drivers/gpio/gpiolib-of.c

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

DEFINITIONS
