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