1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * OF helpers for the GPIO API 4 * 5 * Copyright (c) 2007-2008 MontaVista Software, Inc. 6 * 7 * Author: Anton Vorontsov <avorontsov@ru.mvista.com> 8 */ 9 10 #include <linux/device.h> 11 #include <linux/err.h> 12 #include <linux/errno.h> 13 #include <linux/module.h> 14 #include <linux/io.h> 15 #include <linux/gpio/consumer.h> 16 #include <linux/of.h> 17 #include <linux/of_address.h> 18 #include <linux/of_gpio.h> 19 #include <linux/pinctrl/pinctrl.h> 20 #include <linux/slab.h> 21 #include <linux/gpio/machine.h> 22 23 #include "gpiolib.h" 24 #include "gpiolib-of.h" 25 26 /** 27 * of_gpio_spi_cs_get_count() - special GPIO counting for SPI 28 * @dev: Consuming device 29 * @con_id: Function within the GPIO consumer 30 * 31 * Some elder GPIO controllers need special quirks. Currently we handle 32 * the Freescale and PPC GPIO controller with bindings that doesn't use the 33 * established "cs-gpios" for chip selects but instead rely on 34 * "gpios" for the chip select lines. If we detect this, we redirect 35 * the counting of "cs-gpios" to count "gpios" transparent to the 36 * driver. 37 */ 38 static int of_gpio_spi_cs_get_count(struct device *dev, const char *con_id) 39 { 40 struct device_node *np = dev->of_node; 41 42 if (!IS_ENABLED(CONFIG_SPI_MASTER)) 43 return 0; 44 if (!con_id || strcmp(con_id, "cs")) 45 return 0; 46 if (!of_device_is_compatible(np, "fsl,spi") && 47 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") && 48 !of_device_is_compatible(np, "ibm,ppc4xx-spi")) 49 return 0; 50 return of_gpio_named_count(np, "gpios"); 51 } 52 53 /* 54 * This is used by external users of of_gpio_count() from <linux/of_gpio.h> 55 * 56 * FIXME: get rid of those external users by converting them to GPIO 57 * descriptors and let them all use gpiod_count() 58 */ 59 int of_gpio_get_count(struct device *dev, const char *con_id) 60 { 61 int ret; 62 char propname[32]; 63 unsigned int i; 64 65 ret = of_gpio_spi_cs_get_count(dev, con_id); 66 if (ret > 0) 67 return ret; 68 69 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { 70 if (con_id) 71 snprintf(propname, sizeof(propname), "%s-%s", 72 con_id, gpio_suffixes[i]); 73 else 74 snprintf(propname, sizeof(propname), "%s", 75 gpio_suffixes[i]); 76 77 ret = of_gpio_named_count(dev->of_node, propname); 78 if (ret > 0) 79 break; 80 } 81 return ret ? ret : -ENOENT; 82 } 83 84 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data) 85 { 86 struct of_phandle_args *gpiospec = data; 87 88 return chip->gpiodev->dev.of_node == gpiospec->np && 89 chip->of_xlate && 90 chip->of_xlate(chip, gpiospec, NULL) >= 0; 91 } 92 93 static struct gpio_chip *of_find_gpiochip_by_xlate( 94 struct of_phandle_args *gpiospec) 95 { 96 return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate); 97 } 98 99 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip, 100 struct of_phandle_args *gpiospec, 101 enum of_gpio_flags *flags) 102 { 103 int ret; 104 105 if (chip->of_gpio_n_cells != gpiospec->args_count) 106 return ERR_PTR(-EINVAL); 107 108 ret = chip->of_xlate(chip, gpiospec, flags); 109 if (ret < 0) 110 return ERR_PTR(ret); 111 112 return gpiochip_get_desc(chip, ret); 113 } 114 115 /** 116 * of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs 117 * to set the .valid_mask 118 * @gc: the target gpio_chip 119 * 120 * Return: true if the valid mask needs to be set 121 */ 122 bool of_gpio_need_valid_mask(const struct gpio_chip *gc) 123 { 124 int size; 125 const struct device_node *np = gc->of_node; 126 127 size = of_property_count_u32_elems(np, "gpio-reserved-ranges"); 128 if (size > 0 && size % 2 == 0) 129 return true; 130 return false; 131 } 132 133 static void of_gpio_flags_quirks(const struct device_node *np, 134 const char *propname, 135 enum of_gpio_flags *flags, 136 int index) 137 { 138 /* 139 * Some GPIO fixed regulator quirks. 140 * Note that active low is the default. 141 */ 142 if (IS_ENABLED(CONFIG_REGULATOR) && 143 (of_device_is_compatible(np, "regulator-fixed") || 144 of_device_is_compatible(np, "reg-fixed-voltage") || 145 (!(strcmp(propname, "enable-gpio") && 146 strcmp(propname, "enable-gpios")) && 147 of_device_is_compatible(np, "regulator-gpio")))) { 148 bool active_low = !of_property_read_bool(np, 149 "enable-active-high"); 150 /* 151 * The regulator GPIO handles are specified such that the 152 * presence or absence of "enable-active-high" solely controls 153 * the polarity of the GPIO line. Any phandle flags must 154 * be actively ignored. 155 */ 156 if ((*flags & OF_GPIO_ACTIVE_LOW) && !active_low) { 157 pr_warn("%s GPIO handle specifies active low - ignored\n", 158 of_node_full_name(np)); 159 *flags &= ~OF_GPIO_ACTIVE_LOW; 160 } 161 if (active_low) 162 *flags |= OF_GPIO_ACTIVE_LOW; 163 } 164 /* 165 * Legacy open drain handling for fixed voltage regulators. 166 */ 167 if (IS_ENABLED(CONFIG_REGULATOR) && 168 of_device_is_compatible(np, "reg-fixed-voltage") && 169 of_property_read_bool(np, "gpio-open-drain")) { 170 *flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN); 171 pr_info("%s uses legacy open drain flag - update the DTS if you can\n", 172 of_node_full_name(np)); 173 } 174 175 /* 176 * Legacy handling of SPI active high chip select. If we have a 177 * property named "cs-gpios" we need to inspect the child node 178 * to determine if the flags should have inverted semantics. 179 */ 180 if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") && 181 of_property_read_bool(np, "cs-gpios")) { 182 struct device_node *child; 183 u32 cs; 184 int ret; 185 186 for_each_child_of_node(np, child) { 187 ret = of_property_read_u32(child, "reg", &cs); 188 if (ret) 189 continue; 190 if (cs == index) { 191 /* 192 * SPI children have active low chip selects 193 * by default. This can be specified negatively 194 * by just omitting "spi-cs-high" in the 195 * device node, or actively by tagging on 196 * GPIO_ACTIVE_LOW as flag in the device 197 * tree. If the line is simultaneously 198 * tagged as active low in the device tree 199 * and has the "spi-cs-high" set, we get a 200 * conflict and the "spi-cs-high" flag will 201 * take precedence. 202 */ 203 if (of_property_read_bool(child, "spi-cs-high")) { 204 if (*flags & OF_GPIO_ACTIVE_LOW) { 205 pr_warn("%s GPIO handle specifies active low - ignored\n", 206 of_node_full_name(child)); 207 *flags &= ~OF_GPIO_ACTIVE_LOW; 208 } 209 } else { 210 if (!(*flags & OF_GPIO_ACTIVE_LOW)) 211 pr_info("%s enforce active low on chipselect handle\n", 212 of_node_full_name(child)); 213 *flags |= OF_GPIO_ACTIVE_LOW; 214 } 215 of_node_put(child); 216 break; 217 } 218 } 219 } 220 221 /* Legacy handling of stmmac's active-low PHY reset line */ 222 if (IS_ENABLED(CONFIG_STMMAC_ETH) && 223 !strcmp(propname, "snps,reset-gpio") && 224 of_property_read_bool(np, "snps,reset-active-low")) 225 *flags |= OF_GPIO_ACTIVE_LOW; 226 } 227 228 /** 229 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API 230 * @np: device node to get GPIO from 231 * @propname: property name containing gpio specifier(s) 232 * @index: index of the GPIO 233 * @flags: a flags pointer to fill in 234 * 235 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno 236 * value on the error condition. If @flags is not NULL the function also fills 237 * in flags for the GPIO. 238 */ 239 static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np, 240 const char *propname, int index, enum of_gpio_flags *flags) 241 { 242 struct of_phandle_args gpiospec; 243 struct gpio_chip *chip; 244 struct gpio_desc *desc; 245 int ret; 246 247 ret = of_parse_phandle_with_args_map(np, propname, "gpio", index, 248 &gpiospec); 249 if (ret) { 250 pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n", 251 __func__, propname, np, index); 252 return ERR_PTR(ret); 253 } 254 255 chip = of_find_gpiochip_by_xlate(&gpiospec); 256 if (!chip) { 257 desc = ERR_PTR(-EPROBE_DEFER); 258 goto out; 259 } 260 261 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags); 262 if (IS_ERR(desc)) 263 goto out; 264 265 if (flags) 266 of_gpio_flags_quirks(np, propname, flags, index); 267 268 pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n", 269 __func__, propname, np, index, 270 PTR_ERR_OR_ZERO(desc)); 271 272 out: 273 of_node_put(gpiospec.np); 274 275 return desc; 276 } 277 278 int of_get_named_gpio_flags(const struct device_node *np, const char *list_name, 279 int index, enum of_gpio_flags *flags) 280 { 281 struct gpio_desc *desc; 282 283 desc = of_get_named_gpiod_flags(np, list_name, index, flags); 284 285 if (IS_ERR(desc)) 286 return PTR_ERR(desc); 287 else 288 return desc_to_gpio(desc); 289 } 290 EXPORT_SYMBOL_GPL(of_get_named_gpio_flags); 291 292 /* Converts gpio_lookup_flags into bitmask of GPIO_* values */ 293 static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags) 294 { 295 unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT; 296 297 if (flags & OF_GPIO_ACTIVE_LOW) 298 lflags |= GPIO_ACTIVE_LOW; 299 300 if (flags & OF_GPIO_SINGLE_ENDED) { 301 if (flags & OF_GPIO_OPEN_DRAIN) 302 lflags |= GPIO_OPEN_DRAIN; 303 else 304 lflags |= GPIO_OPEN_SOURCE; 305 } 306 307 if (flags & OF_GPIO_TRANSITORY) 308 lflags |= GPIO_TRANSITORY; 309 310 if (flags & OF_GPIO_PULL_UP) 311 lflags |= GPIO_PULL_UP; 312 313 if (flags & OF_GPIO_PULL_DOWN) 314 lflags |= GPIO_PULL_DOWN; 315 316 if (flags & OF_GPIO_PULL_DISABLE) 317 lflags |= GPIO_PULL_DISABLE; 318 319 return lflags; 320 } 321 322 /** 323 * gpiod_get_from_of_node() - obtain a GPIO from an OF node 324 * @node: handle of the OF node 325 * @propname: name of the DT property representing the GPIO 326 * @index: index of the GPIO to obtain for the consumer 327 * @dflags: GPIO initialization flags 328 * @label: label to attach to the requested GPIO 329 * 330 * Returns: 331 * On successful request the GPIO pin is configured in accordance with 332 * provided @dflags. 333 * 334 * In case of error an ERR_PTR() is returned. 335 */ 336 struct gpio_desc *gpiod_get_from_of_node(const struct device_node *node, 337 const char *propname, int index, 338 enum gpiod_flags dflags, 339 const char *label) 340 { 341 unsigned long lflags; 342 struct gpio_desc *desc; 343 enum of_gpio_flags of_flags; 344 int ret; 345 346 desc = of_get_named_gpiod_flags(node, propname, index, &of_flags); 347 if (!desc || IS_ERR(desc)) 348 return desc; 349 350 ret = gpiod_request(desc, label); 351 if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) 352 return desc; 353 if (ret) 354 return ERR_PTR(ret); 355 356 lflags = of_convert_gpio_flags(of_flags); 357 358 ret = gpiod_configure_flags(desc, propname, lflags, dflags); 359 if (ret < 0) { 360 gpiod_put(desc); 361 return ERR_PTR(ret); 362 } 363 364 return desc; 365 } 366 EXPORT_SYMBOL_GPL(gpiod_get_from_of_node); 367 368 /* 369 * The SPI GPIO bindings happened before we managed to establish that GPIO 370 * properties should be named "foo-gpios" so we have this special kludge for 371 * them. 372 */ 373 static struct gpio_desc *of_find_spi_gpio(struct device_node *np, 374 const char *con_id, 375 unsigned int idx, 376 enum of_gpio_flags *of_flags) 377 { 378 char prop_name[32]; /* 32 is max size of property name */ 379 380 /* 381 * Hopefully the compiler stubs the rest of the function if this 382 * is false. 383 */ 384 if (!IS_ENABLED(CONFIG_SPI_MASTER)) 385 return ERR_PTR(-ENOENT); 386 387 /* Allow this specifically for "spi-gpio" devices */ 388 if (!of_device_is_compatible(np, "spi-gpio") || !con_id) 389 return ERR_PTR(-ENOENT); 390 391 /* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */ 392 snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id); 393 394 return of_get_named_gpiod_flags(np, prop_name, idx, of_flags); 395 } 396 397 /* 398 * The old Freescale bindings use simply "gpios" as name for the chip select 399 * lines rather than "cs-gpios" like all other SPI hardware. Account for this 400 * with a special quirk. 401 */ 402 static struct gpio_desc *of_find_spi_cs_gpio(struct device_node *np, 403 const char *con_id, 404 unsigned int idx, 405 enum of_gpio_flags *of_flags) 406 { 407 if (!IS_ENABLED(CONFIG_SPI_MASTER)) 408 return ERR_PTR(-ENOENT); 409 410 /* Allow this specifically for Freescale and PPC devices */ 411 if (!of_device_is_compatible(np, "fsl,spi") && 412 !of_device_is_compatible(np, "aeroflexgaisler,spictrl") && 413 !of_device_is_compatible(np, "ibm,ppc4xx-spi")) 414 return ERR_PTR(-ENOENT); 415 /* Allow only if asking for "cs-gpios" */ 416 if (!con_id || strcmp(con_id, "cs")) 417 return ERR_PTR(-ENOENT); 418 419 /* 420 * While all other SPI controllers use "cs-gpios" the Freescale 421 * uses just "gpios" so translate to that when "cs-gpios" is 422 * requested. 423 */ 424 return of_get_named_gpiod_flags(np, "gpios", idx, of_flags); 425 } 426 427 /* 428 * Some regulator bindings happened before we managed to establish that GPIO 429 * properties should be named "foo-gpios" so we have this special kludge for 430 * them. 431 */ 432 static struct gpio_desc *of_find_regulator_gpio(struct device_node *np, 433 const char *con_id, 434 unsigned int idx, 435 enum of_gpio_flags *of_flags) 436 { 437 /* These are the connection IDs we accept as legacy GPIO phandles */ 438 const char *whitelist[] = { 439 "wlf,ldoena", /* Arizona */ 440 "wlf,ldo1ena", /* WM8994 */ 441 "wlf,ldo2ena", /* WM8994 */ 442 }; 443 int i; 444 445 if (!IS_ENABLED(CONFIG_REGULATOR)) 446 return ERR_PTR(-ENOENT); 447 448 if (!con_id) 449 return ERR_PTR(-ENOENT); 450 451 i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id); 452 if (i < 0) 453 return ERR_PTR(-ENOENT); 454 455 return of_get_named_gpiod_flags(np, con_id, idx, of_flags); 456 } 457 458 static struct gpio_desc *of_find_arizona_gpio(struct device_node *np, 459 const char *con_id, 460 unsigned int idx, 461 enum of_gpio_flags *of_flags) 462 { 463 if (!IS_ENABLED(CONFIG_MFD_ARIZONA)) 464 return ERR_PTR(-ENOENT); 465 466 if (!con_id || strcmp(con_id, "wlf,reset")) 467 return ERR_PTR(-ENOENT); 468 469 return of_get_named_gpiod_flags(np, con_id, idx, of_flags); 470 } 471 472 static struct gpio_desc *of_find_usb_gpio(struct device_node *np, 473 const char *con_id, 474 unsigned int idx, 475 enum of_gpio_flags *of_flags) 476 { 477 /* 478 * Currently this USB quirk is only for the Fairchild FUSB302 host 479 * which is using an undocumented DT GPIO line named "fcs,int_n" 480 * without the compulsory "-gpios" suffix. 481 */ 482 if (!IS_ENABLED(CONFIG_TYPEC_FUSB302)) 483 return ERR_PTR(-ENOENT); 484 485 if (!con_id || strcmp(con_id, "fcs,int_n")) 486 return ERR_PTR(-ENOENT); 487 488 return of_get_named_gpiod_flags(np, con_id, idx, of_flags); 489 } 490 491 typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np, 492 const char *con_id, 493 unsigned int idx, 494 enum of_gpio_flags *of_flags); 495 static const of_find_gpio_quirk of_find_gpio_quirks[] = { 496 of_find_spi_gpio, 497 of_find_spi_cs_gpio, 498 of_find_regulator_gpio, 499 of_find_arizona_gpio, 500 of_find_usb_gpio, 501 NULL 502 }; 503 504 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id, 505 unsigned int idx, unsigned long *flags) 506 { 507 char prop_name[32]; /* 32 is max size of property name */ 508 enum of_gpio_flags of_flags; 509 const of_find_gpio_quirk *q; 510 struct gpio_desc *desc; 511 unsigned int i; 512 513 /* Try GPIO property "foo-gpios" and "foo-gpio" */ 514 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) { 515 if (con_id) 516 snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id, 517 gpio_suffixes[i]); 518 else 519 snprintf(prop_name, sizeof(prop_name), "%s", 520 gpio_suffixes[i]); 521 522 desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx, 523 &of_flags); 524 525 if (!gpiod_not_found(desc)) 526 break; 527 } 528 529 /* Properly named GPIO was not found, try workarounds */ 530 for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++) 531 desc = (*q)(dev->of_node, con_id, idx, &of_flags); 532 533 if (IS_ERR(desc)) 534 return desc; 535 536 *flags = of_convert_gpio_flags(of_flags); 537 538 return desc; 539 } 540 541 /** 542 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API 543 * @np: device node to get GPIO from 544 * @chip: GPIO chip whose hog is parsed 545 * @idx: Index of the GPIO to parse 546 * @name: GPIO line name 547 * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from 548 * of_find_gpio() or of_parse_own_gpio() 549 * @dflags: gpiod_flags - optional GPIO initialization flags 550 * 551 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno 552 * value on the error condition. 553 */ 554 static struct gpio_desc *of_parse_own_gpio(struct device_node *np, 555 struct gpio_chip *chip, 556 unsigned int idx, const char **name, 557 unsigned long *lflags, 558 enum gpiod_flags *dflags) 559 { 560 struct device_node *chip_np; 561 enum of_gpio_flags xlate_flags; 562 struct of_phandle_args gpiospec; 563 struct gpio_desc *desc; 564 unsigned int i; 565 u32 tmp; 566 int ret; 567 568 chip_np = chip->of_node; 569 if (!chip_np) 570 return ERR_PTR(-EINVAL); 571 572 xlate_flags = 0; 573 *lflags = GPIO_LOOKUP_FLAGS_DEFAULT; 574 *dflags = GPIOD_ASIS; 575 576 ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp); 577 if (ret) 578 return ERR_PTR(ret); 579 580 gpiospec.np = chip_np; 581 gpiospec.args_count = tmp; 582 583 for (i = 0; i < tmp; i++) { 584 ret = of_property_read_u32_index(np, "gpios", idx * tmp + i, 585 &gpiospec.args[i]); 586 if (ret) 587 return ERR_PTR(ret); 588 } 589 590 desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags); 591 if (IS_ERR(desc)) 592 return desc; 593 594 *lflags = of_convert_gpio_flags(xlate_flags); 595 596 if (of_property_read_bool(np, "input")) 597 *dflags |= GPIOD_IN; 598 else if (of_property_read_bool(np, "output-low")) 599 *dflags |= GPIOD_OUT_LOW; 600 else if (of_property_read_bool(np, "output-high")) 601 *dflags |= GPIOD_OUT_HIGH; 602 else { 603 pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n", 604 desc_to_gpio(desc), np); 605 return ERR_PTR(-EINVAL); 606 } 607 608 if (name && of_property_read_string(np, "line-name", name)) 609 *name = np->name; 610 611 return desc; 612 } 613 614 /** 615 * of_gpiochip_add_hog - Add all hogs in a hog device node 616 * @chip: gpio chip to act on 617 * @hog: device node describing the hogs 618 * 619 * Returns error if it fails otherwise 0 on success. 620 */ 621 static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog) 622 { 623 enum gpiod_flags dflags; 624 struct gpio_desc *desc; 625 unsigned long lflags; 626 const char *name; 627 unsigned int i; 628 int ret; 629 630 for (i = 0;; i++) { 631 desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags); 632 if (IS_ERR(desc)) 633 break; 634 635 ret = gpiod_hog(desc, name, lflags, dflags); 636 if (ret < 0) 637 return ret; 638 639 #ifdef CONFIG_OF_DYNAMIC 640 desc->hog = hog; 641 #endif 642 } 643 644 return 0; 645 } 646 647 /** 648 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions 649 * @chip: gpio chip to act on 650 * 651 * This is only used by of_gpiochip_add to request/set GPIO initial 652 * configuration. 653 * It returns error if it fails otherwise 0 on success. 654 */ 655 static int of_gpiochip_scan_gpios(struct gpio_chip *chip) 656 { 657 struct device_node *np; 658 int ret; 659 660 for_each_available_child_of_node(chip->of_node, np) { 661 if (!of_property_read_bool(np, "gpio-hog")) 662 continue; 663 664 ret = of_gpiochip_add_hog(chip, np); 665 if (ret < 0) { 666 of_node_put(np); 667 return ret; 668 } 669 670 of_node_set_flag(np, OF_POPULATED); 671 } 672 673 return 0; 674 } 675 676 #ifdef CONFIG_OF_DYNAMIC 677 /** 678 * of_gpiochip_remove_hog - Remove all hogs in a hog device node 679 * @chip: gpio chip to act on 680 * @hog: device node describing the hogs 681 */ 682 static void of_gpiochip_remove_hog(struct gpio_chip *chip, 683 struct device_node *hog) 684 { 685 struct gpio_desc *desc; 686 687 for_each_gpio_desc_with_flag(chip, desc, FLAG_IS_HOGGED) 688 if (desc->hog == hog) 689 gpiochip_free_own_desc(desc); 690 } 691 692 static int of_gpiochip_match_node(struct gpio_chip *chip, void *data) 693 { 694 return device_match_of_node(&chip->gpiodev->dev, data); 695 } 696 697 static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np) 698 { 699 return gpiochip_find(np, of_gpiochip_match_node); 700 } 701 702 static int of_gpio_notify(struct notifier_block *nb, unsigned long action, 703 void *arg) 704 { 705 struct of_reconfig_data *rd = arg; 706 struct gpio_chip *chip; 707 int ret; 708 709 /* 710 * This only supports adding and removing complete gpio-hog nodes. 711 * Modifying an existing gpio-hog node is not supported (except for 712 * changing its "status" property, which is treated the same as 713 * addition/removal). 714 */ 715 switch (of_reconfig_get_state_change(action, arg)) { 716 case OF_RECONFIG_CHANGE_ADD: 717 if (!of_property_read_bool(rd->dn, "gpio-hog")) 718 return NOTIFY_OK; /* not for us */ 719 720 if (of_node_test_and_set_flag(rd->dn, OF_POPULATED)) 721 return NOTIFY_OK; 722 723 chip = of_find_gpiochip_by_node(rd->dn->parent); 724 if (chip == NULL) 725 return NOTIFY_OK; /* not for us */ 726 727 ret = of_gpiochip_add_hog(chip, rd->dn); 728 if (ret < 0) { 729 pr_err("%s: failed to add hogs for %pOF\n", __func__, 730 rd->dn); 731 of_node_clear_flag(rd->dn, OF_POPULATED); 732 return notifier_from_errno(ret); 733 } 734 break; 735 736 case OF_RECONFIG_CHANGE_REMOVE: 737 if (!of_node_check_flag(rd->dn, OF_POPULATED)) 738 return NOTIFY_OK; /* already depopulated */ 739 740 chip = of_find_gpiochip_by_node(rd->dn->parent); 741 if (chip == NULL) 742 return NOTIFY_OK; /* not for us */ 743 744 of_gpiochip_remove_hog(chip, rd->dn); 745 of_node_clear_flag(rd->dn, OF_POPULATED); 746 break; 747 } 748 749 return NOTIFY_OK; 750 } 751 752 struct notifier_block gpio_of_notifier = { 753 .notifier_call = of_gpio_notify, 754 }; 755 #endif /* CONFIG_OF_DYNAMIC */ 756 757 /** 758 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags 759 * @gc: pointer to the gpio_chip structure 760 * @gpiospec: GPIO specifier as found in the device tree 761 * @flags: a flags pointer to fill in 762 * 763 * This is simple translation function, suitable for the most 1:1 mapped 764 * GPIO chips. This function performs only one sanity check: whether GPIO 765 * is less than ngpios (that is specified in the gpio_chip). 766 */ 767 static int of_gpio_simple_xlate(struct gpio_chip *gc, 768 const struct of_phandle_args *gpiospec, 769 u32 *flags) 770 { 771 /* 772 * We're discouraging gpio_cells < 2, since that way you'll have to 773 * write your own xlate function (that will have to retrieve the GPIO 774 * number and the flags from a single gpio cell -- this is possible, 775 * but not recommended). 776 */ 777 if (gc->of_gpio_n_cells < 2) { 778 WARN_ON(1); 779 return -EINVAL; 780 } 781 782 if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells)) 783 return -EINVAL; 784 785 if (gpiospec->args[0] >= gc->ngpio) 786 return -EINVAL; 787 788 if (flags) 789 *flags = gpiospec->args[1]; 790 791 return gpiospec->args[0]; 792 } 793 794 /** 795 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank) 796 * @np: device node of the GPIO chip 797 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 798 * @data: driver data to store in the struct gpio_chip 799 * 800 * To use this function you should allocate and fill mm_gc with: 801 * 802 * 1) In the gpio_chip structure: 803 * - all the callbacks 804 * - of_gpio_n_cells 805 * - of_xlate callback (optional) 806 * 807 * 3) In the of_mm_gpio_chip structure: 808 * - save_regs callback (optional) 809 * 810 * If succeeded, this function will map bank's memory and will 811 * do all necessary work for you. Then you'll able to use .regs 812 * to manage GPIOs from the callbacks. 813 */ 814 int of_mm_gpiochip_add_data(struct device_node *np, 815 struct of_mm_gpio_chip *mm_gc, 816 void *data) 817 { 818 int ret = -ENOMEM; 819 struct gpio_chip *gc = &mm_gc->gc; 820 821 gc->label = kasprintf(GFP_KERNEL, "%pOF", np); 822 if (!gc->label) 823 goto err0; 824 825 mm_gc->regs = of_iomap(np, 0); 826 if (!mm_gc->regs) 827 goto err1; 828 829 gc->base = -1; 830 831 if (mm_gc->save_regs) 832 mm_gc->save_regs(mm_gc); 833 834 of_node_put(mm_gc->gc.of_node); 835 mm_gc->gc.of_node = of_node_get(np); 836 837 ret = gpiochip_add_data(gc, data); 838 if (ret) 839 goto err2; 840 841 return 0; 842 err2: 843 of_node_put(np); 844 iounmap(mm_gc->regs); 845 err1: 846 kfree(gc->label); 847 err0: 848 pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret); 849 return ret; 850 } 851 EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data); 852 853 /** 854 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank) 855 * @mm_gc: pointer to the of_mm_gpio_chip allocated structure 856 */ 857 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc) 858 { 859 struct gpio_chip *gc = &mm_gc->gc; 860 861 if (!mm_gc) 862 return; 863 864 gpiochip_remove(gc); 865 iounmap(mm_gc->regs); 866 kfree(gc->label); 867 } 868 EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove); 869 870 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip) 871 { 872 int len, i; 873 u32 start, count; 874 struct device_node *np = chip->of_node; 875 876 len = of_property_count_u32_elems(np, "gpio-reserved-ranges"); 877 if (len < 0 || len % 2 != 0) 878 return; 879 880 for (i = 0; i < len; i += 2) { 881 of_property_read_u32_index(np, "gpio-reserved-ranges", 882 i, &start); 883 of_property_read_u32_index(np, "gpio-reserved-ranges", 884 i + 1, &count); 885 if (start >= chip->ngpio || start + count > chip->ngpio) 886 continue; 887 888 bitmap_clear(chip->valid_mask, start, count); 889 } 890 }; 891 892 #ifdef CONFIG_PINCTRL 893 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) 894 { 895 struct device_node *np = chip->of_node; 896 struct of_phandle_args pinspec; 897 struct pinctrl_dev *pctldev; 898 int index = 0, ret; 899 const char *name; 900 static const char group_names_propname[] = "gpio-ranges-group-names"; 901 struct property *group_names; 902 903 if (!np) 904 return 0; 905 906 if (!of_property_read_bool(np, "gpio-ranges") && 907 chip->of_gpio_ranges_fallback) { 908 return chip->of_gpio_ranges_fallback(chip, np); 909 } 910 911 group_names = of_find_property(np, group_names_propname, NULL); 912 913 for (;; index++) { 914 ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 915 index, &pinspec); 916 if (ret) 917 break; 918 919 pctldev = of_pinctrl_get(pinspec.np); 920 of_node_put(pinspec.np); 921 if (!pctldev) 922 return -EPROBE_DEFER; 923 924 if (pinspec.args[2]) { 925 if (group_names) { 926 of_property_read_string_index(np, 927 group_names_propname, 928 index, &name); 929 if (strlen(name)) { 930 pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n", 931 np); 932 break; 933 } 934 } 935 /* npins != 0: linear range */ 936 ret = gpiochip_add_pin_range(chip, 937 pinctrl_dev_get_devname(pctldev), 938 pinspec.args[0], 939 pinspec.args[1], 940 pinspec.args[2]); 941 if (ret) 942 return ret; 943 } else { 944 /* npins == 0: special range */ 945 if (pinspec.args[1]) { 946 pr_err("%pOF: Illegal gpio-range format.\n", 947 np); 948 break; 949 } 950 951 if (!group_names) { 952 pr_err("%pOF: GPIO group range requested but no %s property.\n", 953 np, group_names_propname); 954 break; 955 } 956 957 ret = of_property_read_string_index(np, 958 group_names_propname, 959 index, &name); 960 if (ret) 961 break; 962 963 if (!strlen(name)) { 964 pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n", 965 np); 966 break; 967 } 968 969 ret = gpiochip_add_pingroup_range(chip, pctldev, 970 pinspec.args[0], name); 971 if (ret) 972 return ret; 973 } 974 } 975 976 return 0; 977 } 978 979 #else 980 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; } 981 #endif 982 983 int of_gpiochip_add(struct gpio_chip *chip) 984 { 985 int ret; 986 987 if (!chip->of_node) 988 return 0; 989 990 if (!chip->of_xlate) { 991 chip->of_gpio_n_cells = 2; 992 chip->of_xlate = of_gpio_simple_xlate; 993 } 994 995 if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS) 996 return -EINVAL; 997 998 of_gpiochip_init_valid_mask(chip); 999 1000 ret = of_gpiochip_add_pin_range(chip); 1001 if (ret) 1002 return ret; 1003 1004 of_node_get(chip->of_node); 1005 1006 ret = of_gpiochip_scan_gpios(chip); 1007 if (ret) 1008 of_node_put(chip->of_node); 1009 1010 return ret; 1011 } 1012 1013 void of_gpiochip_remove(struct gpio_chip *chip) 1014 { 1015 of_node_put(chip->of_node); 1016 } 1017 1018 void of_gpio_dev_init(struct gpio_chip *gc, struct gpio_device *gdev) 1019 { 1020 /* Set default OF node to parent's one if present */ 1021 if (gc->parent) 1022 gdev->dev.of_node = gc->parent->of_node; 1023 1024 if (gc->fwnode) 1025 gc->of_node = to_of_node(gc->fwnode); 1026 1027 /* If the gpiochip has an assigned OF node this takes precedence */ 1028 if (gc->of_node) 1029 gdev->dev.of_node = gc->of_node; 1030 else 1031 gc->of_node = gdev->dev.of_node; 1032 } 1033