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v6.13.7
   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/io.h>
  14#include <linux/module.h>
 
 
  15#include <linux/of.h>
  16#include <linux/of_address.h>
  17#include <linux/of_gpio.h>
  18#include <linux/pinctrl/pinctrl.h>
  19#include <linux/slab.h>
  20#include <linux/string.h>
  21
  22#include <linux/gpio/consumer.h>
  23#include <linux/gpio/machine.h>
  24
  25#include "gpiolib.h"
  26#include "gpiolib-of.h"
  27
  28/*
  29 * This is Linux-specific flags. By default controllers' and Linux' mapping
  30 * match, but GPIO controllers are free to translate their own flags to
  31 * Linux-specific in their .xlate callback. Though, 1:1 mapping is recommended.
  32 */
  33enum of_gpio_flags {
  34	OF_GPIO_ACTIVE_LOW = 0x1,
  35	OF_GPIO_SINGLE_ENDED = 0x2,
  36	OF_GPIO_OPEN_DRAIN = 0x4,
  37	OF_GPIO_TRANSITORY = 0x8,
  38	OF_GPIO_PULL_UP = 0x10,
  39	OF_GPIO_PULL_DOWN = 0x20,
  40	OF_GPIO_PULL_DISABLE = 0x40,
  41};
  42
  43/**
  44 * of_gpio_named_count() - Count GPIOs for a device
  45 * @np:		device node to count GPIOs for
  46 * @propname:	property name containing gpio specifier(s)
  47 *
  48 * The function returns the count of GPIOs specified for a node.
  49 * NOTE: The empty GPIO specifiers count too.
  50 *
  51 * Returns:
  52 * Either number of GPIOs defined in the property, or
  53 * *  %-EINVAL for an incorrectly formed "gpios" property, or
  54 * *  %-ENOENT for a missing "gpios" property.
  55 *
  56 * Example::
  57 *
  58 *     gpios = <0
  59 *              &gpio1 1 2
  60 *              0
  61 *              &gpio2 3 4>;
  62 *
  63 * The above example defines four GPIOs, two of which are not specified.
  64 * This function will return '4'
  65 */
  66static int of_gpio_named_count(const struct device_node *np,
  67			       const char *propname)
  68{
  69	return of_count_phandle_with_args(np, propname, "#gpio-cells");
  70}
  71
  72/**
  73 * of_gpio_spi_cs_get_count() - special GPIO counting for SPI
  74 * @np:    Consuming device node
  75 * @con_id: Function within the GPIO consumer
  76 *
  77 * Some elder GPIO controllers need special quirks. Currently we handle
  78 * the Freescale and PPC GPIO controller with bindings that doesn't use the
  79 * established "cs-gpios" for chip selects but instead rely on
  80 * "gpios" for the chip select lines. If we detect this, we redirect
  81 * the counting of "cs-gpios" to count "gpios" transparent to the
  82 * driver.
  83 *
  84 * Returns:
  85 * Either number of GPIOs defined in the property, or
  86 * *  %-EINVAL for an incorrectly formed "gpios" property, or
  87 * *  %-ENOENT for a missing "gpios" property.
  88 */
  89static int of_gpio_spi_cs_get_count(const struct device_node *np,
  90				    const char *con_id)
  91{
  92	if (!IS_ENABLED(CONFIG_SPI_MASTER))
  93		return 0;
  94	if (!con_id || strcmp(con_id, "cs"))
  95		return 0;
  96	if (!of_device_is_compatible(np, "fsl,spi") &&
  97	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl") &&
  98	    !of_device_is_compatible(np, "ibm,ppc4xx-spi"))
  99		return 0;
 100	return of_gpio_named_count(np, "gpios");
 101}
 102
 103int of_gpio_count(const struct fwnode_handle *fwnode, const char *con_id)
 104{
 105	const struct device_node *np = to_of_node(fwnode);
 106	int ret;
 107	char propname[32];
 
 108
 109	ret = of_gpio_spi_cs_get_count(np, con_id);
 110	if (ret > 0)
 111		return ret;
 
 
 
 
 112
 113	for_each_gpio_property_name(propname, con_id) {
 114		ret = of_gpio_named_count(np, propname);
 115		if (ret > 0)
 116			break;
 117	}
 118	return ret ? ret : -ENOENT;
 119}
 120
 121static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip,
 122					    const void *data)
 123{
 124	const struct of_phandle_args *gpiospec = data;
 125
 126	return device_match_of_node(&chip->gpiodev->dev, gpiospec->np) &&
 127				chip->of_xlate &&
 128				chip->of_xlate(chip, gpiospec, NULL) >= 0;
 129}
 130
 131static struct gpio_device *
 132of_find_gpio_device_by_xlate(const struct of_phandle_args *gpiospec)
 133{
 134	return gpio_device_find(gpiospec, of_gpiochip_match_node_and_xlate);
 135}
 136
 137static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
 138					struct of_phandle_args *gpiospec,
 139					enum of_gpio_flags *flags)
 140{
 141	int ret;
 142
 143	if (chip->of_gpio_n_cells != gpiospec->args_count)
 144		return ERR_PTR(-EINVAL);
 145
 146	ret = chip->of_xlate(chip, gpiospec, flags);
 147	if (ret < 0)
 148		return ERR_PTR(ret);
 149
 150	return gpiochip_get_desc(chip, ret);
 151}
 152
 153/*
 154 * Overrides stated polarity of a gpio line and warns when there is a
 155 * discrepancy.
 
 
 156 */
 157static void of_gpio_quirk_polarity(const struct device_node *np,
 158				   bool active_high,
 159				   enum of_gpio_flags *flags)
 160{
 161	if (active_high) {
 162		if (*flags & OF_GPIO_ACTIVE_LOW) {
 163			pr_warn("%s GPIO handle specifies active low - ignored\n",
 164				of_node_full_name(np));
 165			*flags &= ~OF_GPIO_ACTIVE_LOW;
 166		}
 167	} else {
 168		if (!(*flags & OF_GPIO_ACTIVE_LOW))
 169			pr_info("%s enforce active low on GPIO handle\n",
 170				of_node_full_name(np));
 171		*flags |= OF_GPIO_ACTIVE_LOW;
 172	}
 173}
 174
 175/*
 176 * This quirk does static polarity overrides in cases where existing
 177 * DTS specified incorrect polarity.
 178 */
 179static void of_gpio_try_fixup_polarity(const struct device_node *np,
 180				       const char *propname,
 181				       enum of_gpio_flags *flags)
 182{
 183	static const struct {
 184		const char *compatible;
 185		const char *propname;
 186		bool active_high;
 187	} gpios[] = {
 188#if IS_ENABLED(CONFIG_LCD_HX8357)
 189		/*
 190		 * Himax LCD controllers used incorrectly named
 191		 * "gpios-reset" property and also specified wrong
 192		 * polarity.
 193		 */
 194		{ "himax,hx8357",	"gpios-reset",	false },
 195		{ "himax,hx8369",	"gpios-reset",	false },
 196		/*
 197		 * The rb-gpios semantics was undocumented and qi,lb60 (along with
 198		 * the ingenic driver) got it wrong. The active state encodes the
 199		 * NAND ready state, which is high level. Since there's no signal
 200		 * inverter on this board, it should be active-high. Let's fix that
 201		 * here for older DTs so we can re-use the generic nand_gpio_waitrdy()
 202		 * helper, and be consistent with what other drivers do.
 203		 */
 204		{ "qi,lb60",		"rb-gpios",	true },
 205#endif
 206#if IS_ENABLED(CONFIG_PCI_LANTIQ)
 207		/*
 208		 * According to the PCI specification, the RST# pin is an
 209		 * active-low signal. However, most of the device trees that
 210		 * have been widely used for a long time incorrectly describe
 211		 * reset GPIO as active-high, and were also using wrong name
 212		 * for the property.
 213		 */
 214		{ "lantiq,pci-xway",	"gpio-reset",	false },
 215#endif
 216#if IS_ENABLED(CONFIG_TOUCHSCREEN_TSC2005)
 217		/*
 218		 * DTS for Nokia N900 incorrectly specified "active high"
 219		 * polarity for the reset line, while the chip actually
 220		 * treats it as "active low".
 
 
 
 221		 */
 222		{ "ti,tsc2005",		"reset-gpios",	false },
 223#endif
 224	};
 225	unsigned int i;
 226
 227	for (i = 0; i < ARRAY_SIZE(gpios); i++) {
 228		if (of_device_is_compatible(np, gpios[i].compatible) &&
 229		    !strcmp(propname, gpios[i].propname)) {
 230			of_gpio_quirk_polarity(np, gpios[i].active_high, flags);
 231			break;
 232		}
 233	}
 234}
 235
 236static void of_gpio_set_polarity_by_property(const struct device_node *np,
 237					     const char *propname,
 238					     enum of_gpio_flags *flags)
 239{
 240	const struct device_node *np_compat = np;
 241	const struct device_node *np_propname = np;
 242	static const struct {
 243		const char *compatible;
 244		const char *gpio_propname;
 245		const char *polarity_propname;
 246	} gpios[] = {
 247#if IS_ENABLED(CONFIG_FEC)
 248		/* Freescale Fast Ethernet Controller */
 249		{ "fsl,imx25-fec",   "phy-reset-gpios", "phy-reset-active-high" },
 250		{ "fsl,imx27-fec",   "phy-reset-gpios", "phy-reset-active-high" },
 251		{ "fsl,imx28-fec",   "phy-reset-gpios", "phy-reset-active-high" },
 252		{ "fsl,imx6q-fec",   "phy-reset-gpios", "phy-reset-active-high" },
 253		{ "fsl,mvf600-fec",  "phy-reset-gpios", "phy-reset-active-high" },
 254		{ "fsl,imx6sx-fec",  "phy-reset-gpios", "phy-reset-active-high" },
 255		{ "fsl,imx6ul-fec",  "phy-reset-gpios", "phy-reset-active-high" },
 256		{ "fsl,imx8mq-fec",  "phy-reset-gpios", "phy-reset-active-high" },
 257		{ "fsl,imx8qm-fec",  "phy-reset-gpios", "phy-reset-active-high" },
 258		{ "fsl,s32v234-fec", "phy-reset-gpios", "phy-reset-active-high" },
 259#endif
 260#if IS_ENABLED(CONFIG_PCI_IMX6)
 261		{ "fsl,imx6q-pcie",  "reset-gpio", "reset-gpio-active-high" },
 262		{ "fsl,imx6sx-pcie", "reset-gpio", "reset-gpio-active-high" },
 263		{ "fsl,imx6qp-pcie", "reset-gpio", "reset-gpio-active-high" },
 264		{ "fsl,imx7d-pcie",  "reset-gpio", "reset-gpio-active-high" },
 265		{ "fsl,imx8mq-pcie", "reset-gpio", "reset-gpio-active-high" },
 266		{ "fsl,imx8mm-pcie", "reset-gpio", "reset-gpio-active-high" },
 267		{ "fsl,imx8mp-pcie", "reset-gpio", "reset-gpio-active-high" },
 268#endif
 269
 270		/*
 271		 * The regulator GPIO handles are specified such that the
 272		 * presence or absence of "enable-active-high" solely controls
 273		 * the polarity of the GPIO line. Any phandle flags must
 274		 * be actively ignored.
 275		 */
 276#if IS_ENABLED(CONFIG_REGULATOR_FIXED_VOLTAGE)
 277		{ "regulator-fixed",   "gpios",        "enable-active-high" },
 278		{ "regulator-fixed",   "gpio",         "enable-active-high" },
 279		{ "reg-fixed-voltage", "gpios",        "enable-active-high" },
 280		{ "reg-fixed-voltage", "gpio",         "enable-active-high" },
 281#endif
 282#if IS_ENABLED(CONFIG_REGULATOR_GPIO)
 283		{ "regulator-gpio",    "enable-gpio",  "enable-active-high" },
 284		{ "regulator-gpio",    "enable-gpios", "enable-active-high" },
 285#endif
 286#if IS_ENABLED(CONFIG_MMC_ATMELMCI)
 287		{ "atmel,hsmci",       "cd-gpios",     "cd-inverted" },
 288#endif
 289	};
 290	unsigned int i;
 291	bool active_high;
 292
 293#if IS_ENABLED(CONFIG_MMC_ATMELMCI)
 294	/*
 295	 * The Atmel HSMCI has compatible property in the parent node and
 296	 * gpio property in a child node
 297	 */
 298	if (of_device_is_compatible(np->parent, "atmel,hsmci")) {
 299		np_compat = np->parent;
 300		np_propname = np;
 301	}
 302#endif
 303
 304	for (i = 0; i < ARRAY_SIZE(gpios); i++) {
 305		if (of_device_is_compatible(np_compat, gpios[i].compatible) &&
 306		    !strcmp(propname, gpios[i].gpio_propname)) {
 307			active_high = of_property_read_bool(np_propname,
 308						gpios[i].polarity_propname);
 309			of_gpio_quirk_polarity(np, active_high, flags);
 310			break;
 311		}
 
 
 312	}
 313}
 314
 315static void of_gpio_flags_quirks(const struct device_node *np,
 316				 const char *propname,
 317				 enum of_gpio_flags *flags,
 318				 int index)
 319{
 320	of_gpio_try_fixup_polarity(np, propname, flags);
 321	of_gpio_set_polarity_by_property(np, propname, flags);
 322
 323	/*
 324	 * Legacy open drain handling for fixed voltage regulators.
 325	 */
 326	if (IS_ENABLED(CONFIG_REGULATOR) &&
 327	    of_device_is_compatible(np, "reg-fixed-voltage") &&
 328	    of_property_read_bool(np, "gpio-open-drain")) {
 329		*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
 330		pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
 331			of_node_full_name(np));
 332	}
 333
 334	/*
 335	 * Legacy handling of SPI active high chip select. If we have a
 336	 * property named "cs-gpios" we need to inspect the child node
 337	 * to determine if the flags should have inverted semantics.
 338	 */
 339	if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
 340	    of_property_present(np, "cs-gpios")) {
 
 341		u32 cs;
 342		int ret;
 343
 344		for_each_child_of_node_scoped(np, child) {
 345			ret = of_property_read_u32(child, "reg", &cs);
 346			if (ret)
 347				continue;
 348			if (cs == index) {
 349				/*
 350				 * SPI children have active low chip selects
 351				 * by default. This can be specified negatively
 352				 * by just omitting "spi-cs-high" in the
 353				 * device node, or actively by tagging on
 354				 * GPIO_ACTIVE_LOW as flag in the device
 355				 * tree. If the line is simultaneously
 356				 * tagged as active low in the device tree
 357				 * and has the "spi-cs-high" set, we get a
 358				 * conflict and the "spi-cs-high" flag will
 359				 * take precedence.
 360				 */
 361				bool active_high = of_property_read_bool(child,
 362								"spi-cs-high");
 363				of_gpio_quirk_polarity(child, active_high,
 364						       flags);
 
 
 
 
 
 
 
 
 
 365				break;
 366			}
 367		}
 368	}
 369
 370	/* Legacy handling of stmmac's active-low PHY reset line */
 371	if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
 372	    !strcmp(propname, "snps,reset-gpio") &&
 373	    of_property_read_bool(np, "snps,reset-active-low"))
 374		*flags |= OF_GPIO_ACTIVE_LOW;
 375}
 376
 377/**
 378 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
 379 * @np:		device node to get GPIO from
 380 * @propname:	property name containing gpio specifier(s)
 381 * @index:	index of the GPIO
 382 * @flags:	a flags pointer to fill in
 383 *
 384 * Returns:
 385 * GPIO descriptor to use with Linux GPIO API, or one of the errno
 386 * value on the error condition. If @flags is not NULL the function also fills
 387 * in flags for the GPIO.
 388 */
 389static struct gpio_desc *of_get_named_gpiod_flags(const struct device_node *np,
 390		     const char *propname, int index, enum of_gpio_flags *flags)
 391{
 392	struct of_phandle_args gpiospec;
 
 393	struct gpio_desc *desc;
 394	int ret;
 395
 396	ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
 397					     &gpiospec);
 398	if (ret) {
 399		pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
 400			__func__, propname, np, index);
 401		return ERR_PTR(ret);
 402	}
 403
 404	struct gpio_device *gdev __free(gpio_device_put) =
 405				of_find_gpio_device_by_xlate(&gpiospec);
 406	if (!gdev) {
 407		desc = ERR_PTR(-EPROBE_DEFER);
 408		goto out;
 409	}
 410
 411	desc = of_xlate_and_get_gpiod_flags(gpio_device_get_chip(gdev),
 412					    &gpiospec, flags);
 413	if (IS_ERR(desc))
 414		goto out;
 415
 416	if (flags)
 417		of_gpio_flags_quirks(np, propname, flags, index);
 418
 419	pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
 420		 __func__, propname, np, index,
 421		 PTR_ERR_OR_ZERO(desc));
 422
 423out:
 424	of_node_put(gpiospec.np);
 425
 426	return desc;
 427}
 428
 429/**
 430 * of_get_named_gpio() - Get a GPIO number to use with GPIO API
 431 * @np:		device node to get GPIO from
 432 * @propname:	Name of property containing gpio specifier(s)
 433 * @index:	index of the GPIO
 434 *
 435 * **DEPRECATED** This function is deprecated and must not be used in new code.
 436 *
 437 * Returns:
 438 * GPIO number to use with Linux generic GPIO API, or one of the errno
 439 * value on the error condition.
 440 */
 441int of_get_named_gpio(const struct device_node *np, const char *propname,
 442		      int index)
 443{
 444	struct gpio_desc *desc;
 445
 446	desc = of_get_named_gpiod_flags(np, propname, index, NULL);
 447
 448	if (IS_ERR(desc))
 449		return PTR_ERR(desc);
 450	else
 451		return desc_to_gpio(desc);
 452}
 453EXPORT_SYMBOL_GPL(of_get_named_gpio);
 454
 455/* Converts gpio_lookup_flags into bitmask of GPIO_* values */
 456static unsigned long of_convert_gpio_flags(enum of_gpio_flags flags)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 457{
 458	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
 
 
 
 
 
 
 
 
 
 
 459
 460	if (flags & OF_GPIO_ACTIVE_LOW)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 461		lflags |= GPIO_ACTIVE_LOW;
 462
 463	if (flags & OF_GPIO_SINGLE_ENDED) {
 464		if (flags & OF_GPIO_OPEN_DRAIN)
 465			lflags |= GPIO_OPEN_DRAIN;
 466		else
 467			lflags |= GPIO_OPEN_SOURCE;
 468	}
 469
 470	if (flags & OF_GPIO_TRANSITORY)
 471		lflags |= GPIO_TRANSITORY;
 472
 473	if (flags & OF_GPIO_PULL_UP)
 474		lflags |= GPIO_PULL_UP;
 475
 476	if (flags & OF_GPIO_PULL_DOWN)
 477		lflags |= GPIO_PULL_DOWN;
 478
 479	if (flags & OF_GPIO_PULL_DISABLE)
 480		lflags |= GPIO_PULL_DISABLE;
 481
 482	return lflags;
 483}
 
 484
 485static struct gpio_desc *of_find_gpio_rename(struct device_node *np,
 486					     const char *con_id,
 487					     unsigned int idx,
 488					     enum of_gpio_flags *of_flags)
 
 
 
 489{
 490	static const struct of_rename_gpio {
 491		const char *con_id;
 492		const char *legacy_id;	/* NULL - same as con_id */
 493		/*
 494		 * Compatible string can be set to NULL in case where
 495		 * matching to a particular compatible is not practical,
 496		 * but it should only be done for gpio names that have
 497		 * vendor prefix to reduce risk of false positives.
 498		 * Addition of such entries is strongly discouraged.
 499		 */
 500		const char *compatible;
 501	} gpios[] = {
 502#if IS_ENABLED(CONFIG_LCD_HX8357)
 503		/* Himax LCD controllers used "gpios-reset" */
 504		{ "reset",	"gpios-reset",	"himax,hx8357" },
 505		{ "reset",	"gpios-reset",	"himax,hx8369" },
 506#endif
 507#if IS_ENABLED(CONFIG_MFD_ARIZONA)
 508		{ "wlf,reset",	NULL,		NULL },
 509#endif
 510#if IS_ENABLED(CONFIG_RTC_DRV_MOXART)
 511		{ "rtc-data",	"gpio-rtc-data",	"moxa,moxart-rtc" },
 512		{ "rtc-sclk",	"gpio-rtc-sclk",	"moxa,moxart-rtc" },
 513		{ "rtc-reset",	"gpio-rtc-reset",	"moxa,moxart-rtc" },
 514#endif
 515#if IS_ENABLED(CONFIG_NFC_MRVL_I2C)
 516		{ "reset",	"reset-n-io",	"marvell,nfc-i2c" },
 517#endif
 518#if IS_ENABLED(CONFIG_NFC_MRVL_SPI)
 519		{ "reset",	"reset-n-io",	"marvell,nfc-spi" },
 520#endif
 521#if IS_ENABLED(CONFIG_NFC_MRVL_UART)
 522		{ "reset",	"reset-n-io",	"marvell,nfc-uart" },
 523		{ "reset",	"reset-n-io",	"mrvl,nfc-uart" },
 524#endif
 525#if IS_ENABLED(CONFIG_PCI_LANTIQ)
 526		/* MIPS Lantiq PCI */
 527		{ "reset",	"gpio-reset",	"lantiq,pci-xway" },
 528#endif
 529
 530		/*
 531		 * Some regulator bindings happened before we managed to
 532		 * establish that GPIO properties should be named
 533		 * "foo-gpios" so we have this special kludge for them.
 534		 */
 535#if IS_ENABLED(CONFIG_REGULATOR_ARIZONA_LDO1)
 536		{ "wlf,ldoena",  NULL,		NULL }, /* Arizona */
 537#endif
 538#if IS_ENABLED(CONFIG_REGULATOR_WM8994)
 539		{ "wlf,ldo1ena", NULL,		NULL }, /* WM8994 */
 540		{ "wlf,ldo2ena", NULL,		NULL }, /* WM8994 */
 541#endif
 542
 543#if IS_ENABLED(CONFIG_SND_SOC_CS42L56)
 544		{ "reset",	"cirrus,gpio-nreset",	"cirrus,cs42l56" },
 545#endif
 546#if IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448)
 547		{ "i2s1-in-sel-gpio1",	NULL,	"mediatek,mt2701-cs42448-machine" },
 548		{ "i2s1-in-sel-gpio2",	NULL,	"mediatek,mt2701-cs42448-machine" },
 549#endif
 550#if IS_ENABLED(CONFIG_SND_SOC_TLV320AIC3X)
 551		{ "reset",	"gpio-reset",	"ti,tlv320aic3x" },
 552		{ "reset",	"gpio-reset",	"ti,tlv320aic33" },
 553		{ "reset",	"gpio-reset",	"ti,tlv320aic3007" },
 554		{ "reset",	"gpio-reset",	"ti,tlv320aic3104" },
 555		{ "reset",	"gpio-reset",	"ti,tlv320aic3106" },
 556#endif
 557#if IS_ENABLED(CONFIG_SPI_GPIO)
 558		/*
 559		 * The SPI GPIO bindings happened before we managed to
 560		 * establish that GPIO properties should be named
 561		 * "foo-gpios" so we have this special kludge for them.
 562		 */
 563		{ "miso",	"gpio-miso",	"spi-gpio" },
 564		{ "mosi",	"gpio-mosi",	"spi-gpio" },
 565		{ "sck",	"gpio-sck",	"spi-gpio" },
 566#endif
 567
 568		/*
 569		 * The old Freescale bindings use simply "gpios" as name
 570		 * for the chip select lines rather than "cs-gpios" like
 571		 * all other SPI hardware. Allow this specifically for
 572		 * Freescale and PPC devices.
 573		 */
 574#if IS_ENABLED(CONFIG_SPI_FSL_SPI)
 575		{ "cs",		"gpios",	"fsl,spi" },
 576		{ "cs",		"gpios",	"aeroflexgaisler,spictrl" },
 577#endif
 578#if IS_ENABLED(CONFIG_SPI_PPC4xx)
 579		{ "cs",		"gpios",	"ibm,ppc4xx-spi" },
 580#endif
 581
 582#if IS_ENABLED(CONFIG_TYPEC_FUSB302)
 583		/*
 584		 * Fairchild FUSB302 host is using undocumented "fcs,int_n"
 585		 * property without the compulsory "-gpios" suffix.
 586		 */
 587		{ "fcs,int_n",	NULL,		"fcs,fusb302" },
 588#endif
 589	};
 590	struct gpio_desc *desc;
 591	const char *legacy_id;
 592	unsigned int i;
 593
 594	if (!con_id)
 
 
 
 
 595		return ERR_PTR(-ENOENT);
 596
 597	for (i = 0; i < ARRAY_SIZE(gpios); i++) {
 598		if (strcmp(con_id, gpios[i].con_id))
 599			continue;
 600
 601		if (gpios[i].compatible &&
 602		    !of_device_is_compatible(np, gpios[i].compatible))
 603			continue;
 604
 605		legacy_id = gpios[i].legacy_id ?: gpios[i].con_id;
 606		desc = of_get_named_gpiod_flags(np, legacy_id, idx, of_flags);
 607		if (!gpiod_not_found(desc)) {
 608			pr_info("%s uses legacy gpio name '%s' instead of '%s-gpios'\n",
 609				of_node_full_name(np), legacy_id, con_id);
 610			return desc;
 611		}
 612	}
 613
 614	return ERR_PTR(-ENOENT);
 615}
 616
 617static struct gpio_desc *of_find_mt2701_gpio(struct device_node *np,
 
 
 
 
 
 618					     const char *con_id,
 619					     unsigned int idx,
 620					     enum of_gpio_flags *of_flags)
 621{
 622	struct gpio_desc *desc;
 623	const char *legacy_id;
 624
 625	if (!IS_ENABLED(CONFIG_SND_SOC_MT2701_CS42448))
 626		return ERR_PTR(-ENOENT);
 627
 628	if (!of_device_is_compatible(np, "mediatek,mt2701-cs42448-machine"))
 
 
 
 
 
 629		return ERR_PTR(-ENOENT);
 630
 631	if (!con_id || strcmp(con_id, "i2s1-in-sel"))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 632		return ERR_PTR(-ENOENT);
 633
 634	if (idx == 0)
 635		legacy_id = "i2s1-in-sel-gpio1";
 636	else if (idx == 1)
 637		legacy_id = "i2s1-in-sel-gpio2";
 638	else
 639		return ERR_PTR(-ENOENT);
 640
 641	desc = of_get_named_gpiod_flags(np, legacy_id, 0, of_flags);
 642	if (!gpiod_not_found(desc))
 643		pr_info("%s is using legacy gpio name '%s' instead of '%s-gpios'\n",
 644			of_node_full_name(np), legacy_id, con_id);
 645
 
 646	return desc;
 647}
 648
 649/*
 650 * Trigger sources are special, they allow us to use any GPIO as a LED trigger
 651 * and have the name "trigger-sources" no matter which kind of phandle it is
 652 * pointing to, whether to a GPIO, a USB host, a network PHY etc. So in this case
 653 * we allow looking something up that is not named "foo-gpios".
 654 */
 655static struct gpio_desc *of_find_trigger_gpio(struct device_node *np,
 656					      const char *con_id,
 657					      unsigned int idx,
 658					      enum of_gpio_flags *of_flags)
 659{
 660	struct gpio_desc *desc;
 661
 662	if (!IS_ENABLED(CONFIG_LEDS_TRIGGER_GPIO))
 663		return ERR_PTR(-ENOENT);
 664
 665	if (!con_id || strcmp(con_id, "trigger-sources"))
 666		return ERR_PTR(-ENOENT);
 667
 668	desc = of_get_named_gpiod_flags(np, con_id, idx, of_flags);
 669	if (!gpiod_not_found(desc))
 670		pr_debug("%s is used as a trigger\n", of_node_full_name(np));
 671
 672	return desc;
 673}
 674
 675
 676typedef struct gpio_desc *(*of_find_gpio_quirk)(struct device_node *np,
 677						const char *con_id,
 678						unsigned int idx,
 679						enum of_gpio_flags *of_flags);
 680static const of_find_gpio_quirk of_find_gpio_quirks[] = {
 681	of_find_gpio_rename,
 682	of_find_mt2701_gpio,
 683	of_find_trigger_gpio,
 684	NULL
 685};
 686
 687struct gpio_desc *of_find_gpio(struct device_node *np, const char *con_id,
 688			       unsigned int idx, unsigned long *flags)
 689{
 690	char propname[32]; /* 32 is max size of property name */
 691	enum of_gpio_flags of_flags;
 692	const of_find_gpio_quirk *q;
 693	struct gpio_desc *desc;
 
 694
 695	/* Try GPIO property "foo-gpios" and "foo-gpio" */
 696	for_each_gpio_property_name(propname, con_id) {
 697		desc = of_get_named_gpiod_flags(np, propname, idx, &of_flags);
 698		if (!gpiod_not_found(desc))
 
 
 
 
 
 
 
 
 
 699			break;
 700	}
 701
 702	/* Properly named GPIO was not found, try workarounds */
 703	for (q = of_find_gpio_quirks; gpiod_not_found(desc) && *q; q++)
 704		desc = (*q)(np, con_id, idx, &of_flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 705
 706	if (IS_ERR(desc))
 707		return desc;
 708
 709	*flags = of_convert_gpio_flags(of_flags);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 710
 711	return desc;
 712}
 713
 714/**
 715 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
 716 * @np:		device node to get GPIO from
 717 * @chip:	GPIO chip whose hog is parsed
 718 * @idx:	Index of the GPIO to parse
 719 * @name:	GPIO line name
 720 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
 721 *		of_find_gpio() or of_parse_own_gpio()
 722 * @dflags:	gpiod_flags - optional GPIO initialization flags
 723 *
 724 * Returns:
 725 * GPIO descriptor to use with Linux GPIO API, or one of the errno
 726 * value on the error condition.
 727 */
 728static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
 729					   struct gpio_chip *chip,
 730					   unsigned int idx, const char **name,
 731					   unsigned long *lflags,
 732					   enum gpiod_flags *dflags)
 733{
 734	struct device_node *chip_np;
 735	enum of_gpio_flags xlate_flags;
 736	struct of_phandle_args gpiospec;
 737	struct gpio_desc *desc;
 738	unsigned int i;
 739	u32 tmp;
 740	int ret;
 741
 742	chip_np = dev_of_node(&chip->gpiodev->dev);
 743	if (!chip_np)
 744		return ERR_PTR(-EINVAL);
 745
 746	xlate_flags = 0;
 747	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
 748	*dflags = GPIOD_ASIS;
 749
 750	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
 751	if (ret)
 752		return ERR_PTR(ret);
 753
 754	gpiospec.np = chip_np;
 755	gpiospec.args_count = tmp;
 756
 757	for (i = 0; i < tmp; i++) {
 758		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
 759						 &gpiospec.args[i]);
 760		if (ret)
 761			return ERR_PTR(ret);
 762	}
 763
 764	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
 765	if (IS_ERR(desc))
 766		return desc;
 767
 768	*lflags = of_convert_gpio_flags(xlate_flags);
 
 
 
 769
 770	if (of_property_read_bool(np, "input"))
 771		*dflags |= GPIOD_IN;
 772	else if (of_property_read_bool(np, "output-low"))
 773		*dflags |= GPIOD_OUT_LOW;
 774	else if (of_property_read_bool(np, "output-high"))
 775		*dflags |= GPIOD_OUT_HIGH;
 776	else {
 777		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
 778			desc_to_gpio(desc), np);
 779		return ERR_PTR(-EINVAL);
 780	}
 781
 782	if (name && of_property_read_string(np, "line-name", name))
 783		*name = np->name;
 784
 785	return desc;
 786}
 787
 788/**
 789 * of_gpiochip_add_hog - Add all hogs in a hog device node
 790 * @chip:	gpio chip to act on
 791 * @hog:	device node describing the hogs
 792 *
 793 * Returns:
 794 * 0 on success, or negative errno on failure.
 795 */
 796static int of_gpiochip_add_hog(struct gpio_chip *chip, struct device_node *hog)
 797{
 798	enum gpiod_flags dflags;
 799	struct gpio_desc *desc;
 800	unsigned long lflags;
 801	const char *name;
 802	unsigned int i;
 803	int ret;
 804
 805	for (i = 0;; i++) {
 806		desc = of_parse_own_gpio(hog, chip, i, &name, &lflags, &dflags);
 807		if (IS_ERR(desc))
 808			break;
 809
 810		ret = gpiod_hog(desc, name, lflags, dflags);
 811		if (ret < 0)
 812			return ret;
 813
 814#ifdef CONFIG_OF_DYNAMIC
 815		WRITE_ONCE(desc->hog, hog);
 816#endif
 817	}
 818
 819	return 0;
 820}
 821
 822/**
 823 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
 824 * @chip:	gpio chip to act on
 825 *
 826 * This is only used by of_gpiochip_add to request/set GPIO initial
 827 * configuration.
 828 *
 829 * Returns:
 830 * 0 on success, or negative errno on failure.
 831 */
 832static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
 833{
 
 
 
 
 
 
 834	int ret;
 835
 836	for_each_available_child_of_node_scoped(dev_of_node(&chip->gpiodev->dev), np) {
 837		if (!of_property_read_bool(np, "gpio-hog"))
 838			continue;
 839
 840		ret = of_gpiochip_add_hog(chip, np);
 841		if (ret < 0)
 842			return ret;
 843
 844		of_node_set_flag(np, OF_POPULATED);
 845	}
 846
 847	return 0;
 848}
 849
 850#ifdef CONFIG_OF_DYNAMIC
 851/**
 852 * of_gpiochip_remove_hog - Remove all hogs in a hog device node
 853 * @chip:	gpio chip to act on
 854 * @hog:	device node describing the hogs
 855 */
 856static void of_gpiochip_remove_hog(struct gpio_chip *chip,
 857				   struct device_node *hog)
 858{
 859	struct gpio_desc *desc;
 860
 861	for_each_gpio_desc_with_flag(chip, desc, FLAG_IS_HOGGED)
 862		if (READ_ONCE(desc->hog) == hog)
 863			gpiochip_free_own_desc(desc);
 864}
 865
 866static int of_gpiochip_match_node(struct gpio_chip *chip, const void *data)
 867{
 868	return device_match_of_node(&chip->gpiodev->dev, data);
 869}
 870
 871static struct gpio_device *of_find_gpio_device_by_node(struct device_node *np)
 872{
 873	return gpio_device_find(np, of_gpiochip_match_node);
 874}
 875
 876static int of_gpio_notify(struct notifier_block *nb, unsigned long action,
 877			  void *arg)
 878{
 879	struct gpio_device *gdev __free(gpio_device_put) = NULL;
 880	struct of_reconfig_data *rd = arg;
 881	int ret;
 882
 883	/*
 884	 * This only supports adding and removing complete gpio-hog nodes.
 885	 * Modifying an existing gpio-hog node is not supported (except for
 886	 * changing its "status" property, which is treated the same as
 887	 * addition/removal).
 888	 */
 889	switch (of_reconfig_get_state_change(action, arg)) {
 890	case OF_RECONFIG_CHANGE_ADD:
 891		if (!of_property_read_bool(rd->dn, "gpio-hog"))
 892			return NOTIFY_DONE;	/* not for us */
 893
 894		if (of_node_test_and_set_flag(rd->dn, OF_POPULATED))
 895			return NOTIFY_DONE;
 896
 897		gdev = of_find_gpio_device_by_node(rd->dn->parent);
 898		if (!gdev)
 899			return NOTIFY_DONE;	/* not for us */
 900
 901		ret = of_gpiochip_add_hog(gpio_device_get_chip(gdev), rd->dn);
 902		if (ret < 0) {
 903			pr_err("%s: failed to add hogs for %pOF\n", __func__,
 904			       rd->dn);
 905			of_node_clear_flag(rd->dn, OF_POPULATED);
 906			return notifier_from_errno(ret);
 907		}
 908		return NOTIFY_OK;
 909
 910	case OF_RECONFIG_CHANGE_REMOVE:
 911		if (!of_node_check_flag(rd->dn, OF_POPULATED))
 912			return NOTIFY_DONE;	/* already depopulated */
 913
 914		gdev = of_find_gpio_device_by_node(rd->dn->parent);
 915		if (!gdev)
 916			return NOTIFY_DONE;	/* not for us */
 917
 918		of_gpiochip_remove_hog(gpio_device_get_chip(gdev), rd->dn);
 919		of_node_clear_flag(rd->dn, OF_POPULATED);
 920		return NOTIFY_OK;
 921	}
 922
 923	return NOTIFY_DONE;
 924}
 925
 926struct notifier_block gpio_of_notifier = {
 927	.notifier_call = of_gpio_notify,
 928};
 929#endif /* CONFIG_OF_DYNAMIC */
 930
 931/**
 932 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
 933 * @gc:		pointer to the gpio_chip structure
 934 * @gpiospec:	GPIO specifier as found in the device tree
 935 * @flags:	a flags pointer to fill in
 936 *
 937 * This is simple translation function, suitable for the most 1:1 mapped
 938 * GPIO chips. This function performs only one sanity check: whether GPIO
 939 * is less than ngpios (that is specified in the gpio_chip).
 940 *
 941 * Returns:
 942 * GPIO number (>= 0) on success, negative errno on failure.
 943 */
 944static int of_gpio_simple_xlate(struct gpio_chip *gc,
 945				const struct of_phandle_args *gpiospec,
 946				u32 *flags)
 947{
 948	/*
 949	 * We're discouraging gpio_cells < 2, since that way you'll have to
 950	 * write your own xlate function (that will have to retrieve the GPIO
 951	 * number and the flags from a single gpio cell -- this is possible,
 952	 * but not recommended).
 953	 */
 954	if (gc->of_gpio_n_cells < 2) {
 955		WARN_ON(1);
 956		return -EINVAL;
 957	}
 958
 959	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
 960		return -EINVAL;
 961
 962	if (gpiospec->args[0] >= gc->ngpio)
 963		return -EINVAL;
 964
 965	if (flags)
 966		*flags = gpiospec->args[1];
 967
 968	return gpiospec->args[0];
 969}
 970
 971#if IS_ENABLED(CONFIG_OF_GPIO_MM_GPIOCHIP)
 972#include <linux/gpio/legacy-of-mm-gpiochip.h>
 973/**
 974 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
 975 * @np:		device node of the GPIO chip
 976 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
 977 * @data:	driver data to store in the struct gpio_chip
 978 *
 979 * To use this function you should allocate and fill mm_gc with:
 980 *
 981 * 1) In the gpio_chip structure:
 982 *    - all the callbacks
 983 *    - of_gpio_n_cells
 984 *    - of_xlate callback (optional)
 985 *
 986 * 3) In the of_mm_gpio_chip structure:
 987 *    - save_regs callback (optional)
 988 *
 989 * If succeeded, this function will map bank's memory and will
 990 * do all necessary work for you. Then you'll able to use .regs
 991 * to manage GPIOs from the callbacks.
 992 *
 993 * Returns:
 994 * 0 on success, or negative errno on failure.
 995 */
 996int of_mm_gpiochip_add_data(struct device_node *np,
 997			    struct of_mm_gpio_chip *mm_gc,
 998			    void *data)
 999{
1000	int ret = -ENOMEM;
1001	struct gpio_chip *gc = &mm_gc->gc;
1002
1003	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
1004	if (!gc->label)
1005		goto err0;
1006
1007	mm_gc->regs = of_iomap(np, 0);
1008	if (!mm_gc->regs)
1009		goto err1;
1010
1011	gc->base = -1;
1012
1013	if (mm_gc->save_regs)
1014		mm_gc->save_regs(mm_gc);
1015
1016	fwnode_handle_put(mm_gc->gc.fwnode);
1017	mm_gc->gc.fwnode = fwnode_handle_get(of_fwnode_handle(np));
1018
1019	ret = gpiochip_add_data(gc, data);
1020	if (ret)
1021		goto err2;
1022
1023	return 0;
1024err2:
1025	of_node_put(np);
1026	iounmap(mm_gc->regs);
1027err1:
1028	kfree(gc->label);
1029err0:
1030	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
1031	return ret;
1032}
1033EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data);
1034
1035/**
1036 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
1037 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
1038 */
1039void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
1040{
1041	struct gpio_chip *gc = &mm_gc->gc;
1042
 
 
 
1043	gpiochip_remove(gc);
1044	iounmap(mm_gc->regs);
1045	kfree(gc->label);
1046}
1047EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
1048#endif
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1049
1050#ifdef CONFIG_PINCTRL
1051static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
1052{
 
1053	struct of_phandle_args pinspec;
1054	struct pinctrl_dev *pctldev;
1055	struct device_node *np;
1056	int index = 0, ret, trim;
1057	const char *name;
1058	static const char group_names_propname[] = "gpio-ranges-group-names";
1059	bool has_group_names;
1060
1061	np = dev_of_node(&chip->gpiodev->dev);
1062	if (!np)
1063		return 0;
1064
1065	has_group_names = of_property_present(np, group_names_propname);
1066
1067	for (;; index++) {
1068		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
1069				index, &pinspec);
1070		if (ret)
1071			break;
1072
1073		pctldev = of_pinctrl_get(pinspec.np);
1074		of_node_put(pinspec.np);
1075		if (!pctldev)
1076			return -EPROBE_DEFER;
1077
1078		/* Ignore ranges outside of this GPIO chip */
1079		if (pinspec.args[0] >= (chip->offset + chip->ngpio))
1080			continue;
1081		if (pinspec.args[0] + pinspec.args[2] <= chip->offset)
1082			continue;
1083
1084		if (pinspec.args[2]) {
1085			/* npins != 0: linear range */
1086			if (has_group_names) {
1087				of_property_read_string_index(np,
1088						group_names_propname,
1089						index, &name);
1090				if (strlen(name)) {
1091					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
1092						np);
1093					break;
1094				}
1095			}
1096
1097			/* Trim the range to fit this GPIO chip */
1098			if (chip->offset > pinspec.args[0]) {
1099				trim = chip->offset - pinspec.args[0];
1100				pinspec.args[2] -= trim;
1101				pinspec.args[1] += trim;
1102				pinspec.args[0] = 0;
1103			} else {
1104				pinspec.args[0] -= chip->offset;
1105			}
1106			if ((pinspec.args[0] + pinspec.args[2]) > chip->ngpio)
1107				pinspec.args[2] = chip->ngpio - pinspec.args[0];
1108
1109			ret = gpiochip_add_pin_range(chip,
1110					pinctrl_dev_get_devname(pctldev),
1111					pinspec.args[0],
1112					pinspec.args[1],
1113					pinspec.args[2]);
1114			if (ret)
1115				return ret;
1116		} else {
1117			/* npins == 0: special range */
1118			if (pinspec.args[1]) {
1119				pr_err("%pOF: Illegal gpio-range format.\n",
1120					np);
1121				break;
1122			}
1123
1124			if (!has_group_names) {
1125				pr_err("%pOF: GPIO group range requested but no %s property.\n",
1126					np, group_names_propname);
1127				break;
1128			}
1129
1130			ret = of_property_read_string_index(np,
1131						group_names_propname,
1132						index, &name);
1133			if (ret)
1134				break;
1135
1136			if (!strlen(name)) {
1137				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
1138				np);
1139				break;
1140			}
1141
1142			ret = gpiochip_add_pingroup_range(chip, pctldev,
1143						pinspec.args[0], name);
1144			if (ret)
1145				return ret;
1146		}
1147	}
1148
1149	return 0;
1150}
1151
1152#else
1153static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
1154#endif
1155
1156int of_gpiochip_add(struct gpio_chip *chip)
1157{
1158	struct device_node *np;
1159	int ret;
1160
1161	np = dev_of_node(&chip->gpiodev->dev);
1162	if (!np)
1163		return 0;
1164
1165	if (!chip->of_xlate) {
1166		chip->of_gpio_n_cells = 2;
1167		chip->of_xlate = of_gpio_simple_xlate;
1168	}
1169
1170	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
1171		return -EINVAL;
1172
 
 
1173	ret = of_gpiochip_add_pin_range(chip);
1174	if (ret)
1175		return ret;
1176
1177	of_node_get(np);
 
 
 
 
 
1178
1179	ret = of_gpiochip_scan_gpios(chip);
1180	if (ret)
1181		of_node_put(np);
 
 
1182
1183	return ret;
1184}
1185
1186void of_gpiochip_remove(struct gpio_chip *chip)
1187{
1188	of_node_put(dev_of_node(&chip->gpiodev->dev));
 
1189}
v5.4
  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 * This is used by external users of of_gpio_count() from <linux/of_gpio.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 28 *
 29 * FIXME: get rid of those external users by converting them to GPIO
 30 * descriptors and let them all use gpiod_get_count()
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 31 */
 32int of_gpio_get_count(struct device *dev, const char *con_id)
 
 33{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 34	int ret;
 35	char propname[32];
 36	unsigned int i;
 37
 38	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 39		if (con_id)
 40			snprintf(propname, sizeof(propname), "%s-%s",
 41				 con_id, gpio_suffixes[i]);
 42		else
 43			snprintf(propname, sizeof(propname), "%s",
 44				 gpio_suffixes[i]);
 45
 46		ret = of_gpio_named_count(dev->of_node, propname);
 
 47		if (ret > 0)
 48			break;
 49	}
 50	return ret ? ret : -ENOENT;
 51}
 52
 53static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
 
 54{
 55	struct of_phandle_args *gpiospec = data;
 56
 57	return chip->gpiodev->dev.of_node == gpiospec->np &&
 58				chip->of_xlate &&
 59				chip->of_xlate(chip, gpiospec, NULL) >= 0;
 60}
 61
 62static struct gpio_chip *of_find_gpiochip_by_xlate(
 63					struct of_phandle_args *gpiospec)
 64{
 65	return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
 66}
 67
 68static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
 69					struct of_phandle_args *gpiospec,
 70					enum of_gpio_flags *flags)
 71{
 72	int ret;
 73
 74	if (chip->of_gpio_n_cells != gpiospec->args_count)
 75		return ERR_PTR(-EINVAL);
 76
 77	ret = chip->of_xlate(chip, gpiospec, flags);
 78	if (ret < 0)
 79		return ERR_PTR(ret);
 80
 81	return gpiochip_get_desc(chip, ret);
 82}
 83
 84/**
 85 * of_gpio_need_valid_mask() - figure out if the OF GPIO driver needs
 86 * to set the .valid_mask
 87 * @dev: the device for the GPIO provider
 88 * @return: true if the valid mask needs to be set
 89 */
 90bool of_gpio_need_valid_mask(const struct gpio_chip *gc)
 
 
 91{
 92	int size;
 93	struct device_node *np = gc->of_node;
 94
 95	size = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
 96	if (size > 0 && size % 2 == 0)
 97		return true;
 98	return false;
 
 
 
 
 
 99}
100
101static void of_gpio_flags_quirks(struct device_node *np,
102				 const char *propname,
103				 enum of_gpio_flags *flags,
104				 int index)
105{
106	/*
107	 * Handle MMC "cd-inverted" and "wp-inverted" semantics.
108	 */
109	if (IS_ENABLED(CONFIG_MMC)) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
110		/*
111		 * Active low is the default according to the
112		 * SDHCI specification and the device tree
113		 * bindings. However the code in the current
114		 * kernel was written such that the phandle
115		 * flags were always respected, and "cd-inverted"
116		 * would invert the flag from the device phandle.
117		 */
118		if (!strcmp(propname, "cd-gpios")) {
119			if (of_property_read_bool(np, "cd-inverted"))
120				*flags ^= OF_GPIO_ACTIVE_LOW;
121		}
122		if (!strcmp(propname, "wp-gpios")) {
123			if (of_property_read_bool(np, "wp-inverted"))
124				*flags ^= OF_GPIO_ACTIVE_LOW;
 
 
 
125		}
126	}
127	/*
128	 * Some GPIO fixed regulator quirks.
129	 * Note that active low is the default.
130	 */
131	if (IS_ENABLED(CONFIG_REGULATOR) &&
132	    (of_device_is_compatible(np, "regulator-fixed") ||
133	     of_device_is_compatible(np, "reg-fixed-voltage") ||
134	     (!(strcmp(propname, "enable-gpio") &&
135		strcmp(propname, "enable-gpios")) &&
136	      of_device_is_compatible(np, "regulator-gpio")))) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
137		/*
138		 * The regulator GPIO handles are specified such that the
139		 * presence or absence of "enable-active-high" solely controls
140		 * the polarity of the GPIO line. Any phandle flags must
141		 * be actively ignored.
142		 */
143		if (*flags & OF_GPIO_ACTIVE_LOW) {
144			pr_warn("%s GPIO handle specifies active low - ignored\n",
145				of_node_full_name(np));
146			*flags &= ~OF_GPIO_ACTIVE_LOW;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
147		}
148		if (!of_property_read_bool(np, "enable-active-high"))
149			*flags |= OF_GPIO_ACTIVE_LOW;
150	}
 
 
 
 
 
 
 
 
 
 
151	/*
152	 * Legacy open drain handling for fixed voltage regulators.
153	 */
154	if (IS_ENABLED(CONFIG_REGULATOR) &&
155	    of_device_is_compatible(np, "reg-fixed-voltage") &&
156	    of_property_read_bool(np, "gpio-open-drain")) {
157		*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
158		pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
159			of_node_full_name(np));
160	}
161
162	/*
163	 * Legacy handling of SPI active high chip select. If we have a
164	 * property named "cs-gpios" we need to inspect the child node
165	 * to determine if the flags should have inverted semantics.
166	 */
167	if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
168	    of_property_read_bool(np, "cs-gpios")) {
169		struct device_node *child;
170		u32 cs;
171		int ret;
172
173		for_each_child_of_node(np, child) {
174			ret = of_property_read_u32(child, "reg", &cs);
175			if (ret)
176				continue;
177			if (cs == index) {
178				/*
179				 * SPI children have active low chip selects
180				 * by default. This can be specified negatively
181				 * by just omitting "spi-cs-high" in the
182				 * device node, or actively by tagging on
183				 * GPIO_ACTIVE_LOW as flag in the device
184				 * tree. If the line is simultaneously
185				 * tagged as active low in the device tree
186				 * and has the "spi-cs-high" set, we get a
187				 * conflict and the "spi-cs-high" flag will
188				 * take precedence.
189				 */
190				if (of_property_read_bool(child, "spi-cs-high")) {
191					if (*flags & OF_GPIO_ACTIVE_LOW) {
192						pr_warn("%s GPIO handle specifies active low - ignored\n",
193							of_node_full_name(child));
194						*flags &= ~OF_GPIO_ACTIVE_LOW;
195					}
196				} else {
197					if (!(*flags & OF_GPIO_ACTIVE_LOW))
198						pr_info("%s enforce active low on chipselect handle\n",
199							of_node_full_name(child));
200					*flags |= OF_GPIO_ACTIVE_LOW;
201				}
202				of_node_put(child);
203				break;
204			}
205		}
206	}
207
208	/* Legacy handling of stmmac's active-low PHY reset line */
209	if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
210	    !strcmp(propname, "snps,reset-gpio") &&
211	    of_property_read_bool(np, "snps,reset-active-low"))
212		*flags |= OF_GPIO_ACTIVE_LOW;
213}
214
215/**
216 * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
217 * @np:		device node to get GPIO from
218 * @propname:	property name containing gpio specifier(s)
219 * @index:	index of the GPIO
220 * @flags:	a flags pointer to fill in
221 *
222 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
 
223 * value on the error condition. If @flags is not NULL the function also fills
224 * in flags for the GPIO.
225 */
226static struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
227		     const char *propname, int index, enum of_gpio_flags *flags)
228{
229	struct of_phandle_args gpiospec;
230	struct gpio_chip *chip;
231	struct gpio_desc *desc;
232	int ret;
233
234	ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
235					     &gpiospec);
236	if (ret) {
237		pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
238			__func__, propname, np, index);
239		return ERR_PTR(ret);
240	}
241
242	chip = of_find_gpiochip_by_xlate(&gpiospec);
243	if (!chip) {
 
244		desc = ERR_PTR(-EPROBE_DEFER);
245		goto out;
246	}
247
248	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
 
249	if (IS_ERR(desc))
250		goto out;
251
252	if (flags)
253		of_gpio_flags_quirks(np, propname, flags, index);
254
255	pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
256		 __func__, propname, np, index,
257		 PTR_ERR_OR_ZERO(desc));
258
259out:
260	of_node_put(gpiospec.np);
261
262	return desc;
263}
264
265int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
266			    int index, enum of_gpio_flags *flags)
 
 
 
 
 
 
 
 
 
 
 
 
267{
268	struct gpio_desc *desc;
269
270	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
271
272	if (IS_ERR(desc))
273		return PTR_ERR(desc);
274	else
275		return desc_to_gpio(desc);
276}
277EXPORT_SYMBOL_GPL(of_get_named_gpio_flags);
278
279/**
280 * gpiod_get_from_of_node() - obtain a GPIO from an OF node
281 * @node:	handle of the OF node
282 * @propname:	name of the DT property representing the GPIO
283 * @index:	index of the GPIO to obtain for the consumer
284 * @dflags:	GPIO initialization flags
285 * @label:	label to attach to the requested GPIO
286 *
287 * Returns:
288 * On successful request the GPIO pin is configured in accordance with
289 * provided @dflags.
290 *
291 * In case of error an ERR_PTR() is returned.
292 */
293struct gpio_desc *gpiod_get_from_of_node(struct device_node *node,
294					 const char *propname, int index,
295					 enum gpiod_flags dflags,
296					 const char *label)
297{
298	unsigned long lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
299	struct gpio_desc *desc;
300	enum of_gpio_flags flags;
301	bool active_low = false;
302	bool single_ended = false;
303	bool open_drain = false;
304	bool transitory = false;
305	int ret;
306
307	desc = of_get_named_gpiod_flags(node, propname,
308					index, &flags);
309
310	if (!desc || IS_ERR(desc)) {
311		return desc;
312	}
313
314	active_low = flags & OF_GPIO_ACTIVE_LOW;
315	single_ended = flags & OF_GPIO_SINGLE_ENDED;
316	open_drain = flags & OF_GPIO_OPEN_DRAIN;
317	transitory = flags & OF_GPIO_TRANSITORY;
318
319	ret = gpiod_request(desc, label);
320	if (ret == -EBUSY && (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE))
321		return desc;
322	if (ret)
323		return ERR_PTR(ret);
324
325	if (active_low)
326		lflags |= GPIO_ACTIVE_LOW;
327
328	if (single_ended) {
329		if (open_drain)
330			lflags |= GPIO_OPEN_DRAIN;
331		else
332			lflags |= GPIO_OPEN_SOURCE;
333	}
334
335	if (transitory)
336		lflags |= GPIO_TRANSITORY;
337
338	ret = gpiod_configure_flags(desc, propname, lflags, dflags);
339	if (ret < 0) {
340		gpiod_put(desc);
341		return ERR_PTR(ret);
342	}
 
 
 
343
344	return desc;
345}
346EXPORT_SYMBOL_GPL(gpiod_get_from_of_node);
347
348/*
349 * The SPI GPIO bindings happened before we managed to establish that GPIO
350 * properties should be named "foo-gpios" so we have this special kludge for
351 * them.
352 */
353static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
354					  enum of_gpio_flags *of_flags)
355{
356	char prop_name[32]; /* 32 is max size of property name */
357	struct device_node *np = dev->of_node;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
358	struct gpio_desc *desc;
 
 
359
360	/*
361	 * Hopefully the compiler stubs the rest of the function if this
362	 * is false.
363	 */
364	if (!IS_ENABLED(CONFIG_SPI_MASTER))
365		return ERR_PTR(-ENOENT);
366
367	/* Allow this specifically for "spi-gpio" devices */
368	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
369		return ERR_PTR(-ENOENT);
370
371	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
372	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
 
373
374	desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
375	return desc;
 
 
 
 
 
 
 
 
376}
377
378/*
379 * The old Freescale bindings use simply "gpios" as name for the chip select
380 * lines rather than "cs-gpios" like all other SPI hardware. Account for this
381 * with a special quirk.
382 */
383static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
384					     const char *con_id,
385					     unsigned int idx,
386					     unsigned long *flags)
387{
388	struct device_node *np = dev->of_node;
 
389
390	if (!IS_ENABLED(CONFIG_SPI_MASTER))
391		return ERR_PTR(-ENOENT);
392
393	/* Allow this specifically for Freescale devices */
394	if (!of_device_is_compatible(np, "fsl,spi") &&
395	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
396		return ERR_PTR(-ENOENT);
397	/* Allow only if asking for "cs-gpios" */
398	if (!con_id || strcmp(con_id, "cs"))
399		return ERR_PTR(-ENOENT);
400
401	/*
402	 * While all other SPI controllers use "cs-gpios" the Freescale
403	 * uses just "gpios" so translate to that when "cs-gpios" is
404	 * requested.
405	 */
406	return of_find_gpio(dev, NULL, idx, flags);
407}
408
409/*
410 * Some regulator bindings happened before we managed to establish that GPIO
411 * properties should be named "foo-gpios" so we have this special kludge for
412 * them.
413 */
414static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
415						enum of_gpio_flags *of_flags)
416{
417	/* These are the connection IDs we accept as legacy GPIO phandles */
418	const char *whitelist[] = {
419		"wlf,ldoena", /* Arizona */
420		"wlf,ldo1ena", /* WM8994 */
421		"wlf,ldo2ena", /* WM8994 */
422	};
423	struct device_node *np = dev->of_node;
424	struct gpio_desc *desc;
425	int i;
426
427	if (!IS_ENABLED(CONFIG_REGULATOR))
428		return ERR_PTR(-ENOENT);
429
430	if (!con_id)
 
 
 
 
431		return ERR_PTR(-ENOENT);
432
433	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
434	if (i < 0)
435		return ERR_PTR(-ENOENT);
 
436
437	desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
438	return desc;
439}
440
441static struct gpio_desc *of_find_arizona_gpio(struct device *dev,
 
 
 
 
 
 
442					      const char *con_id,
 
443					      enum of_gpio_flags *of_flags)
444{
445	if (!IS_ENABLED(CONFIG_MFD_ARIZONA))
 
 
446		return ERR_PTR(-ENOENT);
447
448	if (!con_id || strcmp(con_id, "wlf,reset"))
449		return ERR_PTR(-ENOENT);
450
451	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);
 
 
 
 
452}
453
454struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
 
 
 
 
 
 
 
 
 
 
 
 
455			       unsigned int idx, unsigned long *flags)
456{
457	char prop_name[32]; /* 32 is max size of property name */
458	enum of_gpio_flags of_flags;
 
459	struct gpio_desc *desc;
460	unsigned int i;
461
462	/* Try GPIO property "foo-gpios" and "foo-gpio" */
463	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
464		if (con_id)
465			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
466				 gpio_suffixes[i]);
467		else
468			snprintf(prop_name, sizeof(prop_name), "%s",
469				 gpio_suffixes[i]);
470
471		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
472						&of_flags);
473
474		if (!IS_ERR(desc) || PTR_ERR(desc) != -ENOENT)
475			break;
476	}
477
478	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
479		/* Special handling for SPI GPIOs if used */
480		desc = of_find_spi_gpio(dev, con_id, &of_flags);
481	}
482
483	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
484		/* This quirk looks up flags and all */
485		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
486		if (!IS_ERR(desc))
487			return desc;
488	}
489
490	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT) {
491		/* Special handling for regulator GPIOs if used */
492		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
493	}
494
495	if (IS_ERR(desc) && PTR_ERR(desc) == -ENOENT)
496		desc = of_find_arizona_gpio(dev, con_id, &of_flags);
497
498	if (IS_ERR(desc))
499		return desc;
500
501	if (of_flags & OF_GPIO_ACTIVE_LOW)
502		*flags |= GPIO_ACTIVE_LOW;
503
504	if (of_flags & OF_GPIO_SINGLE_ENDED) {
505		if (of_flags & OF_GPIO_OPEN_DRAIN)
506			*flags |= GPIO_OPEN_DRAIN;
507		else
508			*flags |= GPIO_OPEN_SOURCE;
509	}
510
511	if (of_flags & OF_GPIO_TRANSITORY)
512		*flags |= GPIO_TRANSITORY;
513
514	if (of_flags & OF_GPIO_PULL_UP)
515		*flags |= GPIO_PULL_UP;
516	if (of_flags & OF_GPIO_PULL_DOWN)
517		*flags |= GPIO_PULL_DOWN;
518
519	return desc;
520}
521
522/**
523 * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
524 * @np:		device node to get GPIO from
525 * @chip:	GPIO chip whose hog is parsed
526 * @idx:	Index of the GPIO to parse
527 * @name:	GPIO line name
528 * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
529 *		of_find_gpio() or of_parse_own_gpio()
530 * @dflags:	gpiod_flags - optional GPIO initialization flags
531 *
532 * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
 
533 * value on the error condition.
534 */
535static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
536					   struct gpio_chip *chip,
537					   unsigned int idx, const char **name,
538					   unsigned long *lflags,
539					   enum gpiod_flags *dflags)
540{
541	struct device_node *chip_np;
542	enum of_gpio_flags xlate_flags;
543	struct of_phandle_args gpiospec;
544	struct gpio_desc *desc;
545	unsigned int i;
546	u32 tmp;
547	int ret;
548
549	chip_np = chip->of_node;
550	if (!chip_np)
551		return ERR_PTR(-EINVAL);
552
553	xlate_flags = 0;
554	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
555	*dflags = 0;
556
557	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
558	if (ret)
559		return ERR_PTR(ret);
560
561	gpiospec.np = chip_np;
562	gpiospec.args_count = tmp;
563
564	for (i = 0; i < tmp; i++) {
565		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
566						 &gpiospec.args[i]);
567		if (ret)
568			return ERR_PTR(ret);
569	}
570
571	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
572	if (IS_ERR(desc))
573		return desc;
574
575	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
576		*lflags |= GPIO_ACTIVE_LOW;
577	if (xlate_flags & OF_GPIO_TRANSITORY)
578		*lflags |= GPIO_TRANSITORY;
579
580	if (of_property_read_bool(np, "input"))
581		*dflags |= GPIOD_IN;
582	else if (of_property_read_bool(np, "output-low"))
583		*dflags |= GPIOD_OUT_LOW;
584	else if (of_property_read_bool(np, "output-high"))
585		*dflags |= GPIOD_OUT_HIGH;
586	else {
587		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
588			desc_to_gpio(desc), np);
589		return ERR_PTR(-EINVAL);
590	}
591
592	if (name && of_property_read_string(np, "line-name", name))
593		*name = np->name;
594
595	return desc;
596}
597
598/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
599 * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
600 * @chip:	gpio chip to act on
601 *
602 * This is only used by of_gpiochip_add to request/set GPIO initial
603 * configuration.
604 * It returns error if it fails otherwise 0 on success.
 
 
605 */
606static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
607{
608	struct gpio_desc *desc = NULL;
609	struct device_node *np;
610	const char *name;
611	unsigned long lflags;
612	enum gpiod_flags dflags;
613	unsigned int i;
614	int ret;
615
616	for_each_available_child_of_node(chip->of_node, np) {
617		if (!of_property_read_bool(np, "gpio-hog"))
618			continue;
619
620		for (i = 0;; i++) {
621			desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
622						 &dflags);
623			if (IS_ERR(desc))
624				break;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
625
626			ret = gpiod_hog(desc, name, lflags, dflags);
627			if (ret < 0) {
628				of_node_put(np);
629				return ret;
630			}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
631		}
 
 
 
 
 
 
 
 
 
 
 
 
 
632	}
633
634	return 0;
635}
636
 
 
 
 
 
637/**
638 * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
639 * @gc:		pointer to the gpio_chip structure
640 * @gpiospec:	GPIO specifier as found in the device tree
641 * @flags:	a flags pointer to fill in
642 *
643 * This is simple translation function, suitable for the most 1:1 mapped
644 * GPIO chips. This function performs only one sanity check: whether GPIO
645 * is less than ngpios (that is specified in the gpio_chip).
 
 
 
646 */
647static int of_gpio_simple_xlate(struct gpio_chip *gc,
648				const struct of_phandle_args *gpiospec,
649				u32 *flags)
650{
651	/*
652	 * We're discouraging gpio_cells < 2, since that way you'll have to
653	 * write your own xlate function (that will have to retrieve the GPIO
654	 * number and the flags from a single gpio cell -- this is possible,
655	 * but not recommended).
656	 */
657	if (gc->of_gpio_n_cells < 2) {
658		WARN_ON(1);
659		return -EINVAL;
660	}
661
662	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
663		return -EINVAL;
664
665	if (gpiospec->args[0] >= gc->ngpio)
666		return -EINVAL;
667
668	if (flags)
669		*flags = gpiospec->args[1];
670
671	return gpiospec->args[0];
672}
673
 
 
674/**
675 * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
676 * @np:		device node of the GPIO chip
677 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
678 * @data:	driver data to store in the struct gpio_chip
679 *
680 * To use this function you should allocate and fill mm_gc with:
681 *
682 * 1) In the gpio_chip structure:
683 *    - all the callbacks
684 *    - of_gpio_n_cells
685 *    - of_xlate callback (optional)
686 *
687 * 3) In the of_mm_gpio_chip structure:
688 *    - save_regs callback (optional)
689 *
690 * If succeeded, this function will map bank's memory and will
691 * do all necessary work for you. Then you'll able to use .regs
692 * to manage GPIOs from the callbacks.
 
 
 
693 */
694int of_mm_gpiochip_add_data(struct device_node *np,
695			    struct of_mm_gpio_chip *mm_gc,
696			    void *data)
697{
698	int ret = -ENOMEM;
699	struct gpio_chip *gc = &mm_gc->gc;
700
701	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
702	if (!gc->label)
703		goto err0;
704
705	mm_gc->regs = of_iomap(np, 0);
706	if (!mm_gc->regs)
707		goto err1;
708
709	gc->base = -1;
710
711	if (mm_gc->save_regs)
712		mm_gc->save_regs(mm_gc);
713
714	mm_gc->gc.of_node = np;
 
715
716	ret = gpiochip_add_data(gc, data);
717	if (ret)
718		goto err2;
719
720	return 0;
721err2:
 
722	iounmap(mm_gc->regs);
723err1:
724	kfree(gc->label);
725err0:
726	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
727	return ret;
728}
729EXPORT_SYMBOL_GPL(of_mm_gpiochip_add_data);
730
731/**
732 * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
733 * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
734 */
735void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
736{
737	struct gpio_chip *gc = &mm_gc->gc;
738
739	if (!mm_gc)
740		return;
741
742	gpiochip_remove(gc);
743	iounmap(mm_gc->regs);
744	kfree(gc->label);
745}
746EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
747
748static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
749{
750	int len, i;
751	u32 start, count;
752	struct device_node *np = chip->of_node;
753
754	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
755	if (len < 0 || len % 2 != 0)
756		return;
757
758	for (i = 0; i < len; i += 2) {
759		of_property_read_u32_index(np, "gpio-reserved-ranges",
760					   i, &start);
761		of_property_read_u32_index(np, "gpio-reserved-ranges",
762					   i + 1, &count);
763		if (start >= chip->ngpio || start + count >= chip->ngpio)
764			continue;
765
766		bitmap_clear(chip->valid_mask, start, count);
767	}
768};
769
770#ifdef CONFIG_PINCTRL
771static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
772{
773	struct device_node *np = chip->of_node;
774	struct of_phandle_args pinspec;
775	struct pinctrl_dev *pctldev;
776	int index = 0, ret;
 
777	const char *name;
778	static const char group_names_propname[] = "gpio-ranges-group-names";
779	struct property *group_names;
780
 
781	if (!np)
782		return 0;
783
784	group_names = of_find_property(np, group_names_propname, NULL);
785
786	for (;; index++) {
787		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
788				index, &pinspec);
789		if (ret)
790			break;
791
792		pctldev = of_pinctrl_get(pinspec.np);
793		of_node_put(pinspec.np);
794		if (!pctldev)
795			return -EPROBE_DEFER;
796
 
 
 
 
 
 
797		if (pinspec.args[2]) {
798			if (group_names) {
 
799				of_property_read_string_index(np,
800						group_names_propname,
801						index, &name);
802				if (strlen(name)) {
803					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
804						np);
805					break;
806				}
807			}
808			/* npins != 0: linear range */
 
 
 
 
 
 
 
 
 
 
 
 
809			ret = gpiochip_add_pin_range(chip,
810					pinctrl_dev_get_devname(pctldev),
811					pinspec.args[0],
812					pinspec.args[1],
813					pinspec.args[2]);
814			if (ret)
815				return ret;
816		} else {
817			/* npins == 0: special range */
818			if (pinspec.args[1]) {
819				pr_err("%pOF: Illegal gpio-range format.\n",
820					np);
821				break;
822			}
823
824			if (!group_names) {
825				pr_err("%pOF: GPIO group range requested but no %s property.\n",
826					np, group_names_propname);
827				break;
828			}
829
830			ret = of_property_read_string_index(np,
831						group_names_propname,
832						index, &name);
833			if (ret)
834				break;
835
836			if (!strlen(name)) {
837				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
838				np);
839				break;
840			}
841
842			ret = gpiochip_add_pingroup_range(chip, pctldev,
843						pinspec.args[0], name);
844			if (ret)
845				return ret;
846		}
847	}
848
849	return 0;
850}
851
852#else
853static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
854#endif
855
856int of_gpiochip_add(struct gpio_chip *chip)
857{
 
858	int ret;
859
860	if (!chip->of_node)
 
861		return 0;
862
863	if (!chip->of_xlate) {
864		chip->of_gpio_n_cells = 2;
865		chip->of_xlate = of_gpio_simple_xlate;
866	}
867
868	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
869		return -EINVAL;
870
871	of_gpiochip_init_valid_mask(chip);
872
873	ret = of_gpiochip_add_pin_range(chip);
874	if (ret)
875		return ret;
876
877	/* If the chip defines names itself, these take precedence */
878	if (!chip->names)
879		devprop_gpiochip_set_names(chip,
880					   of_fwnode_handle(chip->of_node));
881
882	of_node_get(chip->of_node);
883
884	ret = of_gpiochip_scan_gpios(chip);
885	if (ret) {
886		of_node_put(chip->of_node);
887		gpiochip_remove_pin_ranges(chip);
888	}
889
890	return ret;
891}
892
893void of_gpiochip_remove(struct gpio_chip *chip)
894{
895	gpiochip_remove_pin_ranges(chip);
896	of_node_put(chip->of_node);
897}