xref: /linux/drivers/gpio/gpiolib-of.c (revision f4db95b68ae68ebaf91d35cc0487ac1cbd04261e)
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  */
33 enum 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  */
66 static 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  */
89 static 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 
103 int 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 
121 static 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 
131 static struct gpio_device *
132 of_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 
137 static 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  */
157 static 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  */
179 static 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 
236 static 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 
315 static 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_read_bool(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  */
389 static 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 
423 out:
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  */
441 int 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 }
453 EXPORT_SYMBOL_GPL(of_get_named_gpio);
454 
455 /* Converts gpio_lookup_flags into bitmask of GPIO_* values */
456 static 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 
485 static 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 
617 static 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  */
655 static 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 
676 typedef 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);
680 static 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 
687 struct 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  */
728 static 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  */
796 static 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  */
832 static 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  */
856 static 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 
866 static 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 
871 static 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 
876 static 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 
926 struct 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  */
944 static 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  */
996 int 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;
1024 err2:
1025 	of_node_put(np);
1026 	iounmap(mm_gc->regs);
1027 err1:
1028 	kfree(gc->label);
1029 err0:
1030 	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
1031 	return ret;
1032 }
1033 EXPORT_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  */
1039 void 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 }
1047 EXPORT_SYMBOL_GPL(of_mm_gpiochip_remove);
1048 #endif
1049 
1050 #ifdef CONFIG_PINCTRL
1051 static 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
1153 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
1154 #endif
1155 
1156 int 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 
1186 void of_gpiochip_remove(struct gpio_chip *chip)
1187 {
1188 	of_node_put(dev_of_node(&chip->gpiodev->dev));
1189 }
1190