xref: /openbmc/u-boot/drivers/gpio/gpio-uclass.c (revision 6744c0d6)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (c) 2013 Google, Inc
4  */
5 
6 #include <common.h>
7 #include <dm.h>
8 #include <dt-bindings/gpio/gpio.h>
9 #include <errno.h>
10 #include <fdtdec.h>
11 #include <malloc.h>
12 #include <asm/gpio.h>
13 #include <linux/bug.h>
14 #include <linux/ctype.h>
15 
16 DECLARE_GLOBAL_DATA_PTR;
17 
18 /**
19  * gpio_to_device() - Convert global GPIO number to device, number
20  *
21  * Convert the GPIO number to an entry in the list of GPIOs
22  * or GPIO blocks registered with the GPIO controller. Returns
23  * entry on success, NULL on error.
24  *
25  * @gpio:	The numeric representation of the GPIO
26  * @desc:	Returns description (desc->flags will always be 0)
27  * @return 0 if found, -ENOENT if not found
28  */
29 static int gpio_to_device(unsigned int gpio, struct gpio_desc *desc)
30 {
31 	struct gpio_dev_priv *uc_priv;
32 	struct udevice *dev;
33 	int ret;
34 
35 	for (ret = uclass_first_device(UCLASS_GPIO, &dev);
36 	     dev;
37 	     ret = uclass_next_device(&dev)) {
38 		uc_priv = dev_get_uclass_priv(dev);
39 		if (gpio >= uc_priv->gpio_base &&
40 		    gpio < uc_priv->gpio_base + uc_priv->gpio_count) {
41 			desc->dev = dev;
42 			desc->offset = gpio - uc_priv->gpio_base;
43 			desc->flags = 0;
44 			return 0;
45 		}
46 	}
47 
48 	/* No such GPIO */
49 	return ret ? ret : -ENOENT;
50 }
51 
52 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc)
53 {
54 	struct gpio_dev_priv *uc_priv = NULL;
55 	struct udevice *dev;
56 	ulong offset;
57 	int numeric;
58 	int ret;
59 
60 	numeric = isdigit(*name) ? simple_strtoul(name, NULL, 10) : -1;
61 	for (ret = uclass_first_device(UCLASS_GPIO, &dev);
62 	     dev;
63 	     ret = uclass_next_device(&dev)) {
64 		int len;
65 
66 		uc_priv = dev_get_uclass_priv(dev);
67 		if (numeric != -1) {
68 			offset = numeric - uc_priv->gpio_base;
69 			/* Allow GPIOs to be numbered from 0 */
70 			if (offset < uc_priv->gpio_count)
71 				break;
72 		}
73 
74 		len = uc_priv->bank_name ? strlen(uc_priv->bank_name) : 0;
75 
76 		if (!strncasecmp(name, uc_priv->bank_name, len)) {
77 			if (!strict_strtoul(name + len, 10, &offset))
78 				break;
79 		}
80 	}
81 
82 	if (!dev)
83 		return ret ? ret : -EINVAL;
84 
85 	desc->dev = dev;
86 	desc->offset = offset;
87 
88 	return 0;
89 }
90 
91 int gpio_lookup_name(const char *name, struct udevice **devp,
92 		     unsigned int *offsetp, unsigned int *gpiop)
93 {
94 	struct gpio_desc desc;
95 	int ret;
96 
97 	if (devp)
98 		*devp = NULL;
99 	ret = dm_gpio_lookup_name(name, &desc);
100 	if (ret)
101 		return ret;
102 
103 	if (devp)
104 		*devp = desc.dev;
105 	if (offsetp)
106 		*offsetp = desc.offset;
107 	if (gpiop) {
108 		struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(desc.dev);
109 
110 		*gpiop = uc_priv->gpio_base + desc.offset;
111 	}
112 
113 	return 0;
114 }
115 
116 int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
117 			  struct ofnode_phandle_args *args)
118 {
119 	if (args->args_count < 1)
120 		return -EINVAL;
121 
122 	desc->offset = args->args[0];
123 
124 	if (args->args_count < 2)
125 		return 0;
126 
127 	if (args->args[1] & GPIO_ACTIVE_LOW)
128 		desc->flags = GPIOD_ACTIVE_LOW;
129 
130 	return 0;
131 }
132 
133 static int gpio_find_and_xlate(struct gpio_desc *desc,
134 			       struct ofnode_phandle_args *args)
135 {
136 	struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
137 
138 	if (ops->xlate)
139 		return ops->xlate(desc->dev, desc, args);
140 	else
141 		return gpio_xlate_offs_flags(desc->dev, desc, args);
142 }
143 
144 int dm_gpio_request(struct gpio_desc *desc, const char *label)
145 {
146 	struct udevice *dev = desc->dev;
147 	struct gpio_dev_priv *uc_priv;
148 	char *str;
149 	int ret;
150 
151 	uc_priv = dev_get_uclass_priv(dev);
152 	if (uc_priv->name[desc->offset])
153 		return -EBUSY;
154 	str = strdup(label);
155 	if (!str)
156 		return -ENOMEM;
157 	if (gpio_get_ops(dev)->request) {
158 		ret = gpio_get_ops(dev)->request(dev, desc->offset, label);
159 		if (ret) {
160 			free(str);
161 			return ret;
162 		}
163 	}
164 	uc_priv->name[desc->offset] = str;
165 
166 	return 0;
167 }
168 
169 static int dm_gpio_requestf(struct gpio_desc *desc, const char *fmt, ...)
170 {
171 #if !defined(CONFIG_SPL_BUILD) || !defined(CONFIG_USE_TINY_PRINTF)
172 	va_list args;
173 	char buf[40];
174 
175 	va_start(args, fmt);
176 	vscnprintf(buf, sizeof(buf), fmt, args);
177 	va_end(args);
178 	return dm_gpio_request(desc, buf);
179 #else
180 	return dm_gpio_request(desc, fmt);
181 #endif
182 }
183 
184 /**
185  * gpio_request() - [COMPAT] Request GPIO
186  * gpio:	GPIO number
187  * label:	Name for the requested GPIO
188  *
189  * The label is copied and allocated so the caller does not need to keep
190  * the pointer around.
191  *
192  * This function implements the API that's compatible with current
193  * GPIO API used in U-Boot. The request is forwarded to particular
194  * GPIO driver. Returns 0 on success, negative value on error.
195  */
196 int gpio_request(unsigned gpio, const char *label)
197 {
198 	struct gpio_desc desc;
199 	int ret;
200 
201 	ret = gpio_to_device(gpio, &desc);
202 	if (ret)
203 		return ret;
204 
205 	return dm_gpio_request(&desc, label);
206 }
207 
208 /**
209  * gpio_requestf() - [COMPAT] Request GPIO
210  * @gpio:	GPIO number
211  * @fmt:	Format string for the requested GPIO
212  * @...:	Arguments for the printf() format string
213  *
214  * This function implements the API that's compatible with current
215  * GPIO API used in U-Boot. The request is forwarded to particular
216  * GPIO driver. Returns 0 on success, negative value on error.
217  */
218 int gpio_requestf(unsigned gpio, const char *fmt, ...)
219 {
220 #if !defined(CONFIG_SPL_BUILD) || !defined(CONFIG_USE_TINY_PRINTF)
221 	va_list args;
222 	char buf[40];
223 
224 	va_start(args, fmt);
225 	vscnprintf(buf, sizeof(buf), fmt, args);
226 	va_end(args);
227 	return gpio_request(gpio, buf);
228 #else
229 	return gpio_request(gpio, fmt);
230 #endif
231 }
232 
233 int _dm_gpio_free(struct udevice *dev, uint offset)
234 {
235 	struct gpio_dev_priv *uc_priv;
236 	int ret;
237 
238 	uc_priv = dev_get_uclass_priv(dev);
239 	if (!uc_priv->name[offset])
240 		return -ENXIO;
241 	if (gpio_get_ops(dev)->free) {
242 		ret = gpio_get_ops(dev)->free(dev, offset);
243 		if (ret)
244 			return ret;
245 	}
246 
247 	free(uc_priv->name[offset]);
248 	uc_priv->name[offset] = NULL;
249 
250 	return 0;
251 }
252 
253 /**
254  * gpio_free() - [COMPAT] Relinquish GPIO
255  * gpio:	GPIO number
256  *
257  * This function implements the API that's compatible with current
258  * GPIO API used in U-Boot. The request is forwarded to particular
259  * GPIO driver. Returns 0 on success, negative value on error.
260  */
261 int gpio_free(unsigned gpio)
262 {
263 	struct gpio_desc desc;
264 	int ret;
265 
266 	ret = gpio_to_device(gpio, &desc);
267 	if (ret)
268 		return ret;
269 
270 	return _dm_gpio_free(desc.dev, desc.offset);
271 }
272 
273 static int check_reserved(const struct gpio_desc *desc, const char *func)
274 {
275 	struct gpio_dev_priv *uc_priv;
276 
277 	if (!dm_gpio_is_valid(desc))
278 		return -ENOENT;
279 
280 	uc_priv = dev_get_uclass_priv(desc->dev);
281 	if (!uc_priv->name[desc->offset]) {
282 		printf("%s: %s: error: gpio %s%d not reserved\n",
283 		       desc->dev->name, func,
284 		       uc_priv->bank_name ? uc_priv->bank_name : "",
285 		       desc->offset);
286 		return -EBUSY;
287 	}
288 
289 	return 0;
290 }
291 
292 /**
293  * gpio_direction_input() - [COMPAT] Set GPIO direction to input
294  * gpio:	GPIO number
295  *
296  * This function implements the API that's compatible with current
297  * GPIO API used in U-Boot. The request is forwarded to particular
298  * GPIO driver. Returns 0 on success, negative value on error.
299  */
300 int gpio_direction_input(unsigned gpio)
301 {
302 	struct gpio_desc desc;
303 	int ret;
304 
305 	ret = gpio_to_device(gpio, &desc);
306 	if (ret)
307 		return ret;
308 	ret = check_reserved(&desc, "dir_input");
309 	if (ret)
310 		return ret;
311 
312 	return gpio_get_ops(desc.dev)->direction_input(desc.dev, desc.offset);
313 }
314 
315 /**
316  * gpio_direction_output() - [COMPAT] Set GPIO direction to output and set value
317  * gpio:	GPIO number
318  * value:	Logical value to be set on the GPIO pin
319  *
320  * This function implements the API that's compatible with current
321  * GPIO API used in U-Boot. The request is forwarded to particular
322  * GPIO driver. Returns 0 on success, negative value on error.
323  */
324 int gpio_direction_output(unsigned gpio, int value)
325 {
326 	struct gpio_desc desc;
327 	int ret;
328 
329 	ret = gpio_to_device(gpio, &desc);
330 	if (ret)
331 		return ret;
332 	ret = check_reserved(&desc, "dir_output");
333 	if (ret)
334 		return ret;
335 
336 	return gpio_get_ops(desc.dev)->direction_output(desc.dev,
337 							desc.offset, value);
338 }
339 
340 int dm_gpio_get_value(const struct gpio_desc *desc)
341 {
342 	int value;
343 	int ret;
344 
345 	ret = check_reserved(desc, "get_value");
346 	if (ret)
347 		return ret;
348 
349 	value = gpio_get_ops(desc->dev)->get_value(desc->dev, desc->offset);
350 
351 	return desc->flags & GPIOD_ACTIVE_LOW ? !value : value;
352 }
353 
354 int dm_gpio_set_value(const struct gpio_desc *desc, int value)
355 {
356 	int ret;
357 
358 	ret = check_reserved(desc, "set_value");
359 	if (ret)
360 		return ret;
361 
362 	if (desc->flags & GPIOD_ACTIVE_LOW)
363 		value = !value;
364 	gpio_get_ops(desc->dev)->set_value(desc->dev, desc->offset, value);
365 	return 0;
366 }
367 
368 int dm_gpio_get_open_drain(struct gpio_desc *desc)
369 {
370 	struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
371 	int ret;
372 
373 	ret = check_reserved(desc, "get_open_drain");
374 	if (ret)
375 		return ret;
376 
377 	if (ops->set_open_drain)
378 		return ops->get_open_drain(desc->dev, desc->offset);
379 	else
380 		return -ENOSYS;
381 }
382 
383 int dm_gpio_set_open_drain(struct gpio_desc *desc, int value)
384 {
385 	struct dm_gpio_ops *ops = gpio_get_ops(desc->dev);
386 	int ret;
387 
388 	ret = check_reserved(desc, "set_open_drain");
389 	if (ret)
390 		return ret;
391 
392 	if (ops->set_open_drain)
393 		ret = ops->set_open_drain(desc->dev, desc->offset, value);
394 	else
395 		return 0; /* feature not supported -> ignore setting */
396 
397 	return ret;
398 }
399 
400 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags)
401 {
402 	struct udevice *dev = desc->dev;
403 	struct dm_gpio_ops *ops = gpio_get_ops(dev);
404 	int ret;
405 
406 	ret = check_reserved(desc, "set_dir");
407 	if (ret)
408 		return ret;
409 
410 	if (flags & GPIOD_IS_OUT) {
411 		int value = flags & GPIOD_IS_OUT_ACTIVE ? 1 : 0;
412 
413 		if (flags & GPIOD_ACTIVE_LOW)
414 			value = !value;
415 		ret = ops->direction_output(dev, desc->offset, value);
416 	} else  if (flags & GPIOD_IS_IN) {
417 		ret = ops->direction_input(dev, desc->offset);
418 	}
419 	if (ret)
420 		return ret;
421 	/*
422 	 * Update desc->flags here, so that GPIO_ACTIVE_LOW is honoured in
423 	 * futures
424 	 */
425 	desc->flags = flags;
426 
427 	return 0;
428 }
429 
430 int dm_gpio_set_dir(struct gpio_desc *desc)
431 {
432 	return dm_gpio_set_dir_flags(desc, desc->flags);
433 }
434 
435 /**
436  * gpio_get_value() - [COMPAT] Sample GPIO pin and return it's value
437  * gpio:	GPIO number
438  *
439  * This function implements the API that's compatible with current
440  * GPIO API used in U-Boot. The request is forwarded to particular
441  * GPIO driver. Returns the value of the GPIO pin, or negative value
442  * on error.
443  */
444 int gpio_get_value(unsigned gpio)
445 {
446 	int ret;
447 
448 	struct gpio_desc desc;
449 
450 	ret = gpio_to_device(gpio, &desc);
451 	if (ret)
452 		return ret;
453 	return dm_gpio_get_value(&desc);
454 }
455 
456 /**
457  * gpio_set_value() - [COMPAT] Configure logical value on GPIO pin
458  * gpio:	GPIO number
459  * value:	Logical value to be set on the GPIO pin.
460  *
461  * This function implements the API that's compatible with current
462  * GPIO API used in U-Boot. The request is forwarded to particular
463  * GPIO driver. Returns 0 on success, negative value on error.
464  */
465 int gpio_set_value(unsigned gpio, int value)
466 {
467 	struct gpio_desc desc;
468 	int ret;
469 
470 	ret = gpio_to_device(gpio, &desc);
471 	if (ret)
472 		return ret;
473 	return dm_gpio_set_value(&desc, value);
474 }
475 
476 const char *gpio_get_bank_info(struct udevice *dev, int *bit_count)
477 {
478 	struct gpio_dev_priv *priv;
479 
480 	/* Must be called on an active device */
481 	priv = dev_get_uclass_priv(dev);
482 	assert(priv);
483 
484 	*bit_count = priv->gpio_count;
485 	return priv->bank_name;
486 }
487 
488 static const char * const gpio_function[GPIOF_COUNT] = {
489 	"input",
490 	"output",
491 	"unused",
492 	"unknown",
493 	"func",
494 };
495 
496 static int get_function(struct udevice *dev, int offset, bool skip_unused,
497 			const char **namep)
498 {
499 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
500 	struct dm_gpio_ops *ops = gpio_get_ops(dev);
501 
502 	BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
503 	if (!device_active(dev))
504 		return -ENODEV;
505 	if (offset < 0 || offset >= uc_priv->gpio_count)
506 		return -EINVAL;
507 	if (namep)
508 		*namep = uc_priv->name[offset];
509 	if (skip_unused && !uc_priv->name[offset])
510 		return GPIOF_UNUSED;
511 	if (ops->get_function) {
512 		int ret;
513 
514 		ret = ops->get_function(dev, offset);
515 		if (ret < 0)
516 			return ret;
517 		if (ret >= ARRAY_SIZE(gpio_function))
518 			return -ENODATA;
519 		return ret;
520 	}
521 
522 	return GPIOF_UNKNOWN;
523 }
524 
525 int gpio_get_function(struct udevice *dev, int offset, const char **namep)
526 {
527 	return get_function(dev, offset, true, namep);
528 }
529 
530 int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep)
531 {
532 	return get_function(dev, offset, false, namep);
533 }
534 
535 int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize)
536 {
537 	struct dm_gpio_ops *ops = gpio_get_ops(dev);
538 	struct gpio_dev_priv *priv;
539 	char *str = buf;
540 	int func;
541 	int ret;
542 	int len;
543 
544 	BUILD_BUG_ON(GPIOF_COUNT != ARRAY_SIZE(gpio_function));
545 
546 	*buf = 0;
547 	priv = dev_get_uclass_priv(dev);
548 	ret = gpio_get_raw_function(dev, offset, NULL);
549 	if (ret < 0)
550 		return ret;
551 	func = ret;
552 	len = snprintf(str, buffsize, "%s%d: %s",
553 		       priv->bank_name ? priv->bank_name : "",
554 		       offset, gpio_function[func]);
555 	if (func == GPIOF_INPUT || func == GPIOF_OUTPUT ||
556 	    func == GPIOF_UNUSED) {
557 		const char *label;
558 		bool used;
559 
560 		ret = ops->get_value(dev, offset);
561 		if (ret < 0)
562 			return ret;
563 		used = gpio_get_function(dev, offset, &label) != GPIOF_UNUSED;
564 		snprintf(str + len, buffsize - len, ": %d [%c]%s%s",
565 			 ret,
566 			 used ? 'x' : ' ',
567 			 used ? " " : "",
568 			 label ? label : "");
569 	}
570 
571 	return 0;
572 }
573 
574 int gpio_claim_vector(const int *gpio_num_array, const char *fmt)
575 {
576 	int i, ret;
577 	int gpio;
578 
579 	for (i = 0; i < 32; i++) {
580 		gpio = gpio_num_array[i];
581 		if (gpio == -1)
582 			break;
583 		ret = gpio_requestf(gpio, fmt, i);
584 		if (ret)
585 			goto err;
586 		ret = gpio_direction_input(gpio);
587 		if (ret) {
588 			gpio_free(gpio);
589 			goto err;
590 		}
591 	}
592 
593 	return 0;
594 err:
595 	for (i--; i >= 0; i--)
596 		gpio_free(gpio_num_array[i]);
597 
598 	return ret;
599 }
600 
601 /*
602  * get a number comprised of multiple GPIO values. gpio_num_array points to
603  * the array of gpio pin numbers to scan, terminated by -1.
604  */
605 int gpio_get_values_as_int(const int *gpio_list)
606 {
607 	int gpio;
608 	unsigned bitmask = 1;
609 	unsigned vector = 0;
610 	int ret;
611 
612 	while (bitmask &&
613 	       ((gpio = *gpio_list++) != -1)) {
614 		ret = gpio_get_value(gpio);
615 		if (ret < 0)
616 			return ret;
617 		else if (ret)
618 			vector |= bitmask;
619 		bitmask <<= 1;
620 	}
621 
622 	return vector;
623 }
624 
625 int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count)
626 {
627 	unsigned bitmask = 1;
628 	unsigned vector = 0;
629 	int ret, i;
630 
631 	for (i = 0; i < count; i++) {
632 		ret = dm_gpio_get_value(&desc_list[i]);
633 		if (ret < 0)
634 			return ret;
635 		else if (ret)
636 			vector |= bitmask;
637 		bitmask <<= 1;
638 	}
639 
640 	return vector;
641 }
642 
643 static int gpio_request_tail(int ret, ofnode node,
644 			     struct ofnode_phandle_args *args,
645 			     const char *list_name, int index,
646 			     struct gpio_desc *desc, int flags, bool add_index)
647 {
648 	desc->dev = NULL;
649 	desc->offset = 0;
650 	desc->flags = 0;
651 	if (ret)
652 		goto err;
653 
654 	ret = uclass_get_device_by_ofnode(UCLASS_GPIO, args->node,
655 					  &desc->dev);
656 	if (ret) {
657 		debug("%s: uclass_get_device_by_ofnode failed\n", __func__);
658 		goto err;
659 	}
660 	ret = gpio_find_and_xlate(desc, args);
661 	if (ret) {
662 		debug("%s: gpio_find_and_xlate failed\n", __func__);
663 		goto err;
664 	}
665 	ret = dm_gpio_requestf(desc, add_index ? "%s.%s%d" : "%s.%s",
666 			       ofnode_get_name(node),
667 			       list_name, index);
668 	if (ret) {
669 		debug("%s: dm_gpio_requestf failed\n", __func__);
670 		goto err;
671 	}
672 	ret = dm_gpio_set_dir_flags(desc, flags | desc->flags);
673 	if (ret) {
674 		debug("%s: dm_gpio_set_dir failed\n", __func__);
675 		goto err;
676 	}
677 
678 	return 0;
679 err:
680 	debug("%s: Node '%s', property '%s', failed to request GPIO index %d: %d\n",
681 	      __func__, ofnode_get_name(node), list_name, index, ret);
682 	return ret;
683 }
684 
685 static int _gpio_request_by_name_nodev(ofnode node, const char *list_name,
686 				       int index, struct gpio_desc *desc,
687 				       int flags, bool add_index)
688 {
689 	struct ofnode_phandle_args args;
690 	int ret;
691 
692 	ret = ofnode_parse_phandle_with_args(node, list_name, "#gpio-cells", 0,
693 					     index, &args);
694 
695 	return gpio_request_tail(ret, node, &args, list_name, index, desc,
696 				 flags, add_index);
697 }
698 
699 int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
700 			       struct gpio_desc *desc, int flags)
701 {
702 	return _gpio_request_by_name_nodev(node, list_name, index, desc, flags,
703 					   index > 0);
704 }
705 
706 int gpio_request_by_name(struct udevice *dev, const char *list_name, int index,
707 			 struct gpio_desc *desc, int flags)
708 {
709 	struct ofnode_phandle_args args;
710 	int ret;
711 
712 	ret = dev_read_phandle_with_args(dev, list_name, "#gpio-cells", 0,
713 					 index, &args);
714 
715 	return gpio_request_tail(ret, dev_ofnode(dev), &args, list_name,
716 				 index, desc, flags, index > 0);
717 }
718 
719 int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
720 				    struct gpio_desc *desc, int max_count,
721 				    int flags)
722 {
723 	int count;
724 	int ret;
725 
726 	for (count = 0; count < max_count; count++) {
727 		ret = _gpio_request_by_name_nodev(node, list_name, count,
728 						  &desc[count], flags, true);
729 		if (ret == -ENOENT)
730 			break;
731 		else if (ret)
732 			goto err;
733 	}
734 
735 	/* We ran out of GPIOs in the list */
736 	return count;
737 
738 err:
739 	gpio_free_list_nodev(desc, count - 1);
740 
741 	return ret;
742 }
743 
744 int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
745 			      struct gpio_desc *desc, int max_count,
746 			      int flags)
747 {
748 	/*
749 	 * This isn't ideal since we don't use dev->name in the debug()
750 	 * calls in gpio_request_by_name(), but we can do this until
751 	 * gpio_request_list_by_name_nodev() can be dropped.
752 	 */
753 	return gpio_request_list_by_name_nodev(dev_ofnode(dev), list_name, desc,
754 					       max_count, flags);
755 }
756 
757 int gpio_get_list_count(struct udevice *dev, const char *list_name)
758 {
759 	int ret;
760 
761 	ret = fdtdec_parse_phandle_with_args(gd->fdt_blob, dev_of_offset(dev),
762 					     list_name, "#gpio-cells", 0, -1,
763 					     NULL);
764 	if (ret) {
765 		debug("%s: Node '%s', property '%s', GPIO count failed: %d\n",
766 		      __func__, dev->name, list_name, ret);
767 	}
768 
769 	return ret;
770 }
771 
772 int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc)
773 {
774 	/* For now, we don't do any checking of dev */
775 	return _dm_gpio_free(desc->dev, desc->offset);
776 }
777 
778 int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count)
779 {
780 	int i;
781 
782 	/* For now, we don't do any checking of dev */
783 	for (i = 0; i < count; i++)
784 		dm_gpio_free(dev, &desc[i]);
785 
786 	return 0;
787 }
788 
789 int gpio_free_list_nodev(struct gpio_desc *desc, int count)
790 {
791 	return gpio_free_list(NULL, desc, count);
792 }
793 
794 /* We need to renumber the GPIOs when any driver is probed/removed */
795 static int gpio_renumber(struct udevice *removed_dev)
796 {
797 	struct gpio_dev_priv *uc_priv;
798 	struct udevice *dev;
799 	struct uclass *uc;
800 	unsigned base;
801 	int ret;
802 
803 	ret = uclass_get(UCLASS_GPIO, &uc);
804 	if (ret)
805 		return ret;
806 
807 	/* Ensure that we have a base for each bank */
808 	base = 0;
809 	uclass_foreach_dev(dev, uc) {
810 		if (device_active(dev) && dev != removed_dev) {
811 			uc_priv = dev_get_uclass_priv(dev);
812 			uc_priv->gpio_base = base;
813 			base += uc_priv->gpio_count;
814 		}
815 	}
816 
817 	return 0;
818 }
819 
820 int gpio_get_number(const struct gpio_desc *desc)
821 {
822 	struct udevice *dev = desc->dev;
823 	struct gpio_dev_priv *uc_priv;
824 
825 	if (!dev)
826 		return -1;
827 	uc_priv = dev->uclass_priv;
828 
829 	return uc_priv->gpio_base + desc->offset;
830 }
831 
832 static int gpio_post_probe(struct udevice *dev)
833 {
834 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
835 
836 	uc_priv->name = calloc(uc_priv->gpio_count, sizeof(char *));
837 	if (!uc_priv->name)
838 		return -ENOMEM;
839 
840 	return gpio_renumber(NULL);
841 }
842 
843 static int gpio_pre_remove(struct udevice *dev)
844 {
845 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
846 	int i;
847 
848 	for (i = 0; i < uc_priv->gpio_count; i++) {
849 		if (uc_priv->name[i])
850 			free(uc_priv->name[i]);
851 	}
852 	free(uc_priv->name);
853 
854 	return gpio_renumber(dev);
855 }
856 
857 static int gpio_post_bind(struct udevice *dev)
858 {
859 #if defined(CONFIG_NEEDS_MANUAL_RELOC)
860 	struct dm_gpio_ops *ops = (struct dm_gpio_ops *)device_get_ops(dev);
861 	static int reloc_done;
862 
863 	if (!reloc_done) {
864 		if (ops->request)
865 			ops->request += gd->reloc_off;
866 		if (ops->free)
867 			ops->free += gd->reloc_off;
868 		if (ops->direction_input)
869 			ops->direction_input += gd->reloc_off;
870 		if (ops->direction_output)
871 			ops->direction_output += gd->reloc_off;
872 		if (ops->get_value)
873 			ops->get_value += gd->reloc_off;
874 		if (ops->set_value)
875 			ops->set_value += gd->reloc_off;
876 		if (ops->get_open_drain)
877 			ops->get_open_drain += gd->reloc_off;
878 		if (ops->set_open_drain)
879 			ops->set_open_drain += gd->reloc_off;
880 		if (ops->get_function)
881 			ops->get_function += gd->reloc_off;
882 		if (ops->xlate)
883 			ops->xlate += gd->reloc_off;
884 
885 		reloc_done++;
886 	}
887 #endif
888 	return 0;
889 }
890 
891 UCLASS_DRIVER(gpio) = {
892 	.id		= UCLASS_GPIO,
893 	.name		= "gpio",
894 	.flags		= DM_UC_FLAG_SEQ_ALIAS,
895 	.post_probe	= gpio_post_probe,
896 	.post_bind	= gpio_post_bind,
897 	.pre_remove	= gpio_pre_remove,
898 	.per_device_auto_alloc_size = sizeof(struct gpio_dev_priv),
899 };
900