xref: /openbmc/linux/drivers/gpio/gpiolib-of.c (revision 9fb29c73)
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 	     of_device_is_compatible(np, "regulator-gpio"))) {
90 		/*
91 		 * The regulator GPIO handles are specified such that the
92 		 * presence or absence of "enable-active-high" solely controls
93 		 * the polarity of the GPIO line. Any phandle flags must
94 		 * be actively ignored.
95 		 */
96 		if (*flags & OF_GPIO_ACTIVE_LOW) {
97 			pr_warn("%s GPIO handle specifies active low - ignored\n",
98 				of_node_full_name(np));
99 			*flags &= ~OF_GPIO_ACTIVE_LOW;
100 		}
101 		if (!of_property_read_bool(np, "enable-active-high"))
102 			*flags |= OF_GPIO_ACTIVE_LOW;
103 	}
104 	/*
105 	 * Legacy open drain handling for fixed voltage regulators.
106 	 */
107 	if (IS_ENABLED(CONFIG_REGULATOR) &&
108 	    of_device_is_compatible(np, "reg-fixed-voltage") &&
109 	    of_property_read_bool(np, "gpio-open-drain")) {
110 		*flags |= (OF_GPIO_SINGLE_ENDED | OF_GPIO_OPEN_DRAIN);
111 		pr_info("%s uses legacy open drain flag - update the DTS if you can\n",
112 			of_node_full_name(np));
113 	}
114 
115 	/*
116 	 * Legacy handling of SPI active high chip select. If we have a
117 	 * property named "cs-gpios" we need to inspect the child node
118 	 * to determine if the flags should have inverted semantics.
119 	 */
120 	if (IS_ENABLED(CONFIG_SPI_MASTER) &&
121 	    of_property_read_bool(np, "cs-gpios")) {
122 		struct device_node *child;
123 		u32 cs;
124 		int ret;
125 
126 		for_each_child_of_node(np, child) {
127 			ret = of_property_read_u32(child, "reg", &cs);
128 			if (!ret)
129 				continue;
130 			if (cs == index) {
131 				/*
132 				 * SPI children have active low chip selects
133 				 * by default. This can be specified negatively
134 				 * by just omitting "spi-cs-high" in the
135 				 * device node, or actively by tagging on
136 				 * GPIO_ACTIVE_LOW as flag in the device
137 				 * tree. If the line is simultaneously
138 				 * tagged as active low in the device tree
139 				 * and has the "spi-cs-high" set, we get a
140 				 * conflict and the "spi-cs-high" flag will
141 				 * take precedence.
142 				 */
143 				if (of_property_read_bool(np, "spi-cs-high")) {
144 					if (*flags & OF_GPIO_ACTIVE_LOW) {
145 						pr_warn("%s GPIO handle specifies active low - ignored\n",
146 							of_node_full_name(np));
147 						*flags &= ~OF_GPIO_ACTIVE_LOW;
148 					}
149 				} else {
150 					if (!(*flags & OF_GPIO_ACTIVE_LOW))
151 						pr_info("%s enforce active low on chipselect handle\n",
152 							of_node_full_name(np));
153 					*flags |= OF_GPIO_ACTIVE_LOW;
154 				}
155 				break;
156 			}
157 		}
158 	}
159 }
160 
161 /**
162  * of_get_named_gpiod_flags() - Get a GPIO descriptor and flags for GPIO API
163  * @np:		device node to get GPIO from
164  * @propname:	property name containing gpio specifier(s)
165  * @index:	index of the GPIO
166  * @flags:	a flags pointer to fill in
167  *
168  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
169  * value on the error condition. If @flags is not NULL the function also fills
170  * in flags for the GPIO.
171  */
172 struct gpio_desc *of_get_named_gpiod_flags(struct device_node *np,
173 		     const char *propname, int index, enum of_gpio_flags *flags)
174 {
175 	struct of_phandle_args gpiospec;
176 	struct gpio_chip *chip;
177 	struct gpio_desc *desc;
178 	int ret;
179 
180 	ret = of_parse_phandle_with_args_map(np, propname, "gpio", index,
181 					     &gpiospec);
182 	if (ret) {
183 		pr_debug("%s: can't parse '%s' property of node '%pOF[%d]'\n",
184 			__func__, propname, np, index);
185 		return ERR_PTR(ret);
186 	}
187 
188 	chip = of_find_gpiochip_by_xlate(&gpiospec);
189 	if (!chip) {
190 		desc = ERR_PTR(-EPROBE_DEFER);
191 		goto out;
192 	}
193 
194 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, flags);
195 	if (IS_ERR(desc))
196 		goto out;
197 
198 	if (flags)
199 		of_gpio_flags_quirks(np, propname, flags, index);
200 
201 	pr_debug("%s: parsed '%s' property of node '%pOF[%d]' - status (%d)\n",
202 		 __func__, propname, np, index,
203 		 PTR_ERR_OR_ZERO(desc));
204 
205 out:
206 	of_node_put(gpiospec.np);
207 
208 	return desc;
209 }
210 
211 int of_get_named_gpio_flags(struct device_node *np, const char *list_name,
212 			    int index, enum of_gpio_flags *flags)
213 {
214 	struct gpio_desc *desc;
215 
216 	desc = of_get_named_gpiod_flags(np, list_name, index, flags);
217 
218 	if (IS_ERR(desc))
219 		return PTR_ERR(desc);
220 	else
221 		return desc_to_gpio(desc);
222 }
223 EXPORT_SYMBOL(of_get_named_gpio_flags);
224 
225 /*
226  * The SPI GPIO bindings happened before we managed to establish that GPIO
227  * properties should be named "foo-gpios" so we have this special kludge for
228  * them.
229  */
230 static struct gpio_desc *of_find_spi_gpio(struct device *dev, const char *con_id,
231 					  enum of_gpio_flags *of_flags)
232 {
233 	char prop_name[32]; /* 32 is max size of property name */
234 	struct device_node *np = dev->of_node;
235 	struct gpio_desc *desc;
236 
237 	/*
238 	 * Hopefully the compiler stubs the rest of the function if this
239 	 * is false.
240 	 */
241 	if (!IS_ENABLED(CONFIG_SPI_MASTER))
242 		return ERR_PTR(-ENOENT);
243 
244 	/* Allow this specifically for "spi-gpio" devices */
245 	if (!of_device_is_compatible(np, "spi-gpio") || !con_id)
246 		return ERR_PTR(-ENOENT);
247 
248 	/* Will be "gpio-sck", "gpio-mosi" or "gpio-miso" */
249 	snprintf(prop_name, sizeof(prop_name), "%s-%s", "gpio", con_id);
250 
251 	desc = of_get_named_gpiod_flags(np, prop_name, 0, of_flags);
252 	return desc;
253 }
254 
255 /*
256  * Some regulator bindings happened before we managed to establish that GPIO
257  * properties should be named "foo-gpios" so we have this special kludge for
258  * them.
259  */
260 static struct gpio_desc *of_find_regulator_gpio(struct device *dev, const char *con_id,
261 						enum of_gpio_flags *of_flags)
262 {
263 	/* These are the connection IDs we accept as legacy GPIO phandles */
264 	const char *whitelist[] = {
265 		"wlf,ldoena", /* Arizona */
266 		"wlf,ldo1ena", /* WM8994 */
267 		"wlf,ldo2ena", /* WM8994 */
268 	};
269 	struct device_node *np = dev->of_node;
270 	struct gpio_desc *desc;
271 	int i;
272 
273 	if (!IS_ENABLED(CONFIG_REGULATOR))
274 		return ERR_PTR(-ENOENT);
275 
276 	if (!con_id)
277 		return ERR_PTR(-ENOENT);
278 
279 	i = match_string(whitelist, ARRAY_SIZE(whitelist), con_id);
280 	if (i < 0)
281 		return ERR_PTR(-ENOENT);
282 
283 	desc = of_get_named_gpiod_flags(np, con_id, 0, of_flags);
284 	return desc;
285 }
286 
287 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
288 			       unsigned int idx,
289 			       enum gpio_lookup_flags *flags)
290 {
291 	char prop_name[32]; /* 32 is max size of property name */
292 	enum of_gpio_flags of_flags;
293 	struct gpio_desc *desc;
294 	unsigned int i;
295 
296 	/* Try GPIO property "foo-gpios" and "foo-gpio" */
297 	for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
298 		if (con_id)
299 			snprintf(prop_name, sizeof(prop_name), "%s-%s", con_id,
300 				 gpio_suffixes[i]);
301 		else
302 			snprintf(prop_name, sizeof(prop_name), "%s",
303 				 gpio_suffixes[i]);
304 
305 		desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
306 						&of_flags);
307 		/*
308 		 * -EPROBE_DEFER in our case means that we found a
309 		 * valid GPIO property, but no controller has been
310 		 * registered so far.
311 		 *
312 		 * This means we don't need to look any further for
313 		 * alternate name conventions, and we should really
314 		 * preserve the return code for our user to be able to
315 		 * retry probing later.
316 		 */
317 		if (IS_ERR(desc) && PTR_ERR(desc) == -EPROBE_DEFER)
318 			return desc;
319 
320 		if (!IS_ERR(desc) || (PTR_ERR(desc) != -ENOENT))
321 			break;
322 	}
323 
324 	/* Special handling for SPI GPIOs if used */
325 	if (IS_ERR(desc))
326 		desc = of_find_spi_gpio(dev, con_id, &of_flags);
327 
328 	/* Special handling for regulator GPIOs if used */
329 	if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
330 		desc = of_find_regulator_gpio(dev, con_id, &of_flags);
331 
332 	if (IS_ERR(desc))
333 		return desc;
334 
335 	if (of_flags & OF_GPIO_ACTIVE_LOW)
336 		*flags |= GPIO_ACTIVE_LOW;
337 
338 	if (of_flags & OF_GPIO_SINGLE_ENDED) {
339 		if (of_flags & OF_GPIO_OPEN_DRAIN)
340 			*flags |= GPIO_OPEN_DRAIN;
341 		else
342 			*flags |= GPIO_OPEN_SOURCE;
343 	}
344 
345 	if (of_flags & OF_GPIO_TRANSITORY)
346 		*flags |= GPIO_TRANSITORY;
347 
348 	return desc;
349 }
350 
351 /**
352  * of_parse_own_gpio() - Get a GPIO hog descriptor, names and flags for GPIO API
353  * @np:		device node to get GPIO from
354  * @chip:	GPIO chip whose hog is parsed
355  * @idx:	Index of the GPIO to parse
356  * @name:	GPIO line name
357  * @lflags:	gpio_lookup_flags - returned from of_find_gpio() or
358  *		of_parse_own_gpio()
359  * @dflags:	gpiod_flags - optional GPIO initialization flags
360  *
361  * Returns GPIO descriptor to use with Linux GPIO API, or one of the errno
362  * value on the error condition.
363  */
364 static struct gpio_desc *of_parse_own_gpio(struct device_node *np,
365 					   struct gpio_chip *chip,
366 					   unsigned int idx, const char **name,
367 					   enum gpio_lookup_flags *lflags,
368 					   enum gpiod_flags *dflags)
369 {
370 	struct device_node *chip_np;
371 	enum of_gpio_flags xlate_flags;
372 	struct of_phandle_args gpiospec;
373 	struct gpio_desc *desc;
374 	unsigned int i;
375 	u32 tmp;
376 	int ret;
377 
378 	chip_np = chip->of_node;
379 	if (!chip_np)
380 		return ERR_PTR(-EINVAL);
381 
382 	xlate_flags = 0;
383 	*lflags = 0;
384 	*dflags = 0;
385 
386 	ret = of_property_read_u32(chip_np, "#gpio-cells", &tmp);
387 	if (ret)
388 		return ERR_PTR(ret);
389 
390 	gpiospec.np = chip_np;
391 	gpiospec.args_count = tmp;
392 
393 	for (i = 0; i < tmp; i++) {
394 		ret = of_property_read_u32_index(np, "gpios", idx * tmp + i,
395 						 &gpiospec.args[i]);
396 		if (ret)
397 			return ERR_PTR(ret);
398 	}
399 
400 	desc = of_xlate_and_get_gpiod_flags(chip, &gpiospec, &xlate_flags);
401 	if (IS_ERR(desc))
402 		return desc;
403 
404 	if (xlate_flags & OF_GPIO_ACTIVE_LOW)
405 		*lflags |= GPIO_ACTIVE_LOW;
406 	if (xlate_flags & OF_GPIO_TRANSITORY)
407 		*lflags |= GPIO_TRANSITORY;
408 
409 	if (of_property_read_bool(np, "input"))
410 		*dflags |= GPIOD_IN;
411 	else if (of_property_read_bool(np, "output-low"))
412 		*dflags |= GPIOD_OUT_LOW;
413 	else if (of_property_read_bool(np, "output-high"))
414 		*dflags |= GPIOD_OUT_HIGH;
415 	else {
416 		pr_warn("GPIO line %d (%pOFn): no hogging state specified, bailing out\n",
417 			desc_to_gpio(desc), np);
418 		return ERR_PTR(-EINVAL);
419 	}
420 
421 	if (name && of_property_read_string(np, "line-name", name))
422 		*name = np->name;
423 
424 	return desc;
425 }
426 
427 /**
428  * of_gpiochip_scan_gpios - Scan gpio-controller for gpio definitions
429  * @chip:	gpio chip to act on
430  *
431  * This is only used by of_gpiochip_add to request/set GPIO initial
432  * configuration.
433  * It returns error if it fails otherwise 0 on success.
434  */
435 static int of_gpiochip_scan_gpios(struct gpio_chip *chip)
436 {
437 	struct gpio_desc *desc = NULL;
438 	struct device_node *np;
439 	const char *name;
440 	enum gpio_lookup_flags lflags;
441 	enum gpiod_flags dflags;
442 	unsigned int i;
443 	int ret;
444 
445 	for_each_available_child_of_node(chip->of_node, np) {
446 		if (!of_property_read_bool(np, "gpio-hog"))
447 			continue;
448 
449 		for (i = 0;; i++) {
450 			desc = of_parse_own_gpio(np, chip, i, &name, &lflags,
451 						 &dflags);
452 			if (IS_ERR(desc))
453 				break;
454 
455 			ret = gpiod_hog(desc, name, lflags, dflags);
456 			if (ret < 0) {
457 				of_node_put(np);
458 				return ret;
459 			}
460 		}
461 	}
462 
463 	return 0;
464 }
465 
466 /**
467  * of_gpio_simple_xlate - translate gpiospec to the GPIO number and flags
468  * @gc:		pointer to the gpio_chip structure
469  * @gpiospec:	GPIO specifier as found in the device tree
470  * @flags:	a flags pointer to fill in
471  *
472  * This is simple translation function, suitable for the most 1:1 mapped
473  * GPIO chips. This function performs only one sanity check: whether GPIO
474  * is less than ngpios (that is specified in the gpio_chip).
475  */
476 int of_gpio_simple_xlate(struct gpio_chip *gc,
477 			 const struct of_phandle_args *gpiospec, u32 *flags)
478 {
479 	/*
480 	 * We're discouraging gpio_cells < 2, since that way you'll have to
481 	 * write your own xlate function (that will have to retrieve the GPIO
482 	 * number and the flags from a single gpio cell -- this is possible,
483 	 * but not recommended).
484 	 */
485 	if (gc->of_gpio_n_cells < 2) {
486 		WARN_ON(1);
487 		return -EINVAL;
488 	}
489 
490 	if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
491 		return -EINVAL;
492 
493 	if (gpiospec->args[0] >= gc->ngpio)
494 		return -EINVAL;
495 
496 	if (flags)
497 		*flags = gpiospec->args[1];
498 
499 	return gpiospec->args[0];
500 }
501 EXPORT_SYMBOL(of_gpio_simple_xlate);
502 
503 /**
504  * of_mm_gpiochip_add_data - Add memory mapped GPIO chip (bank)
505  * @np:		device node of the GPIO chip
506  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
507  * @data:	driver data to store in the struct gpio_chip
508  *
509  * To use this function you should allocate and fill mm_gc with:
510  *
511  * 1) In the gpio_chip structure:
512  *    - all the callbacks
513  *    - of_gpio_n_cells
514  *    - of_xlate callback (optional)
515  *
516  * 3) In the of_mm_gpio_chip structure:
517  *    - save_regs callback (optional)
518  *
519  * If succeeded, this function will map bank's memory and will
520  * do all necessary work for you. Then you'll able to use .regs
521  * to manage GPIOs from the callbacks.
522  */
523 int of_mm_gpiochip_add_data(struct device_node *np,
524 			    struct of_mm_gpio_chip *mm_gc,
525 			    void *data)
526 {
527 	int ret = -ENOMEM;
528 	struct gpio_chip *gc = &mm_gc->gc;
529 
530 	gc->label = kasprintf(GFP_KERNEL, "%pOF", np);
531 	if (!gc->label)
532 		goto err0;
533 
534 	mm_gc->regs = of_iomap(np, 0);
535 	if (!mm_gc->regs)
536 		goto err1;
537 
538 	gc->base = -1;
539 
540 	if (mm_gc->save_regs)
541 		mm_gc->save_regs(mm_gc);
542 
543 	mm_gc->gc.of_node = np;
544 
545 	ret = gpiochip_add_data(gc, data);
546 	if (ret)
547 		goto err2;
548 
549 	return 0;
550 err2:
551 	iounmap(mm_gc->regs);
552 err1:
553 	kfree(gc->label);
554 err0:
555 	pr_err("%pOF: GPIO chip registration failed with status %d\n", np, ret);
556 	return ret;
557 }
558 EXPORT_SYMBOL(of_mm_gpiochip_add_data);
559 
560 /**
561  * of_mm_gpiochip_remove - Remove memory mapped GPIO chip (bank)
562  * @mm_gc:	pointer to the of_mm_gpio_chip allocated structure
563  */
564 void of_mm_gpiochip_remove(struct of_mm_gpio_chip *mm_gc)
565 {
566 	struct gpio_chip *gc = &mm_gc->gc;
567 
568 	if (!mm_gc)
569 		return;
570 
571 	gpiochip_remove(gc);
572 	iounmap(mm_gc->regs);
573 	kfree(gc->label);
574 }
575 EXPORT_SYMBOL(of_mm_gpiochip_remove);
576 
577 static void of_gpiochip_init_valid_mask(struct gpio_chip *chip)
578 {
579 	int len, i;
580 	u32 start, count;
581 	struct device_node *np = chip->of_node;
582 
583 	len = of_property_count_u32_elems(np,  "gpio-reserved-ranges");
584 	if (len < 0 || len % 2 != 0)
585 		return;
586 
587 	for (i = 0; i < len; i += 2) {
588 		of_property_read_u32_index(np, "gpio-reserved-ranges",
589 					   i, &start);
590 		of_property_read_u32_index(np, "gpio-reserved-ranges",
591 					   i + 1, &count);
592 		if (start >= chip->ngpio || start + count >= chip->ngpio)
593 			continue;
594 
595 		bitmap_clear(chip->valid_mask, start, count);
596 	}
597 };
598 
599 #ifdef CONFIG_PINCTRL
600 static int of_gpiochip_add_pin_range(struct gpio_chip *chip)
601 {
602 	struct device_node *np = chip->of_node;
603 	struct of_phandle_args pinspec;
604 	struct pinctrl_dev *pctldev;
605 	int index = 0, ret;
606 	const char *name;
607 	static const char group_names_propname[] = "gpio-ranges-group-names";
608 	struct property *group_names;
609 
610 	if (!np)
611 		return 0;
612 
613 	group_names = of_find_property(np, group_names_propname, NULL);
614 
615 	for (;; index++) {
616 		ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3,
617 				index, &pinspec);
618 		if (ret)
619 			break;
620 
621 		pctldev = of_pinctrl_get(pinspec.np);
622 		of_node_put(pinspec.np);
623 		if (!pctldev)
624 			return -EPROBE_DEFER;
625 
626 		if (pinspec.args[2]) {
627 			if (group_names) {
628 				of_property_read_string_index(np,
629 						group_names_propname,
630 						index, &name);
631 				if (strlen(name)) {
632 					pr_err("%pOF: Group name of numeric GPIO ranges must be the empty string.\n",
633 						np);
634 					break;
635 				}
636 			}
637 			/* npins != 0: linear range */
638 			ret = gpiochip_add_pin_range(chip,
639 					pinctrl_dev_get_devname(pctldev),
640 					pinspec.args[0],
641 					pinspec.args[1],
642 					pinspec.args[2]);
643 			if (ret)
644 				return ret;
645 		} else {
646 			/* npins == 0: special range */
647 			if (pinspec.args[1]) {
648 				pr_err("%pOF: Illegal gpio-range format.\n",
649 					np);
650 				break;
651 			}
652 
653 			if (!group_names) {
654 				pr_err("%pOF: GPIO group range requested but no %s property.\n",
655 					np, group_names_propname);
656 				break;
657 			}
658 
659 			ret = of_property_read_string_index(np,
660 						group_names_propname,
661 						index, &name);
662 			if (ret)
663 				break;
664 
665 			if (!strlen(name)) {
666 				pr_err("%pOF: Group name of GPIO group range cannot be the empty string.\n",
667 				np);
668 				break;
669 			}
670 
671 			ret = gpiochip_add_pingroup_range(chip, pctldev,
672 						pinspec.args[0], name);
673 			if (ret)
674 				return ret;
675 		}
676 	}
677 
678 	return 0;
679 }
680 
681 #else
682 static int of_gpiochip_add_pin_range(struct gpio_chip *chip) { return 0; }
683 #endif
684 
685 int of_gpiochip_add(struct gpio_chip *chip)
686 {
687 	int status;
688 
689 	if (!chip->of_node)
690 		return 0;
691 
692 	if (!chip->of_xlate) {
693 		chip->of_gpio_n_cells = 2;
694 		chip->of_xlate = of_gpio_simple_xlate;
695 	}
696 
697 	if (chip->of_gpio_n_cells > MAX_PHANDLE_ARGS)
698 		return -EINVAL;
699 
700 	of_gpiochip_init_valid_mask(chip);
701 
702 	status = of_gpiochip_add_pin_range(chip);
703 	if (status)
704 		return status;
705 
706 	/* If the chip defines names itself, these take precedence */
707 	if (!chip->names)
708 		devprop_gpiochip_set_names(chip,
709 					   of_fwnode_handle(chip->of_node));
710 
711 	of_node_get(chip->of_node);
712 
713 	return of_gpiochip_scan_gpios(chip);
714 }
715 
716 void of_gpiochip_remove(struct gpio_chip *chip)
717 {
718 	gpiochip_remove_pin_ranges(chip);
719 	of_node_put(chip->of_node);
720 }
721