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