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