xref: /linux/drivers/gpio/gpiolib-of.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
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 				break;
158 			}
159 		}
160 	}
161 }
162 
163 /**
164  * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
165  * @np:		device node to get GPIO from
166  * @propname:	property name containing gpio specifier(s)
167  * @index:	index of the GPIO
168  * @flags:	a flags pointer to fill in
169  *
170  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
171  * value on the error condition. If @flags is not NULL the function also fills
172  * in flags for the GPIO.
173  */
174 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
175 		     const char *propname, int index, enum of_gpio_flags *flags)
176 {
177 	struct of_phandle_args gpiospec;
178 	struct gpio_chip *chip;
179 	struct gpio_desc *desc;
180 	int ret;
181 
182 	ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
183 					     &gpiospec);
184 	if (ret) {
185 		pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
186 			__func__, propname, np, index);
187 		return ERR_PTR(ret);
188 	}
189 
190 	chip = of_find_gpiochip_by_xlate(&gpiospec);
191 	if (!chip) {
192 		desc = ERR_PTR(-EPROBE_DEFER);
193 		goto out;
194 	}
195 
196 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
197 	if (IS_ERR(desc))
198 		goto out;
199 
200 	if (flags)
201 		of_gpio_flags_quirks(np, propname, flags, index);
202 
203 	pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
204 		 __func__, propname, np, index,
205 		 PTR_ERR_OR_ZERO(desc));
206 
207 out:
208 	of_node_put(gpiospec.np);
209 
210 	return desc;
211 }
212 
213 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
214 			    int index, enum of_gpio_flags *flags)
215 {
216 	struct gpio_desc *desc;
217 
218 	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
219 
220 	if (IS_ERR(desc))
221 		return PTR_ERR(desc);
222 	else
223 		return desc_to_gpio(desc);
224 }
225 EXPORT_SYMBOL(of_get_named_gpio_flags);
226 
227 /*
228  * The SPI GPIO bindings happened before we managed to establish that GPIO
229  * properties should be named "foo-gpios" so we have this special kludge for
230  * them.
231  */
232 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
233 					  enum of_gpio_flags *of_flags)
234 {
235 	char prop_name[32]; /* 32 is max size of property name */
236 	struct device_node *np = dev->of_node;
237 	struct gpio_desc *desc;
238 
239 	/*
240 	 * Hopefully the compiler stubs the rest of the function if this
241 	 * is false.
242 	 */
243 	if (!IS_ENABLED(CONFIG_SPI_MASTER))
244 		return ERR_PTR(-ENOENT);
245 
246 	/* Allow this specifically for "spi-gpio" devices */
247 	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
248 		return ERR_PTR(-ENOENT);
249 
250 	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
251 	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
252 
253 	desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
254 	return desc;
255 }
256 
257 /*
258  * Some regulator bindings happened before we managed to establish that GPIO
259  * properties should be named "foo-gpios" so we have this special kludge for
260  * them.
261  */
262 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
263 						enum of_gpio_flags *of_flags)
264 {
265 	/* These are the connection IDs we accept as legacy GPIO phandles */
266 	const char *whitelist[] = {
267 		"wlf,ldoena", /* Arizona */
268 		"wlf,ldo1ena", /* WM8994 */
269 		"wlf,ldo2ena", /* WM8994 */
270 	};
271 	struct device_node *np = dev->of_node;
272 	struct gpio_desc *desc;
273 	int i;
274 
275 	if (!IS_ENABLED(CONFIG_REGULATOR))
276 		return ERR_PTR(-ENOENT);
277 
278 	if (!con_id)
279 		return ERR_PTR(-ENOENT);
280 
281 	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
282 	if (i < 0)
283 		return ERR_PTR(-ENOENT);
284 
285 	desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
286 	return desc;
287 }
288 
289 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
290 			       unsigned int idx, unsigned long *flags)
291 {
292 	char prop_name[32]; /* 32 is max size of property name */
293 	enum of_gpio_flags of_flags;
294 	struct gpio_desc *desc;
295 	unsigned int i;
296 
297 	/* Try GPIO property "foo-gpios" and "foo-gpio" */
298 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
299 		if (con_id)
300 			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
301 				 gpio_suffixes[i]);
302 		else
303 			snprintf(prop_name, sizeof(prop_name), "%s",
304 				 gpio_suffixes[i]);
305 
306 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
307 						&of_flags);
308 		/*
309 		 * -EPROBE_DEFER in our case means that we found a
310 		 * valid GPIO property, but no controller has been
311 		 * registered so far.
312 		 *
313 		 * This means we don't need to look any further for
314 		 * alternate name conventions, and we should really
315 		 * preserve the return code for our user to be able to
316 		 * retry probing later.
317 		 */
318 		if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
319 			return desc;
320 
321 		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
322 			break;
323 	}
324 
325 	/* Special handling for SPI GPIOs if used */
326 	if (IS_ERR(desc))
327 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
328 
329 	/* Special handling for regulator GPIOs if used */
330 	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
331 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
332 
333 	if (IS_ERR(desc))
334 		return desc;
335 
336 	if (of_flags & OF_GPIO_ACTIVE_LOW)
337 		*flags |= GPIO_ACTIVE_LOW;
338 
339 	if (of_flags & OF_GPIO_SINGLE_ENDED) {
340 		if (of_flags & OF_GPIO_OPEN_DRAIN)
341 			*flags |= GPIO_OPEN_DRAIN;
342 		else
343 			*flags |= GPIO_OPEN_SOURCE;
344 	}
345 
346 	if (of_flags & OF_GPIO_TRANSITORY)
347 		*flags |= GPIO_TRANSITORY;
348 
349 	if (of_flags & OF_GPIO_PULL_UP)
350 		*flags |= GPIO_PULL_UP;
351 	if (of_flags & OF_GPIO_PULL_DOWN)
352 		*flags |= GPIO_PULL_DOWN;
353 
354 	return desc;
355 }
356 
357 /**
358  * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
359  * @np:		device node to get GPIO from
360  * @chip:	GPIO chip whose hog is parsed
361  * @idx:	Index of the GPIO to parse
362  * @name:	GPIO line name
363  * @lflags:	bitmask of gpio_lookup_flags GPIO_* values - returned from
364  *		of_find_gpio() or of_parse_own_gpio()
365  * @dflags:	gpiod_flags - optional GPIO initialization flags
366  *
367  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
368  * value on the error condition.
369  */
370 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
371 					   struct gpio_chip *chip,
372 					   unsigned int idx, const char **name,
373 					   unsigned long *lflags,
374 					   enum gpiod_flags *dflags)
375 {
376 	struct device_node *chip_np;
377 	enum of_gpio_flags xlate_flags;
378 	struct of_phandle_args gpiospec;
379 	struct gpio_desc *desc;
380 	unsigned int i;
381 	u32 tmp;
382 	int ret;
383 
384 	chip_np = chip->of_node;
385 	if (!chip_np)
386 		return ERR_PTR(-EINVAL);
387 
388 	xlate_flags = 0;
389 	*lflags = GPIO_LOOKUP_FLAGS_DEFAULT;
390 	*dflags = 0;
391 
392 	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
393 	if (ret)
394 		return ERR_PTR(ret);
395 
396 	gpiospec.np = chip_np;
397 	gpiospec.args_count = tmp;
398 
399 	for (i = 0; i < tmp; i++) {
400 		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
401 						 &gpiospec.args[i]);
402 		if (ret)
403 			return ERR_PTR(ret);
404 	}
405 
406 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
407 	if (IS_ERR(desc))
408 		return desc;
409 
410 	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
411 		*lflags |= GPIO_ACTIVE_LOW;
412 	if (xlate_flags & OF_GPIO_TRANSITORY)
413 		*lflags |= GPIO_TRANSITORY;
414 
415 	if (of_property_read_bool(np, "input"))
416 		*dflags |= GPIOD_IN;
417 	else if (of_property_read_bool(np, "output-low"))
418 		*dflags |= GPIOD_OUT_LOW;
419 	else if (of_property_read_bool(np, "output-high"))
420 		*dflags |= GPIOD_OUT_HIGH;
421 	else {
422 		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
423 			desc_to_gpio(desc), np);
424 		return ERR_PTR(-EINVAL);
425 	}
426 
427 	if (name && of_property_read_string(np, "line-name", name))
428 		*name = np->name;
429 
430 	return desc;
431 }
432 
433 /**
434  * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
435  * @chip:	gpio chip to act on
436  *
437  * This is only used by of_gpiochip_add to request/set GPIO initial
438  * configuration.
439  * It returns error if it fails otherwise 0 on success.
440  */
441 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
442 {
443 	struct gpio_desc *desc = NULL;
444 	struct device_node *np;
445 	const char *name;
446 	unsigned long lflags;
447 	enum gpiod_flags dflags;
448 	unsigned int i;
449 	int ret;
450 
451 	for_each_available_child_of_node(chip->of_node, np) {
452 		if (!of_property_read_bool(np, "gpio-hog"))
453 			continue;
454 
455 		for (i = 0;; i++) {
456 			desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
457 						 &dflags);
458 			if (IS_ERR(desc))
459 				break;
460 
461 			ret = gpiod_hog(desc, name, lflags, dflags);
462 			if (ret < 0) {
463 				of_node_put(np);
464 				return ret;
465 			}
466 		}
467 	}
468 
469 	return 0;
470 }
471 
472 /**
473  * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
474  * @gc:		pointer to the gpio_chip structure
475  * @gpiospec:	GPIO specifier as found in the device tree
476  * @flags:	a flags pointer to fill in
477  *
478  * This is simple translation function, suitable for the most 1:1 mapped
479  * GPIO chips. This function performs only one sanity check: whether GPIO
480  * is less than ngpios (that is specified in the gpio_chip).
481  */
482 int of_gpio_simple_xlate(struct gpio_chip *gc,
483 			 const struct of_phandle_args *gpiospec, u32 *flags)
484 {
485 	/*
486 	 * We're discouraging gpio_cells < 2, since that way you'll have to
487 	 * write your own xlate function (that will have to retrieve the GPIO
488 	 * number and the flags from a single gpio cell -- this is possible,
489 	 * but not recommended).
490 	 */
491 	if (gc->of_gpio_n_cells < 2) {
492 		WARN_ON(1);
493 		return -EINVAL;
494 	}
495 
496 	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
497 		return -EINVAL;
498 
499 	if (gpiospec->args[0] >= gc->ngpio)
500 		return -EINVAL;
501 
502 	if (flags)
503 		*flags = gpiospec->args[1];
504 
505 	return gpiospec->args[0];
506 }
507 EXPORT_SYMBOL(of_gpio_simple_xlate);
508 
509 /**
510  * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
511  * @np:		device node of the GPIO chip
512  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
513  * @data:	driver data to store in the struct gpio_chip
514  *
515  * To use this function you should allocate and fill mm_gc with:
516  *
517  * 1) In the gpio_chip structure:
518  *    - all the callbacks
519  *    - of_gpio_n_cells
520  *    - of_xlate callback (optional)
521  *
522  * 3) In the of_mm_gpio_chip structure:
523  *    - save_regs callback (optional)
524  *
525  * If succeeded, this function will map bank's memory and will
526  * do all necessary work for you. Then you'll able to use .regs
527  * to manage GPIOs from the callbacks.
528  */
529 int of_mm_gpiochip_add_data(struct device_node *np,
530 			    struct of_mm_gpio_chip *mm_gc,
531 			    void *data)
532 {
533 	int ret = -ENOMEM;
534 	struct gpio_chip *gc = &mm_gc->gc;
535 
536 	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
537 	if (!gc->label)
538 		goto err0;
539 
540 	mm_gc->regs = of_iomap(np, 0);
541 	if (!mm_gc->regs)
542 		goto err1;
543 
544 	gc->base = -1;
545 
546 	if (mm_gc->save_regs)
547 		mm_gc->save_regs(mm_gc);
548 
549 	mm_gc->gc.of_node = np;
550 
551 	ret = gpiochip_add_data(gc, data);
552 	if (ret)
553 		goto err2;
554 
555 	return 0;
556 err2:
557 	iounmap(mm_gc->regs);
558 err1:
559 	kfree(gc->label);
560 err0:
561 	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
562 	return ret;
563 }
564 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
565 
566 /**
567  * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
568  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
569  */
570 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
571 {
572 	struct gpio_chip *gc = &mm_gc->gc;
573 
574 	if (!mm_gc)
575 		return;
576 
577 	gpiochip_remove(gc);
578 	iounmap(mm_gc->regs);
579 	kfree(gc->label);
580 }
581 EXPORT_SYMBOL(of_mm_gpiochip_remove);
582 
583 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
584 {
585 	int len, i;
586 	u32 start, count;
587 	struct device_node *np = chip->of_node;
588 
589 	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
590 	if (len < 0 || len % 2 != 0)
591 		return;
592 
593 	for (i = 0; i < len; i += 2) {
594 		of_property_read_u32_index(np, "gpio-reserved-ranges",
595 					   i, &start);
596 		of_property_read_u32_index(np, "gpio-reserved-ranges",
597 					   i + 1, &count);
598 		if (start >= chip->ngpio || start + count >= chip->ngpio)
599 			continue;
600 
601 		bitmap_clear(chip->valid_mask, start, count);
602 	}
603 };
604 
605 #ifdef CONFIG_PINCTRL
606 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
607 {
608 	struct device_node *np = chip->of_node;
609 	struct of_phandle_args pinspec;
610 	struct pinctrl_dev *pctldev;
611 	int index = 0, ret;
612 	const char *name;
613 	static const char group_names_propname[] = "gpio-ranges-group-names";
614 	struct property *group_names;
615 
616 	if (!np)
617 		return 0;
618 
619 	group_names = of_find_property(np, group_names_propname, NULL);
620 
621 	for (;; index++) {
622 		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
623 				index, &pinspec);
624 		if (ret)
625 			break;
626 
627 		pctldev = of_pinctrl_get(pinspec.np);
628 		of_node_put(pinspec.np);
629 		if (!pctldev)
630 			return -EPROBE_DEFER;
631 
632 		if (pinspec.args[2]) {
633 			if (group_names) {
634 				of_property_read_string_index(np,
635 						group_names_propname,
636 						index, &name);
637 				if (strlen(name)) {
638 					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
639 						np);
640 					break;
641 				}
642 			}
643 			/* npins != 0: linear range */
644 			ret = gpiochip_add_pin_range(chip,
645 					pinctrl_dev_get_devname(pctldev),
646 					pinspec.args[0],
647 					pinspec.args[1],
648 					pinspec.args[2]);
649 			if (ret)
650 				return ret;
651 		} else {
652 			/* npins == 0: special range */
653 			if (pinspec.args[1]) {
654 				pr_err("%pOF: Illegal gpio-range format.\n",
655 					np);
656 				break;
657 			}
658 
659 			if (!group_names) {
660 				pr_err("%pOF: GPIO group range requested but no %s property.\n",
661 					np, group_names_propname);
662 				break;
663 			}
664 
665 			ret = of_property_read_string_index(np,
666 						group_names_propname,
667 						index, &name);
668 			if (ret)
669 				break;
670 
671 			if (!strlen(name)) {
672 				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
673 				np);
674 				break;
675 			}
676 
677 			ret = gpiochip_add_pingroup_range(chip, pctldev,
678 						pinspec.args[0], name);
679 			if (ret)
680 				return ret;
681 		}
682 	}
683 
684 	return 0;
685 }
686 
687 #else
688 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
689 #endif
690 
691 int of_gpiochip_add(struct gpio_chip *chip)
692 {
693 	int status;
694 
695 	if (!chip->of_node)
696 		return 0;
697 
698 	if (!chip->of_xlate) {
699 		chip->of_gpio_n_cells = 2;
700 		chip->of_xlate = of_gpio_simple_xlate;
701 	}
702 
703 	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
704 		return -EINVAL;
705 
706 	of_gpiochip_init_valid_mask(chip);
707 
708 	status = of_gpiochip_add_pin_range(chip);
709 	if (status)
710 		return status;
711 
712 	/* If the chip defines names itself, these take precedence */
713 	if (!chip->names)
714 		devprop_gpiochip_set_names(chip,
715 					   of_fwnode_handle(chip->of_node));
716 
717 	of_node_get(chip->of_node);
718 
719 	status = of_gpiochip_scan_gpios(chip);
720 	if (status) {
721 		of_node_put(chip->of_node);
722 		gpiochip_remove_pin_ranges(chip);
723 	}
724 
725 	return status;
726 }
727 
728 void of_gpiochip_remove(struct gpio_chip *chip)
729 {
730 	gpiochip_remove_pin_ranges(chip);
731 	of_node_put(chip->of_node);
732 }
733