summaryrefslogtreecommitdiff
path: root/include/asm-generic/gpio.h
blob: 859f41a0d41bed97f9341c637763f7a9a398453d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * Copyright (c) 2011 The Chromium OS Authors.
 * Copyright (c) 2011, NVIDIA Corp. All rights reserved.
 */

#ifndef _ASM_GENERIC_GPIO_H_
#define _ASM_GENERIC_GPIO_H_

#include <dm/ofnode.h>

struct ofnode_phandle_args;

/*
 * Generic GPIO API for U-Boot
 *
 * --
 * NB: This is deprecated. Please use the driver model functions instead:
 *
 *    - gpio_request_by_name()
 *    - dm_gpio_get_value() etc.
 *
 * For now we need a dm_ prefix on some functions to avoid name collision.
 * --
 *
 * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
 * by the SOC/architecture.
 *
 * Each GPIO can be an input or output. If an input then its value can
 * be read as 0 or 1. If an output then its value can be set to 0 or 1.
 * If you try to write an input then the value is undefined. If you try
 * to read an output, barring something very unusual,  you will get
 * back the value of the output that you previously set.
 *
 * In some cases the operation may fail, for example if the GPIO number
 * is out of range, or the GPIO is not available because its pin is
 * being used by another function. In that case, functions may return
 * an error value of -1.
 */

/**
 * @deprecated	Please use driver model instead
 * Request a GPIO. This should be called before any of the other functions
 * are used on this GPIO.
 *
 * Note: With driver model, the label is allocated so there is no need for
 * the caller to preserve it.
 *
 * @param gpio	GPIO number
 * @param label	User label for this GPIO
 * @return 0 if ok, -1 on error
 */
int gpio_request(unsigned gpio, const char *label);

/**
 * @deprecated	Please use driver model instead
 * Stop using the GPIO.  This function should not alter pin configuration.
 *
 * @param gpio	GPIO number
 * @return 0 if ok, -1 on error
 */
int gpio_free(unsigned gpio);

/**
 * @deprecated	Please use driver model instead
 * Make a GPIO an input.
 *
 * @param gpio	GPIO number
 * @return 0 if ok, -1 on error
 */
int gpio_direction_input(unsigned gpio);

/**
 * @deprecated	Please use driver model instead
 * Make a GPIO an output, and set its value.
 *
 * @param gpio	GPIO number
 * @param value	GPIO value (0 for low or 1 for high)
 * @return 0 if ok, -1 on error
 */
int gpio_direction_output(unsigned gpio, int value);

/**
 * @deprecated	Please use driver model instead
 * Get a GPIO's value. This will work whether the GPIO is an input
 * or an output.
 *
 * @param gpio	GPIO number
 * @return 0 if low, 1 if high, -1 on error
 */
int gpio_get_value(unsigned gpio);

/**
 * @deprecated	Please use driver model instead
 * Set an output GPIO's value. The GPIO must already be an output or
 * this function may have no effect.
 *
 * @param gpio	GPIO number
 * @param value	GPIO value (0 for low or 1 for high)
 * @return 0 if ok, -1 on error
 */
int gpio_set_value(unsigned gpio, int value);

/* State of a GPIO, as reported by get_function() */
enum gpio_func_t {
	GPIOF_INPUT = 0,
	GPIOF_OUTPUT,
	GPIOF_UNUSED,		/* Not claimed */
	GPIOF_UNKNOWN,		/* Not known */
	GPIOF_FUNC,		/* Not used as a GPIO */

	GPIOF_COUNT,
};

struct udevice;

struct gpio_desc {
	struct udevice *dev;	/* Device, NULL for invalid GPIO */
	unsigned long flags;
#define GPIOD_IS_OUT		BIT(1)	/* GPIO is an output */
#define GPIOD_IS_IN		BIT(2)	/* GPIO is an input */
#define GPIOD_ACTIVE_LOW	BIT(3)	/* GPIO is active when value is low */
#define GPIOD_IS_OUT_ACTIVE	BIT(4)	/* set output active */
#define GPIOD_OPEN_DRAIN	BIT(5)	/* GPIO is open drain type */
#define GPIOD_OPEN_SOURCE	BIT(6)	/* GPIO is open source type */
#define GPIOD_PULL_UP		BIT(7)	/* GPIO has pull-up enabled */
#define GPIOD_PULL_DOWN		BIT(8)	/* GPIO has pull-down enabled */

	uint offset;		/* GPIO offset within the device */
	/*
	 * We could consider adding the GPIO label in here. Possibly we could
	 * use this structure for internal GPIO information.
	 */
};

/* helper to compute the value of the gpio output */
#define GPIOD_FLAGS_OUTPUT_MASK (GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE)
#define GPIOD_FLAGS_OUTPUT(flags) \
	(((((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_IS_OUT_ACTIVE) || \
	  (((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_ACTIVE_LOW)))

/**
 * dm_gpio_is_valid() - Check if a GPIO is valid
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @return true if valid, false if not
 */
static inline bool dm_gpio_is_valid(const struct gpio_desc *desc)
{
	return desc->dev != NULL;
}

/**
 * gpio_get_status() - get the current GPIO status as a string
 *
 * Obtain the current GPIO status as a string which can be presented to the
 * user. A typical string is:
 *
 * "b4:  in: 1 [x] sdmmc_cd"
 *
 * which means this is GPIO bank b, offset 4, currently set to input, current
 * value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
 *
 * TODO(sjg@chromium.org): This should use struct gpio_desc
 *
 * @dev:	Device to check
 * @offset:	Offset of device GPIO to check
 * @buf:	Place to put string
 * @buffsize:	Size of string including \0
 */
int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);

/**
 * gpio_get_function() - get the current function for a GPIO pin
 *
 * Note this returns GPIOF_UNUSED if the GPIO is not requested.
 *
 * TODO(sjg@chromium.org): This should use struct gpio_desc
 *
 * @dev:	Device to check
 * @offset:	Offset of device GPIO to check
 * @namep:	If non-NULL, this is set to the name given when the GPIO
 *		was requested, or -1 if it has not been requested
 * @return  -ENODATA if the driver returned an unknown function,
 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
 * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
 * function from enum gpio_func_t.
 */
int gpio_get_function(struct udevice *dev, int offset, const char **namep);

/**
 * gpio_get_raw_function() - get the current raw function for a GPIO pin
 *
 * Note this does not return GPIOF_UNUSED - it will always return the GPIO
 * driver's view of a pin function, even if it is not correctly set up.
 *
 * TODO(sjg@chromium.org): This should use struct gpio_desc
 *
 * @dev:	Device to check
 * @offset:	Offset of device GPIO to check
 * @namep:	If non-NULL, this is set to the name given when the GPIO
 *		was requested, or -1 if it has not been requested
 * @return  -ENODATA if the driver returned an unknown function,
 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
 * Otherwise returns the function from enum gpio_func_t.
 */
int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);

/**
 * gpio_requestf() - request a GPIO using a format string for the owner
 *
 * This is a helper function for gpio_request(). It allows you to provide
 * a printf()-format string for the GPIO owner. It calls gpio_request() with
 * the string that is created
 */
int gpio_requestf(unsigned gpio, const char *fmt, ...)
		__attribute__ ((format (__printf__, 2, 3)));

struct fdtdec_phandle_args;

/**
 * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
 *
 * This routine sets the offset field to args[0] and the flags field to
 * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
 */
int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
			  struct ofnode_phandle_args *args);

/**
 * struct struct dm_gpio_ops - Driver model GPIO operations
 *
 * Refer to functions above for description. These function largely copy
 * the old API.
 *
 * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
 * new DM GPIO API, this should be really easy to flip over to the Linux
 * GPIO API-alike interface.
 *
 * Also it would be useful to standardise additional functions like
 * pullup, slew rate and drive strength.
 *
 * gpio_request() and gpio_free() are optional - if NULL then they will
 * not be called.
 *
 * Note that @offset is the offset from the base GPIO of the device. So
 * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
 * where o is the number of GPIO lines controlled by the device. A device
 * is typically used to control a single bank of GPIOs. Within complex
 * SoCs there may be many banks and therefore many devices all referring
 * to the different IO addresses within the SoC.
 *
 * The uclass combines all GPIO devices together to provide a consistent
 * numbering from 0 to n-1, where n is the number of GPIOs in total across
 * all devices. Be careful not to confuse offset with gpio in the parameters.
 */
struct dm_gpio_ops {
	int (*request)(struct udevice *dev, unsigned offset, const char *label);
	int (*rfree)(struct udevice *dev, unsigned int offset);
	int (*direction_input)(struct udevice *dev, unsigned offset);
	int (*direction_output)(struct udevice *dev, unsigned offset,
				int value);
	int (*get_value)(struct udevice *dev, unsigned offset);
	int (*set_value)(struct udevice *dev, unsigned offset, int value);
	/**
	 * get_function() Get the GPIO function
	 *
	 * @dev:     Device to check
	 * @offset:  GPIO offset within that device
	 * @return current function - GPIOF_...
	 */
	int (*get_function)(struct udevice *dev, unsigned offset);

	/**
	 * xlate() - Translate phandle arguments into a GPIO description
	 *
	 * This function should set up the fields in desc according to the
	 * information in the arguments. The uclass will have set up:
	 *
	 *   @desc->dev to @dev
	 *   @desc->flags to 0
	 *   @desc->offset to 0
	 *
	 * This method is optional and defaults to gpio_xlate_offs_flags,
	 * which will parse offset and the GPIO_ACTIVE_LOW flag in the first
	 * two arguments.
	 *
	 * Note that @dev is passed in as a parameter to follow driver model
	 * uclass conventions, even though it is already available as
	 * desc->dev.
	 *
	 * @dev:	GPIO device
	 * @desc:	Place to put GPIO description
	 * @args:	Arguments provided in description
	 * @return 0 if OK, -ve on error
	 */
	int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
		     struct ofnode_phandle_args *args);

	/**
	 * set_dir_flags() - Set GPIO dir flags
	 *
	 * This function should set up the GPIO configuration according to the
	 * information provide by the direction flags bitfield.
	 *
	 * This method is optional.
	 *
	 * @dev:	GPIO device
	 * @offset:	GPIO offset within that device
	 * @flags:	GPIO configuration to use
	 * @return 0 if OK, -ve on error
	 */
	int (*set_dir_flags)(struct udevice *dev, unsigned int offset,
			     ulong flags);

	/**
	 * get_dir_flags() - Get GPIO dir flags
	 *
	 * This function return the GPIO direction flags used.
	 *
	 * This method is optional.
	 *
	 * @dev:	GPIO device
	 * @offset:	GPIO offset within that device
	 * @flags:	place to put the used direction flags by GPIO
	 * @return 0 if OK, -ve on error
	 */
	int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
			     ulong *flags);
};

/**
 * struct gpio_dev_priv - information about a device used by the uclass
 *
 * The uclass combines all active GPIO devices into a unified numbering
 * scheme. To do this it maintains some private information about each
 * device.
 *
 * To implement driver model support in your GPIO driver, add a probe
 * handler, and set @gpio_count and @bank_name correctly in that handler.
 * This tells the uclass the name of the GPIO bank and the number of GPIOs
 * it contains.
 *
 * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
 * 'A0', 'A1', etc.
 * @gpio_count: Number of GPIOs in this device
 * @gpio_base: Base GPIO number for this device. For the first active device
 * this will be 0; the numbering for others will follow sequentially so that
 * @gpio_base for device 1 will equal the number of GPIOs in device 0.
 * @name: Array of pointers to the name for each GPIO in this bank. The
 * value of the pointer will be NULL if the GPIO has not been claimed.
 */
struct gpio_dev_priv {
	const char *bank_name;
	unsigned gpio_count;
	unsigned gpio_base;
	char **name;
};

/* Access the GPIO operations for a device */
#define gpio_get_ops(dev)	((struct dm_gpio_ops *)(dev)->driver->ops)

/**
 * gpio_get_bank_info - Return information about a GPIO bank/device
 *
 * This looks up a device and returns both its GPIO base name and the number
 * of GPIOs it controls.
 *
 * @dev: Device to look up
 * @offset_count: Returns number of GPIOs within this bank
 * @return bank name of this device
 */
const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);

/**
 * dm_gpio_lookup_name() - Look up a named GPIO and return its description
 *
 * The name of a GPIO is typically its bank name followed by a number from 0.
 * For example A0 is the first GPIO in bank A. Each bank is a separate driver
 * model device.
 *
 * @name:	Name to look up
 * @desc:	Returns description, on success
 * @return 0 if OK, -ve on error
 */
int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);

/**
 * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
 *
 * @name:	Name to look up
 * @desc:	Returns GPIO description, on success, else NULL
 * @return:	Returns 0 if OK, else -ENODEV
 */
int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);

/**
 * gpio_hog_probe_all() - probe all gpio devices with
 * gpio-hog subnodes.
 *
 * @return:	Returns return value from device_probe()
 */
int gpio_hog_probe_all(void);

/**
 * gpio_lookup_name - Look up a GPIO name and return its details
 *
 * This is used to convert a named GPIO into a device, offset and GPIO
 * number.
 *
 * @name: GPIO name to look up
 * @devp: Returns pointer to device which contains this GPIO
 * @offsetp: Returns the offset number within this device
 * @gpiop: Returns the absolute GPIO number, numbered from 0
 */
int gpio_lookup_name(const char *name, struct udevice **devp,
		     unsigned int *offsetp, unsigned int *gpiop);

/**
 * gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
 *
 * This puts the value of the first GPIO into bit 0, the second into bit 1,
 * etc. then returns the resulting integer.
 *
 * @gpio_list: List of GPIOs to collect
 * @return resulting integer value, or -ve on error
 */
int gpio_get_values_as_int(const int *gpio_list);

/**
 * dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
 *
 * This puts the value of the first GPIO into bit 0, the second into bit 1,
 * etc. then returns the resulting integer.
 *
 * @desc_list: List of GPIOs to collect
 * @count: Number of GPIOs
 * @return resulting integer value, or -ve on error
 */
int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count);

/**
 * gpio_claim_vector() - claim a number of GPIOs for input
 *
 * @gpio_num_array:	array of gpios to claim, terminated by -1
 * @fmt:		format string for GPIO names, e.g. "board_id%d"
 * @return 0 if OK, -ve on error
 */
int gpio_claim_vector(const int *gpio_num_array, const char *fmt);

/**
 * gpio_request_by_name() - Locate and request a GPIO by name
 *
 * This operates by looking up the given list name in the device (device
 * tree property) and requesting the GPIO for use. The property must exist
 * in @dev's node.
 *
 * Use @flags to specify whether the GPIO should be an input or output. In
 * principle this can also come from the device tree binding but most
 * bindings don't provide this information. Specifically, when the GPIO uclass
 * calls the xlate() method, it can return default flags, which are then
 * ORed with this @flags.
 *
 * If we find that requesting the GPIO is not always needed we could add a
 * new function or a new GPIOD_NO_REQUEST flag.
 *
 * At present driver model has no reference counting so if one device
 * requests a GPIO which subsequently is unbound, the @desc->dev pointer
 * will be invalid. However this will only happen if the GPIO device is
 * unbound, not if it is removed, so this seems like a reasonable limitation
 * for now. There is no real use case for unbinding drivers in normal
 * operation.
 *
 * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
 * generate terms and each specific device may add additional details in
 * a binding file in the same directory.
 *
 * @dev:	Device requesting the GPIO
 * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
 * @index:	Index number of the GPIO in that list use request (0=first)
 * @desc:	Returns GPIO description information. If there is no such
 *		GPIO, dev->dev will be NULL.
 * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
 * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
 * something wrong with the list, or other -ve for another error (e.g.
 * -EBUSY if a GPIO was already requested)
 */
int gpio_request_by_name(struct udevice *dev, const char *list_name,
			 int index, struct gpio_desc *desc, int flags);

/**
 * gpio_request_list_by_name() - Request a list of GPIOs
 *
 * Reads all the GPIOs from a list and requests them. See
 * gpio_request_by_name() for additional details. Lists should not be
 * misused to hold unrelated or optional GPIOs. They should only be used
 * for things like parallel data lines. A zero phandle terminates the list
 * the list.
 *
 * This function will either succeed, and request all GPIOs in the list, or
 * fail and request none (it will free already-requested GPIOs in case of
 * an error part-way through).
 *
 * @dev:	Device requesting the GPIO
 * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
 * @desc_list:	Returns a list of GPIO description information
 * @max_count:	Maximum number of GPIOs to return (@desc_list must be at least
 *		this big)
 * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
 * @return number of GPIOs requested, or -ve on error
 */
int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
			      struct gpio_desc *desc_list, int max_count,
			      int flags);

/**
 * dm_gpio_request() - manually request a GPIO
 *
 * Note: This function should only be used for testing / debugging. Instead.
 * use gpio_request_by_name() to pull GPIOs from the device tree.
 *
 * @desc:	GPIO description of GPIO to request (see dm_gpio_lookup_name())
 * @label:	Label to attach to the GPIO while claimed
 * @return 0 if OK, -ve on error
 */
int dm_gpio_request(struct gpio_desc *desc, const char *label);

/**
 * gpio_get_list_count() - Returns the number of GPIOs in a list
 *
 * Counts the GPIOs in a list. See gpio_request_by_name() for additional
 * details.
 *
 * @dev:	Device requesting the GPIO
 * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
 * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
 * does not exist
 */
int gpio_get_list_count(struct udevice *dev, const char *list_name);

/**
 * gpio_request_by_name_nodev() - request GPIOs without a device
 *
 * This is a version of gpio_request_list_by_name() that does not use a
 * device. Avoid it unless the caller is not yet using driver model
 */
int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
			       struct gpio_desc *desc, int flags);

/**
 * gpio_request_list_by_name_nodev() - request GPIOs without a device
 *
 * This is a version of gpio_request_list_by_name() that does not use a
 * device. Avoid it unless the caller is not yet using driver model
 */
int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
				    struct gpio_desc *desc_list, int max_count,
				    int flags);

/**
 * gpio_dev_request_index() - request single GPIO from gpio device
 *
 * @dev:	GPIO device
 * @nodename:	Name of node for which gpio gets requested, used
 *		for the gpio label name
 * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
 * @index:	Index number of the GPIO in that list use request (0=first)
 * @flags:	GPIOD_* flags
 * @dtflags:	GPIO flags read from DT defined see GPIOD_*
 * @desc:	returns GPIO descriptor filled from this function
 * @return:	return value from gpio_request_tail()
 */
int gpio_dev_request_index(struct udevice *dev, const char *nodename,
			   char *list_name, int index, int flags,
			   int dtflags, struct gpio_desc *desc);

/**
 * dm_gpio_free() - Free a single GPIO
 *
 * This frees a single GPIOs previously returned from gpio_request_by_name().
 *
 * @dev:	Device which requested the GPIO
 * @desc:	GPIO to free
 * @return 0 if OK, -ve on error
 */
int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);

/**
 * gpio_free_list() - Free a list of GPIOs
 *
 * This frees a list of GPIOs previously returned from
 * gpio_request_list_by_name().
 *
 * @dev:	Device which requested the GPIOs
 * @desc:	List of GPIOs to free
 * @count:	Number of GPIOs in the list
 * @return 0 if OK, -ve on error
 */
int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);

/**
 * gpio_free_list_nodev() - free GPIOs without a device
 *
 * This is a version of gpio_free_list() that does not use a
 * device. Avoid it unless the caller is not yet using driver model
 */
int gpio_free_list_nodev(struct gpio_desc *desc, int count);

/**
 * dm_gpio_get_value() - Get the value of a GPIO
 *
 * This is the driver model version of the existing gpio_get_value() function
 * and should be used instead of that.
 *
 * For now, these functions have a dm_ prefix since they conflict with
 * existing names.
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @return GPIO value (0 for inactive, 1 for active) or -ve on error
 */
int dm_gpio_get_value(const struct gpio_desc *desc);

int dm_gpio_set_value(const struct gpio_desc *desc, int value);

/**
 * dm_gpio_set_dir() - Set the direction for a GPIO
 *
 * This sets up the direction according to the GPIO flags: desc->flags.
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @return 0 if OK, -ve on error
 */
int dm_gpio_set_dir(struct gpio_desc *desc);

/**
 * dm_gpio_set_dir_flags() - Set direction using description and added flags
 *
 * This sets up the direction according to the provided flags and the GPIO
 * description (desc->flags) which include direction information.
 * Note that desc->flags is updated by this function.
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @flags:	New flags to use
 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
 */
int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);

/**
 * dm_gpio_get_dir_flags() - Get direction flags
 *
 * read the current direction flags
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @flags:	place to put the used flags
 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
 */
int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags);

/**
 * gpio_get_number() - Get the global GPIO number of a GPIO
 *
 * This should only be used for debugging or interest. It returns the number
 * that should be used for gpio_get_value() etc. to access this GPIO.
 *
 * @desc:	GPIO description containing device, offset and flags,
 *		previously returned by gpio_request_by_name()
 * @return GPIO number, or -ve if not found
 */
int gpio_get_number(const struct gpio_desc *desc);

#endif	/* _ASM_GENERIC_GPIO_H_ */