1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3  * Copyright (c) 2011 The Chromium OS Authors.
4  * Copyright (c) 2011, NVIDIA Corp. All rights reserved.
5  */
6 
7 #ifndef _ASM_GENERIC_GPIO_H_
8 #define _ASM_GENERIC_GPIO_H_
9 
10 #include <dm/ofnode.h>
11 #include <linux/bitops.h>
12 
13 struct acpi_gpio;
14 struct ofnode_phandle_args;
15 
16 /*
17  * Generic GPIO API for U-Boot
18  *
19  * --
20  * NB: This is deprecated. Please use the driver model functions instead:
21  *
22  *    - gpio_request_by_name()
23  *    - dm_gpio_get_value() etc.
24  *
25  * For now we need a dm_ prefix on some functions to avoid name collision.
26  * --
27  *
28  * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
29  * by the SOC/architecture.
30  *
31  * Each GPIO can be an input or output. If an input then its value can
32  * be read as 0 or 1. If an output then its value can be set to 0 or 1.
33  * If you try to write an input then the value is undefined. If you try
34  * to read an output, barring something very unusual,  you will get
35  * back the value of the output that you previously set.
36  *
37  * In some cases the operation may fail, for example if the GPIO number
38  * is out of range, or the GPIO is not available because its pin is
39  * being used by another function. In that case, functions may return
40  * an error value of -1.
41  */
42 
43 /**
44  * @deprecated	Please use driver model instead
45  * Request a GPIO. This should be called before any of the other functions
46  * are used on this GPIO.
47  *
48  * Note: With driver model, the label is allocated so there is no need for
49  * the caller to preserve it.
50  *
51  * @param gpio	GPIO number
52  * @param label	User label for this GPIO
53  * Return: 0 if ok, -1 on error
54  */
55 int gpio_request(unsigned gpio, const char *label);
56 
57 /**
58  * @deprecated	Please use driver model instead
59  * Stop using the GPIO.  This function should not alter pin configuration.
60  *
61  * @param gpio	GPIO number
62  * Return: 0 if ok, -1 on error
63  */
64 int gpio_free(unsigned gpio);
65 
66 /**
67  * @deprecated	Please use driver model instead
68  * Make a GPIO an input.
69  *
70  * @param gpio	GPIO number
71  * Return: 0 if ok, -1 on error
72  */
73 int gpio_direction_input(unsigned gpio);
74 
75 /**
76  * @deprecated	Please use driver model instead
77  * Make a GPIO an output, and set its value.
78  *
79  * @param gpio	GPIO number
80  * @param value	GPIO value (0 for low or 1 for high)
81  * Return: 0 if ok, -1 on error
82  */
83 int gpio_direction_output(unsigned gpio, int value);
84 
85 /**
86  * @deprecated	Please use driver model instead
87  * Get a GPIO's value. This will work whether the GPIO is an input
88  * or an output.
89  *
90  * @param gpio	GPIO number
91  * Return: 0 if low, 1 if high, -1 on error
92  */
93 int gpio_get_value(unsigned gpio);
94 
95 /**
96  * @deprecated	Please use driver model instead
97  * Set an output GPIO's value. The GPIO must already be an output or
98  * this function may have no effect.
99  *
100  * @param gpio	GPIO number
101  * @param value	GPIO value (0 for low or 1 for high)
102  * Return: 0 if ok, -1 on error
103  */
104 int gpio_set_value(unsigned gpio, int value);
105 
106 /* State of a GPIO, as reported by get_function() */
107 enum gpio_func_t {
108 	GPIOF_INPUT = 0,
109 	GPIOF_OUTPUT,
110 	GPIOF_UNUSED,		/* Not claimed */
111 	GPIOF_UNKNOWN,		/* Not known */
112 	GPIOF_FUNC,		/* Not used as a GPIO */
113 
114 	GPIOF_COUNT,
115 };
116 
117 struct udevice;
118 
119 struct gpio_desc {
120 	struct udevice *dev;	/* Device, NULL for invalid GPIO */
121 	unsigned long flags;
122 #define GPIOD_IS_OUT		BIT(1)	/* GPIO is an output */
123 #define GPIOD_IS_IN		BIT(2)	/* GPIO is an input */
124 #define GPIOD_ACTIVE_LOW	BIT(3)	/* GPIO is active when value is low */
125 #define GPIOD_IS_OUT_ACTIVE	BIT(4)	/* set output active */
126 #define GPIOD_OPEN_DRAIN	BIT(5)	/* GPIO is open drain type */
127 #define GPIOD_OPEN_SOURCE	BIT(6)	/* GPIO is open source type */
128 #define GPIOD_PULL_UP		BIT(7)	/* GPIO has pull-up enabled */
129 #define GPIOD_PULL_DOWN		BIT(8)	/* GPIO has pull-down enabled */
130 #define GPIOD_IS_AF		BIT(9)	/* GPIO is an alternate function */
131 
132 /* Flags for updating the above */
133 #define GPIOD_MASK_DIR		(GPIOD_IS_OUT | GPIOD_IS_IN | \
134 					GPIOD_IS_OUT_ACTIVE)
135 #define GPIOD_MASK_DSTYPE	(GPIOD_OPEN_DRAIN | GPIOD_OPEN_SOURCE)
136 #define GPIOD_MASK_PULL		(GPIOD_PULL_UP | GPIOD_PULL_DOWN)
137 
138 	uint offset;		/* GPIO offset within the device */
139 	/*
140 	 * We could consider adding the GPIO label in here. Possibly we could
141 	 * use this structure for internal GPIO information.
142 	 */
143 };
144 
145 /**
146  * dm_gpio_is_valid() - Check if a GPIO is valid
147  *
148  * @desc:	GPIO description containing device, offset and flags,
149  *		previously returned by gpio_request_by_name()
150  * Return: true if valid, false if not
151  */
dm_gpio_is_valid(const struct gpio_desc * desc)152 static inline bool dm_gpio_is_valid(const struct gpio_desc *desc)
153 {
154 	return desc->dev != NULL;
155 }
156 
157 /**
158  * gpio_get_status() - get the current GPIO status as a string
159  *
160  * Obtain the current GPIO status as a string which can be presented to the
161  * user. A typical string is:
162  *
163  * "b4:  in: 1 [x] sdmmc_cd"
164  *
165  * which means this is GPIO bank b, offset 4, currently set to input, current
166  * value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
167  *
168  * TODO(sjg@chromium.org): This should use struct gpio_desc
169  *
170  * @dev:	Device to check
171  * @offset:	Offset of device GPIO to check
172  * @buf:	Place to put string
173  * @buffsize:	Size of string including \0
174  */
175 int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);
176 
177 /**
178  * gpio_get_function() - get the current function for a GPIO pin
179  *
180  * Note this returns GPIOF_UNUSED if the GPIO is not requested.
181  *
182  * TODO(sjg@chromium.org): This should use struct gpio_desc
183  *
184  * @dev:	Device to check
185  * @offset:	Offset of device GPIO to check
186  * @namep:	If non-NULL, this is set to the name given when the GPIO
187  *		was requested, or -1 if it has not been requested
188  * Return:  -ENODATA if the driver returned an unknown function,
189  * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
190  * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
191  * function from enum gpio_func_t.
192  */
193 int gpio_get_function(struct udevice *dev, int offset, const char **namep);
194 
195 /**
196  * gpio_get_raw_function() - get the current raw function for a GPIO pin
197  *
198  * Note this does not return GPIOF_UNUSED - it will always return the GPIO
199  * driver's view of a pin function, even if it is not correctly set up.
200  *
201  * TODO(sjg@chromium.org): This should use struct gpio_desc
202  *
203  * @dev:	Device to check
204  * @offset:	Offset of device GPIO to check
205  * @namep:	If non-NULL, this is set to the name given when the GPIO
206  *		was requested, or -1 if it has not been requested
207  * Return:  -ENODATA if the driver returned an unknown function,
208  * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
209  * Otherwise returns the function from enum gpio_func_t.
210  */
211 int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
212 
213 /**
214  * gpio_requestf() - request a GPIO using a format string for the owner
215  *
216  * This is a helper function for gpio_request(). It allows you to provide
217  * a printf()-format string for the GPIO owner. It calls gpio_request() with
218  * the string that is created
219  */
220 int gpio_requestf(unsigned gpio, const char *fmt, ...)
221 		__attribute__ ((format (__printf__, 2, 3)));
222 
223 struct fdtdec_phandle_args;
224 
225 /**
226  * gpio_flags_xlate() - convert DT flags to internal flags
227  *
228  * This routine converts the GPIO_* flags from the generic DT binding to the
229  * GPIOD_* flags used internally. It can be called from driver xlate functions.
230  */
231 unsigned long gpio_flags_xlate(uint32_t arg);
232 
233 /**
234  * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
235  *
236  * This routine sets the offset field to args[0] and the flags field to
237  * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
238  */
239 int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
240 			  struct ofnode_phandle_args *args);
241 
242 /**
243  * struct struct dm_gpio_ops - Driver model GPIO operations
244  *
245  * Refer to functions above for description. These function largely copy
246  * the old API.
247  *
248  * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
249  * new DM GPIO API, this should be really easy to flip over to the Linux
250  * GPIO API-alike interface.
251  *
252  * Also it would be useful to standardise additional functions like
253  * pullup, slew rate and drive strength.
254  *
255  * gpio_request() and gpio_free() are optional - if NULL then they will
256  * not be called.
257  *
258  * Note that @offset is the offset from the base GPIO of the device. So
259  * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
260  * where o is the number of GPIO lines controlled by the device. A device
261  * is typically used to control a single bank of GPIOs. Within complex
262  * SoCs there may be many banks and therefore many devices all referring
263  * to the different IO addresses within the SoC.
264  *
265  * The uclass combines all GPIO devices together to provide a consistent
266  * numbering from 0 to n-1, where n is the number of GPIOs in total across
267  * all devices. Be careful not to confuse offset with gpio in the parameters.
268  */
269 struct dm_gpio_ops {
270 	int (*request)(struct udevice *dev, unsigned offset, const char *label);
271 	int (*rfree)(struct udevice *dev, unsigned int offset);
272 
273 	/**
274 	 * direction_input() - deprecated
275 	 *
276 	 * Equivalent to set_flags(...GPIOD_IS_IN)
277 	 */
278 	int (*direction_input)(struct udevice *dev, unsigned offset);
279 
280 	/**
281 	 * direction_output() - deprecated
282 	 *
283 	 * Equivalent to set_flags(...GPIOD_IS_OUT) with GPIOD_IS_OUT_ACTIVE
284 	 * also set if @value
285 	 */
286 	int (*direction_output)(struct udevice *dev, unsigned offset,
287 				int value);
288 
289 	int (*get_value)(struct udevice *dev, unsigned offset);
290 
291 	/**
292 	 * set_value() - Sets the GPIO value of an output
293 	 *
294 	 * If the driver provides an @set_flags() method then that is used
295 	 * in preference to this, with GPIOD_IS_OUT_ACTIVE set according to
296 	 * @value.
297 	 */
298 	int (*set_value)(struct udevice *dev, unsigned offset, int value);
299 	/**
300 	 * get_function() Get the GPIO function
301 	 *
302 	 * @dev:     Device to check
303 	 * @offset:  GPIO offset within that device
304 	 * @return current function - GPIOF_...
305 	 */
306 	int (*get_function)(struct udevice *dev, unsigned offset);
307 
308 	/**
309 	 * xlate() - Translate phandle arguments into a GPIO description
310 	 *
311 	 * This function should set up the fields in desc according to the
312 	 * information in the arguments. The uclass will have set up:
313 	 *
314 	 *   @desc->dev to @dev
315 	 *   @desc->flags to 0
316 	 *   @desc->offset to 0
317 	 *
318 	 * This method is optional and defaults to gpio_xlate_offs_flags,
319 	 * which will parse offset and the GPIO_ACTIVE_LOW flag in the first
320 	 * two arguments.
321 	 *
322 	 * Note that @dev is passed in as a parameter to follow driver model
323 	 * uclass conventions, even though it is already available as
324 	 * desc->dev.
325 	 *
326 	 * @dev:	GPIO device
327 	 * @desc:	Place to put GPIO description
328 	 * @args:	Arguments provided in description
329 	 * @return 0 if OK, -ve on error
330 	 */
331 	int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
332 		     struct ofnode_phandle_args *args);
333 
334 	/**
335 	 * set_flags() - Adjust GPIO flags
336 	 *
337 	 * This function should set up the GPIO configuration according to the
338 	 * information provided by @flags.
339 	 *
340 	 * If any flags cannot be set (e.g. the driver or hardware does not
341 	 * support them or this particular GPIO does not have the requested
342 	 * feature), the driver should return -EINVAL.
343 	 *
344 	 * The uclass checks that flags do not obviously conflict (e.g. input
345 	 * and output). If the driver finds other conflicts it should return
346 	 * -ERECALLCONFLICT
347 	 *
348 	 * Note that GPIOD_ACTIVE_LOW should be ignored, since the uclass
349 	 * adjusts for it automatically. For example, for an output GPIO,
350 	 * GPIOD_ACTIVE_LOW causes GPIOD_IS_OUT_ACTIVE to be inverted by the
351 	 * uclass, so the driver always sees the value that should be set at the
352 	 * pin (1=high, 0=low).
353 	 *
354 	 * This method is required and should be implemented by new drivers. At
355 	 * some point, it will supersede direction_input() and
356 	 * direction_output(), which wil be removed.
357 	 *
358 	 * @dev:	GPIO device
359 	 * @offset:	GPIO offset within that device
360 	 * @flags:	New flags value (GPIOD_...)
361 	 *
362 	 * @return 0 if OK, -EINVAL if unsupported, -ERECALLCONFLICT if flags
363 	 *	conflict in some *	non-obvious way and were not applied,
364 	 *	other -ve on error
365 	 */
366 	int (*set_flags)(struct udevice *dev, unsigned int offset, ulong flags);
367 
368 	/**
369 	 * get_flags() - Get GPIO flags
370 	 *
371 	 * This function return the GPIO flags used. It should read this from
372 	 * the hardware directly.
373 	 *
374 	 * This method is optional.
375 	 *
376 	 * @dev:	GPIO device
377 	 * @offset:	GPIO offset within that device
378 	 * @flagsp:	place to put the current flags value
379 	 * @return 0 if OK, -ve on error
380 	 */
381 	int (*get_flags)(struct udevice *dev, unsigned int offset,
382 			 ulong *flagsp);
383 
384 #if CONFIG_IS_ENABLED(ACPIGEN)
385 	/**
386 	 * get_acpi() - Get the ACPI info for a GPIO
387 	 *
388 	 * This converts a GPIO to an ACPI structure for adding to the ACPI
389 	 * tables.
390 	 *
391 	 * @desc:	GPIO description to convert
392 	 * @gpio:	Output ACPI GPIO information
393 	 * @return ACPI pin number or -ve on error
394 	 */
395 	int (*get_acpi)(const struct gpio_desc *desc, struct acpi_gpio *gpio);
396 #endif
397 };
398 
399 /**
400  * struct gpio_dev_priv - information about a device used by the uclass
401  *
402  * The uclass combines all active GPIO devices into a unified numbering
403  * scheme. To do this it maintains some private information about each
404  * device.
405  *
406  * To implement driver model support in your GPIO driver, add a probe
407  * handler, and set @gpio_count and @bank_name correctly in that handler.
408  * This tells the uclass the name of the GPIO bank and the number of GPIOs
409  * it contains.
410  *
411  * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
412  * 'A0', 'A1', etc.
413  * @gpio_count: Number of GPIOs in this device
414  * @gpio_base: Base GPIO number for this device. For the first active device
415  * this will be 0; the numbering for others will follow sequentially so that
416  * @gpio_base for device 1 will equal the number of GPIOs in device 0.
417  * @claimed: Array of bits indicating which GPIOs in the bank are claimed.
418  * @name: Array of pointers to the name for each GPIO in this bank. The
419  * value of the pointer will be NULL if the GPIO has not been claimed.
420  */
421 struct gpio_dev_priv {
422 	const char *bank_name;
423 	unsigned gpio_count;
424 	unsigned gpio_base;
425 	u32 *claimed;
426 	char **name;
427 };
428 
429 /* Access the GPIO operations for a device */
430 #define gpio_get_ops(dev)	((struct dm_gpio_ops *)(dev)->driver->ops)
431 
432 /**
433  * gpio_get_bank_info - Return information about a GPIO bank/device
434  *
435  * This looks up a device and returns both its GPIO base name and the number
436  * of GPIOs it controls.
437  *
438  * @dev: Device to look up
439  * @offset_count: Returns number of GPIOs within this bank
440  * Return: bank name of this device
441  */
442 const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
443 
444 /**
445  * dm_gpio_lookup_name() - Look up a named GPIO and return its description
446  *
447  * The name of a GPIO is typically its bank name followed by a number from 0.
448  * For example A0 is the first GPIO in bank A. Each bank is a separate driver
449  * model device.
450  *
451  * @name:	Name to look up
452  * @desc:	Returns description, on success
453  * Return: 0 if OK, -ve on error
454  */
455 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
456 
457 /**
458  * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
459  *
460  * @name:	Name to look up
461  * @desc:	Returns GPIO description, on success, else NULL
462  * @return:	Returns 0 if OK, else -ENODEV
463  */
464 int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);
465 
466 /**
467  * gpio_lookup_name - Look up a GPIO name and return its details
468  *
469  * This is used to convert a named GPIO into a device, offset and GPIO
470  * number.
471  *
472  * @name: GPIO name to look up
473  * @devp: Returns pointer to device which contains this GPIO
474  * @offsetp: Returns the offset number within this device
475  * @gpiop: Returns the absolute GPIO number, numbered from 0
476  */
477 int gpio_lookup_name(const char *name, struct udevice **devp,
478 		     unsigned int *offsetp, unsigned int *gpiop);
479 
480 /**
481  * gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
482  *
483  * This puts the value of the first GPIO into bit 0, the second into bit 1,
484  * etc. then returns the resulting integer.
485  *
486  * @gpio_list: List of GPIOs to collect
487  * Return: resulting integer value, or -ve on error
488  */
489 int gpio_get_values_as_int(const int *gpio_list);
490 
491 /**
492  * dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
493  *
494  * This puts the value of the first GPIO into bit 0, the second into bit 1,
495  * etc. then returns the resulting integer.
496  *
497  * @desc_list: List of GPIOs to collect
498  * @count: Number of GPIOs
499  * Return: resulting integer value, or -ve on error
500  */
501 int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count);
502 
503 /**
504  * dm_gpio_get_values_as_int_base3() - Create a base-3 int from a list of GPIOs
505  *
506  * This uses pull-ups/pull-downs to figure out whether a GPIO line is externally
507  * pulled down, pulled up or floating. This allows three different strap values
508  * for each pin:
509  *    0 : external pull-down
510  *    1 : external pull-up
511  *    2 : floating
512  *
513  * With this it is possible to obtain more combinations from the same number of
514  * strapping pins, when compared to dm_gpio_get_values_as_int(). The external
515  * pull resistors should be made stronger that the internal SoC pull resistors,
516  * for this to work.
517  *
518  * With 2 pins, 6 combinations are possible, compared with 4
519  * With 3 pins, 27 are possible, compared with 8
520  *
521  * @desc_list: List of GPIOs to collect
522  * @count: Number of GPIOs
523  * Return: resulting integer value, or -ve on error
524  */
525 int dm_gpio_get_values_as_int_base3(struct gpio_desc *desc_list,
526 				    int count);
527 
528 /**
529  * gpio_claim_vector() - claim a number of GPIOs for input
530  *
531  * @gpio_num_array:	array of gpios to claim, terminated by -1
532  * @fmt:		format string for GPIO names, e.g. "board_id%d"
533  * Return: 0 if OK, -ve on error
534  */
535 int gpio_claim_vector(const int *gpio_num_array, const char *fmt);
536 
537 /**
538  * gpio_request_by_name() - Locate and request a GPIO by name
539  *
540  * This operates by looking up the given list name in the device (device
541  * tree property) and requesting the GPIO for use. The property must exist
542  * in @dev's node.
543  *
544  * Use @flags to specify whether the GPIO should be an input or output. In
545  * principle this can also come from the device tree binding but most
546  * bindings don't provide this information. Specifically, when the GPIO uclass
547  * calls the xlate() method, it can return default flags, which are then
548  * ORed with this @flags.
549  *
550  * If we find that requesting the GPIO is not always needed we could add a
551  * new function or a new GPIOD_NO_REQUEST flag.
552  *
553  * At present driver model has no reference counting so if one device
554  * requests a GPIO which subsequently is unbound, the @desc->dev pointer
555  * will be invalid. However this will only happen if the GPIO device is
556  * unbound, not if it is removed, so this seems like a reasonable limitation
557  * for now. There is no real use case for unbinding drivers in normal
558  * operation.
559  *
560  * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
561  * generate terms and each specific device may add additional details in
562  * a binding file in the same directory.
563  *
564  * @dev:	Device requesting the GPIO
565  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
566  * @index:	Index number of the GPIO in that list use request (0=first)
567  * @desc:	Returns GPIO description information. If there is no such
568  *		GPIO, @desc->dev will be NULL.
569  * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
570  * Return: 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
571  * something wrong with the list, or other -ve for another error (e.g.
572  * -EBUSY if a GPIO was already requested)
573  */
574 int gpio_request_by_name(struct udevice *dev, const char *list_name,
575 			 int index, struct gpio_desc *desc, int flags);
576 
577 /* gpio_request_by_line_name - Locate and request a GPIO by line name
578  *
579  * Request a GPIO using the offset of the provided line name in the
580  * gpio-line-names property found in the OF node of the GPIO udevice.
581  *
582  * This allows boards to implement common behaviours using GPIOs while not
583  * requiring specific GPIO offsets be used.
584  *
585  * @dev:        An instance of a GPIO controller udevice, or NULL to search
586  *              all GPIO controller devices
587  * @line_name:	The name of the GPIO (e.g. "bmc-secure-boot")
588  * @desc:	A GPIO descriptor that is populated with the requested GPIO
589  *              upon return
590  * @flags:	The GPIO settings apply to the request
591  * @return 0 if the named line was found and requested successfully, or a
592  * negative error code if the GPIO cannot be found or the request failed.
593  */
594 int gpio_request_by_line_name(struct udevice *dev, const char *line_name,
595 			      struct gpio_desc *desc, int flags);
596 
597 /**
598  * gpio_request_list_by_name() - Request a list of GPIOs
599  *
600  * Reads all the GPIOs from a list and requests them. See
601  * gpio_request_by_name() for additional details. Lists should not be
602  * misused to hold unrelated or optional GPIOs. They should only be used
603  * for things like parallel data lines. A zero phandle terminates the list
604  * the list.
605  *
606  * This function will either succeed, and request all GPIOs in the list, or
607  * fail and request none (it will free already-requested GPIOs in case of
608  * an error part-way through).
609  *
610  * @dev:	Device requesting the GPIO
611  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
612  * @desc_list:	Returns a list of GPIO description information
613  * @max_count:	Maximum number of GPIOs to return (@desc_list must be at least
614  *		this big)
615  * @flags:	Indicates the GPIO input/output settings (GPIOD_...)
616  * Return: number of GPIOs requested, or -ve on error
617  */
618 int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
619 			      struct gpio_desc *desc_list, int max_count,
620 			      int flags);
621 
622 /**
623  * dm_gpio_request() - manually request a GPIO
624  *
625  * Note: This function should only be used for testing / debugging. Instead.
626  * use gpio_request_by_name() to pull GPIOs from the device tree.
627  *
628  * @desc:	GPIO description of GPIO to request (see dm_gpio_lookup_name())
629  * @label:	Label to attach to the GPIO while claimed
630  * Return: 0 if OK, -ve on error
631  */
632 int dm_gpio_request(struct gpio_desc *desc, const char *label);
633 
634 struct phandle_2_arg;
635 int gpio_request_by_phandle(struct udevice *dev,
636 			    const struct phandle_2_arg *cells,
637 			    struct gpio_desc *desc, int flags);
638 
639 /**
640  * gpio_get_list_count() - Returns the number of GPIOs in a list
641  *
642  * Counts the GPIOs in a list. See gpio_request_by_name() for additional
643  * details.
644  *
645  * @dev:	Device requesting the GPIO
646  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
647  * Return: number of GPIOs (0 for an empty property) or -ENOENT if the list
648  * does not exist
649  */
650 int gpio_get_list_count(struct udevice *dev, const char *list_name);
651 
652 /**
653  * gpio_request_by_name_nodev() - request GPIOs without a device
654  *
655  * This is a version of gpio_request_list_by_name() that does not use a
656  * device. Avoid it unless the caller is not yet using driver model
657  */
658 int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
659 			       struct gpio_desc *desc, int flags);
660 
661 /**
662  * gpio_request_list_by_name_nodev() - request GPIOs without a device
663  *
664  * This is a version of gpio_request_list_by_name() that does not use a
665  * device. Avoid it unless the caller is not yet using driver model
666  */
667 int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
668 				    struct gpio_desc *desc_list, int max_count,
669 				    int flags);
670 
671 /**
672  * gpio_dev_request_index() - request single GPIO from gpio device
673  *
674  * @dev:	GPIO device
675  * @nodename:	Name of node for which gpio gets requested, used
676  *		for the gpio label name
677  * @list_name:	Name of GPIO list (e.g. "board-id-gpios")
678  * @index:	Index number of the GPIO in that list use request (0=first)
679  * @flags:	GPIOD_* flags
680  * @dtflags:	GPIO flags read from DT defined see GPIOD_*
681  * @desc:	returns GPIO descriptor filled from this function
682  * @return:	return value from gpio_request_tail()
683  */
684 int gpio_dev_request_index(struct udevice *dev, const char *nodename,
685 			   char *list_name, int index, int flags,
686 			   int dtflags, struct gpio_desc *desc);
687 
688 /**
689  * dm_gpio_free() - Free a single GPIO
690  *
691  * This frees a single GPIOs previously returned from gpio_request_by_name().
692  *
693  * @dev:	Device which requested the GPIO
694  * @desc:	GPIO to free
695  * Return: 0 if OK, -ve on error
696  */
697 int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
698 
699 /**
700  * gpio_free_list() - Free a list of GPIOs
701  *
702  * This frees a list of GPIOs previously returned from
703  * gpio_request_list_by_name().
704  *
705  * @dev:	Device which requested the GPIOs
706  * @desc:	List of GPIOs to free
707  * @count:	Number of GPIOs in the list
708  * Return: 0 if OK, -ve on error
709  */
710 int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
711 
712 /**
713  * gpio_free_list_nodev() - free GPIOs without a device
714  *
715  * This is a version of gpio_free_list() that does not use a
716  * device. Avoid it unless the caller is not yet using driver model
717  */
718 int gpio_free_list_nodev(struct gpio_desc *desc, int count);
719 
720 /**
721  * dm_gpio_get_value() - Get the value of a GPIO
722  *
723  * This is the driver model version of the existing gpio_get_value() function
724  * and should be used instead of that.
725  *
726  * For now, these functions have a dm_ prefix since they conflict with
727  * existing names.
728  *
729  * @desc:	GPIO description containing device, offset and flags,
730  *		previously returned by gpio_request_by_name()
731  * Return: GPIO value (0 for inactive, 1 for active) or -ve on error
732  */
733 int dm_gpio_get_value(const struct gpio_desc *desc);
734 
735 int dm_gpio_set_value(const struct gpio_desc *desc, int value);
736 
737 /**
738  * dm_gpio_clrset_flags() - Update flags
739  *
740  * This updates the flags as directled. Note that desc->flags is updated by this
741  * function on success. If any changes cannot be made, best efforts are made.
742  *
743  * By use of @clr and @set any of flags can be individually updated, or left
744  * alone
745  *
746  * @desc:	GPIO description containing device, offset and flags,
747  *		previously returned by gpio_request_by_name()
748  * @clr:	Flags to clear (GPIOD_...)
749  * @set:	Flags to set (GPIOD_...)
750  * Return: 0 if OK, -EINVAL if the flags had obvious conflicts,
751  * -ERECALLCONFLICT if there was a non-obvious hardware conflict when attempting
752  * to set the flags
753  */
754 int dm_gpio_clrset_flags(struct gpio_desc *desc, ulong clr, ulong set);
755 
756 /**
757  * dm_gpio_set_dir_flags() - Set direction using description and added flags
758  *
759  * This sets up the direction according to the provided flags and the GPIO
760  * description (desc->flags) which include direction information.
761  * Note that desc->flags is updated by this function.
762  *
763  * @desc:	GPIO description containing device, offset and flags,
764  *		previously returned by gpio_request_by_name()
765  * @flags:	New flags to use
766  * Return: 0 if OK, -ve on error, in which case desc->flags is not updated
767  */
768 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
769 
770 /**
771  * dm_gpios_clrset_flags() - Sets flags for a set of GPIOs
772  *
773  * This clears and sets flags individually for each GPIO.
774  *
775  * @desc:	List of GPIOs to update
776  * @count:	Number of GPIOs in the list
777  * @clr:	Flags to clear (GPIOD_...), e.g. GPIOD_MASK_DIR if you are
778  *		changing the direction
779  * @set:	Flags to set (GPIOD_...)
780  * Return: 0 if OK, -ve on error
781  */
782 int dm_gpios_clrset_flags(struct gpio_desc *desc, int count, ulong clr,
783 			  ulong set);
784 
785 /**
786  * dm_gpio_get_flags() - Get flags
787  *
788  * Read the current flags
789  *
790  * @desc:	GPIO description containing device, offset and flags,
791  *		previously returned by gpio_request_by_name()
792  * @flags:	place to put the used flags
793  * Return: 0 if OK, -ve on error, in which case desc->flags is not updated
794  */
795 int dm_gpio_get_flags(struct gpio_desc *desc, ulong *flags);
796 
797 /**
798  * gpio_get_number() - Get the global GPIO number of a GPIO
799  *
800  * This should only be used for debugging or interest. It returns the number
801  * that should be used for gpio_get_value() etc. to access this GPIO.
802  *
803  * @desc:	GPIO description containing device, offset and flags,
804  *		previously returned by gpio_request_by_name()
805  * Return: GPIO number, or -ve if not found
806  */
807 int gpio_get_number(const struct gpio_desc *desc);
808 
809 /**
810  * gpio_get_acpi() - Get the ACPI pin for a GPIO
811  *
812  * This converts a GPIO to an ACPI pin number for adding to the ACPI
813  * tables. If the GPIO is invalid, the pin_count and pins[0] are set to 0
814  *
815  * @desc:	GPIO description to convert
816  * @gpio:	Output ACPI GPIO information
817  * Return: ACPI pin number or -ve on error
818  */
819 int gpio_get_acpi(const struct gpio_desc *desc, struct acpi_gpio *gpio);
820 
821 /**
822  * devm_gpiod_get_index - Resource-managed gpiod_get()
823  * @dev:	GPIO consumer
824  * @con_id:	function within the GPIO consumer
825  * @index:	index of the GPIO to obtain in the consumer
826  * @flags:	optional GPIO initialization flags
827  *
828  * Managed gpiod_get(). GPIO descriptors returned from this function are
829  * automatically disposed on device unbind.
830  * Return the GPIO descriptor corresponding to the function con_id of device
831  * dev, -ENOENT if no GPIO has been assigned to the requested function, or
832  * another IS_ERR() code if an error occurred while trying to acquire the GPIO.
833  */
834 struct gpio_desc *devm_gpiod_get_index(struct udevice *dev, const char *id,
835 				       unsigned int index, int flags);
836 
837 #define devm_gpiod_get(dev, id, flags) devm_gpiod_get_index(dev, id, 0, flags)
838 /**
839  * gpiod_get_optional - obtain an optional GPIO for a given GPIO function
840  * @dev: GPIO consumer, can be NULL for system-global GPIOs
841  * @con_id: function within the GPIO consumer
842  * @index:	index of the GPIO to obtain in the consumer
843  * @flags: optional GPIO initialization flags
844  *
845  * This is equivalent to devm_gpiod_get(), except that when no GPIO was
846  * assigned to the requested function it will return NULL. This is convenient
847  * for drivers that need to handle optional GPIOs.
848  */
849 struct gpio_desc *devm_gpiod_get_index_optional(struct udevice *dev,
850 						const char *id,
851 						unsigned int index,
852 						int flags);
853 
854 #define devm_gpiod_get_optional(dev, id, flags) \
855 	devm_gpiod_get_index_optional(dev, id, 0, flags)
856 
857 /**
858  * devm_gpiod_put - Resource-managed gpiod_put()
859  * @dev:	GPIO consumer
860  * @desc:	GPIO descriptor to dispose of
861  *
862  * Dispose of a GPIO descriptor obtained with devm_gpiod_get() or
863  * devm_gpiod_get_index(). Normally this function will not be called as the GPIO
864  * will be disposed of by the resource management code.
865  */
866 void devm_gpiod_put(struct udevice *dev, struct gpio_desc *desc);
867 
868 #endif	/* _ASM_GENERIC_GPIO_H_ */
869