xref: /openbmc/linux/drivers/gpio/gpiolib-of.c (revision e52a6321)
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 
25 static int of_gpiochip_match_node_and_xlate(struct gpio_chip *chip, void *data)
26 {
27 	struct of_phandle_args *gpiospec = data;
28 
29 	return chip->gpiodev->dev.of_node == gpiospec->np &&
30 				chip->of_xlate &&
31 				chip->of_xlate(chip, gpiospec, NULL) >= 0;
32 }
33 
34 static struct gpio_chip *of_find_gpiochip_by_xlate(
35 					struct of_phandle_args *gpiospec)
36 {
37 	return gpiochip_find(gpiospec, of_gpiochip_match_node_and_xlate);
38 }
39 
40 static struct gpio_desc *of_xlate_and_get_gpiod_flags(struct gpio_chip *chip,
41 					struct of_phandle_args *gpiospec,
42 					enum of_gpio_flags *flags)
43 {
44 	int ret;
45 
46 	if (chip->of_gpio_n_cells != gpiospec->args_count)
47 		return ERR_PTR(-EINVAL);
48 
49 	ret = chip->of_xlate(chip, gpiospec, flags);
50 	if (ret < 0)
51 		return ERR_PTR(ret);
52 
53 	return gpiochip_get_desc(chip, ret);
54 }
55 
56 static void of_gpio_flags_quirks(struct device_node *np,
57 				 const char *propname,
58 				 enum of_gpio_flags *flags,
59 				 int index)
60 {
61 	/*
62 	 * Handle MMC "cd-inverted" and "wp-inverted" semantics.
63 	 */
64 	if (IS_ENABLED(CONFIG_MMC)) {
65 		/*
66 		 * Active low is the default according to the
67 		 * SDHCI specification and the device tree
68 		 * bindings. However the code in the current
69 		 * kernel was written such that the phandle
70 		 * flags were always respected, and "cd-inverted"
71 		 * would invert the flag from the device phandle.
72 		 */
73 		if (!strcmp(propname, "cd-gpios")) {
74 			if (of_property_read_bool(np, "cd-inverted"))
75 				*flags ^= OF_GPIO_ACTIVE_LOW;
76 		}
77 		if (!strcmp(propname, "wp-gpios")) {
78 			if (of_property_read_bool(np, "wp-inverted"))
79 				*flags ^= OF_GPIO_ACTIVE_LOW;
80 		}
81 	}
82 	/*
83 	 * Some GPIO fixed regulator quirks.
84 	 * Note that active low is the default.
85 	 */
86 	if (IS_ENABLED(CONFIG_REGULATOR) &&
87 	    (of_device_is_compatible(np, "regulator-fixed") ||
88 	     of_device_is_compatible(np, "reg-fixed-voltage") ||
89 	     (!(strcmp(propname, "enable-gpio") &&
90 		strcmp(propname, "enable-gpios")) &&
91 	      of_device_is_compatible(np, "regulator-gpio")))) {
92 		/*
93 		 * The regulator GPIO handles are specified such that the
94 		 * presence or absence of "enable-active-high" solely controls
95 		 * the polarity of the GPIO line. Any phandle flags must
96 		 * be actively ignored.
97 		 */
98 		if (*flags & OF_GPIO_ACTIVE_LOW) {
99 			pr_warn("%s GPIO handle specifies active low - ignored\n",
100 				of_node_full_name(np));
101 			*flags &= ~OF_GPIO_ACTIVE_LOW;
102 		}
103 		if (!of_property_read_bool(np, "enable-active-high"))
104 			*flags |= OF_GPIO_ACTIVE_LOW;
105 	}
106 	/*
107 	 * Legacy open drain handling for fixed voltage regulators.
108 	 */
109 	if (IS_ENABLED(CONFIG_REGULATOR) &&
110 	    of_device_is_compatible(np, "reg-fixed-voltage") &&
111 	    of_property_read_bool(np, "gpio-open-drain")) {
112 		*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
113 		pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
114 			of_node_full_name(np));
115 	}
116 
117 	/*
118 	 * Legacy handling of SPI active high chip select. If we have a
119 	 * property named "cs-gpios" we need to inspect the child node
120 	 * to determine if the flags should have inverted semantics.
121 	 */
122 	if (IS_ENABLED(CONFIG_SPI_MASTER) && !strcmp(propname, "cs-gpios") &&
123 	    of_property_read_bool(np, "cs-gpios")) {
124 		struct device_node *child;
125 		u32 cs;
126 		int ret;
127 
128 		for_each_child_of_node(np, child) {
129 			ret = of_property_read_u32(child, "reg", &cs);
130 			if (ret)
131 				continue;
132 			if (cs == index) {
133 				/*
134 				 * SPI children have active low chip selects
135 				 * by default. This can be specified negatively
136 				 * by just omitting "spi-cs-high" in the
137 				 * device node, or actively by tagging on
138 				 * GPIO_ACTIVE_LOW as flag in the device
139 				 * tree. If the line is simultaneously
140 				 * tagged as active low in the device tree
141 				 * and has the "spi-cs-high" set, we get a
142 				 * conflict and the "spi-cs-high" flag will
143 				 * take precedence.
144 				 */
145 				if (of_property_read_bool(child, "spi-cs-high")) {
146 					if (*flags & OF_GPIO_ACTIVE_LOW) {
147 						pr_warn("%s GPIO handle specifies active low - ignored\n",
148 							of_node_full_name(child));
149 						*flags &= ~OF_GPIO_ACTIVE_LOW;
150 					}
151 				} else {
152 					if (!(*flags & OF_GPIO_ACTIVE_LOW))
153 						pr_info("%s enforce active low on chipselect handle\n",
154 							of_node_full_name(child));
155 					*flags |= OF_GPIO_ACTIVE_LOW;
156 				}
157 				of_node_put(child);
158 				break;
159 			}
160 		}
161 	}
162 
163 	/* Legacy handling of stmmac's active-low PHY reset line */
164 	if (IS_ENABLED(CONFIG_STMMAC_ETH) &&
165 	    !strcmp(propname, "snps,reset-gpio") &&
166 	    of_property_read_bool(np, "snps,reset-active-low"))
167 		*flags |= OF_GPIO_ACTIVE_LOW;
168 }
169 
170 /**
171  * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
172  * @np:		device node to get GPIO from
173  * @propname:	property name containing gpio specifier(s)
174  * @index:	index of the GPIO
175  * @flags:	a flags pointer to fill in
176  *
177  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
178  * value on the error condition. If @flags is not NULL the function also fills
179  * in flags for the GPIO.
180  */
181 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
182 		     const char *propname, int index, enum of_gpio_flags *flags)
183 {
184 	struct of_phandle_args gpiospec;
185 	struct gpio_chip *chip;
186 	struct gpio_desc *desc;
187 	int ret;
188 
189 	ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
190 					     &gpiospec);
191 	if (ret) {
192 		pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
193 			__func__, propname, np, index);
194 		return ERR_PTR(ret);
195 	}
196 
197 	chip = of_find_gpiochip_by_xlate(&gpiospec);
198 	if (!chip) {
199 		desc = ERR_PTR(-EPROBE_DEFER);
200 		goto out;
201 	}
202 
203 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
204 	if (IS_ERR(desc))
205 		goto out;
206 
207 	if (flags)
208 		of_gpio_flags_quirks(np, propname, flags, index);
209 
210 	pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
211 		 __func__, propname, np, index,
212 		 PTR_ERR_OR_ZERO(desc));
213 
214 out:
215 	of_node_put(gpiospec.np);
216 
217 	return desc;
218 }
219 
220 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
221 			    int index, enum of_gpio_flags *flags)
222 {
223 	struct gpio_desc *desc;
224 
225 	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
226 
227 	if (IS_ERR(desc))
228 		return PTR_ERR(desc);
229 	else
230 		return desc_to_gpio(desc);
231 }
232 EXPORT_SYMBOL(of_get_named_gpio_flags);
233 
234 /*
235  * The SPI GPIO bindings happened before we managed to establish that GPIO
236  * properties should be named "foo-gpios" so we have this special kludge for
237  * them.
238  */
239 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
240 					  enum of_gpio_flags *of_flags)
241 {
242 	char prop_name[32]; /* 32 is max size of property name */
243 	struct device_node *np = dev->of_node;
244 	struct gpio_desc *desc;
245 
246 	/*
247 	 * Hopefully the compiler stubs the rest of the function if this
248 	 * is false.
249 	 */
250 	if (!IS_ENABLED(CONFIG_SPI_MASTER))
251 		return ERR_PTR(-ENOENT);
252 
253 	/* Allow this specifically for "spi-gpio" devices */
254 	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
255 		return ERR_PTR(-ENOENT);
256 
257 	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
258 	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
259 
260 	desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
261 	return desc;
262 }
263 
264 /*
265  * The old Freescale bindings use simply "gpios" as name for the chip select
266  * lines rather than "cs-gpios" like all other SPI hardware. Account for this
267  * with a special quirk.
268  */
269 static struct gpio_desc *of_find_spi_cs_gpio(struct device *dev,
270 					     const char *con_id,
271 					     unsigned int idx,
272 					     unsigned long *flags)
273 {
274 	struct device_node *np = dev->of_node;
275 
276 	if (!IS_ENABLED(CONFIG_SPI_MASTER))
277 		return ERR_PTR(-ENOENT);
278 
279 	/* Allow this specifically for Freescale devices */
280 	if (!of_device_is_compatible(np, "fsl,spi") &&
281 	    !of_device_is_compatible(np, "aeroflexgaisler,spictrl"))
282 		return ERR_PTR(-ENOENT);
283 	/* Allow only if asking for "cs-gpios" */
284 	if (!con_id || strcmp(con_id, "cs"))
285 		return ERR_PTR(-ENOENT);
286 
287 	/*
288 	 * While all other SPI controllers use "cs-gpios" the Freescale
289 	 * uses just "gpios" so translate to that when "cs-gpios" is
290 	 * requested.
291 	 */
292 	return of_find_gpio(dev, NULL, idx, flags);
293 }
294 
295 /*
296  * Some regulator bindings happened before we managed to establish that GPIO
297  * properties should be named "foo-gpios" so we have this special kludge for
298  * them.
299  */
300 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
301 						enum of_gpio_flags *of_flags)
302 {
303 	/* These are the connection IDs we accept as legacy GPIO phandles */
304 	const char *whitelist[] = {
305 		"wlf,ldoena", /* Arizona */
306 		"wlf,ldo1ena", /* WM8994 */
307 		"wlf,ldo2ena", /* WM8994 */
308 	};
309 	struct device_node *np = dev->of_node;
310 	struct gpio_desc *desc;
311 	int i;
312 
313 	if (!IS_ENABLED(CONFIG_REGULATOR))
314 		return ERR_PTR(-ENOENT);
315 
316 	if (!con_id)
317 		return ERR_PTR(-ENOENT);
318 
319 	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
320 	if (i < 0)
321 		return ERR_PTR(-ENOENT);
322 
323 	desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
324 	return desc;
325 }
326 
327 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
328 			       unsigned int idx, unsigned long *flags)
329 {
330 	char prop_name[32]; /* 32 is max size of property name */
331 	enum of_gpio_flags of_flags;
332 	struct gpio_desc *desc;
333 	unsigned int i;
334 
335 	/* Try GPIO property "foo-gpios" and "foo-gpio" */
336 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
337 		if (con_id)
338 			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
339 				 gpio_suffixes[i]);
340 		else
341 			snprintf(prop_name, sizeof(prop_name), "%s",
342 				 gpio_suffixes[i]);
343 
344 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
345 						&of_flags);
346 		/*
347 		 * -EPROBE_DEFER in our case means that we found a
348 		 * valid GPIO property, but no controller has been
349 		 * registered so far.
350 		 *
351 		 * This means we don't need to look any further for
352 		 * alternate name conventions, and we should really
353 		 * preserve the return code for our user to be able to
354 		 * retry probing later.
355 		 */
356 		if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
357 			return desc;
358 
359 		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
360 			break;
361 	}
362 
363 	/* Special handling for SPI GPIOs if used */
364 	if (IS_ERR(desc))
365 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
366 	if (IS_ERR(desc)) {
367 		/* This quirk looks up flags and all */
368 		desc = of_find_spi_cs_gpio(dev, con_id, idx, flags);
369 		if (!IS_ERR(desc))
370 			return desc;
371 	}
372 
373 	/* Special handling for regulator GPIOs if used */
374 	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
375 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
376 
377 	if (IS_ERR(desc))
378 		return desc;
379 
380 	if (of_flags & OF_GPIO_ACTIVE_LOW)
381 		*flags |= GPIO_ACTIVE_LOW;
382 
383 	if (of_flags & OF_GPIO_SINGLE_ENDED) {
384 		if (of_flags & OF_GPIO_OPEN_DRAIN)
385 			*flags |= GPIO_OPEN_DRAIN;
386 		else
387 			*flags |= GPIO_OPEN_SOURCE;
388 	}
389 
390 	if (of_flags & OF_GPIO_TRANSITORY)
391 		*flags |= GPIO_TRANSITORY;
392 
393 	if (of_flags & OF_GPIO_PULL_UP)
394 		*flags |= GPIO_PULL_UP;
395 	if (of_flags & OF_GPIO_PULL_DOWN)
396 		*flags |= GPIO_PULL_DOWN;
397 
398 	return desc;
399 }
400 
401 /**
402  * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
403  * @np:		device node to get GPIO from
404  * @chip:	GPIO chip whose hog is parsed
405  * @idx:	Index of the GPIO to parse
406  * @name:	GPIO line name
407  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
408  *		of_find_gpio() or of_parse_own_gpio()
409  * @dflags:	gpiod_flags - optional GPIO initialization flags
410  *
411  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
412  * value on the error condition.
413  */
414 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
415 					   struct gpio_chip *chip,
416 					   unsigned int idx, const char **name,
417 					   unsigned long *lflags,
418 					   enum gpiod_flags *dflags)
419 {
420 	struct device_node *chip_np;
421 	enum of_gpio_flags xlate_flags;
422 	struct of_phandle_args gpiospec;
423 	struct gpio_desc *desc;
424 	unsigned int i;
425 	u32 tmp;
426 	int ret;
427 
428 	chip_np = chip->of_node;
429 	if (!chip_np)
430 		return ERR_PTR(-EINVAL);
431 
432 	xlate_flags = 0;
433 	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
434 	*dflags = 0;
435 
436 	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
437 	if (ret)
438 		return ERR_PTR(ret);
439 
440 	gpiospec.np = chip_np;
441 	gpiospec.args_count = tmp;
442 
443 	for (i = 0; i < tmp; i++) {
444 		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
445 						 &gpiospec.args[i]);
446 		if (ret)
447 			return ERR_PTR(ret);
448 	}
449 
450 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
451 	if (IS_ERR(desc))
452 		return desc;
453 
454 	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
455 		*lflags |= GPIO_ACTIVE_LOW;
456 	if (xlate_flags & OF_GPIO_TRANSITORY)
457 		*lflags |= GPIO_TRANSITORY;
458 
459 	if (of_property_read_bool(np, "input"))
460 		*dflags |= GPIOD_IN;
461 	else if (of_property_read_bool(np, "output-low"))
462 		*dflags |= GPIOD_OUT_LOW;
463 	else if (of_property_read_bool(np, "output-high"))
464 		*dflags |= GPIOD_OUT_HIGH;
465 	else {
466 		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
467 			desc_to_gpio(desc), np);
468 		return ERR_PTR(-EINVAL);
469 	}
470 
471 	if (name && of_property_read_string(np, "line-name", name))
472 		*name = np->name;
473 
474 	return desc;
475 }
476 
477 /**
478  * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
479  * @chip:	gpio chip to act on
480  *
481  * This is only used by of_gpiochip_add to request/set GPIO initial
482  * configuration.
483  * It returns error if it fails otherwise 0 on success.
484  */
485 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
486 {
487 	struct gpio_desc *desc = NULL;
488 	struct device_node *np;
489 	const char *name;
490 	unsigned long lflags;
491 	enum gpiod_flags dflags;
492 	unsigned int i;
493 	int ret;
494 
495 	for_each_available_child_of_node(chip->of_node, np) {
496 		if (!of_property_read_bool(np, "gpio-hog"))
497 			continue;
498 
499 		for (i = 0;; i++) {
500 			desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
501 						 &dflags);
502 			if (IS_ERR(desc))
503 				break;
504 
505 			ret = gpiod_hog(desc, name, lflags, dflags);
506 			if (ret < 0) {
507 				of_node_put(np);
508 				return ret;
509 			}
510 		}
511 	}
512 
513 	return 0;
514 }
515 
516 /**
517  * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
518  * @gc:		pointer to the gpio_chip structure
519  * @gpiospec:	GPIO specifier as found in the device tree
520  * @flags:	a flags pointer to fill in
521  *
522  * This is simple translation function, suitable for the most 1:1 mapped
523  * GPIO chips. This function performs only one sanity check: whether GPIO
524  * is less than ngpios (that is specified in the gpio_chip).
525  */
526 int of_gpio_simple_xlate(struct gpio_chip *gc,
527 			 const struct of_phandle_args *gpiospec, u32 *flags)
528 {
529 	/*
530 	 * We're discouraging gpio_cells < 2, since that way you'll have to
531 	 * write your own xlate function (that will have to retrieve the GPIO
532 	 * number and the flags from a single gpio cell -- this is possible,
533 	 * but not recommended).
534 	 */
535 	if (gc->of_gpio_n_cells < 2) {
536 		WARN_ON(1);
537 		return -EINVAL;
538 	}
539 
540 	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
541 		return -EINVAL;
542 
543 	if (gpiospec->args[0] >= gc->ngpio)
544 		return -EINVAL;
545 
546 	if (flags)
547 		*flags = gpiospec->args[1];
548 
549 	return gpiospec->args[0];
550 }
551 EXPORT_SYMBOL(of_gpio_simple_xlate);
552 
553 /**
554  * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
555  * @np:		device node of the GPIO chip
556  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
557  * @data:	driver data to store in the struct gpio_chip
558  *
559  * To use this function you should allocate and fill mm_gc with:
560  *
561  * 1) In the gpio_chip structure:
562  *    - all the callbacks
563  *    - of_gpio_n_cells
564  *    - of_xlate callback (optional)
565  *
566  * 3) In the of_mm_gpio_chip structure:
567  *    - save_regs callback (optional)
568  *
569  * If succeeded, this function will map bank's memory and will
570  * do all necessary work for you. Then you'll able to use .regs
571  * to manage GPIOs from the callbacks.
572  */
573 int of_mm_gpiochip_add_data(struct device_node *np,
574 			    struct of_mm_gpio_chip *mm_gc,
575 			    void *data)
576 {
577 	int ret = -ENOMEM;
578 	struct gpio_chip *gc = &mm_gc->gc;
579 
580 	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
581 	if (!gc->label)
582 		goto err0;
583 
584 	mm_gc->regs = of_iomap(np, 0);
585 	if (!mm_gc->regs)
586 		goto err1;
587 
588 	gc->base = -1;
589 
590 	if (mm_gc->save_regs)
591 		mm_gc->save_regs(mm_gc);
592 
593 	mm_gc->gc.of_node = np;
594 
595 	ret = gpiochip_add_data(gc, data);
596 	if (ret)
597 		goto err2;
598 
599 	return 0;
600 err2:
601 	iounmap(mm_gc->regs);
602 err1:
603 	kfree(gc->label);
604 err0:
605 	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
606 	return ret;
607 }
608 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
609 
610 /**
611  * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
612  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
613  */
614 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
615 {
616 	struct gpio_chip *gc = &mm_gc->gc;
617 
618 	if (!mm_gc)
619 		return;
620 
621 	gpiochip_remove(gc);
622 	iounmap(mm_gc->regs);
623 	kfree(gc->label);
624 }
625 EXPORT_SYMBOL(of_mm_gpiochip_remove);
626 
627 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
628 {
629 	int len, i;
630 	u32 start, count;
631 	struct device_node *np = chip->of_node;
632 
633 	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
634 	if (len < 0 || len % 2 != 0)
635 		return;
636 
637 	for (i = 0; i < len; i += 2) {
638 		of_property_read_u32_index(np, "gpio-reserved-ranges",
639 					   i, &start);
640 		of_property_read_u32_index(np, "gpio-reserved-ranges",
641 					   i + 1, &count);
642 		if (start >= chip->ngpio || start + count >= chip->ngpio)
643 			continue;
644 
645 		bitmap_clear(chip->valid_mask, start, count);
646 	}
647 };
648 
649 #ifdef CONFIG_PINCTRL
650 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
651 {
652 	struct device_node *np = chip->of_node;
653 	struct of_phandle_args pinspec;
654 	struct pinctrl_dev *pctldev;
655 	int index = 0, ret;
656 	const char *name;
657 	static const char group_names_propname[] = "gpio-ranges-group-names";
658 	struct property *group_names;
659 
660 	if (!np)
661 		return 0;
662 
663 	group_names = of_find_property(np, group_names_propname, NULL);
664 
665 	for (;; index++) {
666 		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
667 				index, &pinspec);
668 		if (ret)
669 			break;
670 
671 		pctldev = of_pinctrl_get(pinspec.np);
672 		of_node_put(pinspec.np);
673 		if (!pctldev)
674 			return -EPROBE_DEFER;
675 
676 		if (pinspec.args[2]) {
677 			if (group_names) {
678 				of_property_read_string_index(np,
679 						group_names_propname,
680 						index, &name);
681 				if (strlen(name)) {
682 					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
683 						np);
684 					break;
685 				}
686 			}
687 			/* npins != 0: linear range */
688 			ret = gpiochip_add_pin_range(chip,
689 					pinctrl_dev_get_devname(pctldev),
690 					pinspec.args[0],
691 					pinspec.args[1],
692 					pinspec.args[2]);
693 			if (ret)
694 				return ret;
695 		} else {
696 			/* npins == 0: special range */
697 			if (pinspec.args[1]) {
698 				pr_err("%pOF: Illegal gpio-range format.\n",
699 					np);
700 				break;
701 			}
702 
703 			if (!group_names) {
704 				pr_err("%pOF: GPIO group range requested but no %s property.\n",
705 					np, group_names_propname);
706 				break;
707 			}
708 
709 			ret = of_property_read_string_index(np,
710 						group_names_propname,
711 						index, &name);
712 			if (ret)
713 				break;
714 
715 			if (!strlen(name)) {
716 				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
717 				np);
718 				break;
719 			}
720 
721 			ret = gpiochip_add_pingroup_range(chip, pctldev,
722 						pinspec.args[0], name);
723 			if (ret)
724 				return ret;
725 		}
726 	}
727 
728 	return 0;
729 }
730 
731 #else
732 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
733 #endif
734 
735 int of_gpiochip_add(struct gpio_chip *chip)
736 {
737 	int status;
738 
739 	if (!chip->of_node)
740 		return 0;
741 
742 	if (!chip->of_xlate) {
743 		chip->of_gpio_n_cells = 2;
744 		chip->of_xlate = of_gpio_simple_xlate;
745 	}
746 
747 	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
748 		return -EINVAL;
749 
750 	of_gpiochip_init_valid_mask(chip);
751 
752 	status = of_gpiochip_add_pin_range(chip);
753 	if (status)
754 		return status;
755 
756 	/* If the chip defines names itself, these take precedence */
757 	if (!chip->names)
758 		devprop_gpiochip_set_names(chip,
759 					   of_fwnode_handle(chip->of_node));
760 
761 	of_node_get(chip->of_node);
762 
763 	status = of_gpiochip_scan_gpios(chip);
764 	if (status) {
765 		of_node_put(chip->of_node);
766 		gpiochip_remove_pin_ranges(chip);
767 	}
768 
769 	return status;
770 }
771 
772 void of_gpiochip_remove(struct gpio_chip *chip)
773 {
774 	gpiochip_remove_pin_ranges(chip);
775 	of_node_put(chip->of_node);
776 }
777