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