, 717 size_t count, 718 loff_t *f_ps) 719 { 720 struct lineevent_state *le = filep->private_data; 721 unsigned int copied; 722 int ret; 723 724 if (count < sizeof(struct gpioevent_data)) 725 return -EINVAL; 726 727 do { 728 if (kfifo_is_empty(&le->events)) { 729 if (filep->f_flags & O_NONBLOCK) 730 return -EAGAIN; 731 732 ret = wait_event_interruptible(le->wait, 733 !kfifo_is_empty(&le->events)); 734 if (ret) 735 return ret; 736 } 737 738 if (mutex_lock_interruptible(&le->read_lock)) 739 return -ERESTARTSYS; 740 ret = kfifo_to_user(&le->events, buf, count, &copied); 741 mutex_unlock(&le->read_lock); 742 743 if (ret) 744 return ret; 745 746 /* 747 * If we couldn't read anything from the fifo (a different 748 * thread might have been faster) we either return -EAGAIN if 749 * the file descriptor is non-blocking, otherwise we go back to 750 * sleep and wait for more data to arrive. 751 */ 752 if (copied == 0 && (filep->f_flags & O_NONBLOCK)) 753 return -EAGAIN; 754 755 } while (copied == 0); 756 757 return copied; 758 } 759 760 static int lineevent_release(struct inode *inode, struct file *filep) 761 { 762 struct lineevent_state *le = filep->private_data; 763 struct gpio_device *gdev = le->gdev; 764 765 free_irq(le->irq, le); 766 gpiod_free(le->desc); 767 kfree(le->label); 768 kfree(le); 769 put_device(&gdev->dev); 770 return 0; 771 } 772 773 static long lineevent_ioctl(struct file *filep, unsigned int cmd, 774 unsigned long arg) 775 { 776 struct lineevent_state *le = filep->private_data; 777 void __user *ip = (void __user *)arg; 778 struct gpiohandle_data ghd; 779 780 /* 781 * We can get the value for an event line but not set it, 782 * because it is input by definition. 783 */ 784 if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { 785 int val; 786 787 memset(&ghd, 0, sizeof(ghd)); 788 789 val = gpiod_get_value_cansleep(le->desc); 790 if (val < 0) 791 return val; 792 ghd.values[0] = val; 793 794 if (copy_to_user(ip, &ghd, sizeof(ghd))) 795 return -EFAULT; 796 797 return 0; 798 } 799 return -EINVAL; 800 } 801 802 #ifdef CONFIG_COMPAT 803 static long lineevent_ioctl_compat(struct file *filep, unsigned int cmd, 804 unsigned long arg) 805 { 806 return lineevent_ioctl(filep, cmd, (unsigned long)compat_ptr(arg)); 807 } 808 #endif 809 810 static const struct file_operations lineevent_fileops = { 811 .release = lineevent_release, 812 .read = lineevent_read, 813 .poll = lineevent_poll, 814 .owner = THIS_MODULE, 815 .llseek = noop_llseek, 816 .unlocked_ioctl = lineevent_ioctl, 817 #ifdef CONFIG_COMPAT 818 .compat_ioctl = lineevent_ioctl_compat, 819 #endif 820 }; 821 822 static irqreturn_t lineevent_irq_thread(int irq, void *p) 823 { 824 struct lineevent_state *le = p; 825 struct gpioevent_data ge; 826 int ret; 827 828 /* Do not leak kernel stack to userspace */ 829 memset(&ge, 0, sizeof(ge)); 830 831 /* 832 * We may be running from a nested threaded interrupt in which case 833 * we didn't get the timestamp from lineevent_irq_handler(). 834 */ 835 if (!le->timestamp) 836 ge.timestamp = ktime_get_real_ns(); 837 else 838 ge.timestamp = le->timestamp; 839 840 if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE 841 && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { 842 int level = gpiod_get_value_cansleep(le->desc); 843 if (level) 844 /* Emit low-to-high event */ 845 ge.id = GPIOEVENT_EVENT_RISING_EDGE; 846 else 847 /* Emit high-to-low event */ 848 ge.id = GPIOEVENT_EVENT_FALLING_EDGE; 849 } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { 850 /* Emit low-to-high event */ 851 ge.id = GPIOEVENT_EVENT_RISING_EDGE; 852 } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { 853 /* Emit high-to-low event */ 854 ge.id = GPIOEVENT_EVENT_FALLING_EDGE; 855 } else { 856 return IRQ_NONE; 857 } 858 859 ret = kfifo_put(&le->events, ge); 860 if (ret != 0) 861 wake_up_poll(&le->wait, EPOLLIN); 862 863 return IRQ_HANDLED; 864 } 865 866 static irqreturn_t lineevent_irq_handler(int irq, void *p) 867 { 868 struct lineevent_state *le = p; 869 870 /* 871 * Just store the timestamp in hardirq context so we get it as 872 * close in time as possible to the actual event. 873 */ 874 le->timestamp = ktime_get_real_ns(); 875 876 return IRQ_WAKE_THREAD; 877 } 878 879 static int lineevent_create(struct gpio_device *gdev, void __user *ip) 880 { 881 struct gpioevent_request eventreq; 882 struct lineevent_state *le; 883 struct gpio_desc *desc; 884 struct file *file; 885 u32 offset; 886 u32 lflags; 887 u32 eflags; 888 int fd; 889 int ret; 890 int irqflags = 0; 891 892 if (copy_from_user(&eventreq, ip, sizeof(eventreq))) 893 return -EFAULT; 894 895 le = kzalloc(sizeof(*le), GFP_KERNEL); 896 if (!le) 897 return -ENOMEM; 898 le->gdev = gdev; 899 get_device(&gdev->dev); 900 901 /* Make sure this is terminated */ 902 eventreq.consumer_label[sizeof(eventreq.consumer_label)-1] = '\0'; 903 if (strlen(eventreq.consumer_label)) { 904 le->label = kstrdup(eventreq.consumer_label, 905 GFP_KERNEL); 906 if (!le->label) { 907 ret = -ENOMEM; 908 goto out_free_le; 909 } 910 } 911 912 offset = eventreq.lineoffset; 913 lflags = eventreq.handleflags; 914 eflags = eventreq.eventflags; 915 916 if (offset >= gdev->ngpio) { 917 ret = -EINVAL; 918 goto out_free_label; 919 } 920 921 /* Return an error if a unknown flag is set */ 922 if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || 923 (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) { 924 ret = -EINVAL; 925 goto out_free_label; 926 } 927 928 /* This is just wrong: we don't look for events on output lines */ 929 if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { 930 ret = -EINVAL; 931 goto out_free_label; 932 } 933 934 desc = &gdev->descs[offset]; 935 ret = gpiod_request(desc, le->label); 936 if (ret) 937 goto out_free_label; 938 le->desc = desc; 939 le->eflags = eflags; 940 941 if (lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW) 942 set_bit(FLAG_ACTIVE_LOW, &desc->flags); 943 if (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) 944 set_bit(FLAG_OPEN_DRAIN, &desc->flags); 945 if (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE) 946 set_bit(FLAG_OPEN_SOURCE, &desc->flags); 947 948 ret = gpiod_direction_input(desc); 949 if (ret) 950 goto out_free_desc; 951 952 le->irq = gpiod_to_irq(desc); 953 if (le->irq <= 0) { 954 ret = -ENODEV; 955 goto out_free_desc; 956 } 957 958 if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) 959 irqflags |= IRQF_TRIGGER_RISING; 960 if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) 961 irqflags |= IRQF_TRIGGER_FALLING; 962 irqflags |= IRQF_ONESHOT; 963 964 INIT_KFIFO(le->events); 965 init_waitqueue_head(&le->wait); 966 mutex_init(&le->read_lock); 967 968 /* Request a thread to read the events */ 969 ret = request_threaded_irq(le->irq, 970 lineevent_irq_handler, 971 lineevent_irq_thread, 972 irqflags, 973 le->label, 974 le); 975 if (ret) 976 goto out_free_desc; 977 978 fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); 979 if (fd < 0) { 980 ret = fd; 981 goto out_free_irq; 982 } 983 984 file = anon_inode_getfile("gpio-event", 985 &lineevent_fileops, 986 le, 987 O_RDONLY | O_CLOEXEC); 988 if (IS_ERR(file)) { 989 ret = PTR_ERR(file); 990 goto out_put_unused_fd; 991 } 992 993 eventreq.fd = fd; 994 if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { 995 /* 996 * fput() will trigger the release() callback, so do not go onto 997 * the regular error cleanup path here. 998 */ 999 fput(file); 1000 put_unused_fd(fd); 1001 return -EFAULT; 1002 } 1003 1004 fd_install(fd, file); 1005 1006 return 0; 1007 1008 out_put_unused_fd: 1009 put_unused_fd(fd); 1010 out_free_irq: 1011 free_irq(le->irq, le); 1012 out_free_desc: 1013 gpiod_free(le->desc); 1014 out_free_label: 1015 kfree(le->label); 1016 out_free_le: 1017 kfree(le); 1018 put_device(&gdev->dev); 1019 return ret; 1020 } 1021 1022 /* 1023 * gpio_ioctl() - ioctl handler for the GPIO chardev 1024 */ 1025 static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) 1026 { 1027 struct gpio_device *gdev = filp->private_data; 1028 struct gpio_chip *chip = gdev->chip; 1029 void __user *ip = (void __user *)arg; 1030 1031 /* We fail any subsequent ioctl():s when the chip is gone */ 1032 if (!chip) 1033 return -ENODEV; 1034 1035 /* Fill in the struct and pass to userspace */ 1036 if (cmd == GPIO_GET_CHIPINFO_IOCTL) { 1037 struct gpiochip_info chipinfo; 1038 1039 memset(&chipinfo, 0, sizeof(chipinfo)); 1040 1041 strncpy(chipinfo.name, dev_name(&gdev->dev), 1042 sizeof(chipinfo.name)); 1043 chipinfo.name[sizeof(chipinfo.name)-1] = '\0'; 1044 strncpy(chipinfo.label, gdev->label, 1045 sizeof(chipinfo.label)); 1046 chipinfo.label[sizeof(chipinfo.label)-1] = '\0'; 1047 chipinfo.lines = gdev->ngpio; 1048 if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) 1049 return -EFAULT; 1050 return 0; 1051 } else if (cmd == GPIO_GET_LINEINFO_IOCTL) { 1052 struct gpioline_info lineinfo; 1053 struct gpio_desc *desc; 1054 1055 if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) 1056 return -EFAULT; 1057 if (lineinfo.line_offset >= gdev->ngpio) 1058 return -EINVAL; 1059 1060 desc = &gdev->descs[lineinfo.line_offset]; 1061 if (desc->name) { 1062 strncpy(lineinfo.name, desc->name, 1063 sizeof(lineinfo.name)); 1064 lineinfo.name[sizeof(lineinfo.name)-1] = '\0'; 1065 } else { 1066 lineinfo.name[0] = '\0'; 1067 } 1068 if (desc->label) { 1069 strncpy(lineinfo.consumer, desc->label, 1070 sizeof(lineinfo.consumer)); 1071 lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0'; 1072 } else { 1073 lineinfo.consumer[0] = '\0'; 1074 } 1075 1076 /* 1077 * Userspace only need to know that the kernel is using 1078 * this GPIO so it can't use it. 1079 */ 1080 lineinfo.flags = 0; 1081 if (test_bit(FLAG_REQUESTED, &desc->flags) || 1082 test_bit(FLAG_IS_HOGGED, &desc->flags) || 1083 test_bit(FLAG_USED_AS_IRQ, &desc->flags) || 1084 test_bit(FLAG_EXPORT, &desc->flags) || 1085 test_bit(FLAG_SYSFS, &desc->flags)) 1086 lineinfo.flags |= GPIOLINE_FLAG_KERNEL; 1087 if (test_bit(FLAG_IS_OUT, &desc->flags)) 1088 lineinfo.flags |= GPIOLINE_FLAG_IS_OUT; 1089 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 1090 lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW; 1091 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) 1092 lineinfo.flags |= GPIOLINE_FLAG_OPEN_DRAIN; 1093 if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) 1094 lineinfo.flags |= GPIOLINE_FLAG_OPEN_SOURCE; 1095 1096 if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) 1097 return -EFAULT; 1098 return 0; 1099 } else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) { 1100 return linehandle_create(gdev, ip); 1101 } else if (cmd == GPIO_GET_LINEEVENT_IOCTL) { 1102 return lineevent_create(gdev, ip); 1103 } 1104 return -EINVAL; 1105 } 1106 1107 #ifdef CONFIG_COMPAT 1108 static long gpio_ioctl_compat(struct file *filp, unsigned int cmd, 1109 unsigned long arg) 1110 { 1111 return gpio_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); 1112 } 1113 #endif 1114 1115 /** 1116 * gpio_chrdev_open() - open the chardev for ioctl operations 1117 * @inode: inode for this chardev 1118 * @filp: file struct for storing private data 1119 * Returns 0 on success 1120 */ 1121 static int gpio_chrdev_open(struct inode *inode, struct file *filp) 1122 { 1123 struct gpio_device *gdev = container_of(inode->i_cdev, 1124 struct gpio_device, chrdev); 1125 1126 /* Fail on open if the backing gpiochip is gone */ 1127 if (!gdev->chip) 1128 return -ENODEV; 1129 get_device(&gdev->dev); 1130 filp->private_data = gdev; 1131 1132 return nonseekable_open(inode, filp); 1133 } 1134 1135 /** 1136 * gpio_chrdev_release() - close chardev after ioctl operations 1137 * @inode: inode for this chardev 1138 * @filp: file struct for storing private data 1139 * Returns 0 on success 1140 */ 1141 static int gpio_chrdev_release(struct inode *inode, struct file *filp) 1142 { 1143 struct gpio_device *gdev = container_of(inode->i_cdev, 1144 struct gpio_device, chrdev); 1145 1146 put_device(&gdev->dev); 1147 return 0; 1148 } 1149 1150 1151 static const struct file_operations gpio_fileops = { 1152 .release = gpio_chrdev_release, 1153 .open = gpio_chrdev_open, 1154 .owner = THIS_MODULE, 1155 .llseek = no_llseek, 1156 .unlocked_ioctl = gpio_ioctl, 1157 #ifdef CONFIG_COMPAT 1158 .compat_ioctl = gpio_ioctl_compat, 1159 #endif 1160 }; 1161 1162 static void gpiodevice_release(struct device *dev) 1163 { 1164 struct gpio_device *gdev = dev_get_drvdata(dev); 1165 1166 list_del(&gdev->list); 1167 ida_simple_remove(&gpio_ida, gdev->id); 1168 kfree_const(gdev->label); 1169 kfree(gdev->descs); 1170 kfree(gdev); 1171 } 1172 1173 static int gpiochip_setup_dev(struct gpio_device *gdev) 1174 { 1175 int status; 1176 1177 cdev_init(&gdev->chrdev, &gpio_fileops); 1178 gdev->chrdev.owner = THIS_MODULE; 1179 gdev->dev.devt = MKDEV(MAJOR(gpio_devt), gdev->id); 1180 1181 status = cdev_device_add(&gdev->chrdev, &gdev->dev); 1182 if (status) 1183 return status; 1184 1185 chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", 1186 MAJOR(gpio_devt), gdev->id); 1187 1188 status = gpiochip_sysfs_register(gdev); 1189 if (status) 1190 goto err_remove_device; 1191 1192 /* From this point, the .release() function cleans up gpio_device */ 1193 gdev->dev.release = gpiodevice_release; 1194 pr_debug("%s: registered GPIOs %d to %d on device: %s (%s)\n", 1195 __func__, gdev->base, gdev->base + gdev->ngpio - 1, 1196 dev_name(&gdev->dev), gdev->chip->label ? : "generic"); 1197 1198 return 0; 1199 1200 err_remove_device: 1201 cdev_device_del(&gdev->chrdev, &gdev->dev); 1202 return status; 1203 } 1204 1205 static void gpiochip_machine_hog(struct gpio_chip *chip, struct gpiod_hog *hog) 1206 { 1207 struct gpio_desc *desc; 1208 int rv; 1209 1210 desc = gpiochip_get_desc(chip, hog->chip_hwnum); 1211 if (IS_ERR(desc)) { 1212 pr_err("%s: unable to get GPIO desc: %ld\n", 1213 __func__, PTR_ERR(desc)); 1214 return; 1215 } 1216 1217 if (test_bit(FLAG_IS_HOGGED, &desc->flags)) 1218 return; 1219 1220 rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags); 1221 if (rv) 1222 pr_err("%s: unable to hog GPIO line (%s:%u): %d\n", 1223 __func__, chip->label, hog->chip_hwnum, rv); 1224 } 1225 1226 static void machine_gpiochip_add(struct gpio_chip *chip) 1227 { 1228 struct gpiod_hog *hog; 1229 1230 mutex_lock(&gpio_machine_hogs_mutex); 1231 1232 list_for_each_entry(hog, &gpio_machine_hogs, list) { 1233 if (!strcmp(chip->label, hog->chip_label)) 1234 gpiochip_machine_hog(chip, hog); 1235 } 1236 1237 mutex_unlock(&gpio_machine_hogs_mutex); 1238 } 1239 1240 static void gpiochip_setup_devs(void) 1241 { 1242 struct gpio_device *gdev; 1243 int err; 1244 1245 list_for_each_entry(gdev, &gpio_devices, list) { 1246 err = gpiochip_setup_dev(gdev); 1247 if (err) 1248 pr_err("%s: Failed to initialize gpio device (%d)\n", 1249 dev_name(&gdev->dev), err); 1250 } 1251 } 1252 1253 int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data, 1254 struct lock_class_key *lock_key, 1255 struct lock_class_key *request_key) 1256 { 1257 unsigned long flags; 1258 int status = 0; 1259 unsigned i; 1260 int base = chip->base; 1261 struct gpio_device *gdev; 1262 1263 /* 1264 * First: allocate and populate the internal stat container, and 1265 * set up the struct device. 1266 */ 1267 gdev = kzalloc(sizeof(*gdev), GFP_KERNEL); 1268 if (!gdev) 1269 return -ENOMEM; 1270 gdev->dev.bus = &gpio_bus_type; 1271 gdev->chip = chip; 1272 chip->gpiodev = gdev; 1273 if (chip->parent) { 1274 gdev->dev.parent = chip->parent; 1275 gdev->dev.of_node = chip->parent->of_node; 1276 } 1277 1278 #ifdef CONFIG_OF_GPIO 1279 /* If the gpiochip has an assigned OF node this takes precedence */ 1280 if (chip->of_node) 1281 gdev->dev.of_node = chip->of_node; 1282 else 1283 chip->of_node = gdev->dev.of_node; 1284 #endif 1285 1286 gdev->id = ida_simple_get(&gpio_ida, 0, 0, GFP_KERNEL); 1287 if (gdev->id < 0) { 1288 status = gdev->id; 1289 goto err_free_gdev; 1290 } 1291 dev_set_name(&gdev->dev, "gpiochip%d", gdev->id); 1292 device_initialize(&gdev->dev); 1293 dev_set_drvdata(&gdev->dev, gdev); 1294 if (chip->parent && chip->parent->driver) 1295 gdev->owner = chip->parent->driver->owner; 1296 else if (chip->owner) 1297 /* TODO: remove chip->owner */ 1298 gdev->owner = chip->owner; 1299 else 1300 gdev->owner = THIS_MODULE; 1301 1302 gdev->descs = kcalloc(chip->ngpio, sizeof(gdev->descs[0]), GFP_KERNEL); 1303 if (!gdev->descs) { 1304 status = -ENOMEM; 1305 goto err_free_ida; 1306 } 1307 1308 if (chip->ngpio == 0) { 1309 chip_err(chip, "tried to insert a GPIO chip with zero lines\n"); 1310 status = -EINVAL; 1311 goto err_free_descs; 1312 } 1313 1314 if (chip->ngpio > FASTPATH_NGPIO) 1315 chip_warn(chip, "line cnt %u is greater than fast path cnt %u\n", 1316 chip->ngpio, FASTPATH_NGPIO); 1317 1318 gdev->label = kstrdup_const(chip->label ?: "unknown", GFP_KERNEL); 1319 if (!gdev->label) { 1320 status = -ENOMEM; 1321 goto err_free_descs; 1322 } 1323 1324 gdev->ngpio = chip->ngpio; 1325 gdev->data = data; 1326 1327 spin_lock_irqsave(&gpio_lock, flags); 1328 1329 /* 1330 * TODO: this allocates a Linux GPIO number base in the global 1331 * GPIO numberspace for this chip. In the long run we want to 1332 * get *rid* of this numberspace and use only descriptors, but 1333 * it may be a pipe dream. It will not happen before we get rid 1334 * of the sysfs interface anyways. 1335 */ 1336 if (base < 0) { 1337 base = gpiochip_find_base(chip->ngpio); 1338 if (base < 0) { 1339 status = base; 1340 spin_unlock_irqrestore(&gpio_lock, flags); 1341 goto err_free_label; 1342 } 1343 /* 1344 * TODO: it should not be necessary to reflect the assigned 1345 * base outside of the GPIO subsystem. Go over drivers and 1346 * see if anyone makes use of this, else drop this and assign 1347 * a poison instead. 1348 */ 1349 chip->base = base; 1350 } 1351 gdev->base = base; 1352 1353 status = gpiodev_add_to_list(gdev); 1354 if (status) { 1355 spin_unlock_irqrestore(&gpio_lock, flags); 1356 goto err_free_label; 1357 } 1358 1359 spin_unlock_irqrestore(&gpio_lock, flags); 1360 1361 for (i = 0; i < chip->ngpio; i++) 1362 gdev->descs[i].gdev = gdev; 1363 1364 #ifdef CONFIG_PINCTRL 1365 INIT_LIST_HEAD(&gdev->pin_ranges); 1366 #endif 1367 1368 status = gpiochip_set_desc_names(chip); 1369 if (status) 1370 goto err_remove_from_list; 1371 1372 status = gpiochip_irqchip_init_valid_mask(chip); 1373 if (status) 1374 goto err_remove_from_list; 1375 1376 status = gpiochip_alloc_valid_mask(chip); 1377 if (status) 1378 goto err_remove_irqchip_mask; 1379 1380 status = gpiochip_add_irqchip(chip, lock_key, request_key); 1381 if (status) 1382 goto err_remove_chip; 1383 1384 status = of_gpiochip_add(chip); 1385 if (status) 1386 goto err_remove_chip; 1387 1388 status = gpiochip_init_valid_mask(chip); 1389 if (status) 1390 goto err_remove_chip; 1391 1392 for (i = 0; i < chip->ngpio; i++) { 1393 struct gpio_desc *desc = &gdev->descs[i]; 1394 1395 if (chip->get_direction && gpiochip_line_is_valid(chip, i)) 1396 desc->flags = !chip->get_direction(chip, i) ? 1397 (1 << FLAG_IS_OUT) : 0; 1398 else 1399 desc->flags = !chip->direction_input ? 1400 (1 << FLAG_IS_OUT) : 0; 1401 } 1402 1403 acpi_gpiochip_add(chip); 1404 1405 machine_gpiochip_add(chip); 1406 1407 /* 1408 * By first adding the chardev, and then adding the device, 1409 * we get a device node entry in sysfs under 1410 * /sys/bus/gpio/devices/gpiochipN/dev that can be used for 1411 * coldplug of device nodes and other udev business. 1412 * We can do this only if gpiolib has been initialized. 1413 * Otherwise, defer until later. 1414 */ 1415 if (gpiolib_initialized) { 1416 status = gpiochip_setup_dev(gdev); 1417 if (status) 1418 goto err_remove_chip; 1419 } 1420 return 0; 1421 1422 err_remove_chip: 1423 acpi_gpiochip_remove(chip); 1424 gpiochip_free_hogs(chip); 1425 of_gpiochip_remove(chip); 1426 gpiochip_free_valid_mask(chip); 1427 err_remove_irqchip_mask: 1428 gpiochip_irqchip_free_valid_mask(chip); 1429 err_remove_from_list: 1430 spin_lock_irqsave(&gpio_lock, flags); 1431 list_del(&gdev->list); 1432 spin_unlock_irqrestore(&gpio_lock, flags); 1433 err_free_label: 1434 kfree_const(gdev->label); 1435 err_free_descs: 1436 kfree(gdev->descs); 1437 err_free_ida: 1438 ida_simple_remove(&gpio_ida, gdev->id); 1439 err_free_gdev: 1440 /* failures here can mean systems won't boot... */ 1441 pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__, 1442 gdev->base, gdev->base + gdev->ngpio - 1, 1443 chip->label ? : "generic", status); 1444 kfree(gdev); 1445 return status; 1446 } 1447 EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); 1448 1449 /** 1450 * gpiochip_get_data() - get per-subdriver data for the chip 1451 * @chip: GPIO chip 1452 * 1453 * Returns: 1454 * The per-subdriver data for the chip. 1455 */ 1456 void *gpiochip_get_data(struct gpio_chip *chip) 1457 { 1458 return chip->gpiodev->data; 1459 } 1460 EXPORT_SYMBOL_GPL(gpiochip_get_data); 1461 1462 /** 1463 * gpiochip_remove() - unregister a gpio_chip 1464 * @chip: the chip to unregister 1465 * 1466 * A gpio_chip with any GPIOs still requested may not be removed. 1467 */ 1468 void gpiochip_remove(struct gpio_chip *chip) 1469 { 1470 struct gpio_device *gdev = chip->gpiodev; 1471 struct gpio_desc *desc; 1472 unsigned long flags; 1473 unsigned i; 1474 bool requested = false; 1475 1476 /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ 1477 gpiochip_sysfs_unregister(gdev); 1478 gpiochip_free_hogs(chip); 1479 /* Numb the device, cancelling all outstanding operations */ 1480 gdev->chip = NULL; 1481 gpiochip_irqchip_remove(chip); 1482 acpi_gpiochip_remove(chip); 1483 gpiochip_remove_pin_ranges(chip); 1484 of_gpiochip_remove(chip); 1485 gpiochip_free_valid_mask(chip); 1486 /* 1487 * We accept no more calls into the driver from this point, so 1488 * NULL the driver data pointer 1489 */ 1490 gdev->data = NULL; 1491 1492 spin_lock_irqsave(&gpio_lock, flags); 1493 for (i = 0; i < gdev->ngpio; i++) { 1494 desc = &gdev->descs[i]; 1495 if (test_bit(FLAG_REQUESTED, &desc->flags)) 1496 requested = true; 1497 } 1498 spin_unlock_irqrestore(&gpio_lock, flags); 1499 1500 if (requested) 1501 dev_crit(&gdev->dev, 1502 "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); 1503 1504 /* 1505 * The gpiochip side puts its use of the device to rest here: 1506 * if there are no userspace clients, the chardev and device will 1507 * be removed, else it will be dangling until the last user is 1508 * gone. 1509 */ 1510 cdev_device_del(&gdev->chrdev, &gdev->dev); 1511 put_device(&gdev->dev); 1512 } 1513 EXPORT_SYMBOL_GPL(gpiochip_remove); 1514 1515 static void devm_gpio_chip_release(struct device *dev, void *res) 1516 { 1517 struct gpio_chip *chip = *(struct gpio_chip **)res; 1518 1519 gpiochip_remove(chip); 1520 } 1521 1522 /** 1523 * devm_gpiochip_add_data() - Resource manager gpiochip_add_data() 1524 * @dev: pointer to the device that gpio_chip belongs to. 1525 * @chip: the chip to register, with chip->base initialized 1526 * @data: driver-private data associated with this chip 1527 * 1528 * Context: potentially before irqs will work 1529 * 1530 * The gpio chip automatically be released when the device is unbound. 1531 * 1532 * Returns: 1533 * A negative errno if the chip can't be registered, such as because the 1534 * chip->base is invalid or already associated with a different chip. 1535 * Otherwise it returns zero as a success code. 1536 */ 1537 int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip, 1538 void *data) 1539 { 1540 struct gpio_chip **ptr; 1541 int ret; 1542 1543 ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr), 1544 GFP_KERNEL); 1545 if (!ptr) 1546 return -ENOMEM; 1547 1548 ret = gpiochip_add_data(chip, data); 1549 if (ret < 0) { 1550 devres_free(ptr); 1551 return ret; 1552 } 1553 1554 *ptr = chip; 1555 devres_add(dev, ptr); 1556 1557 return 0; 1558 } 1559 EXPORT_SYMBOL_GPL(devm_gpiochip_add_data); 1560 1561 /** 1562 * gpiochip_find() - iterator for locating a specific gpio_chip 1563 * @data: data to pass to match function 1564 * @match: Callback function to check gpio_chip 1565 * 1566 * Similar to bus_find_device. It returns a reference to a gpio_chip as 1567 * determined by a user supplied @match callback. The callback should return 1568 * 0 if the device doesn't match and non-zero if it does. If the callback is 1569 * non-zero, this function will return to the caller and not iterate over any 1570 * more gpio_chips. 1571 */ 1572 struct gpio_chip *gpiochip_find(void *data, 1573 int (*match)(struct gpio_chip *chip, 1574 void *data)) 1575 { 1576 struct gpio_device *gdev; 1577 struct gpio_chip *chip = NULL; 1578 unsigned long flags; 1579 1580 spin_lock_irqsave(&gpio_lock, flags); 1581 list_for_each_entry(gdev, &gpio_devices, list) 1582 if (gdev->chip && match(gdev->chip, data)) { 1583 chip = gdev->chip; 1584 break; 1585 } 1586 1587 spin_unlock_irqrestore(&gpio_lock, flags); 1588 1589 return chip; 1590 } 1591 EXPORT_SYMBOL_GPL(gpiochip_find); 1592 1593 static int gpiochip_match_name(struct gpio_chip *chip, void *data) 1594 { 1595 const char *name = data; 1596 1597 return !strcmp(chip->label, name); 1598 } 1599 1600 static struct gpio_chip *find_chip_by_name(const char *name) 1601 { 1602 return gpiochip_find((void *)name, gpiochip_match_name); 1603 } 1604 1605 #ifdef CONFIG_GPIOLIB_IRQCHIP 1606 1607 /* 1608 * The following is irqchip helper code for gpiochips. 1609 */ 1610 1611 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip) 1612 { 1613 if (!gpiochip->irq.need_valid_mask) 1614 return 0; 1615 1616 gpiochip->irq.valid_mask = gpiochip_allocate_mask(gpiochip); 1617 if (!gpiochip->irq.valid_mask) 1618 return -ENOMEM; 1619 1620 return 0; 1621 } 1622 1623 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip) 1624 { 1625 kfree(gpiochip->irq.valid_mask); 1626 gpiochip->irq.valid_mask = NULL; 1627 } 1628 1629 bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gpiochip, 1630 unsigned int offset) 1631 { 1632 if (!gpiochip_line_is_valid(gpiochip, offset)) 1633 return false; 1634 /* No mask means all valid */ 1635 if (likely(!gpiochip->irq.valid_mask)) 1636 return true; 1637 return test_bit(offset, gpiochip->irq.valid_mask); 1638 } 1639 EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid); 1640 1641 /** 1642 * gpiochip_set_cascaded_irqchip() - connects a cascaded irqchip to a gpiochip 1643 * @gpiochip: the gpiochip to set the irqchip chain to 1644 * @parent_irq: the irq number corresponding to the parent IRQ for this 1645 * chained irqchip 1646 * @parent_handler: the parent interrupt handler for the accumulated IRQ 1647 * coming out of the gpiochip. If the interrupt is nested rather than 1648 * cascaded, pass NULL in this handler argument 1649 */ 1650 static void gpiochip_set_cascaded_irqchip(struct gpio_chip *gpiochip, 1651 unsigned int parent_irq, 1652 irq_flow_handler_t parent_handler) 1653 { 1654 if (!gpiochip->irq.domain) { 1655 chip_err(gpiochip, "called %s before setting up irqchip\n", 1656 __func__); 1657 return; 1658 } 1659 1660 if (parent_handler) { 1661 if (gpiochip->can_sleep) { 1662 chip_err(gpiochip, 1663 "you cannot have chained interrupts on a chip that may sleep\n"); 1664 return; 1665 } 1666 /* 1667 * The parent irqchip is already using the chip_data for this 1668 * irqchip, so our callbacks simply use the handler_data. 1669 */ 1670 irq_set_chained_handler_and_data(parent_irq, parent_handler, 1671 gpiochip); 1672 1673 gpiochip->irq.parent_irq = parent_irq; 1674 gpiochip->irq.parents = &gpiochip->irq.parent_irq; 1675 gpiochip->irq.num_parents = 1; 1676 } 1677 } 1678 1679 /** 1680 * gpiochip_set_chained_irqchip() - connects a chained irqchip to a gpiochip 1681 * @gpiochip: the gpiochip to set the irqchip chain to 1682 * @irqchip: the irqchip to chain to the gpiochip 1683 * @parent_irq: the irq number corresponding to the parent IRQ for this 1684 * chained irqchip 1685 * @parent_handler: the parent interrupt handler for the accumulated IRQ 1686 * coming out of the gpiochip. 1687 */ 1688 void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip, 1689 struct irq_chip *irqchip, 1690 unsigned int parent_irq, 1691 irq_flow_handler_t parent_handler) 1692 { 1693 if (gpiochip->irq.threaded) { 1694 chip_err(gpiochip, "tried to chain a threaded gpiochip\n"); 1695 return; 1696 } 1697 1698 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, parent_handler); 1699 } 1700 EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip); 1701 1702 /** 1703 * gpiochip_set_nested_irqchip() - connects a nested irqchip to a gpiochip 1704 * @gpiochip: the gpiochip to set the irqchip nested handler to 1705 * @irqchip: the irqchip to nest to the gpiochip 1706 * @parent_irq: the irq number corresponding to the parent IRQ for this 1707 * nested irqchip 1708 */ 1709 void gpiochip_set_nested_irqchip(struct gpio_chip *gpiochip, 1710 struct irq_chip *irqchip, 1711 unsigned int parent_irq) 1712 { 1713 gpiochip_set_cascaded_irqchip(gpiochip, parent_irq, NULL); 1714 } 1715 EXPORT_SYMBOL_GPL(gpiochip_set_nested_irqchip); 1716 1717 /** 1718 * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip 1719 * @d: the irqdomain used by this irqchip 1720 * @irq: the global irq number used by this GPIO irqchip irq 1721 * @hwirq: the local IRQ/GPIO line offset on this gpiochip 1722 * 1723 * This function will set up the mapping for a certain IRQ line on a 1724 * gpiochip by assigning the gpiochip as chip data, and using the irqchip 1725 * stored inside the gpiochip. 1726 */ 1727 int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, 1728 irq_hw_number_t hwirq) 1729 { 1730 struct gpio_chip *chip = d->host_data; 1731 int err = 0; 1732 1733 if (!gpiochip_irqchip_irq_valid(chip, hwirq)) 1734 return -ENXIO; 1735 1736 irq_set_chip_data(irq, chip); 1737 /* 1738 * This lock class tells lockdep that GPIO irqs are in a different 1739 * category than their parents, so it won't report false recursion. 1740 */ 1741 irq_set_lockdep_class(irq, chip->irq.lock_key, chip->irq.request_key); 1742 irq_set_chip_and_handler(irq, chip->irq.chip, chip->irq.handler); 1743 /* Chips that use nested thread handlers have them marked */ 1744 if (chip->irq.threaded) 1745 irq_set_nested_thread(irq, 1); 1746 irq_set_noprobe(irq); 1747 1748 if (chip->irq.num_parents == 1) 1749 err = irq_set_parent(irq, chip->irq.parents[0]); 1750 else if (chip->irq.map) 1751 err = irq_set_parent(irq, chip->irq.map[hwirq]); 1752 1753 if (err < 0) 1754 return err; 1755 1756 /* 1757 * No set-up of the hardware will happen if IRQ_TYPE_NONE 1758 * is passed as default type. 1759 */ 1760 if (chip->irq.default_type != IRQ_TYPE_NONE) 1761 irq_set_irq_type(irq, chip->irq.default_type); 1762 1763 return 0; 1764 } 1765 EXPORT_SYMBOL_GPL(gpiochip_irq_map); 1766 1767 void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) 1768 { 1769 struct gpio_chip *chip = d->host_data; 1770 1771 if (chip->irq.threaded) 1772 irq_set_nested_thread(irq, 0); 1773 irq_set_chip_and_handler(irq, NULL, NULL); 1774 irq_set_chip_data(irq, NULL); 1775 } 1776 EXPORT_SYMBOL_GPL(gpiochip_irq_unmap); 1777 1778 static const struct irq_domain_ops gpiochip_domain_ops = { 1779 .map = gpiochip_irq_map, 1780 .unmap = gpiochip_irq_unmap, 1781 /* Virtually all GPIO irqchips are twocell:ed */ 1782 .xlate = irq_domain_xlate_twocell, 1783 }; 1784 1785 static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset) 1786 { 1787 if (!gpiochip_irqchip_irq_valid(chip, offset)) 1788 return -ENXIO; 1789 1790 return irq_create_mapping(chip->irq.domain, offset); 1791 } 1792 1793 static int gpiochip_irq_reqres(struct irq_data *d) 1794 { 1795 struct gpio_chip *chip = irq_data_get_irq_chip_data(d); 1796 1797 return gpiochip_reqres_irq(chip, d->hwirq); 1798 } 1799 1800 static void gpiochip_irq_relres(struct irq_data *d) 1801 { 1802 struct gpio_chip *chip = irq_data_get_irq_chip_data(d); 1803 1804 gpiochip_relres_irq(chip, d->hwirq); 1805 } 1806 1807 static void gpiochip_irq_enable(struct irq_data *d) 1808 { 1809 struct gpio_chip *chip = irq_data_get_irq_chip_data(d); 1810 1811 gpiochip_enable_irq(chip, d->hwirq); 1812 if (chip->irq.irq_enable) 1813 chip->irq.irq_enable(d); 1814 else 1815 chip->irq.chip->irq_unmask(d); 1816 } 1817 1818 static void gpiochip_irq_disable(struct irq_data *d) 1819 { 1820 struct gpio_chip *chip = irq_data_get_irq_chip_data(d); 1821 1822 if (chip->irq.irq_disable) 1823 chip->irq.irq_disable(d); 1824 else 1825 chip->irq.chip->irq_mask(d); 1826 gpiochip_disable_irq(chip, d->hwirq); 1827 } 1828 1829 static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip) 1830 { 1831 struct irq_chip *irqchip = gpiochip->irq.chip; 1832 1833 if (!irqchip->irq_request_resources && 1834 !irqchip->irq_release_resources) { 1835 irqchip->irq_request_resources = gpiochip_irq_reqres; 1836 irqchip->irq_release_resources = gpiochip_irq_relres; 1837 } 1838 if (WARN_ON(gpiochip->irq.irq_enable)) 1839 return; 1840 /* Check if the irqchip already has this hook... */ 1841 if (irqchip->irq_enable == gpiochip_irq_enable) { 1842 /* 1843 * ...and if so, give a gentle warning that this is bad 1844 * practice. 1845 */ 1846 chip_info(gpiochip, 1847 "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n"); 1848 return; 1849 } 1850 gpiochip->irq.irq_enable = irqchip->irq_enable; 1851 gpiochip->irq.irq_disable = irqchip->irq_disable; 1852 irqchip->irq_enable = gpiochip_irq_enable; 1853 irqchip->irq_disable = gpiochip_irq_disable; 1854 } 1855 1856 /** 1857 * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip 1858 * @gpiochip: the GPIO chip to add the IRQ chip to 1859 * @lock_key: lockdep class for IRQ lock 1860 * @request_key: lockdep class for IRQ request 1861 */ 1862 static int gpiochip_add_irqchip(struct gpio_chip *gpiochip, 1863 struct lock_class_key *lock_key, 1864 struct lock_class_key *request_key) 1865 { 1866 struct irq_chip *irqchip = gpiochip->irq.chip; 1867 const struct irq_domain_ops *ops; 1868 struct device_node *np; 1869 unsigned int type; 1870 unsigned int i; 1871 1872 if (!irqchip) 1873 return 0; 1874 1875 if (gpiochip->irq.parent_handler && gpiochip->can_sleep) { 1876 chip_err(gpiochip, "you cannot have chained interrupts on a chip that may sleep\n"); 1877 return -EINVAL; 1878 } 1879 1880 np = gpiochip->gpiodev->dev.of_node; 1881 type = gpiochip->irq.default_type; 1882 1883 /* 1884 * Specifying a default trigger is a terrible idea if DT or ACPI is 1885 * used to configure the interrupts, as you may end up with 1886 * conflicting triggers. Tell the user, and reset to NONE. 1887 */ 1888 if (WARN(np && type != IRQ_TYPE_NONE, 1889 "%s: Ignoring %u default trigger\n", np->full_name, type)) 1890 type = IRQ_TYPE_NONE; 1891 1892 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) { 1893 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent), 1894 "Ignoring %u default trigger\n", type); 1895 type = IRQ_TYPE_NONE; 1896 } 1897 1898 gpiochip->to_irq = gpiochip_to_irq; 1899 gpiochip->irq.default_type = type; 1900 gpiochip->irq.lock_key = lock_key; 1901 gpiochip->irq.request_key = request_key; 1902 1903 if (gpiochip->irq.domain_ops) 1904 ops = gpiochip->irq.domain_ops; 1905 else 1906 ops = &gpiochip_domain_ops; 1907 1908 gpiochip->irq.domain = irq_domain_add_simple(np, gpiochip->ngpio, 1909 gpiochip->irq.first, 1910 ops, gpiochip); 1911 if (!gpiochip->irq.domain) 1912 return -EINVAL; 1913 1914 if (gpiochip->irq.parent_handler) { 1915 void *data = gpiochip->irq.parent_handler_data ?: gpiochip; 1916 1917 for (i = 0; i < gpiochip->irq.num_parents; i++) { 1918 /* 1919 * The parent IRQ chip is already using the chip_data 1920 * for this IRQ chip, so our callbacks simply use the 1921 * handler_data. 1922 */ 1923 irq_set_chained_handler_and_data(gpiochip->irq.parents[i], 1924 gpiochip->irq.parent_handler, 1925 data); 1926 } 1927 } 1928 1929 gpiochip_set_irq_hooks(gpiochip); 1930 1931 acpi_gpiochip_request_interrupts(gpiochip); 1932 1933 return 0; 1934 } 1935 1936 /** 1937 * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip 1938 * @gpiochip: the gpiochip to remove the irqchip from 1939 * 1940 * This is called only from gpiochip_remove() 1941 */ 1942 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) 1943 { 1944 struct irq_chip *irqchip = gpiochip->irq.chip; 1945 unsigned int offset; 1946 1947 acpi_gpiochip_free_interrupts(gpiochip); 1948 1949 if (irqchip && gpiochip->irq.parent_handler) { 1950 struct gpio_irq_chip *irq = &gpiochip->irq; 1951 unsigned int i; 1952 1953 for (i = 0; i < irq->num_parents; i++) 1954 irq_set_chained_handler_and_data(irq->parents[i], 1955 NULL, NULL); 1956 } 1957 1958 /* Remove all IRQ mappings and delete the domain */ 1959 if (gpiochip->irq.domain) { 1960 unsigned int irq; 1961 1962 for (offset = 0; offset < gpiochip->ngpio; offset++) { 1963 if (!gpiochip_irqchip_irq_valid(gpiochip, offset)) 1964 continue; 1965 1966 irq = irq_find_mapping(gpiochip->irq.domain, offset); 1967 irq_dispose_mapping(irq); 1968 } 1969 1970 irq_domain_remove(gpiochip->irq.domain); 1971 } 1972 1973 if (irqchip) { 1974 if (irqchip->irq_request_resources == gpiochip_irq_reqres) { 1975 irqchip->irq_request_resources = NULL; 1976 irqchip->irq_release_resources = NULL; 1977 } 1978 if (irqchip->irq_enable == gpiochip_irq_enable) { 1979 irqchip->irq_enable = gpiochip->irq.irq_enable; 1980 irqchip->irq_disable = gpiochip->irq.irq_disable; 1981 } 1982 } 1983 gpiochip->irq.irq_enable = NULL; 1984 gpiochip->irq.irq_disable = NULL; 1985 gpiochip->irq.chip = NULL; 1986 1987 gpiochip_irqchip_free_valid_mask(gpiochip); 1988 } 1989 1990 /** 1991 * gpiochip_irqchip_add_key() - adds an irqchip to a gpiochip 1992 * @gpiochip: the gpiochip to add the irqchip to 1993 * @irqchip: the irqchip to add to the gpiochip 1994 * @first_irq: if not dynamically assigned, the base (first) IRQ to 1995 * allocate gpiochip irqs from 1996 * @handler: the irq handler to use (often a predefined irq core function) 1997 * @type: the default type for IRQs on this irqchip, pass IRQ_TYPE_NONE 1998 * to have the core avoid setting up any default type in the hardware. 1999 * @threaded: whether this irqchip uses a nested thread handler 2000 * @lock_key: lockdep class for IRQ lock 2001 * @request_key: lockdep class for IRQ request 2002 * 2003 * This function closely associates a certain irqchip with a certain 2004 * gpiochip, providing an irq domain to translate the local IRQs to 2005 * global irqs in the gpiolib core, and making sure that the gpiochip 2006 * is passed as chip data to all related functions. Driver callbacks 2007 * need to use gpiochip_get_data() to get their local state containers back 2008 * from the gpiochip passed as chip data. An irqdomain will be stored 2009 * in the gpiochip that shall be used by the driver to handle IRQ number 2010 * translation. The gpiochip will need to be initialized and registered 2011 * before calling this function. 2012 * 2013 * This function will handle two cell:ed simple IRQs and assumes all 2014 * the pins on the gpiochip can generate a unique IRQ. Everything else 2015 * need to be open coded. 2016 */ 2017 int gpiochip_irqchip_add_key(struct gpio_chip *gpiochip, 2018 struct irq_chip *irqchip, 2019 unsigned int first_irq, 2020 irq_flow_handler_t handler, 2021 unsigned int type, 2022 bool threaded, 2023 struct lock_class_key *lock_key, 2024 struct lock_class_key *request_key) 2025 { 2026 struct device_node *of_node; 2027 2028 if (!gpiochip || !irqchip) 2029 return -EINVAL; 2030 2031 if (!gpiochip->parent) { 2032 pr_err("missing gpiochip .dev parent pointer\n"); 2033 return -EINVAL; 2034 } 2035 gpiochip->irq.threaded = threaded; 2036 of_node = gpiochip->parent->of_node; 2037 #ifdef CONFIG_OF_GPIO 2038 /* 2039 * If the gpiochip has an assigned OF node this takes precedence 2040 * FIXME: get rid of this and use gpiochip->parent->of_node 2041 * everywhere 2042 */ 2043 if (gpiochip->of_node) 2044 of_node = gpiochip->of_node; 2045 #endif 2046 /* 2047 * Specifying a default trigger is a terrible idea if DT or ACPI is 2048 * used to configure the interrupts, as you may end-up with 2049 * conflicting triggers. Tell the user, and reset to NONE. 2050 */ 2051 if (WARN(of_node && type != IRQ_TYPE_NONE, 2052 "%pOF: Ignoring %d default trigger\n", of_node, type)) 2053 type = IRQ_TYPE_NONE; 2054 if (has_acpi_companion(gpiochip->parent) && type != IRQ_TYPE_NONE) { 2055 acpi_handle_warn(ACPI_HANDLE(gpiochip->parent), 2056 "Ignoring %d default trigger\n", type); 2057 type = IRQ_TYPE_NONE; 2058 } 2059 2060 gpiochip->irq.chip = irqchip; 2061 gpiochip->irq.handler = handler; 2062 gpiochip->irq.default_type = type; 2063 gpiochip->to_irq = gpiochip_to_irq; 2064 gpiochip->irq.lock_key = lock_key; 2065 gpiochip->irq.request_key = request_key; 2066 gpiochip->irq.domain = irq_domain_add_simple(of_node, 2067 gpiochip->ngpio, first_irq, 2068 &gpiochip_domain_ops, gpiochip); 2069 if (!gpiochip->irq.domain) { 2070 gpiochip->irq.chip = NULL; 2071 return -EINVAL; 2072 } 2073 2074 gpiochip_set_irq_hooks(gpiochip); 2075 2076 acpi_gpiochip_request_interrupts(gpiochip); 2077 2078 return 0; 2079 } 2080 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_key); 2081 2082 #else /* CONFIG_GPIOLIB_IRQCHIP */ 2083 2084 static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip, 2085 struct lock_class_key *lock_key, 2086 struct lock_class_key *request_key) 2087 { 2088 return 0; 2089 } 2090 2091 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {} 2092 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip) 2093 { 2094 return 0; 2095 } 2096 static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip) 2097 { } 2098 2099 #endif /* CONFIG_GPIOLIB_IRQCHIP */ 2100 2101 /** 2102 * gpiochip_generic_request() - request the gpio function for a pin 2103 * @chip: the gpiochip owning the GPIO 2104 * @offset: the offset of the GPIO to request for GPIO function 2105 */ 2106 int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset) 2107 { 2108 return pinctrl_gpio_request(chip->gpiodev->base + offset); 2109 } 2110 EXPORT_SYMBOL_GPL(gpiochip_generic_request); 2111 2112 /** 2113 * gpiochip_generic_free() - free the gpio function from a pin 2114 * @chip: the gpiochip to request the gpio function for 2115 * @offset: the offset of the GPIO to free from GPIO function 2116 */ 2117 void gpiochip_generic_free(struct gpio_chip *chip, unsigned offset) 2118 { 2119 pinctrl_gpio_free(chip->gpiodev->base + offset); 2120 } 2121 EXPORT_SYMBOL_GPL(gpiochip_generic_free); 2122 2123 /** 2124 * gpiochip_generic_config() - apply configuration for a pin 2125 * @chip: the gpiochip owning the GPIO 2126 * @offset: the offset of the GPIO to apply the configuration 2127 * @config: the configuration to be applied 2128 */ 2129 int gpiochip_generic_config(struct gpio_chip *chip, unsigned offset, 2130 unsigned long config) 2131 { 2132 return pinctrl_gpio_set_config(chip->gpiodev->base + offset, config); 2133 } 2134 EXPORT_SYMBOL_GPL(gpiochip_generic_config); 2135 2136 #ifdef CONFIG_PINCTRL 2137 2138 /** 2139 * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping 2140 * @chip: the gpiochip to add the range for 2141 * @pctldev: the pin controller to map to 2142 * @gpio_offset: the start offset in the current gpio_chip number space 2143 * @pin_group: name of the pin group inside the pin controller 2144 * 2145 * Calling this function directly from a DeviceTree-supported 2146 * pinctrl driver is DEPRECATED. Please see Section 2.1 of 2147 * Documentation/devicetree/bindings/gpio/gpio.txt on how to 2148 * bind pinctrl and gpio drivers via the "gpio-ranges" property. 2149 */ 2150 int gpiochip_add_pingroup_range(struct gpio_chip *chip, 2151 struct pinctrl_dev *pctldev, 2152 unsigned int gpio_offset, const char *pin_group) 2153 { 2154 struct gpio_pin_range *pin_range; 2155 struct gpio_device *gdev = chip->gpiodev; 2156 int ret; 2157 2158 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); 2159 if (!pin_range) { 2160 chip_err(chip, "failed to allocate pin ranges\n"); 2161 return -ENOMEM; 2162 } 2163 2164 /* Use local offset as range ID */ 2165 pin_range->range.id = gpio_offset; 2166 pin_range->range.gc = chip; 2167 pin_range->range.name = chip->label; 2168 pin_range->range.base = gdev->base + gpio_offset; 2169 pin_range->pctldev = pctldev; 2170 2171 ret = pinctrl_get_group_pins(pctldev, pin_group, 2172 &pin_range->range.pins, 2173 &pin_range->range.npins); 2174 if (ret < 0) { 2175 kfree(pin_range); 2176 return ret; 2177 } 2178 2179 pinctrl_add_gpio_range(pctldev, &pin_range->range); 2180 2181 chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n", 2182 gpio_offset, gpio_offset + pin_range->range.npins - 1, 2183 pinctrl_dev_get_devname(pctldev), pin_group); 2184 2185 list_add_tail(&pin_range->node, &gdev->pin_ranges); 2186 2187 return 0; 2188 } 2189 EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); 2190 2191 /** 2192 * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping 2193 * @chip: the gpiochip to add the range for 2194 * @pinctl_name: the dev_name() of the pin controller to map to 2195 * @gpio_offset: the start offset in the current gpio_chip number space 2196 * @pin_offset: the start offset in the pin controller number space 2197 * @npins: the number of pins from the offset of each pin space (GPIO and 2198 * pin controller) to accumulate in this range 2199 * 2200 * Returns: 2201 * 0 on success, or a negative error-code on failure. 2202 * 2203 * Calling this function directly from a DeviceTree-supported 2204 * pinctrl driver is DEPRECATED. Please see Section 2.1 of 2205 * Documentation/devicetree/bindings/gpio/gpio.txt on how to 2206 * bind pinctrl and gpio drivers via the "gpio-ranges" property. 2207 */ 2208 int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name, 2209 unsigned int gpio_offset, unsigned int pin_offset, 2210 unsigned int npins) 2211 { 2212 struct gpio_pin_range *pin_range; 2213 struct gpio_device *gdev = chip->gpiodev; 2214 int ret; 2215 2216 pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); 2217 if (!pin_range) { 2218 chip_err(chip, "failed to allocate pin ranges\n"); 2219 return -ENOMEM; 2220 } 2221 2222 /* Use local offset as range ID */ 2223 pin_range->range.id = gpio_offset; 2224 pin_range->range.gc = chip; 2225 pin_range->range.name = chip->label; 2226 pin_range->range.base = gdev->base + gpio_offset; 2227 pin_range->range.pin_base = pin_offset; 2228 pin_range->range.npins = npins; 2229 pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, 2230 &pin_range->range); 2231 if (IS_ERR(pin_range->pctldev)) { 2232 ret = PTR_ERR(pin_range->pctldev); 2233 chip_err(chip, "could not create pin range\n"); 2234 kfree(pin_range); 2235 return ret; 2236 } 2237 chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n", 2238 gpio_offset, gpio_offset + npins - 1, 2239 pinctl_name, 2240 pin_offset, pin_offset + npins - 1); 2241 2242 list_add_tail(&pin_range->node, &gdev->pin_ranges); 2243 2244 return 0; 2245 } 2246 EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); 2247 2248 /** 2249 * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings 2250 * @chip: the chip to remove all the mappings for 2251 */ 2252 void gpiochip_remove_pin_ranges(struct gpio_chip *chip) 2253 { 2254 struct gpio_pin_range *pin_range, *tmp; 2255 struct gpio_device *gdev = chip->gpiodev; 2256 2257 list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) { 2258 list_del(&pin_range->node); 2259 pinctrl_remove_gpio_range(pin_range->pctldev, 2260 &pin_range->range); 2261 kfree(pin_range); 2262 } 2263 } 2264 EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); 2265 2266 #endif /* CONFIG_PINCTRL */ 2267 2268 /* These "optional" allocation calls help prevent drivers from stomping 2269 * on each other, and help provide better diagnostics in debugfs. 2270 * They're called even less than the "set direction" calls. 2271 */ 2272 static int gpiod_request_commit(struct gpio_desc *desc, const char *label) 2273 { 2274 struct gpio_chip *chip = desc->gdev->chip; 2275 int status; 2276 unsigned long flags; 2277 unsigned offset; 2278 2279 if (label) { 2280 label = kstrdup_const(label, GFP_KERNEL); 2281 if (!label) 2282 return -ENOMEM; 2283 } 2284 2285 spin_lock_irqsave(&gpio_lock, flags); 2286 2287 /* NOTE: gpio_request() can be called in early boot, 2288 * before IRQs are enabled, for non-sleeping (SOC) GPIOs. 2289 */ 2290 2291 if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { 2292 desc_set_label(desc, label ? : "?"); 2293 status = 0; 2294 } else { 2295 kfree_const(label); 2296 status = -EBUSY; 2297 goto done; 2298 } 2299 2300 if (chip->request) { 2301 /* chip->request may sleep */ 2302 spin_unlock_irqrestore(&gpio_lock, flags); 2303 offset = gpio_chip_hwgpio(desc); 2304 if (gpiochip_line_is_valid(chip, offset)) 2305 status = chip->request(chip, offset); 2306 else 2307 status = -EINVAL; 2308 spin_lock_irqsave(&gpio_lock, flags); 2309 2310 if (status < 0) { 2311 desc_set_label(desc, NULL); 2312 kfree_const(label); 2313 clear_bit(FLAG_REQUESTED, &desc->flags); 2314 goto done; 2315 } 2316 } 2317 if (chip->get_direction) { 2318 /* chip->get_direction may sleep */ 2319 spin_unlock_irqrestore(&gpio_lock, flags); 2320 gpiod_get_direction(desc); 2321 spin_lock_irqsave(&gpio_lock, flags); 2322 } 2323 done: 2324 spin_unlock_irqrestore(&gpio_lock, flags); 2325 return status; 2326 } 2327 2328 /* 2329 * This descriptor validation needs to be inserted verbatim into each 2330 * function taking a descriptor, so we need to use a preprocessor 2331 * macro to avoid endless duplication. If the desc is NULL it is an 2332 * optional GPIO and calls should just bail out. 2333 */ 2334 static int validate_desc(const struct gpio_desc *desc, const char *func) 2335 { 2336 if (!desc) 2337 return 0; 2338 if (IS_ERR(desc)) { 2339 pr_warn("%s: invalid GPIO (errorpointer)\n", func); 2340 return PTR_ERR(desc); 2341 } 2342 if (!desc->gdev) { 2343 pr_warn("%s: invalid GPIO (no device)\n", func); 2344 return -EINVAL; 2345 } 2346 if (!desc->gdev->chip) { 2347 dev_warn(&desc->gdev->dev, 2348 "%s: backing chip is gone\n", func); 2349 return 0; 2350 } 2351 return 1; 2352 } 2353 2354 #define VALIDATE_DESC(desc) do { \ 2355 int __valid = validate_desc(desc, __func__); \ 2356 if (__valid <= 0) \ 2357 return __valid; \ 2358 } while (0) 2359 2360 #define VALIDATE_DESC_VOID(desc) do { \ 2361 int __valid = validate_desc(desc, __func__); \ 2362 if (__valid <= 0) \ 2363 return; \ 2364 } while (0) 2365 2366 int gpiod_request(struct gpio_desc *desc, const char *label) 2367 { 2368 int status = -EPROBE_DEFER; 2369 struct gpio_device *gdev; 2370 2371 VALIDATE_DESC(desc); 2372 gdev = desc->gdev; 2373 2374 if (try_module_get(gdev->owner)) { 2375 status = gpiod_request_commit(desc, label); 2376 if (status < 0) 2377 module_put(gdev->owner); 2378 else 2379 get_device(&gdev->dev); 2380 } 2381 2382 if (status) 2383 gpiod_dbg(desc, "%s: status %d\n", __func__, status); 2384 2385 return status; 2386 } 2387 2388 static bool gpiod_free_commit(struct gpio_desc *desc) 2389 { 2390 bool ret = false; 2391 unsigned long flags; 2392 struct gpio_chip *chip; 2393 2394 might_sleep(); 2395 2396 gpiod_unexport(desc); 2397 2398 spin_lock_irqsave(&gpio_lock, flags); 2399 2400 chip = desc->gdev->chip; 2401 if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) { 2402 if (chip->free) { 2403 spin_unlock_irqrestore(&gpio_lock, flags); 2404 might_sleep_if(chip->can_sleep); 2405 chip->free(chip, gpio_chip_hwgpio(desc)); 2406 spin_lock_irqsave(&gpio_lock, flags); 2407 } 2408 kfree_const(desc->label); 2409 desc_set_label(desc, NULL); 2410 clear_bit(FLAG_ACTIVE_LOW, &desc->flags); 2411 clear_bit(FLAG_REQUESTED, &desc->flags); 2412 clear_bit(FLAG_OPEN_DRAIN, &desc->flags); 2413 clear_bit(FLAG_OPEN_SOURCE, &desc->flags); 2414 clear_bit(FLAG_IS_HOGGED, &desc->flags); 2415 ret = true; 2416 } 2417 2418 spin_unlock_irqrestore(&gpio_lock, flags); 2419 return ret; 2420 } 2421 2422 void gpiod_free(struct gpio_desc *desc) 2423 { 2424 if (desc && desc->gdev && gpiod_free_commit(desc)) { 2425 module_put(desc->gdev->owner); 2426 put_device(&desc->gdev->dev); 2427 } else { 2428 WARN_ON(extra_checks); 2429 } 2430 } 2431 2432 /** 2433 * gpiochip_is_requested - return string iff signal was requested 2434 * @chip: controller managing the signal 2435 * @offset: of signal within controller's 0..(ngpio - 1) range 2436 * 2437 * Returns NULL if the GPIO is not currently requested, else a string. 2438 * The string returned is the label passed to gpio_request(); if none has been 2439 * passed it is a meaningless, non-NULL constant. 2440 * 2441 * This function is for use by GPIO controller drivers. The label can 2442 * help with diagnostics, and knowing that the signal is used as a GPIO 2443 * can help avoid accidentally multiplexing it to another controller. 2444 */ 2445 const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset) 2446 { 2447 struct gpio_desc *desc; 2448 2449 if (offset >= chip->ngpio) 2450 return NULL; 2451 2452 desc = &chip->gpiodev->descs[offset]; 2453 2454 if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) 2455 return NULL; 2456 return desc->label; 2457 } 2458 EXPORT_SYMBOL_GPL(gpiochip_is_requested); 2459 2460 /** 2461 * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor 2462 * @chip: GPIO chip 2463 * @hwnum: hardware number of the GPIO for which to request the descriptor 2464 * @label: label for the GPIO 2465 * @flags: flags for this GPIO or 0 if default 2466 * 2467 * Function allows GPIO chip drivers to request and use their own GPIO 2468 * descriptors via gpiolib API. Difference to gpiod_request() is that this 2469 * function will not increase reference count of the GPIO chip module. This 2470 * allows the GPIO chip module to be unloaded as needed (we assume that the 2471 * GPIO chip driver handles freeing the GPIOs it has requested). 2472 * 2473 * Returns: 2474 * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error 2475 * code on failure. 2476 */ 2477 struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *chip, u16 hwnum, 2478 const char *label, 2479 enum gpiod_flags flags) 2480 { 2481 struct gpio_desc *desc = gpiochip_get_desc(chip, hwnum); 2482 int err; 2483 2484 if (IS_ERR(desc)) { 2485 chip_err(chip, "failed to get GPIO descriptor\n"); 2486 return desc; 2487 } 2488 2489 err = gpiod_request_commit(desc, label); 2490 if (err < 0) 2491 return ERR_PTR(err); 2492 2493 err = gpiod_configure_flags(desc, label, 0, flags); 2494 if (err) { 2495 chip_err(chip, "setup of own GPIO %s failed\n", label); 2496 gpiod_free_commit(desc); 2497 return ERR_PTR(err); 2498 } 2499 2500 return desc; 2501 } 2502 EXPORT_SYMBOL_GPL(gpiochip_request_own_desc); 2503 2504 /** 2505 * gpiochip_free_own_desc - Free GPIO requested by the chip driver 2506 * @desc: GPIO descriptor to free 2507 * 2508 * Function frees the given GPIO requested previously with 2509 * gpiochip_request_own_desc(). 2510 */ 2511 void gpiochip_free_own_desc(struct gpio_desc *desc) 2512 { 2513 if (desc) 2514 gpiod_free_commit(desc); 2515 } 2516 EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); 2517 2518 /* 2519 * Drivers MUST set GPIO direction before making get/set calls. In 2520 * some cases this is done in early boot, before IRQs are enabled. 2521 * 2522 * As a rule these aren't called more than once (except for drivers 2523 * using the open-drain emulation idiom) so these are natural places 2524 * to accumulate extra debugging checks. Note that we can't (yet) 2525 * rely on gpio_request() having been called beforehand. 2526 */ 2527 2528 /** 2529 * gpiod_direction_input - set the GPIO direction to input 2530 * @desc: GPIO to set to input 2531 * 2532 * Set the direction of the passed GPIO to input, such as gpiod_get_value() can 2533 * be called safely on it. 2534 * 2535 * Return 0 in case of success, else an error code. 2536 */ 2537 int gpiod_direction_input(struct gpio_desc *desc) 2538 { 2539 struct gpio_chip *chip; 2540 int status = 0; 2541 2542 VALIDATE_DESC(desc); 2543 chip = desc->gdev->chip; 2544 2545 /* 2546 * It is legal to have no .get() and .direction_input() specified if 2547 * the chip is output-only, but you can't specify .direction_input() 2548 * and not support the .get() operation, that doesn't make sense. 2549 */ 2550 if (!chip->get && chip->direction_input) { 2551 gpiod_warn(desc, 2552 "%s: missing get() but have direction_input()\n", 2553 __func__); 2554 return -EIO; 2555 } 2556 2557 /* 2558 * If we have a .direction_input() callback, things are simple, 2559 * just call it. Else we are some input-only chip so try to check the 2560 * direction (if .get_direction() is supported) else we silently 2561 * assume we are in input mode after this. 2562 */ 2563 if (chip->direction_input) { 2564 status = chip->direction_input(chip, gpio_chip_hwgpio(desc)); 2565 } else if (chip->get_direction && 2566 (chip->get_direction(chip, gpio_chip_hwgpio(desc)) != 1)) { 2567 gpiod_warn(desc, 2568 "%s: missing direction_input() operation and line is output\n", 2569 __func__); 2570 return -EIO; 2571 } 2572 if (status == 0) 2573 clear_bit(FLAG_IS_OUT, &desc->flags); 2574 2575 trace_gpio_direction(desc_to_gpio(desc), 1, status); 2576 2577 return status; 2578 } 2579 EXPORT_SYMBOL_GPL(gpiod_direction_input); 2580 2581 static int gpio_set_drive_single_ended(struct gpio_chip *gc, unsigned offset, 2582 enum pin_config_param mode) 2583 { 2584 unsigned long config = { PIN_CONF_PACKED(mode, 0) }; 2585 2586 return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP; 2587 } 2588 2589 static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) 2590 { 2591 struct gpio_chip *gc = desc->gdev->chip; 2592 int val = !!value; 2593 int ret = 0; 2594 2595 /* 2596 * It's OK not to specify .direction_output() if the gpiochip is 2597 * output-only, but if there is then not even a .set() operation it 2598 * is pretty tricky to drive the output line. 2599 */ 2600 if (!gc->set && !gc->direction_output) { 2601 gpiod_warn(desc, 2602 "%s: missing set() and direction_output() operations\n", 2603 __func__); 2604 return -EIO; 2605 } 2606 2607 if (gc->direction_output) { 2608 ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val); 2609 } else { 2610 /* Check that we are in output mode if we can */ 2611 if (gc->get_direction && 2612 gc->get_direction(gc, gpio_chip_hwgpio(desc))) { 2613 gpiod_warn(desc, 2614 "%s: missing direction_output() operation\n", 2615 __func__); 2616 return -EIO; 2617 } 2618 /* 2619 * If we can't actively set the direction, we are some 2620 * output-only chip, so just drive the output as desired. 2621 */ 2622 gc->set(gc, gpio_chip_hwgpio(desc), val); 2623 } 2624 2625 if (!ret) 2626 set_bit(FLAG_IS_OUT, &desc->flags); 2627 trace_gpio_value(desc_to_gpio(desc), 0, val); 2628 trace_gpio_direction(desc_to_gpio(desc), 0, ret); 2629 return ret; 2630 } 2631 2632 /** 2633 * gpiod_direction_output_raw - set the GPIO direction to output 2634 * @desc: GPIO to set to output 2635 * @value: initial output value of the GPIO 2636 * 2637 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can 2638 * be called safely on it. The initial value of the output must be specified 2639 * as raw value on the physical line without regard for the ACTIVE_LOW status. 2640 * 2641 * Return 0 in case of success, else an error code. 2642 */ 2643 int gpiod_direction_output_raw(struct gpio_desc *desc, int value) 2644 { 2645 VALIDATE_DESC(desc); 2646 return gpiod_direction_output_raw_commit(desc, value); 2647 } 2648 EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); 2649 2650 /** 2651 * gpiod_direction_output - set the GPIO direction to output 2652 * @desc: GPIO to set to output 2653 * @value: initial output value of the GPIO 2654 * 2655 * Set the direction of the passed GPIO to output, such as gpiod_set_value() can 2656 * be called safely on it. The initial value of the output must be specified 2657 * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into 2658 * account. 2659 * 2660 * Return 0 in case of success, else an error code. 2661 */ 2662 int gpiod_direction_output(struct gpio_desc *desc, int value) 2663 { 2664 struct gpio_chip *gc; 2665 int ret; 2666 2667 VALIDATE_DESC(desc); 2668 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 2669 value = !value; 2670 else 2671 value = !!value; 2672 2673 /* GPIOs used for enabled IRQs shall not be set as output */ 2674 if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) && 2675 test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) { 2676 gpiod_err(desc, 2677 "%s: tried to set a GPIO tied to an IRQ as output\n", 2678 __func__); 2679 return -EIO; 2680 } 2681 2682 gc = desc->gdev->chip; 2683 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { 2684 /* First see if we can enable open drain in hardware */ 2685 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), 2686 PIN_CONFIG_DRIVE_OPEN_DRAIN); 2687 if (!ret) 2688 goto set_output_value; 2689 /* Emulate open drain by not actively driving the line high */ 2690 if (value) 2691 return gpiod_direction_input(desc); 2692 } 2693 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { 2694 ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), 2695 PIN_CONFIG_DRIVE_OPEN_SOURCE); 2696 if (!ret) 2697 goto set_output_value; 2698 /* Emulate open source by not actively driving the line low */ 2699 if (!value) 2700 return gpiod_direction_input(desc); 2701 } else { 2702 gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), 2703 PIN_CONFIG_DRIVE_PUSH_PULL); 2704 } 2705 2706 set_output_value: 2707 return gpiod_direction_output_raw_commit(desc, value); 2708 } 2709 EXPORT_SYMBOL_GPL(gpiod_direction_output); 2710 2711 /** 2712 * gpiod_set_debounce - sets @debounce time for a GPIO 2713 * @desc: descriptor of the GPIO for which to set debounce time 2714 * @debounce: debounce time in microseconds 2715 * 2716 * Returns: 2717 * 0 on success, %-ENOTSUPP if the controller doesn't support setting the 2718 * debounce time. 2719 */ 2720 int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce) 2721 { 2722 struct gpio_chip *chip; 2723 unsigned long config; 2724 2725 VALIDATE_DESC(desc); 2726 chip = desc->gdev->chip; 2727 if (!chip->set || !chip->set_config) { 2728 gpiod_dbg(desc, 2729 "%s: missing set() or set_config() operations\n", 2730 __func__); 2731 return -ENOTSUPP; 2732 } 2733 2734 config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce); 2735 return chip->set_config(chip, gpio_chip_hwgpio(desc), config); 2736 } 2737 EXPORT_SYMBOL_GPL(gpiod_set_debounce); 2738 2739 /** 2740 * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset 2741 * @desc: descriptor of the GPIO for which to configure persistence 2742 * @transitory: True to lose state on suspend or reset, false for persistence 2743 * 2744 * Returns: 2745 * 0 on success, otherwise a negative error code. 2746 */ 2747 int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) 2748 { 2749 struct gpio_chip *chip; 2750 unsigned long packed; 2751 int gpio; 2752 int rc; 2753 2754 VALIDATE_DESC(desc); 2755 /* 2756 * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for 2757 * persistence state. 2758 */ 2759 if (transitory) 2760 set_bit(FLAG_TRANSITORY, &desc->flags); 2761 else 2762 clear_bit(FLAG_TRANSITORY, &desc->flags); 2763 2764 /* If the driver supports it, set the persistence state now */ 2765 chip = desc->gdev->chip; 2766 if (!chip->set_config) 2767 return 0; 2768 2769 packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE, 2770 !transitory); 2771 gpio = gpio_chip_hwgpio(desc); 2772 rc = chip->set_config(chip, gpio, packed); 2773 if (rc == -ENOTSUPP) { 2774 dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n", 2775 gpio); 2776 return 0; 2777 } 2778 2779 return rc; 2780 } 2781 EXPORT_SYMBOL_GPL(gpiod_set_transitory); 2782 2783 /** 2784 * gpiod_is_active_low - test whether a GPIO is active-low or not 2785 * @desc: the gpio descriptor to test 2786 * 2787 * Returns 1 if the GPIO is active-low, 0 otherwise. 2788 */ 2789 int gpiod_is_active_low(const struct gpio_desc *desc) 2790 { 2791 VALIDATE_DESC(desc); 2792 return test_bit(FLAG_ACTIVE_LOW, &desc->flags); 2793 } 2794 EXPORT_SYMBOL_GPL(gpiod_is_active_low); 2795 2796 /* I/O calls are only valid after configuration completed; the relevant 2797 * "is this a valid GPIO" error checks should already have been done. 2798 * 2799 * "Get" operations are often inlinable as reading a pin value register, 2800 * and masking the relevant bit in that register. 2801 * 2802 * When "set" operations are inlinable, they involve writing that mask to 2803 * one register to set a low value, or a different register to set it high. 2804 * Otherwise locking is needed, so there may be little value to inlining. 2805 * 2806 *------------------------------------------------------------------------ 2807 * 2808 * IMPORTANT!!! The hot paths -- get/set value -- assume that callers 2809 * have requested the GPIO. That can include implicit requesting by 2810 * a direction setting call. Marking a gpio as requested locks its chip 2811 * in memory, guaranteeing that these table lookups need no more locking 2812 * and that gpiochip_remove() will fail. 2813 * 2814 * REVISIT when debugging, consider adding some instrumentation to ensure 2815 * that the GPIO was actually requested. 2816 */ 2817 2818 static int gpiod_get_raw_value_commit(const struct gpio_desc *desc) 2819 { 2820 struct gpio_chip *chip; 2821 int offset; 2822 int value; 2823 2824 chip = desc->gdev->chip; 2825 offset = gpio_chip_hwgpio(desc); 2826 value = chip->get ? chip->get(chip, offset) : -EIO; 2827 value = value < 0 ? value : !!value; 2828 trace_gpio_value(desc_to_gpio(desc), 1, value); 2829 return value; 2830 } 2831 2832 static int gpio_chip_get_multiple(struct gpio_chip *chip, 2833 unsigned long *mask, unsigned long *bits) 2834 { 2835 if (chip->get_multiple) { 2836 return chip->get_multiple(chip, mask, bits); 2837 } else if (chip->get) { 2838 int i, value; 2839 2840 for_each_set_bit(i, mask, chip->ngpio) { 2841 value = chip->get(chip, i); 2842 if (value < 0) 2843 return value; 2844 __assign_bit(i, bits, value); 2845 } 2846 return 0; 2847 } 2848 return -EIO; 2849 } 2850 2851 int gpiod_get_array_value_complex(bool raw, bool can_sleep, 2852 unsigned int array_size, 2853 struct gpio_desc **desc_array, 2854 struct gpio_array *array_info, 2855 unsigned long *value_bitmap) 2856 { 2857 int err, i = 0; 2858 2859 /* 2860 * Validate array_info against desc_array and its size. 2861 * It should immediately follow desc_array if both 2862 * have been obtained from the same gpiod_get_array() call. 2863 */ 2864 if (array_info && array_info->desc == desc_array && 2865 array_size <= array_info->size && 2866 (void *)array_info == desc_array + array_info->size) { 2867 if (!can_sleep) 2868 WARN_ON(array_info->chip->can_sleep); 2869 2870 err = gpio_chip_get_multiple(array_info->chip, 2871 array_info->get_mask, 2872 value_bitmap); 2873 if (err) 2874 return err; 2875 2876 if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) 2877 bitmap_xor(value_bitmap, value_bitmap, 2878 array_info->invert_mask, array_size); 2879 2880 if (bitmap_full(array_info->get_mask, array_size)) 2881 return 0; 2882 2883 i = find_first_zero_bit(array_info->get_mask, array_size); 2884 } else { 2885 array_info = NULL; 2886 } 2887 2888 while (i < array_size) { 2889 struct gpio_chip *chip = desc_array[i]->gdev->chip; 2890 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)]; 2891 unsigned long *mask, *bits; 2892 int first, j, ret; 2893 2894 if (likely(chip->ngpio <= FASTPATH_NGPIO)) { 2895 mask = fastpath; 2896 } else { 2897 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio), 2898 sizeof(*mask), 2899 can_sleep ? GFP_KERNEL : GFP_ATOMIC); 2900 if (!mask) 2901 return -ENOMEM; 2902 } 2903 2904 bits = mask + BITS_TO_LONGS(chip->ngpio); 2905 bitmap_zero(mask, chip->ngpio); 2906 2907 if (!can_sleep) 2908 WARN_ON(chip->can_sleep); 2909 2910 /* collect all inputs belonging to the same chip */ 2911 first = i; 2912 do { 2913 const struct gpio_desc *desc = desc_array[i]; 2914 int hwgpio = gpio_chip_hwgpio(desc); 2915 2916 __set_bit(hwgpio, mask); 2917 i++; 2918 2919 if (array_info) 2920 i = find_next_zero_bit(array_info->get_mask, 2921 array_size, i); 2922 } while ((i < array_size) && 2923 (desc_array[i]->gdev->chip == chip)); 2924 2925 ret = gpio_chip_get_multiple(chip, mask, bits); 2926 if (ret) { 2927 if (mask != fastpath) 2928 kfree(mask); 2929 return ret; 2930 } 2931 2932 for (j = first; j < i; ) { 2933 const struct gpio_desc *desc = desc_array[j]; 2934 int hwgpio = gpio_chip_hwgpio(desc); 2935 int value = test_bit(hwgpio, bits); 2936 2937 if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 2938 value = !value; 2939 __assign_bit(j, value_bitmap, value); 2940 trace_gpio_value(desc_to_gpio(desc), 1, value); 2941 j++; 2942 2943 if (array_info) 2944 j = find_next_zero_bit(array_info->get_mask, i, 2945 j); 2946 } 2947 2948 if (mask != fastpath) 2949 kfree(mask); 2950 } 2951 return 0; 2952 } 2953 2954 /** 2955 * gpiod_get_raw_value() - return a gpio's raw value 2956 * @desc: gpio whose value will be returned 2957 * 2958 * Return the GPIO's raw value, i.e. the value of the physical line disregarding 2959 * its ACTIVE_LOW status, or negative errno on failure. 2960 * 2961 * This function should be called from contexts where we cannot sleep, and will 2962 * complain if the GPIO chip functions potentially sleep. 2963 */ 2964 int gpiod_get_raw_value(const struct gpio_desc *desc) 2965 { 2966 VALIDATE_DESC(desc); 2967 /* Should be using gpio_get_value_cansleep() */ 2968 WARN_ON(desc->gdev->chip->can_sleep); 2969 return gpiod_get_raw_value_commit(desc); 2970 } 2971 EXPORT_SYMBOL_GPL(gpiod_get_raw_value); 2972 2973 /** 2974 * gpiod_get_value() - return a gpio's value 2975 * @desc: gpio whose value will be returned 2976 * 2977 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into 2978 * account, or negative errno on failure. 2979 * 2980 * This function should be called from contexts where we cannot sleep, and will 2981 * complain if the GPIO chip functions potentially sleep. 2982 */ 2983 int gpiod_get_value(const struct gpio_desc *desc) 2984 { 2985 int value; 2986 2987 VALIDATE_DESC(desc); 2988 /* Should be using gpio_get_value_cansleep() */ 2989 WARN_ON(desc->gdev->chip->can_sleep); 2990 2991 value = gpiod_get_raw_value_commit(desc); 2992 if (value < 0) 2993 return value; 2994 2995 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 2996 value = !value; 2997 2998 return value; 2999 } 3000 EXPORT_SYMBOL_GPL(gpiod_get_value); 3001 3002 /** 3003 * gpiod_get_raw_array_value() - read raw values from an array of GPIOs 3004 * @array_size: number of elements in the descriptor array / value bitmap 3005 * @desc_array: array of GPIO descriptors whose values will be read 3006 * @array_info: information on applicability of fast bitmap processing path 3007 * @value_bitmap: bitmap to store the read values 3008 * 3009 * Read the raw values of the GPIOs, i.e. the values of the physical lines 3010 * without regard for their ACTIVE_LOW status. Return 0 in case of success, 3011 * else an error code. 3012 * 3013 * This function should be called from contexts where we cannot sleep, 3014 * and it will complain if the GPIO chip functions potentially sleep. 3015 */ 3016 int gpiod_get_raw_array_value(unsigned int array_size, 3017 struct gpio_desc **desc_array, 3018 struct gpio_array *array_info, 3019 unsigned long *value_bitmap) 3020 { 3021 if (!desc_array) 3022 return -EINVAL; 3023 return gpiod_get_array_value_complex(true, false, array_size, 3024 desc_array, array_info, 3025 value_bitmap); 3026 } 3027 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value); 3028 3029 /** 3030 * gpiod_get_array_value() - read values from an array of GPIOs 3031 * @array_size: number of elements in the descriptor array / value bitmap 3032 * @desc_array: array of GPIO descriptors whose values will be read 3033 * @array_info: information on applicability of fast bitmap processing path 3034 * @value_bitmap: bitmap to store the read values 3035 * 3036 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status 3037 * into account. Return 0 in case of success, else an error code. 3038 * 3039 * This function should be called from contexts where we cannot sleep, 3040 * and it will complain if the GPIO chip functions potentially sleep. 3041 */ 3042 int gpiod_get_array_value(unsigned int array_size, 3043 struct gpio_desc **desc_array, 3044 struct gpio_array *array_info, 3045 unsigned long *value_bitmap) 3046 { 3047 if (!desc_array) 3048 return -EINVAL; 3049 return gpiod_get_array_value_complex(false, false, array_size, 3050 desc_array, array_info, 3051 value_bitmap); 3052 } 3053 EXPORT_SYMBOL_GPL(gpiod_get_array_value); 3054 3055 /* 3056 * gpio_set_open_drain_value_commit() - Set the open drain gpio's value. 3057 * @desc: gpio descriptor whose state need to be set. 3058 * @value: Non-zero for setting it HIGH otherwise it will set to LOW. 3059 */ 3060 static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) 3061 { 3062 int err = 0; 3063 struct gpio_chip *chip = desc->gdev->chip; 3064 int offset = gpio_chip_hwgpio(desc); 3065 3066 if (value) { 3067 err = chip->direction_input(chip, offset); 3068 if (!err) 3069 clear_bit(FLAG_IS_OUT, &desc->flags); 3070 } else { 3071 err = chip->direction_output(chip, offset, 0); 3072 if (!err) 3073 set_bit(FLAG_IS_OUT, &desc->flags); 3074 } 3075 trace_gpio_direction(desc_to_gpio(desc), value, err); 3076 if (err < 0) 3077 gpiod_err(desc, 3078 "%s: Error in set_value for open drain err %d\n", 3079 __func__, err); 3080 } 3081 3082 /* 3083 * _gpio_set_open_source_value() - Set the open source gpio's value. 3084 * @desc: gpio descriptor whose state need to be set. 3085 * @value: Non-zero for setting it HIGH otherwise it will set to LOW. 3086 */ 3087 static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value) 3088 { 3089 int err = 0; 3090 struct gpio_chip *chip = desc->gdev->chip; 3091 int offset = gpio_chip_hwgpio(desc); 3092 3093 if (value) { 3094 err = chip->direction_output(chip, offset, 1); 3095 if (!err) 3096 set_bit(FLAG_IS_OUT, &desc->flags); 3097 } else { 3098 err = chip->direction_input(chip, offset); 3099 if (!err) 3100 clear_bit(FLAG_IS_OUT, &desc->flags); 3101 } 3102 trace_gpio_direction(desc_to_gpio(desc), !value, err); 3103 if (err < 0) 3104 gpiod_err(desc, 3105 "%s: Error in set_value for open source err %d\n", 3106 __func__, err); 3107 } 3108 3109 static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) 3110 { 3111 struct gpio_chip *chip; 3112 3113 chip = desc->gdev->chip; 3114 trace_gpio_value(desc_to_gpio(desc), 0, value); 3115 chip->set(chip, gpio_chip_hwgpio(desc), value); 3116 } 3117 3118 /* 3119 * set multiple outputs on the same chip; 3120 * use the chip's set_multiple function if available; 3121 * otherwise set the outputs sequentially; 3122 * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word 3123 * defines which outputs are to be changed 3124 * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word 3125 * defines the values the outputs specified by mask are to be set to 3126 */ 3127 static void gpio_chip_set_multiple(struct gpio_chip *chip, 3128 unsigned long *mask, unsigned long *bits) 3129 { 3130 if (chip->set_multiple) { 3131 chip->set_multiple(chip, mask, bits); 3132 } else { 3133 unsigned int i; 3134 3135 /* set outputs if the corresponding mask bit is set */ 3136 for_each_set_bit(i, mask, chip->ngpio) 3137 chip->set(chip, i, test_bit(i, bits)); 3138 } 3139 } 3140 3141 int gpiod_set_array_value_complex(bool raw, bool can_sleep, 3142 unsigned int array_size, 3143 struct gpio_desc **desc_array, 3144 struct gpio_array *array_info, 3145 unsigned long *value_bitmap) 3146 { 3147 int i = 0; 3148 3149 /* 3150 * Validate array_info against desc_array and its size. 3151 * It should immediately follow desc_array if both 3152 * have been obtained from the same gpiod_get_array() call. 3153 */ 3154 if (array_info && array_info->desc == desc_array && 3155 array_size <= array_info->size && 3156 (void *)array_info == desc_array + array_info->size) { 3157 if (!can_sleep) 3158 WARN_ON(array_info->chip->can_sleep); 3159 3160 if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) 3161 bitmap_xor(value_bitmap, value_bitmap, 3162 array_info->invert_mask, array_size); 3163 3164 gpio_chip_set_multiple(array_info->chip, array_info->set_mask, 3165 value_bitmap); 3166 3167 if (bitmap_full(array_info->set_mask, array_size)) 3168 return 0; 3169 3170 i = find_first_zero_bit(array_info->set_mask, array_size); 3171 } else { 3172 array_info = NULL; 3173 } 3174 3175 while (i < array_size) { 3176 struct gpio_chip *chip = desc_array[i]->gdev->chip; 3177 unsigned long fastpath[2 * BITS_TO_LONGS(FASTPATH_NGPIO)]; 3178 unsigned long *mask, *bits; 3179 int count = 0; 3180 3181 if (likely(chip->ngpio <= FASTPATH_NGPIO)) { 3182 mask = fastpath; 3183 } else { 3184 mask = kmalloc_array(2 * BITS_TO_LONGS(chip->ngpio), 3185 sizeof(*mask), 3186 can_sleep ? GFP_KERNEL : GFP_ATOMIC); 3187 if (!mask) 3188 return -ENOMEM; 3189 } 3190 3191 bits = mask + BITS_TO_LONGS(chip->ngpio); 3192 bitmap_zero(mask, chip->ngpio); 3193 3194 if (!can_sleep) 3195 WARN_ON(chip->can_sleep); 3196 3197 do { 3198 struct gpio_desc *desc = desc_array[i]; 3199 int hwgpio = gpio_chip_hwgpio(desc); 3200 int value = test_bit(i, value_bitmap); 3201 3202 /* 3203 * Pins applicable for fast input but not for 3204 * fast output processing may have been already 3205 * inverted inside the fast path, skip them. 3206 */ 3207 if (!raw && !(array_info && 3208 test_bit(i, array_info->invert_mask)) && 3209 test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 3210 value = !value; 3211 trace_gpio_value(desc_to_gpio(desc), 0, value); 3212 /* 3213 * collect all normal outputs belonging to the same chip 3214 * open drain and open source outputs are set individually 3215 */ 3216 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) { 3217 gpio_set_open_drain_value_commit(desc, value); 3218 } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) { 3219 gpio_set_open_source_value_commit(desc, value); 3220 } else { 3221 __set_bit(hwgpio, mask); 3222 if (value) 3223 __set_bit(hwgpio, bits); 3224 else 3225 __clear_bit(hwgpio, bits); 3226 count++; 3227 } 3228 i++; 3229 3230 if (array_info) 3231 i = find_next_zero_bit(array_info->set_mask, 3232 array_size, i); 3233 } while ((i < array_size) && 3234 (desc_array[i]->gdev->chip == chip)); 3235 /* push collected bits to outputs */ 3236 if (count != 0) 3237 gpio_chip_set_multiple(chip, mask, bits); 3238 3239 if (mask != fastpath) 3240 kfree(mask); 3241 } 3242 return 0; 3243 } 3244 3245 /** 3246 * gpiod_set_raw_value() - assign a gpio's raw value 3247 * @desc: gpio whose value will be assigned 3248 * @value: value to assign 3249 * 3250 * Set the raw value of the GPIO, i.e. the value of its physical line without 3251 * regard for its ACTIVE_LOW status. 3252 * 3253 * This function should be called from contexts where we cannot sleep, and will 3254 * complain if the GPIO chip functions potentially sleep. 3255 */ 3256 void gpiod_set_raw_value(struct gpio_desc *desc, int value) 3257 { 3258 VALIDATE_DESC_VOID(desc); 3259 /* Should be using gpiod_set_value_cansleep() */ 3260 WARN_ON(desc->gdev->chip->can_sleep); 3261 gpiod_set_raw_value_commit(desc, value); 3262 } 3263 EXPORT_SYMBOL_GPL(gpiod_set_raw_value); 3264 3265 /** 3266 * gpiod_set_value_nocheck() - set a GPIO line value without checking 3267 * @desc: the descriptor to set the value on 3268 * @value: value to set 3269 * 3270 * This sets the value of a GPIO line backing a descriptor, applying 3271 * different semantic quirks like active low and open drain/source 3272 * handling. 3273 */ 3274 static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value) 3275 { 3276 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 3277 value = !value; 3278 if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) 3279 gpio_set_open_drain_value_commit(desc, value); 3280 else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) 3281 gpio_set_open_source_value_commit(desc, value); 3282 else 3283 gpiod_set_raw_value_commit(desc, value); 3284 } 3285 3286 /** 3287 * gpiod_set_value() - assign a gpio's value 3288 * @desc: gpio whose value will be assigned 3289 * @value: value to assign 3290 * 3291 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW, 3292 * OPEN_DRAIN and OPEN_SOURCE flags into account. 3293 * 3294 * This function should be called from contexts where we cannot sleep, and will 3295 * complain if the GPIO chip functions potentially sleep. 3296 */ 3297 void gpiod_set_value(struct gpio_desc *desc, int value) 3298 { 3299 VALIDATE_DESC_VOID(desc); 3300 WARN_ON(desc->gdev->chip->can_sleep); 3301 gpiod_set_value_nocheck(desc, value); 3302 } 3303 EXPORT_SYMBOL_GPL(gpiod_set_value); 3304 3305 /** 3306 * gpiod_set_raw_array_value() - assign values to an array of GPIOs 3307 * @array_size: number of elements in the descriptor array / value bitmap 3308 * @desc_array: array of GPIO descriptors whose values will be assigned 3309 * @array_info: information on applicability of fast bitmap processing path 3310 * @value_bitmap: bitmap of values to assign 3311 * 3312 * Set the raw values of the GPIOs, i.e. the values of the physical lines 3313 * without regard for their ACTIVE_LOW status. 3314 * 3315 * This function should be called from contexts where we cannot sleep, and will 3316 * complain if the GPIO chip functions potentially sleep. 3317 */ 3318 int gpiod_set_raw_array_value(unsigned int array_size, 3319 struct gpio_desc **desc_array, 3320 struct gpio_array *array_info, 3321 unsigned long *value_bitmap) 3322 { 3323 if (!desc_array) 3324 return -EINVAL; 3325 return gpiod_set_array_value_complex(true, false, array_size, 3326 desc_array, array_info, value_bitmap); 3327 } 3328 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value); 3329 3330 /** 3331 * gpiod_set_array_value() - assign values to an array of GPIOs 3332 * @array_size: number of elements in the descriptor array / value bitmap 3333 * @desc_array: array of GPIO descriptors whose values will be assigned 3334 * @array_info: information on applicability of fast bitmap processing path 3335 * @value_bitmap: bitmap of values to assign 3336 * 3337 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status 3338 * into account. 3339 * 3340 * This function should be called from contexts where we cannot sleep, and will 3341 * complain if the GPIO chip functions potentially sleep. 3342 */ 3343 int gpiod_set_array_value(unsigned int array_size, 3344 struct gpio_desc **desc_array, 3345 struct gpio_array *array_info, 3346 unsigned long *value_bitmap) 3347 { 3348 if (!desc_array) 3349 return -EINVAL; 3350 return gpiod_set_array_value_complex(false, false, array_size, 3351 desc_array, array_info, 3352 value_bitmap); 3353 } 3354 EXPORT_SYMBOL_GPL(gpiod_set_array_value); 3355 3356 /** 3357 * gpiod_cansleep() - report whether gpio value access may sleep 3358 * @desc: gpio to check 3359 * 3360 */ 3361 int gpiod_cansleep(const struct gpio_desc *desc) 3362 { 3363 VALIDATE_DESC(desc); 3364 return desc->gdev->chip->can_sleep; 3365 } 3366 EXPORT_SYMBOL_GPL(gpiod_cansleep); 3367 3368 /** 3369 * gpiod_set_consumer_name() - set the consumer name for the descriptor 3370 * @desc: gpio to set the consumer name on 3371 * @name: the new consumer name 3372 */ 3373 int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name) 3374 { 3375 VALIDATE_DESC(desc); 3376 if (name) { 3377 name = kstrdup_const(name, GFP_KERNEL); 3378 if (!name) 3379 return -ENOMEM; 3380 } 3381 3382 kfree_const(desc->label); 3383 desc_set_label(desc, name); 3384 3385 return 0; 3386 } 3387 EXPORT_SYMBOL_GPL(gpiod_set_consumer_name); 3388 3389 /** 3390 * gpiod_to_irq() - return the IRQ corresponding to a GPIO 3391 * @desc: gpio whose IRQ will be returned (already requested) 3392 * 3393 * Return the IRQ corresponding to the passed GPIO, or an error code in case of 3394 * error. 3395 */ 3396 int gpiod_to_irq(const struct gpio_desc *desc) 3397 { 3398 struct gpio_chip *chip; 3399 int offset; 3400 3401 /* 3402 * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics 3403 * requires this function to not return zero on an invalid descriptor 3404 * but rather a negative error number. 3405 */ 3406 if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip) 3407 return -EINVAL; 3408 3409 chip = desc->gdev->chip; 3410 offset = gpio_chip_hwgpio(desc); 3411 if (chip->to_irq) { 3412 int retirq = chip->to_irq(chip, offset); 3413 3414 /* Zero means NO_IRQ */ 3415 if (!retirq) 3416 return -ENXIO; 3417 3418 return retirq; 3419 } 3420 return -ENXIO; 3421 } 3422 EXPORT_SYMBOL_GPL(gpiod_to_irq); 3423 3424 /** 3425 * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ 3426 * @chip: the chip the GPIO to lock belongs to 3427 * @offset: the offset of the GPIO to lock as IRQ 3428 * 3429 * This is used directly by GPIO drivers that want to lock down 3430 * a certain GPIO line to be used for IRQs. 3431 */ 3432 int gpiochip_lock_as_irq(struct gpio_chip *chip, unsigned int offset) 3433 { 3434 struct gpio_desc *desc; 3435 3436 desc = gpiochip_get_desc(chip, offset); 3437 if (IS_ERR(desc)) 3438 return PTR_ERR(desc); 3439 3440 /* 3441 * If it's fast: flush the direction setting if something changed 3442 * behind our back 3443 */ 3444 if (!chip->can_sleep && chip->get_direction) { 3445 int dir = gpiod_get_direction(desc); 3446 3447 if (dir < 0) { 3448 chip_err(chip, "%s: cannot get GPIO direction\n", 3449 __func__); 3450 return dir; 3451 } 3452 } 3453 3454 if (test_bit(FLAG_IS_OUT, &desc->flags)) { 3455 chip_err(chip, 3456 "%s: tried to flag a GPIO set as output for IRQ\n", 3457 __func__); 3458 return -EIO; 3459 } 3460 3461 set_bit(FLAG_USED_AS_IRQ, &desc->flags); 3462 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); 3463 3464 /* 3465 * If the consumer has not set up a label (such as when the 3466 * IRQ is referenced from .to_irq()) we set up a label here 3467 * so it is clear this is used as an interrupt. 3468 */ 3469 if (!desc->label) 3470 desc_set_label(desc, "interrupt"); 3471 3472 return 0; 3473 } 3474 EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); 3475 3476 /** 3477 * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ 3478 * @chip: the chip the GPIO to lock belongs to 3479 * @offset: the offset of the GPIO to lock as IRQ 3480 * 3481 * This is used directly by GPIO drivers that want to indicate 3482 * that a certain GPIO is no longer used exclusively for IRQ. 3483 */ 3484 void gpiochip_unlock_as_irq(struct gpio_chip *chip, unsigned int offset) 3485 { 3486 struct gpio_desc *desc; 3487 3488 desc = gpiochip_get_desc(chip, offset); 3489 if (IS_ERR(desc)) 3490 return; 3491 3492 clear_bit(FLAG_USED_AS_IRQ, &desc->flags); 3493 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); 3494 3495 /* If we only had this marking, erase it */ 3496 if (desc->label && !strcmp(desc->label, "interrupt")) 3497 desc_set_label(desc, NULL); 3498 } 3499 EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); 3500 3501 void gpiochip_disable_irq(struct gpio_chip *chip, unsigned int offset) 3502 { 3503 struct gpio_desc *desc = gpiochip_get_desc(chip, offset); 3504 3505 if (!IS_ERR(desc) && 3506 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) 3507 clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); 3508 } 3509 EXPORT_SYMBOL_GPL(gpiochip_disable_irq); 3510 3511 void gpiochip_enable_irq(struct gpio_chip *chip, unsigned int offset) 3512 { 3513 struct gpio_desc *desc = gpiochip_get_desc(chip, offset); 3514 3515 if (!IS_ERR(desc) && 3516 !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) { 3517 WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags)); 3518 set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); 3519 } 3520 } 3521 EXPORT_SYMBOL_GPL(gpiochip_enable_irq); 3522 3523 bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset) 3524 { 3525 if (offset >= chip->ngpio) 3526 return false; 3527 3528 return test_bit(FLAG_USED_AS_IRQ, &chip->gpiodev->descs[offset].flags); 3529 } 3530 EXPORT_SYMBOL_GPL(gpiochip_line_is_irq); 3531 3532 int gpiochip_reqres_irq(struct gpio_chip *chip, unsigned int offset) 3533 { 3534 int ret; 3535 3536 if (!try_module_get(chip->gpiodev->owner)) 3537 return -ENODEV; 3538 3539 ret = gpiochip_lock_as_irq(chip, offset); 3540 if (ret) { 3541 chip_err(chip, "unable to lock HW IRQ %u for IRQ\n", offset); 3542 module_put(chip->gpiodev->owner); 3543 return ret; 3544 } 3545 return 0; 3546 } 3547 EXPORT_SYMBOL_GPL(gpiochip_reqres_irq); 3548 3549 void gpiochip_relres_irq(struct gpio_chip *chip, unsigned int offset) 3550 { 3551 gpiochip_unlock_as_irq(chip, offset); 3552 module_put(chip->gpiodev->owner); 3553 } 3554 EXPORT_SYMBOL_GPL(gpiochip_relres_irq); 3555 3556 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset) 3557 { 3558 if (offset >= chip->ngpio) 3559 return false; 3560 3561 return test_bit(FLAG_OPEN_DRAIN, &chip->gpiodev->descs[offset].flags); 3562 } 3563 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain); 3564 3565 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset) 3566 { 3567 if (offset >= chip->ngpio) 3568 return false; 3569 3570 return test_bit(FLAG_OPEN_SOURCE, &chip->gpiodev->descs[offset].flags); 3571 } 3572 EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source); 3573 3574 bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset) 3575 { 3576 if (offset >= chip->ngpio) 3577 return false; 3578 3579 return !test_bit(FLAG_TRANSITORY, &chip->gpiodev->descs[offset].flags); 3580 } 3581 EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent); 3582 3583 /** 3584 * gpiod_get_raw_value_cansleep() - return a gpio's raw value 3585 * @desc: gpio whose value will be returned 3586 * 3587 * Return the GPIO's raw value, i.e. the value of the physical line disregarding 3588 * its ACTIVE_LOW status, or negative errno on failure. 3589 * 3590 * This function is to be called from contexts that can sleep. 3591 */ 3592 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) 3593 { 3594 might_sleep_if(extra_checks); 3595 VALIDATE_DESC(desc); 3596 return gpiod_get_raw_value_commit(desc); 3597 } 3598 EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); 3599 3600 /** 3601 * gpiod_get_value_cansleep() - return a gpio's value 3602 * @desc: gpio whose value will be returned 3603 * 3604 * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into 3605 * account, or negative errno on failure. 3606 * 3607 * This function is to be called from contexts that can sleep. 3608 */ 3609 int gpiod_get_value_cansleep(const struct gpio_desc *desc) 3610 { 3611 int value; 3612 3613 might_sleep_if(extra_checks); 3614 VALIDATE_DESC(desc); 3615 value = gpiod_get_raw_value_commit(desc); 3616 if (value < 0) 3617 return value; 3618 3619 if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) 3620 value = !value; 3621 3622 return value; 3623 } 3624 EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); 3625 3626 /** 3627 * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs 3628 * @array_size: number of elements in the descriptor array / value bitmap 3629 * @desc_array: array of GPIO descriptors whose values will be read 3630 * @array_info: information on applicability of fast bitmap processing path 3631 * @value_bitmap: bitmap to store the read values 3632 * 3633 * Read the raw values of the GPIOs, i.e. the values of the physical lines 3634 * without regard for their ACTIVE_LOW status. Return 0 in case of success, 3635 * else an error code. 3636 * 3637 * This function is to be called from contexts that can sleep. 3638 */ 3639 int gpiod_get_raw_array_value_cansleep(unsigned int array_size, 3640 struct gpio_desc **desc_array, 3641 struct gpio_array *array_info, 3642 unsigned long *value_bitmap) 3643 { 3644 might_sleep_if(extra_checks); 3645 if (!desc_array) 3646 return -EINVAL; 3647 return gpiod_get_array_value_complex(true, true, array_size, 3648 desc_array, array_info, 3649 value_bitmap); 3650 } 3651 EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep); 3652 3653 /** 3654 * gpiod_get_array_value_cansleep() - read values from an array of GPIOs 3655 * @array_size: number of elements in the descriptor array / value bitmap 3656 * @desc_array: array of GPIO descriptors whose values will be read 3657 * @array_info: information on applicability of fast bitmap processing path 3658 * @value_bitmap: bitmap to store the read values 3659 * 3660 * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status 3661 * into account. Return 0 in case of success, else an error code. 3662 * 3663 * This function is to be called from contexts that can sleep. 3664 */ 3665 int gpiod_get_array_value_cansleep(unsigned int array_size, 3666 struct gpio_desc **desc_array, 3667 struct gpio_array *array_info, 3668 unsigned long *value_bitmap) 3669 { 3670 might_sleep_if(extra_checks); 3671 if (!desc_array) 3672 return -EINVAL; 3673 return gpiod_get_array_value_complex(false, true, array_size, 3674 desc_array, array_info, 3675 value_bitmap); 3676 } 3677 EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep); 3678 3679 /** 3680 * gpiod_set_raw_value_cansleep() - assign a gpio's raw value 3681 * @desc: gpio whose value will be assigned 3682 * @value: value to assign 3683 * 3684 * Set the raw value of the GPIO, i.e. the value of its physical line without 3685 * regard for its ACTIVE_LOW status. 3686 * 3687 * This function is to be called from contexts that can sleep. 3688 */ 3689 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) 3690 { 3691 might_sleep_if(extra_checks); 3692 VALIDATE_DESC_VOID(desc); 3693 gpiod_set_raw_value_commit(desc, value); 3694 } 3695 EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); 3696 3697 /** 3698 * gpiod_set_value_cansleep() - assign a gpio's value 3699 * @desc: gpio whose value will be assigned 3700 * @value: value to assign 3701 * 3702 * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into 3703 * account 3704 * 3705 * This function is to be called from contexts that can sleep. 3706 */ 3707 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) 3708 { 3709 might_sleep_if(extra_checks); 3710 VALIDATE_DESC_VOID(desc); 3711 gpiod_set_value_nocheck(desc, value); 3712 } 3713 EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); 3714 3715 /** 3716 * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs 3717 * @array_size: number of elements in the descriptor array / value bitmap 3718 * @desc_array: array of GPIO descriptors whose values will be assigned 3719 * @array_info: information on applicability of fast bitmap processing path 3720 * @value_bitmap: bitmap of values to assign 3721 * 3722 * Set the raw values of the GPIOs, i.e. the values of the physical lines 3723 * without regard for their ACTIVE_LOW status. 3724 * 3725 * This function is to be called from contexts that can sleep. 3726 */ 3727 int gpiod_set_raw_array_value_cansleep(unsigned int array_size, 3728 struct gpio_desc **desc_array, 3729 struct gpio_array *array_info, 3730 unsigned long *value_bitmap) 3731 { 3732 might_sleep_if(extra_checks); 3733 if (!desc_array) 3734 return -EINVAL; 3735 return gpiod_set_array_value_complex(true, true, array_size, desc_array, 3736 array_info, value_bitmap); 3737 } 3738 EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep); 3739 3740 /** 3741 * gpiod_add_lookup_tables() - register GPIO device consumers 3742 * @tables: list of tables of consumers to register 3743 * @n: number of tables in the list 3744 */ 3745 void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) 3746 { 3747 unsigned int i; 3748 3749 mutex_lock(&gpio_lookup_lock); 3750 3751 for (i = 0; i < n; i++) 3752 list_add_tail(&tables[i]->list, &gpio_lookup_list); 3753 3754 mutex_unlock(&gpio_lookup_lock); 3755 } 3756 3757 /** 3758 * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs 3759 * @array_size: number of elements in the descriptor array / value bitmap 3760 * @desc_array: array of GPIO descriptors whose values will be assigned 3761 * @array_info: information on applicability of fast bitmap processing path 3762 * @value_bitmap: bitmap of values to assign 3763 * 3764 * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status 3765 * into account. 3766 * 3767 * This function is to be called from contexts that can sleep. 3768 */ 3769 int gpiod_set_array_value_cansleep(unsigned int array_size, 3770 struct gpio_desc **desc_array, 3771 struct gpio_array *array_info, 3772 unsigned long *value_bitmap) 3773 { 3774 might_sleep_if(extra_checks); 3775 if (!desc_array) 3776 return -EINVAL; 3777 return gpiod_set_array_value_complex(false, true, array_size, 3778 desc_array, array_info, 3779 value_bitmap); 3780 } 3781 EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); 3782 3783 /** 3784 * gpiod_add_lookup_table() - register GPIO device consumers 3785 * @table: table of consumers to register 3786 */ 3787 void gpiod_add_lookup_table(struct gpiod_lookup_table *table) 3788 { 3789 mutex_lock(&gpio_lookup_lock); 3790 3791 list_add_tail(&table->list, &gpio_lookup_list); 3792 3793 mutex_unlock(&gpio_lookup_lock); 3794 } 3795 EXPORT_SYMBOL_GPL(gpiod_add_lookup_table); 3796 3797 /** 3798 * gpiod_remove_lookup_table() - unregister GPIO device consumers 3799 * @table: table of consumers to unregister 3800 */ 3801 void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) 3802 { 3803 mutex_lock(&gpio_lookup_lock); 3804 3805 list_del(&table->list); 3806 3807 mutex_unlock(&gpio_lookup_lock); 3808 } 3809 EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table); 3810 3811 /** 3812 * gpiod_add_hogs() - register a set of GPIO hogs from machine code 3813 * @hogs: table of gpio hog entries with a zeroed sentinel at the end 3814 */ 3815 void gpiod_add_hogs(struct gpiod_hog *hogs) 3816 { 3817 struct gpio_chip *chip; 3818 struct gpiod_hog *hog; 3819 3820 mutex_lock(&gpio_machine_hogs_mutex); 3821 3822 for (hog = &hogs[0]; hog->chip_label; hog++) { 3823 list_add_tail(&hog->list, &gpio_machine_hogs); 3824 3825 /* 3826 * The chip may have been registered earlier, so check if it 3827 * exists and, if so, try to hog the line now. 3828 */ 3829 chip = find_chip_by_name(hog->chip_label); 3830 if (chip) 3831 gpiochip_machine_hog(chip, hog); 3832 } 3833 3834 mutex_unlock(&gpio_machine_hogs_mutex); 3835 } 3836 EXPORT_SYMBOL_GPL(gpiod_add_hogs); 3837 3838 static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) 3839 { 3840 const char *dev_id = dev ? dev_name(dev) : NULL; 3841 struct gpiod_lookup_table *table; 3842 3843 mutex_lock(&gpio_lookup_lock); 3844 3845 list_for_each_entry(table, &gpio_lookup_list, list) { 3846 if (table->dev_id && dev_id) { 3847 /* 3848 * Valid strings on both ends, must be identical to have 3849 * a match 3850 */ 3851 if (!strcmp(table->dev_id, dev_id)) 3852 goto found; 3853 } else { 3854 /* 3855 * One of the pointers is NULL, so both must be to have 3856 * a match 3857 */ 3858 if (dev_id == table->dev_id) 3859 goto found; 3860 } 3861 } 3862 table = NULL; 3863 3864 found: 3865 mutex_unlock(&gpio_lookup_lock); 3866 return table; 3867 } 3868 3869 static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, 3870 unsigned int idx, 3871 enum gpio_lookup_flags *flags) 3872 { 3873 struct gpio_desc *desc = ERR_PTR(-ENOENT); 3874 struct gpiod_lookup_table *table; 3875 struct gpiod_lookup *p; 3876 3877 table = gpiod_find_lookup_table(dev); 3878 if (!table) 3879 return desc; 3880 3881 for (p = &table->table[0]; p->chip_label; p++) { 3882 struct gpio_chip *chip; 3883 3884 /* idx must always match exactly */ 3885 if (p->idx != idx) 3886 continue; 3887 3888 /* If the lookup entry has a con_id, require exact match */ 3889 if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) 3890 continue; 3891 3892 chip = find_chip_by_name(p->chip_label); 3893 3894 if (!chip) { 3895 /* 3896 * As the lookup table indicates a chip with 3897 * p->chip_label should exist, assume it may 3898 * still appear later and let the interested 3899 * consumer be probed again or let the Deferred 3900 * Probe infrastructure handle the error. 3901 */ 3902 dev_warn(dev, "cannot find GPIO chip %s, deferring\n", 3903 p->chip_label); 3904 return ERR_PTR(-EPROBE_DEFER); 3905 } 3906 3907 if (chip->ngpio <= p->chip_hwnum) { 3908 dev_err(dev, 3909 "requested GPIO %d is out of range [0..%d] for chip %s\n", 3910 idx, chip->ngpio, chip->label); 3911 return ERR_PTR(-EINVAL); 3912 } 3913 3914 desc = gpiochip_get_desc(chip, p->chip_hwnum); 3915 *flags = p->flags; 3916 3917 return desc; 3918 } 3919 3920 return desc; 3921 } 3922 3923 static int dt_gpio_count(struct device *dev, const char *con_id) 3924 { 3925 int ret; 3926 char propname[32]; 3927 unsigned int i; 3928 3929 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { 3930 if (con_id) 3931 snprintf(propname, sizeof(propname), "%s-%s", 3932 con_id, gpio_suffixes[i]); 3933 else 3934 snprintf(propname, sizeof(propname), "%s", 3935 gpio_suffixes[i]); 3936 3937 ret = of_gpio_named_count(dev->of_node, propname); 3938 if (ret > 0) 3939 break; 3940 } 3941 return ret ? ret : -ENOENT; 3942 } 3943 3944 static int platform_gpio_count(struct device *dev, const char *con_id) 3945 { 3946 struct gpiod_lookup_table *table; 3947 struct gpiod_lookup *p; 3948 unsigned int count = 0; 3949 3950 table = gpiod_find_lookup_table(dev); 3951 if (!table) 3952 return -ENOENT; 3953 3954 for (p = &table->table[0]; p->chip_label; p++) { 3955 if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || 3956 (!con_id && !p->con_id)) 3957 count++; 3958 } 3959 if (!count) 3960 return -ENOENT; 3961 3962 return count; 3963 } 3964 3965 /** 3966 * gpiod_count - return the number of GPIOs associated with a device / function 3967 * or -ENOENT if no GPIO has been assigned to the requested function 3968 * @dev: GPIO consumer, can be NULL for system-global GPIOs 3969 * @con_id: function within the GPIO consumer 3970 */ 3971 int gpiod_count(struct device *dev, const char *con_id) 3972 { 3973 int count = -ENOENT; 3974 3975 if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) 3976 count = dt_gpio_count(dev, con_id); 3977 else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) 3978 count = acpi_gpio_count(dev, con_id); 3979 3980 if (count < 0) 3981 count = platform_gpio_count(dev, con_id); 3982 3983 return count; 3984 } 3985 EXPORT_SYMBOL_GPL(gpiod_count); 3986 3987 /** 3988 * gpiod_get - obtain a GPIO for a given GPIO function 3989 * @dev: GPIO consumer, can be NULL for system-global GPIOs 3990 * @con_id: function within the GPIO consumer 3991 * @flags: optional GPIO initialization flags 3992 * 3993 * Return the GPIO descriptor corresponding to the function con_id of device 3994 * dev, -ENOENT if no GPIO has been assigned to the requested function, or 3995 * another IS_ERR() code if an error occurred while trying to acquire the GPIO. 3996 */ 3997 struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id, 3998 enum gpiod_flags flags) 3999 { 4000 return gpiod_get_index(dev, con_id, 0, flags); 4001 } 4002 EXPORT_SYMBOL_GPL(gpiod_get); 4003 4004 /** 4005 * gpiod_get_optional - obtain an optional GPIO for a given GPIO function 4006 * @dev: GPIO consumer, can be NULL for system-global GPIOs 4007 * @con_id: function within the GPIO consumer 4008 * @flags: optional GPIO initialization flags 4009 * 4010 * This is equivalent to gpiod_get(), except that when no GPIO was assigned to 4011 * the requested function it will return NULL. This is convenient for drivers 4012 * that need to handle optional GPIOs. 4013 */ 4014 struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, 4015 const char *con_id, 4016 enum gpiod_flags flags) 4017 { 4018 return gpiod_get_index_optional(dev, con_id, 0, flags); 4019 } 4020 EXPORT_SYMBOL_GPL(gpiod_get_optional); 4021 4022 4023 /** 4024 * gpiod_configure_flags - helper function to configure a given GPIO 4025 * @desc: gpio whose value will be assigned 4026 * @con_id: function within the GPIO consumer 4027 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or 4028 * of_get_gpio_hog() 4029 * @dflags: gpiod_flags - optional GPIO initialization flags 4030 * 4031 * Return 0 on success, -ENOENT if no GPIO has been assigned to the 4032 * requested function and/or index, or another IS_ERR() code if an error 4033 * occurred while trying to acquire the GPIO. 4034 */ 4035 int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, 4036 unsigned long lflags, enum gpiod_flags dflags) 4037 { 4038 int status; 4039 4040 if (lflags & GPIO_ACTIVE_LOW) 4041 set_bit(FLAG_ACTIVE_LOW, &desc->flags); 4042 4043 if (lflags & GPIO_OPEN_DRAIN) 4044 set_bit(FLAG_OPEN_DRAIN, &desc->flags); 4045 else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) { 4046 /* 4047 * This enforces open drain mode from the consumer side. 4048 * This is necessary for some busses like I2C, but the lookup 4049 * should *REALLY* have specified them as open drain in the 4050 * first place, so print a little warning here. 4051 */ 4052 set_bit(FLAG_OPEN_DRAIN, &desc->flags); 4053 gpiod_warn(desc, 4054 "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n"); 4055 } 4056 4057 if (lflags & GPIO_OPEN_SOURCE) 4058 set_bit(FLAG_OPEN_SOURCE, &desc->flags); 4059 4060 status = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY)); 4061 if (status < 0) 4062 return status; 4063 4064 /* No particular flag request, return here... */ 4065 if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { 4066 pr_debug("no flags found for %s\n", con_id); 4067 return 0; 4068 } 4069 4070 /* Process flags */ 4071 if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) 4072 status = gpiod_direction_output(desc, 4073 !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL)); 4074 else 4075 status = gpiod_direction_input(desc); 4076 4077 return status; 4078 } 4079 4080 /** 4081 * gpiod_get_index - obtain a GPIO from a multi-index GPIO function 4082 * @dev: GPIO consumer, can be NULL for system-global GPIOs 4083 * @con_id: function within the GPIO consumer 4084 * @idx: index of the GPIO to obtain in the consumer 4085 * @flags: optional GPIO initialization flags 4086 * 4087 * This variant of gpiod_get() allows to access GPIOs other than the first 4088 * defined one for functions that define several GPIOs. 4089 * 4090 * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the 4091 * requested function and/or index, or another IS_ERR() code if an error 4092 * occurred while trying to acquire the GPIO. 4093 */ 4094 struct gpio_desc *__must_check gpiod_get_index(struct device *dev, 4095 const char *con_id, 4096 unsigned int idx, 4097 enum gpiod_flags flags) 4098 { 4099 struct gpio_desc *desc = NULL; 4100 int status; 4101 enum gpio_lookup_flags lookupflags = 0; 4102 /* Maybe we have a device name, maybe not */ 4103 const char *devname = dev ? dev_name(dev) : "?"; 4104 4105 dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id); 4106 4107 if (dev) { 4108 /* Using device tree? */ 4109 if (IS_ENABLED(CONFIG_OF) && dev->of_node) { 4110 dev_dbg(dev, "using device tree for GPIO lookup\n"); 4111 desc = of_find_gpio(dev, con_id, idx, &lookupflags); 4112 } else if (ACPI_COMPANION(dev)) { 4113 dev_dbg(dev, "using ACPI for GPIO lookup\n"); 4114 desc = acpi_find_gpio(dev, con_id, idx, &flags, &lookupflags); 4115 } 4116 } 4117 4118 /* 4119 * Either we are not using DT or ACPI, or their lookup did not return 4120 * a result. In that case, use platform lookup as a fallback. 4121 */ 4122 if (!desc || desc == ERR_PTR(-ENOENT)) { 4123 dev_dbg(dev, "using lookup tables for GPIO lookup\n"); 4124 desc = gpiod_find(dev, con_id, idx, &lookupflags); 4125 } 4126 4127 if (IS_ERR(desc)) { 4128 dev_dbg(dev, "No GPIO consumer %s found\n", con_id); 4129 return desc; 4130 } 4131 4132 /* 4133 * If a connection label was passed use that, else attempt to use 4134 * the device name as label 4135 */ 4136 status = gpiod_request(desc, con_id ? con_id : devname); 4137 if (status < 0) { 4138 if (status == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) { 4139 /* 4140 * This happens when there are several consumers for 4141 * the same GPIO line: we just return here without 4142 * further initialization. It is a bit if a hack. 4143 * This is necessary to support fixed regulators. 4144 * 4145 * FIXME: Make this more sane and safe. 4146 */ 4147 dev_info(dev, "nonexclusive access to GPIO for %s\n", 4148 con_id ? con_id : devname); 4149 return desc; 4150 } else { 4151 return ERR_PTR(status); 4152 } 4153 } 4154 4155 status = gpiod_configure_flags(desc, con_id, lookupflags, flags); 4156 if (status < 0) { 4157 dev_dbg(dev, "setup of GPIO %s failed\n", con_id); 4158 gpiod_put(desc); 4159 return ERR_PTR(status); 4160 } 4161 4162 return desc; 4163 } 4164 EXPORT_SYMBOL_GPL(gpiod_get_index); 4165 4166 /** 4167 * gpiod_get_from_of_node() - obtain a GPIO from an OF node 4168 * @node: handle of the OF node 4169 * @propname: name of the DT property representing the GPIO 4170 * @index: index of the GPIO to obtain for the consumer 4171 * @dflags: GPIO initialization flags 4172 * @label: label to attach to the requested GPIO 4173 * 4174 * Returns: 4175 * On successful request the GPIO pin is configured in accordance with 4176 * provided @dflags. If the node does not have the requested GPIO 4177 * property, NULL is returned. 4178 * 4179 * In case of error an ERR_PTR() is returned. 4180 */ 4181 struct gpio_desc *gpiod_get_from_of_node(struct device_node *node, 4182 const char *propname, int index, 4183 enum gpiod_flags dflags, 4184 const char *label) 4185 { 4186 struct gpio_desc *desc; 4187 unsigned long lflags = 0; 4188 enum of_gpio_flags flags; 4189 bool active_low = false; 4190 bool single_ended = false; 4191 bool open_drain = false; 4192 bool transitory = false; 4193 int ret; 4194 4195 desc = of_get_named_gpiod_flags(node, propname, 4196 index, &flags); 4197 4198 if (!desc || IS_ERR(desc)) { 4199 /* If it is not there, just return NULL */ 4200 if (PTR_ERR(desc) == -ENOENT) 4201 return NULL; 4202 return desc; 4203 } 4204 4205 active_low = flags & OF_GPIO_ACTIVE_LOW; 4206 single_ended = flags & OF_GPIO_SINGLE_ENDED; 4207 open_drain = flags & OF_GPIO_OPEN_DRAIN; 4208 transitory = flags & OF_GPIO_TRANSITORY; 4209 4210 ret = gpiod_request(desc, label); 4211 if (ret == -EBUSY && (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) 4212 return desc; 4213 if (ret) 4214 return ERR_PTR(ret); 4215 4216 if (active_low) 4217 lflags |= GPIO_ACTIVE_LOW; 4218 4219 if (single_ended) { 4220 if (open_drain) 4221 lflags |= GPIO_OPEN_DRAIN; 4222 else 4223 lflags |= GPIO_OPEN_SOURCE; 4224 } 4225 4226 if (transitory) 4227 lflags |= GPIO_TRANSITORY; 4228 4229 ret = gpiod_configure_flags(desc, propname, lflags, dflags); 4230 if (ret < 0) { 4231 gpiod_put(desc); 4232 return ERR_PTR(ret); 4233 } 4234 4235 return desc; 4236 } 4237 EXPORT_SYMBOL(gpiod_get_from_of_node); 4238 4239 /** 4240 * fwnode_get_named_gpiod - obtain a GPIO from firmware node 4241 * @fwnode: handle of the firmware node 4242 * @propname: name of the firmware property representing the GPIO 4243 * @index: index of the GPIO to obtain for the consumer 4244 * @dflags: GPIO initialization flags 4245 * @label: label to attach to the requested GPIO 4246 * 4247 * This function can be used for drivers that get their configuration 4248 * from opaque firmware. 4249 * 4250 * The function properly finds the corresponding GPIO using whatever is the 4251 * underlying firmware interface and then makes sure that the GPIO 4252 * descriptor is requested before it is returned to the caller. 4253 * 4254 * Returns: 4255 * On successful request the GPIO pin is configured in accordance with 4256 * provided @dflags. 4257 * 4258 * In case of error an ERR_PTR() is returned. 4259 */ 4260 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, 4261 const char *propname, int index, 4262 enum gpiod_flags dflags, 4263 const char *label) 4264 { 4265 struct gpio_desc *desc = ERR_PTR(-ENODEV); 4266 unsigned long lflags = 0; 4267 int ret; 4268 4269 if (!fwnode) 4270 return ERR_PTR(-EINVAL); 4271 4272 if (is_of_node(fwnode)) { 4273 desc = gpiod_get_from_of_node(to_of_node(fwnode), 4274 propname, index, 4275 dflags, 4276 label); 4277 return desc; 4278 } else if (is_acpi_node(fwnode)) { 4279 struct acpi_gpio_info info; 4280 4281 desc = acpi_node_get_gpiod(fwnode, propname, index, &info); 4282 if (IS_ERR(desc)) 4283 return desc; 4284 4285 acpi_gpio_update_gpiod_flags(&dflags, &info); 4286 4287 if (info.polarity == GPIO_ACTIVE_LOW) 4288 lflags |= GPIO_ACTIVE_LOW; 4289 } 4290 4291 /* Currently only ACPI takes this path */ 4292 ret = gpiod_request(desc, label); 4293 if (ret) 4294 return ERR_PTR(ret); 4295 4296 ret = gpiod_configure_flags(desc, propname, lflags, dflags); 4297 if (ret < 0) { 4298 gpiod_put(desc); 4299 return ERR_PTR(ret); 4300 } 4301 4302 return desc; 4303 } 4304 EXPORT_SYMBOL_GPL(fwnode_get_named_gpiod); 4305 4306 /** 4307 * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO 4308 * function 4309 * @dev: GPIO consumer, can be NULL for system-global GPIOs 4310 * @con_id: function within the GPIO consumer 4311 * @index: index of the GPIO to obtain in the consumer 4312 * @flags: optional GPIO initialization flags 4313 * 4314 * This is equivalent to gpiod_get_index(), except that when no GPIO with the 4315 * specified index was assigned to the requested function it will return NULL. 4316 * This is convenient for drivers that need to handle optional GPIOs. 4317 */ 4318 struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, 4319 const char *con_id, 4320 unsigned int index, 4321 enum gpiod_flags flags) 4322 { 4323 struct gpio_desc *desc; 4324 4325 desc = gpiod_get_index(dev, con_id, index, flags); 4326 if (IS_ERR(desc)) { 4327 if (PTR_ERR(desc) == -ENOENT) 4328 return NULL; 4329 } 4330 4331 return desc; 4332 } 4333 EXPORT_SYMBOL_GPL(gpiod_get_index_optional); 4334 4335 /** 4336 * gpiod_hog - Hog the specified GPIO desc given the provided flags 4337 * @desc: gpio whose value will be assigned 4338 * @name: gpio line name 4339 * @lflags: gpio_lookup_flags - returned from of_find_gpio() or 4340 * of_get_gpio_hog() 4341 * @dflags: gpiod_flags - optional GPIO initialization flags 4342 */ 4343 int gpiod_hog(struct gpio_desc *desc, const char *name, 4344 unsigned long lflags, enum gpiod_flags dflags) 4345 { 4346 struct gpio_chip *chip; 4347 struct gpio_desc *local_desc; 4348 int hwnum; 4349 int status; 4350 4351 chip = gpiod_to_chip(desc); 4352 hwnum = gpio_chip_hwgpio(desc); 4353 4354 /* 4355 * FIXME: not very elegant that we call gpiod_configure_flags() 4356 * twice here (once inside gpiochip_request_own_desc() and 4357 * again here), but the gpiochip_request_own_desc() is external 4358 * and cannot really pass the lflags so this is the lesser evil 4359 * at the moment. Pass zero as dflags on this first call so we 4360 * don't screw anything up. 4361 */ 4362 local_desc = gpiochip_request_own_desc(chip, hwnum, name, 0); 4363 if (IS_ERR(local_desc)) { 4364 status = PTR_ERR(local_desc); 4365 pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n", 4366 name, chip->label, hwnum, status); 4367 return status; 4368 } 4369 4370 status = gpiod_configure_flags(desc, name, lflags, dflags); 4371 if (status < 0) { 4372 pr_err("setup of hog GPIO %s (chip %s, offset %d) failed, %d\n", 4373 name, chip->label, hwnum, status); 4374 gpiochip_free_own_desc(desc); 4375 return status; 4376 } 4377 4378 /* Mark GPIO as hogged so it can be identified and removed later */ 4379 set_bit(FLAG_IS_HOGGED, &desc->flags); 4380 4381 pr_info("GPIO line %d (%s) hogged as %s%s\n", 4382 desc_to_gpio(desc), name, 4383 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input", 4384 (dflags&GPIOD_FLAGS_BIT_DIR_OUT) ? 4385 (dflags&GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low":""); 4386 4387 return 0; 4388 } 4389 4390 /** 4391 * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog 4392 * @chip: gpio chip to act on 4393 * 4394 * This is only used by of_gpiochip_remove to free hogged gpios 4395 */ 4396 static void gpiochip_free_hogs(struct gpio_chip *chip) 4397 { 4398 int id; 4399 4400 for (id = 0; id < chip->ngpio; id++) { 4401 if (test_bit(FLAG_IS_HOGGED, &chip->gpiodev->descs[id].flags)) 4402 gpiochip_free_own_desc(&chip->gpiodev->descs[id]); 4403 } 4404 } 4405 4406 /** 4407 * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function 4408 * @dev: GPIO consumer, can be NULL for system-global GPIOs 4409 * @con_id: function within the GPIO consumer 4410 * @flags: optional GPIO initialization flags 4411 * 4412 * This function acquires all the GPIOs defined under a given function. 4413 * 4414 * Return a struct gpio_descs containing an array of descriptors, -ENOENT if 4415 * no GPIO has been assigned to the requested function, or another IS_ERR() 4416 * code if an error occurred while trying to acquire the GPIOs. 4417 */ 4418 struct gpio_descs *__must_check gpiod_get_array(struct device *dev, 4419 const char *con_id, 4420 enum gpiod_flags flags) 4421 { 4422 struct gpio_desc *desc; 4423 struct gpio_descs *descs; 4424 struct gpio_array *array_info = NULL; 4425 struct gpio_chip *chip; 4426 int count, bitmap_size; 4427 4428 count = gpiod_count(dev, con_id); 4429 if (count < 0) 4430 return ERR_PTR(count); 4431 4432 descs = kzalloc(struct_size(descs, desc, count), GFP_KERNEL); 4433 if (!descs) 4434 return ERR_PTR(-ENOMEM); 4435 4436 for (descs->ndescs = 0; descs->ndescs < count; ) { 4437 desc = gpiod_get_index(dev, con_id, descs->ndescs, flags); 4438 if (IS_ERR(desc)) { 4439 gpiod_put_array(descs); 4440 return ERR_CAST(desc); 4441 } 4442 4443 descs->desc[descs->ndescs] = desc; 4444 4445 chip = gpiod_to_chip(desc); 4446 /* 4447 * If pin hardware number of array member 0 is also 0, select 4448 * its chip as a candidate for fast bitmap processing path. 4449 */ 4450 if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) { 4451 struct gpio_descs *array; 4452 4453 bitmap_size = BITS_TO_LONGS(chip->ngpio > count ? 4454 chip->ngpio : count); 4455 4456 array = kzalloc(struct_size(descs, desc, count) + 4457 struct_size(array_info, invert_mask, 4458 3 * bitmap_size), GFP_KERNEL); 4459 if (!array) { 4460 gpiod_put_array(descs); 4461 return ERR_PTR(-ENOMEM); 4462 } 4463 4464 memcpy(array, descs, 4465 struct_size(descs, desc, descs->ndescs + 1)); 4466 kfree(descs); 4467 4468 descs = array; 4469 array_info = (void *)(descs->desc + count); 4470 array_info->get_mask = array_info->invert_mask + 4471 bitmap_size; 4472 array_info->set_mask = array_info->get_mask + 4473 bitmap_size; 4474 4475 array_info->desc = descs->desc; 4476 array_info->size = count; 4477 array_info->chip = chip; 4478 bitmap_set(array_info->get_mask, descs->ndescs, 4479 count - descs->ndescs); 4480 bitmap_set(array_info->set_mask, descs->ndescs, 4481 count - descs->ndescs); 4482 descs->info = array_info; 4483 } 4484 /* Unmark array members which don't belong to the 'fast' chip */ 4485 if (array_info && array_info->chip != chip) { 4486 __clear_bit(descs->ndescs, array_info->get_mask); 4487 __clear_bit(descs->ndescs, array_info->set_mask); 4488 } 4489 /* 4490 * Detect array members which belong to the 'fast' chip 4491 * but their pins are not in hardware order. 4492 */ 4493 else if (array_info && 4494 gpio_chip_hwgpio(desc) != descs->ndescs) { 4495 /* 4496 * Don't use fast path if all array members processed so 4497 * far belong to the same chip as this one but its pin 4498 * hardware number is different from its array index. 4499 */ 4500 if (bitmap_full(array_info->get_mask, descs->ndescs)) { 4501 array_info = NULL; 4502 } else { 4503 __clear_bit(descs->ndescs, 4504 array_info->get_mask); 4505 __clear_bit(descs->ndescs, 4506 array_info->set_mask); 4507 } 4508 } else if (array_info) { 4509 /* Exclude open drain or open source from fast output */ 4510 if (gpiochip_line_is_open_drain(chip, descs->ndescs) || 4511 gpiochip_line_is_open_source(chip, descs->ndescs)) 4512 __clear_bit(descs->ndescs, 4513 array_info->set_mask); 4514 /* Identify 'fast' pins which require invertion */ 4515 if (gpiod_is_active_low(desc)) 4516 __set_bit(descs->ndescs, 4517 array_info->invert_mask); 4518 } 4519 4520 descs->ndescs++; 4521 } 4522 if (array_info) 4523 dev_dbg(dev, 4524 "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n", 4525 array_info->chip->label, array_info->size, 4526 *array_info->get_mask, *array_info->set_mask, 4527 *array_info->invert_mask); 4528 return descs; 4529 } 4530 EXPORT_SYMBOL_GPL(gpiod_get_array); 4531 4532 /** 4533 * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO 4534 * function 4535 * @dev: GPIO consumer, can be NULL for system-global GPIOs 4536 * @con_id: function within the GPIO consumer 4537 * @flags: optional GPIO initialization flags 4538 * 4539 * This is equivalent to gpiod_get_array(), except that when no GPIO was 4540 * assigned to the requested function it will return NULL. 4541 */ 4542 struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, 4543 const char *con_id, 4544 enum gpiod_flags flags) 4545 { 4546 struct gpio_descs *descs; 4547 4548 descs = gpiod_get_array(dev, con_id, flags); 4549 if (IS_ERR(descs) && (PTR_ERR(descs) == -ENOENT)) 4550 return NULL; 4551 4552 return descs; 4553 } 4554 EXPORT_SYMBOL_GPL(gpiod_get_array_optional); 4555 4556 /** 4557 * gpiod_put - dispose of a GPIO descriptor 4558 * @desc: GPIO descriptor to dispose of 4559 * 4560 * No descriptor can be used after gpiod_put() has been called on it. 4561 */ 4562 void gpiod_put(struct gpio_desc *desc) 4563 { 4564 gpiod_free(desc); 4565 } 4566 EXPORT_SYMBOL_GPL(gpiod_put); 4567 4568 /** 4569 * gpiod_put_array - dispose of multiple GPIO descriptors 4570 * @descs: struct gpio_descs containing an array of descriptors 4571 */ 4572 void gpiod_put_array(struct gpio_descs *descs) 4573 { 4574 unsigned int i; 4575 4576 for (i = 0; i < descs->ndescs; i++) 4577 gpiod_put(descs->desc[i]); 4578 4579 kfree(descs); 4580 } 4581 EXPORT_SYMBOL_GPL(gpiod_put_array); 4582 4583 static int __init gpiolib_dev_init(void) 4584 { 4585 int ret; 4586 4587 /* Register GPIO sysfs bus */ 4588 ret = bus_register(&gpio_bus_type); 4589 if (ret < 0) { 4590 pr_err("gpiolib: could not register GPIO bus type\n"); 4591 return ret; 4592 } 4593 4594 ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, "gpiochip"); 4595 if (ret < 0) { 4596 pr_err("gpiolib: failed to allocate char dev region\n"); 4597 bus_unregister(&gpio_bus_type); 4598 } else { 4599 gpiolib_initialized = true; 4600 gpiochip_setup_devs(); 4601 } 4602 return ret; 4603 } 4604 core_initcall(gpiolib_dev_init); 4605 4606 #ifdef CONFIG_DEBUG_FS 4607 4608 static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) 4609 { 4610 unsigned i; 4611 struct gpio_chip *chip = gdev->chip; 4612 unsigned gpio = gdev->base; 4613 struct gpio_desc *gdesc = &gdev->descs[0]; 4614 bool is_out; 4615 bool is_irq; 4616 bool active_low; 4617 4618 for (i = 0; i < gdev->ngpio; i++, gpio++, gdesc++) { 4619 if (!test_bit(FLAG_REQUESTED, &gdesc->flags)) { 4620 if (gdesc->name) { 4621 seq_printf(s, " gpio-%-3d (%-20.20s)\n", 4622 gpio, gdesc->name); 4623 } 4624 continue; 4625 } 4626 4627 gpiod_get_direction(gdesc); 4628 is_out = test_bit(FLAG_IS_OUT, &gdesc->flags); 4629 is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags); 4630 active_low = test_bit(FLAG_ACTIVE_LOW, &gdesc->flags); 4631 seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s", 4632 gpio, gdesc->name ? gdesc->name : "", gdesc->label, 4633 is_out ? "out" : "in ", 4634 chip->get ? (chip->get(chip, i) ? "hi" : "lo") : "? ", 4635 is_irq ? "IRQ " : "", 4636 active_low ? "ACTIVE LOW" : ""); 4637 seq_printf(s, "\n"); 4638 } 4639 } 4640 4641 static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) 4642 { 4643 unsigned long flags; 4644 struct gpio_device *gdev = NULL; 4645 loff_t index = *pos; 4646 4647 s->private = ""; 4648 4649 spin_lock_irqsave(&gpio_lock, flags); 4650 list_for_each_entry(gdev, &gpio_devices, list) 4651 if (index-- == 0) { 4652 spin_unlock_irqrestore(&gpio_lock, flags); 4653 return gdev; 4654 } 4655 spin_unlock_irqrestore(&gpio_lock, flags); 4656 4657 return NULL; 4658 } 4659 4660 static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) 4661 { 4662 unsigned long flags; 4663 struct gpio_device *gdev = v; 4664 void *ret = NULL; 4665 4666 spin_lock_irqsave(&gpio_lock, flags); 4667 if (list_is_last(&gdev->list, &gpio_devices)) 4668 ret = NULL; 4669 else 4670 ret = list_entry(gdev->list.next, struct gpio_device, list); 4671 spin_unlock_irqrestore(&gpio_lock, flags); 4672 4673 s->private = "\n"; 4674 ++*pos; 4675 4676 return ret; 4677 } 4678 4679 static void gpiolib_seq_stop(struct seq_file *s, void *v) 4680 { 4681 } 4682 4683 static int gpiolib_seq_show(struct seq_file *s, void *v) 4684 { 4685 struct gpio_device *gdev = v; 4686 struct gpio_chip *chip = gdev->chip; 4687 struct device *parent; 4688 4689 if (!chip) { 4690 seq_printf(s, "%s%s: (dangling chip)", (char *)s->private, 4691 dev_name(&gdev->dev)); 4692 return 0; 4693 } 4694 4695 seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private, 4696 dev_name(&gdev->dev), 4697 gdev->base, gdev->base + gdev->ngpio - 1); 4698 parent = chip->parent; 4699 if (parent) 4700 seq_printf(s, ", parent: %s/%s", 4701 parent->bus ? parent->bus->name : "no-bus", 4702 dev_name(parent)); 4703 if (chip->label) 4704 seq_printf(s, ", %s", chip->label); 4705 if (chip->can_sleep) 4706 seq_printf(s, ", can sleep"); 4707 seq_printf(s, ":\n"); 4708 4709 if (chip->dbg_show) 4710 chip->dbg_show(s, chip); 4711 else 4712 gpiolib_dbg_show(s, gdev); 4713 4714 return 0; 4715 } 4716 4717 static const struct seq_operations gpiolib_seq_ops = { 4718 .start = gpiolib_seq_start, 4719 .next = gpiolib_seq_next, 4720 .stop = gpiolib_seq_stop, 4721 .show = gpiolib_seq_show, 4722 }; 4723 4724 static int gpiolib_open(struct inode *inode, struct file *file) 4725 { 4726 return seq_open(file, &gpiolib_seq_ops); 4727 } 4728 4729 static const struct file_operations gpiolib_operations = { 4730 .owner = THIS_MODULE, 4731 .open = gpiolib_open, 4732 .read = seq_read, 4733 .llseek = seq_lseek, 4734 .release = seq_release, 4735 }; 4736 4737 static int __init gpiolib_debugfs_init(void) 4738 { 4739 /* /sys/kernel/debug/gpio */ 4740 (void) debugfs_create_file("gpio", S_IFREG | S_IRUGO, 4741 NULL, NULL, &gpiolib_operations); 4742 return 0; 4743 } 4744 subsys_initcall(gpiolib_debugfs_init); 4745 4746 #endif /* DEBUG_FS */ 4747