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 */
  38static 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 */
  59int 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
  84static 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
  93static 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
  99static 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 */
 122bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
 123{
 124	int size;
 125	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
 133static void of_gpio_flags_quirks(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 */
 239static struct gpio_desc *of_get_named_gpiod_flags(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
 272out:
 273	of_node_put(gpiospec.np);
 274
 275	return desc;
 
 276}
 277
 278int of_get_named_gpio_flags(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}
 290EXPORT_SYMBOL_GPL(of_get_named_gpio_flags);
 291
 292/**
 293 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
 294 * @node:	handle of the OF node
 295 * @propname:	name of the DT property representing the GPIO
 296 * @index:	index of the GPIO to obtain for the consumer
 297 * @dflags:	GPIO initialization flags
 298 * @label:	label to attach to the requested GPIO
 299 *
 300 * Returns:
 301 * On successful request the GPIO pin is configured in accordance with
 302 * provided @dflags.
 303 *
 304 * In case of error an ERR_PTR() is returned.
 305 */
 306struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
 307					 const char *propname, int index,
 308					 enum gpiod_flags dflags,
 309					 const char *label)
 310{
 311	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
 312	struct gpio_desc *desc;
 313	enum of_gpio_flags flags;
 314	bool active_low = false;
 315	bool single_ended = false;
 316	bool open_drain = false;
 317	bool transitory = false;
 318	int ret;
 319
 320	desc = of_get_named_gpiod_flags(node, propname,
 321					index, &flags);
 322
 323	if (!desc || IS_ERR(desc)) {
 324		return desc;
 325	}
 326
 327	active_low = flags & OF_GPIO_ACTIVE_LOW;
 328	single_ended = flags & OF_GPIO_SINGLE_ENDED;
 329	open_drain = flags & OF_GPIO_OPEN_DRAIN;
 330	transitory = flags & OF_GPIO_TRANSITORY;
 331
 332	ret = gpiod_request(desc, label);
 333	if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
 334		return desc;
 335	if (ret)
 336		return ERR_PTR(ret);
 337
 338	if (active_low)
 339		lflags |= GPIO_ACTIVE_LOW;
 340
 341	if (single_ended) {
 342		if (open_drain)
 343			lflags |= GPIO_OPEN_DRAIN;
 344		else
 345			lflags |= GPIO_OPEN_SOURCE;
 346	}
 347
 348	if (transitory)
 349		lflags |= GPIO_TRANSITORY;
 350
 351	if (flags & OF_GPIO_PULL_UP)
 352		lflags |= GPIO_PULL_UP;
 353
 354	if (flags & OF_GPIO_PULL_DOWN)
 355		lflags |= GPIO_PULL_DOWN;
 356
 357	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
 358	if (ret < 0) {
 359		gpiod_put(desc);
 360		return ERR_PTR(ret);
 361	}
 362
 363	return desc;
 364}
 365EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
 366
 367/*
 368 * The SPI GPIO bindings happened before we managed to establish that GPIO
 369 * properties should be named "foo-gpios" so we have this special kludge for
 370 * them.
 371 */
 372static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
 373					  enum of_gpio_flags *of_flags)
 374{
 375	char prop_name[32]; /* 32 is max size of property name */
 376	struct device_node *np = dev->of_node;
 377	struct gpio_desc *desc;
 378
 379	/*
 380	 * Hopefully the compiler stubs the rest of the function if this
 381	 * is false.
 382	 */
 383	if (!IS_ENABLED(CONFIG_SPI_MASTER))
 384		return ERR_PTR(-ENOENT);
 385
 386	/* Allow this specifically for "spi-gpio" devices */
 387	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
 388		return ERR_PTR(-ENOENT);
 389
 390	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
 391	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
 392
 393	desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
 394	return desc;
 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 */
 402static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
 403					     const char *con_id,
 404					     unsigned int idx,
 405					     unsigned long *flags)
 406{
 407	struct device_node *np = dev->of_node;
 408
 409	if (!IS_ENABLED(CONFIG_SPI_MASTER))
 410		return ERR_PTR(-ENOENT);
 411
 412	/* Allow this specifically for Freescale and PPC devices */
 413	if (!of_device_is_compatible(np, "fsl,spi") &&
 414	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
 415	    !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
 416		return ERR_PTR(-ENOENT);
 417	/* Allow only if asking for "cs-gpios" */
 418	if (!con_id || strcmp(con_id, "cs"))
 419		return ERR_PTR(-ENOENT);
 420
 421	/*
 422	 * While all other SPI controllers use "cs-gpios" the Freescale
 423	 * uses just "gpios" so translate to that when "cs-gpios" is
 424	 * requested.
 425	 */
 426	return of_find_gpio(dev, NULL, idx, flags);
 427}
 428
 429/*
 430 * Some regulator bindings happened before we managed to establish that GPIO
 431 * properties should be named "foo-gpios" so we have this special kludge for
 432 * them.
 433 */
 434static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
 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	struct device_node *np = dev->of_node;
 444	struct gpio_desc *desc;
 445	int i;
 446
 447	if (!IS_ENABLED(CONFIG_REGULATOR))
 448		return ERR_PTR(-ENOENT);
 449
 450	if (!con_id)
 451		return ERR_PTR(-ENOENT);
 452
 453	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
 454	if (i < 0)
 455		return ERR_PTR(-ENOENT);
 456
 457	desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
 458	return desc;
 459}
 460
 461static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
 462					      const char *con_id,
 463					      enum of_gpio_flags *of_flags)
 464{
 465	if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
 466		return ERR_PTR(-ENOENT);
 467
 468	if (!con_id || strcmp(con_id, "wlf,reset"))
 469		return ERR_PTR(-ENOENT);
 470
 471	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
 472}
 473
 474static struct gpio_desc *of_find_usb_gpio(struct device *dev,
 475					  const char *con_id,
 476					  enum of_gpio_flags *of_flags)
 477{
 478	/*
 479	 * Currently this USB quirk is only for the Fairchild FUSB302 host which is using
 480	 * an undocumented DT GPIO line named "fcs,int_n" without the compulsory "-gpios"
 481	 * suffix.
 482	 */
 483	if (!IS_ENABLED(CONFIG_TYPEC_FUSB302))
 484		return ERR_PTR(-ENOENT);
 485
 486	if (!con_id || strcmp(con_id, "fcs,int_n"))
 487		return ERR_PTR(-ENOENT);
 488
 489	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
 490}
 491
 492struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 493			       unsigned int idx, unsigned long *flags)
 494{
 495	char prop_name[32]; /* 32 is max size of property name */
 496	enum of_gpio_flags of_flags;
 497	struct gpio_desc *desc;
 498	unsigned int i;
 499
 500	/* Try GPIO property "foo-gpios" and "foo-gpio" */
 501	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 502		if (con_id)
 503			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
 504				 gpio_suffixes[i]);
 505		else
 506			snprintf(prop_name, sizeof(prop_name), "%s",
 507				 gpio_suffixes[i]);
 508
 509		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
 510						&of_flags);
 511
 512		if (!IS_ERR(desc) || PTR_ERR(desc) != -ENOENT)
 513			break;
 514	}
 515
 516	if (PTR_ERR(desc) == -ENOENT) {
 517		/* Special handling for SPI GPIOs if used */
 518		desc = of_find_spi_gpio(dev, con_id, &of_flags);
 519	}
 520
 521	if (PTR_ERR(desc) == -ENOENT) {
 522		/* This quirk looks up flags and all */
 523		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
 524		if (!IS_ERR(desc))
 525			return desc;
 526	}
 527
 528	if (PTR_ERR(desc) == -ENOENT) {
 529		/* Special handling for regulator GPIOs if used */
 530		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
 531	}
 532
 533	if (PTR_ERR(desc) == -ENOENT)
 534		desc = of_find_arizona_gpio(dev, con_id, &of_flags);
 535
 536	if (PTR_ERR(desc) == -ENOENT)
 537		desc = of_find_usb_gpio(dev, con_id, &of_flags);
 538
 539	if (IS_ERR(desc))
 540		return desc;
 541
 542	if (of_flags & OF_GPIO_ACTIVE_LOW)
 543		*flags |= GPIO_ACTIVE_LOW;
 544
 545	if (of_flags & OF_GPIO_SINGLE_ENDED) {
 546		if (of_flags & OF_GPIO_OPEN_DRAIN)
 547			*flags |= GPIO_OPEN_DRAIN;
 548		else
 549			*flags |= GPIO_OPEN_SOURCE;
 550	}
 551
 552	if (of_flags & OF_GPIO_TRANSITORY)
 553		*flags |= GPIO_TRANSITORY;
 554
 555	if (of_flags & OF_GPIO_PULL_UP)
 556		*flags |= GPIO_PULL_UP;
 557	if (of_flags & OF_GPIO_PULL_DOWN)
 558		*flags |= GPIO_PULL_DOWN;
 559
 560	return desc;
 561}
 562
 563/**
 564 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
 565 * @np:		device node to get GPIO from
 566 * @chip:	GPIO chip whose hog is parsed
 567 * @idx:	Index of the GPIO to parse
 568 * @name:	GPIO line name
 569 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
 570 *		of_find_gpio() or of_parse_own_gpio()
 571 * @dflags:	gpiod_flags - optional GPIO initialization flags
 572 *
 573 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
 574 * value on the error condition.
 575 */
 576static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
 577					   struct gpio_chip *chip,
 578					   unsigned int idx, const char **name,
 579					   unsigned long *lflags,
 580					   enum gpiod_flags *dflags)
 581{
 582	struct device_node *chip_np;
 583	enum of_gpio_flags xlate_flags;
 584	struct of_phandle_args gpiospec;
 585	struct gpio_desc *desc;
 586	unsigned int i;
 587	u32 tmp;
 588	int ret;
 589
 590	chip_np = chip->of_node;
 591	if (!chip_np)
 592		return ERR_PTR(-EINVAL);
 593
 594	xlate_flags = 0;
 595	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
 596	*dflags = 0;
 597
 598	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
 599	if (ret)
 600		return ERR_PTR(ret);
 601
 602	gpiospec.np = chip_np;
 603	gpiospec.args_count = tmp;
 604
 
 
 605	for (i = 0; i < tmp; i++) {
 606		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
 607						 &gpiospec.args[i]);
 608		if (ret)
 609			return ERR_PTR(ret);
 610	}
 611
 612	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
 613	if (IS_ERR(desc))
 614		return desc;
 
 
 
 
 615
 616	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
 617		*lflags |= GPIO_ACTIVE_LOW;
 618	if (xlate_flags & OF_GPIO_TRANSITORY)
 619		*lflags |= GPIO_TRANSITORY;
 620	if (xlate_flags & OF_GPIO_PULL_UP)
 621		*lflags |= GPIO_PULL_UP;
 622	if (xlate_flags & OF_GPIO_PULL_DOWN)
 623		*lflags |= GPIO_PULL_DOWN;
 624
 625	if (of_property_read_bool(np, "input"))
 626		*dflags |= GPIOD_IN;
 627	else if (of_property_read_bool(np, "output-low"))
 628		*dflags |= GPIOD_OUT_LOW;
 629	else if (of_property_read_bool(np, "output-high"))
 630		*dflags |= GPIOD_OUT_HIGH;
 631	else {
 632		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
 633			desc_to_gpio(desc), np);
 634		return ERR_PTR(-EINVAL);
 635	}
 636
 637	if (name && of_property_read_string(np, "line-name", name))
 638		*name = np->name;
 639
 640	return desc;
 641}
 642
 643/**
 644 * of_gpiochip_add_hog - Add all hogs in a hog device node
 645 * @chip:	gpio chip to act on
 646 * @hog:	device node describing the hogs
 647 *
 648 * Returns error if it fails otherwise 0 on success.
 649 */
 650static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
 651{
 652	enum gpiod_flags dflags;
 653	struct gpio_desc *desc;
 654	unsigned long lflags;
 655	const char *name;
 656	unsigned int i;
 657	int ret;
 658
 659	for (i = 0;; i++) {
 660		desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);
 661		if (IS_ERR(desc))
 662			break;
 663
 664		ret = gpiod_hog(desc, name, lflags, dflags);
 665		if (ret < 0)
 666			return ret;
 667
 668#ifdef CONFIG_OF_DYNAMIC
 669		desc->hog = hog;
 670#endif
 671	}
 672
 673	return 0;
 674}
 675
 676/**
 677 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
 678 * @chip:	gpio chip to act on
 679 *
 680 * This is only used by of_gpiochip_add to request/set GPIO initial
 681 * configuration.
 682 * It returns error if it fails otherwise 0 on success.
 683 */
 684static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
 685{
 
 686	struct device_node *np;
 687	int ret;
 
 
 688
 689	for_each_available_child_of_node(chip->of_node, np) {
 690		if (!of_property_read_bool(np, "gpio-hog"))
 691			continue;
 692
 693		ret = of_gpiochip_add_hog(chip, np);
 694		if (ret < 0) {
 695			of_node_put(np);
 696			return ret;
 697		}
 698
 699		of_node_set_flag(np, OF_POPULATED);
 700	}
 701
 702	return 0;
 703}
 704
 705#ifdef CONFIG_OF_DYNAMIC
 706/**
 707 * of_gpiochip_remove_hog - Remove all hogs in a hog device node
 708 * @chip:	gpio chip to act on
 709 * @hog:	device node describing the hogs
 710 */
 711static void of_gpiochip_remove_hog(struct gpio_chip *chip,
 712				   struct device_node *hog)
 713{
 714	struct gpio_desc *descs = chip->gpiodev->descs;
 715	unsigned int i;
 716
 717	for (i = 0; i < chip->ngpio; i++) {
 718		if (test_bit(FLAG_IS_HOGGED, &descs[i].flags) &&
 719		    descs[i].hog == hog)
 720			gpiochip_free_own_desc(&descs[i]);
 721	}
 722}
 723
 724static int of_gpiochip_match_node(struct gpio_chip *chip, void *data)
 725{
 726	return chip->gpiodev->dev.of_node == data;
 727}
 728
 729static struct gpio_chip *of_find_gpiochip_by_node(struct device_node *np)
 730{
 731	return gpiochip_find(np, of_gpiochip_match_node);
 732}
 733
 734static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
 735			  void *arg)
 736{
 737	struct of_reconfig_data *rd = arg;
 738	struct gpio_chip *chip;
 739	int ret;
 740
 741	/*
 742	 * This only supports adding and removing complete gpio-hog nodes.
 743	 * Modifying an existing gpio-hog node is not supported (except for
 744	 * changing its "status" property, which is treated the same as
 745	 * addition/removal).
 746	 */
 747	switch (of_reconfig_get_state_change(action, arg)) {
 748	case OF_RECONFIG_CHANGE_ADD:
 749		if (!of_property_read_bool(rd->dn, "gpio-hog"))
 750			return NOTIFY_OK;	/* not for us */
 751
 752		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
 753			return NOTIFY_OK;
 754
 755		chip = of_find_gpiochip_by_node(rd->dn->parent);
 756		if (chip == NULL)
 757			return NOTIFY_OK;	/* not for us */
 758
 759		ret = of_gpiochip_add_hog(chip, rd->dn);
 760		if (ret < 0) {
 761			pr_err("%s: failed to add hogs for %pOF\n", __func__,
 762			       rd->dn);
 763			of_node_clear_flag(rd->dn, OF_POPULATED);
 764			return notifier_from_errno(ret);
 765		}
 766		break;
 767
 768	case OF_RECONFIG_CHANGE_REMOVE:
 769		if (!of_node_check_flag(rd->dn, OF_POPULATED))
 770			return NOTIFY_OK;	/* already depopulated */
 771
 772		chip = of_find_gpiochip_by_node(rd->dn->parent);
 773		if (chip == NULL)
 774			return NOTIFY_OK;	/* not for us */
 775
 776		of_gpiochip_remove_hog(chip, rd->dn);
 777		of_node_clear_flag(rd->dn, OF_POPULATED);
 778		break;
 779	}
 780
 781	return NOTIFY_OK;
 782}
 783
 784struct notifier_block gpio_of_notifier = {
 785	.notifier_call = of_gpio_notify,
 786};
 787#endif /* CONFIG_OF_DYNAMIC */
 788
 789/**
 790 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
 791 * @gc:		pointer to the gpio_chip structure
 792 * @gpiospec:	GPIO specifier as found in the device tree
 
 793 * @flags:	a flags pointer to fill in
 794 *
 795 * This is simple translation function, suitable for the most 1:1 mapped
 796 * GPIO chips. This function performs only one sanity check: whether GPIO
 797 * is less than ngpios (that is specified in the gpio_chip).
 798 */
 799static int of_gpio_simple_xlate(struct gpio_chip *gc,
 800				const struct of_phandle_args *gpiospec,
 801				u32 *flags)
 802{
 803	/*
 804	 * We're discouraging gpio_cells < 2, since that way you'll have to
 805	 * write your own xlate function (that will have to retrieve the GPIO
 806	 * number and the flags from a single gpio cell -- this is possible,
 807	 * but not recommended).
 808	 */
 809	if (gc->of_gpio_n_cells < 2) {
 810		WARN_ON(1);
 811		return -EINVAL;
 812	}
 813
 814	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
 815		return -EINVAL;
 816
 817	if (gpiospec->args[0] >= gc->ngpio)
 818		return -EINVAL;
 819
 820	if (flags)
 821		*flags = gpiospec->args[1];
 822
 823	return gpiospec->args[0];
 824}
 
 825
 826/**
 827 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
 828 * @np:		device node of the GPIO chip
 829 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 830 * @data:	driver data to store in the struct gpio_chip
 831 *
 832 * To use this function you should allocate and fill mm_gc with:
 833 *
 834 * 1) In the gpio_chip structure:
 835 *    - all the callbacks
 836 *    - of_gpio_n_cells
 837 *    - of_xlate callback (optional)
 838 *
 839 * 3) In the of_mm_gpio_chip structure:
 840 *    - save_regs callback (optional)
 841 *
 842 * If succeeded, this function will map bank's memory and will
 843 * do all necessary work for you. Then you'll able to use .regs
 844 * to manage GPIOs from the callbacks.
 845 */
 846int of_mm_gpiochip_add_data(struct device_node *np,
 847			    struct of_mm_gpio_chip *mm_gc,
 848			    void *data)
 849{
 850	int ret = -ENOMEM;
 851	struct gpio_chip *gc = &mm_gc->gc;
 852
 853	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
 854	if (!gc->label)
 855		goto err0;
 856
 857	mm_gc->regs = of_iomap(np, 0);
 858	if (!mm_gc->regs)
 859		goto err1;
 860
 861	gc->base = -1;
 862
 863	if (mm_gc->save_regs)
 864		mm_gc->save_regs(mm_gc);
 865
 866	mm_gc->gc.of_node = np;
 867
 868	ret = gpiochip_add_data(gc, data);
 869	if (ret)
 870		goto err2;
 871
 872	return 0;
 873err2:
 874	iounmap(mm_gc->regs);
 875err1:
 876	kfree(gc->label);
 877err0:
 878	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
 
 879	return ret;
 880}
 881EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data);
 882
 883/**
 884 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
 885 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 886 */
 887void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
 888{
 889	struct gpio_chip *gc = &mm_gc->gc;
 890
 891	if (!mm_gc)
 892		return;
 893
 894	gpiochip_remove(gc);
 895	iounmap(mm_gc->regs);
 896	kfree(gc->label);
 897}
 898EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
 899
 900static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
 901{
 902	int len, i;
 903	u32 start, count;
 904	struct device_node *np = chip->of_node;
 905
 906	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
 907	if (len < 0 || len % 2 != 0)
 908		return;
 909
 910	for (i = 0; i < len; i += 2) {
 911		of_property_read_u32_index(np, "gpio-reserved-ranges",
 912					   i, &start);
 913		of_property_read_u32_index(np, "gpio-reserved-ranges",
 914					   i + 1, &count);
 915		if (start >= chip->ngpio || start + count >= chip->ngpio)
 916			continue;
 917
 918		bitmap_clear(chip->valid_mask, start, count);
 919	}
 920};
 921
 922#ifdef CONFIG_PINCTRL
 923static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
 924{
 925	struct device_node *np = chip->of_node;
 926	struct of_phandle_args pinspec;
 927	struct pinctrl_dev *pctldev;
 928	int index = 0, ret;
 929	const char *name;
 930	static const char group_names_propname[] = "gpio-ranges-group-names";
 931	struct property *group_names;
 932
 933	if (!np)
 934		return 0;
 935
 936	group_names = of_find_property(np, group_names_propname, NULL);
 937
 938	for (;; index++) {
 939		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
 940				index, &pinspec);
 941		if (ret)
 942			break;
 943
 944		pctldev = of_pinctrl_get(pinspec.np);
 945		of_node_put(pinspec.np);
 946		if (!pctldev)
 947			return -EPROBE_DEFER;
 948
 949		if (pinspec.args[2]) {
 950			if (group_names) {
 951				of_property_read_string_index(np,
 952						group_names_propname,
 953						index, &name);
 954				if (strlen(name)) {
 955					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
 956						np);
 957					break;
 958				}
 959			}
 960			/* npins != 0: linear range */
 961			ret = gpiochip_add_pin_range(chip,
 962					pinctrl_dev_get_devname(pctldev),
 963					pinspec.args[0],
 964					pinspec.args[1],
 965					pinspec.args[2]);
 966			if (ret)
 967				return ret;
 968		} else {
 969			/* npins == 0: special range */
 970			if (pinspec.args[1]) {
 971				pr_err("%pOF: Illegal gpio-range format.\n",
 972					np);
 973				break;
 974			}
 975
 976			if (!group_names) {
 977				pr_err("%pOF: GPIO group range requested but no %s property.\n",
 978					np, group_names_propname);
 979				break;
 980			}
 981
 982			ret = of_property_read_string_index(np,
 983						group_names_propname,
 984						index, &name);
 985			if (ret)
 986				break;
 987
 988			if (!strlen(name)) {
 989				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
 990				np);
 991				break;
 992			}
 993
 994			ret = gpiochip_add_pingroup_range(chip, pctldev,
 995						pinspec.args[0], name);
 996			if (ret)
 997				return ret;
 998		}
 999	}
1000
1001	return 0;
1002}
1003
1004#else
1005static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
1006#endif
1007
1008int of_gpiochip_add(struct gpio_chip *chip)
1009{
1010	int ret;
 
 
 
1011
1012	if (!chip->of_node)
1013		return 0;
1014
1015	if (!chip->of_xlate) {
1016		chip->of_gpio_n_cells = 2;
1017		chip->of_xlate = of_gpio_simple_xlate;
1018	}
1019
1020	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
1021		return -EINVAL;
1022
1023	of_gpiochip_init_valid_mask(chip);
1024
1025	ret = of_gpiochip_add_pin_range(chip);
1026	if (ret)
1027		return ret;
1028
1029	/* If the chip defines names itself, these take precedence */
1030	if (!chip->names)
1031		devprop_gpiochip_set_names(chip,
1032					   of_fwnode_handle(chip->of_node));
1033
1034	of_node_get(chip->of_node);
1035
1036	ret = of_gpiochip_scan_gpios(chip);
1037	if (ret)
1038		of_node_put(chip->of_node);
1039
1040	return ret;
1041}
1042
1043void of_gpiochip_remove(struct gpio_chip *chip)
1044{
 
1045	of_node_put(chip->of_node);
1046}