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Simon Glass9d2cb8e2011-10-07 13:53:50 +00001/*
2 * Copyright (c) 2011 The Chromium OS Authors.
Joe Hershberger5f533ae2011-11-11 15:55:35 -06003 * Copyright (c) 2011, NVIDIA Corp. All rights reserved.
Wolfgang Denk1a459662013-07-08 09:37:19 +02004 * SPDX-License-Identifier: GPL-2.0+
Simon Glass9d2cb8e2011-10-07 13:53:50 +00005 */
6
Joe Hershberger5f533ae2011-11-11 15:55:35 -06007#ifndef _ASM_GENERIC_GPIO_H_
8#define _ASM_GENERIC_GPIO_H_
9
Simon Glass9d2cb8e2011-10-07 13:53:50 +000010/*
11 * Generic GPIO API for U-Boot
12 *
13 * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
14 * by the SOC/architecture.
15 *
16 * Each GPIO can be an input or output. If an input then its value can
17 * be read as 0 or 1. If an output then its value can be set to 0 or 1.
18 * If you try to write an input then the value is undefined. If you try
19 * to read an output, barring something very unusual, you will get
20 * back the value of the output that you previously set.
21 *
22 * In some cases the operation may fail, for example if the GPIO number
23 * is out of range, or the GPIO is not available because its pin is
24 * being used by another function. In that case, functions may return
25 * an error value of -1.
26 */
27
28/**
Marcel Ziswiler25ca3852014-10-10 17:31:41 +020029 * Request a GPIO. This should be called before any of the other functions
30 * are used on this GPIO.
Simon Glass9d2cb8e2011-10-07 13:53:50 +000031 *
Simon Glassb892d122014-10-04 11:29:42 -060032 * Note: With driver model, the label is allocated so there is no need for
33 * the caller to preserve it.
34 *
Nikita Kiryanov94740e42012-11-26 23:06:32 +000035 * @param gp GPIO number
36 * @param label User label for this GPIO
Simon Glass9d2cb8e2011-10-07 13:53:50 +000037 * @return 0 if ok, -1 on error
38 */
Joe Hershberger5f533ae2011-11-11 15:55:35 -060039int gpio_request(unsigned gpio, const char *label);
40
41/**
42 * Stop using the GPIO. This function should not alter pin configuration.
43 *
44 * @param gpio GPIO number
45 * @return 0 if ok, -1 on error
46 */
47int gpio_free(unsigned gpio);
48
49/**
50 * Make a GPIO an input.
51 *
52 * @param gpio GPIO number
53 * @return 0 if ok, -1 on error
54 */
55int gpio_direction_input(unsigned gpio);
Simon Glass9d2cb8e2011-10-07 13:53:50 +000056
57/**
58 * Make a GPIO an output, and set its value.
59 *
Joe Hershberger5f533ae2011-11-11 15:55:35 -060060 * @param gpio GPIO number
Simon Glass9d2cb8e2011-10-07 13:53:50 +000061 * @param value GPIO value (0 for low or 1 for high)
62 * @return 0 if ok, -1 on error
63 */
Joe Hershberger5f533ae2011-11-11 15:55:35 -060064int gpio_direction_output(unsigned gpio, int value);
Simon Glass9d2cb8e2011-10-07 13:53:50 +000065
66/**
67 * Get a GPIO's value. This will work whether the GPIO is an input
68 * or an output.
69 *
Joe Hershberger5f533ae2011-11-11 15:55:35 -060070 * @param gpio GPIO number
Simon Glass9d2cb8e2011-10-07 13:53:50 +000071 * @return 0 if low, 1 if high, -1 on error
72 */
Joe Hershberger5f533ae2011-11-11 15:55:35 -060073int gpio_get_value(unsigned gpio);
Simon Glass9d2cb8e2011-10-07 13:53:50 +000074
75/**
Joe Hershberger5f533ae2011-11-11 15:55:35 -060076 * Set an output GPIO's value. The GPIO must already be an output or
Simon Glass9d2cb8e2011-10-07 13:53:50 +000077 * this function may have no effect.
78 *
Joe Hershberger5f533ae2011-11-11 15:55:35 -060079 * @param gpio GPIO number
Simon Glass9d2cb8e2011-10-07 13:53:50 +000080 * @param value GPIO value (0 for low or 1 for high)
81 * @return 0 if ok, -1 on error
82 */
Joe Hershberger5f533ae2011-11-11 15:55:35 -060083int gpio_set_value(unsigned gpio, int value);
Simon Glass96495d92014-02-26 15:59:24 -070084
Simon Glass89e64052014-08-11 09:23:52 -060085/* State of a GPIO, as reported by get_function() */
Simon Glass6449a502014-10-04 11:29:43 -060086enum gpio_func_t {
Simon Glass96495d92014-02-26 15:59:24 -070087 GPIOF_INPUT = 0,
88 GPIOF_OUTPUT,
Simon Glass89e64052014-08-11 09:23:52 -060089 GPIOF_UNUSED, /* Not claimed */
90 GPIOF_UNKNOWN, /* Not known */
91 GPIOF_FUNC, /* Not used as a GPIO */
92
93 GPIOF_COUNT,
Simon Glass96495d92014-02-26 15:59:24 -070094};
95
Heiko Schocher54c5d082014-05-22 12:43:05 +020096struct udevice;
Simon Glass96495d92014-02-26 15:59:24 -070097
Simon Glassae7123f2015-01-05 20:05:27 -070098struct gpio_desc {
99 struct udevice *dev; /* Device, NULL for invalid GPIO */
100 unsigned long flags;
101#define GPIOD_REQUESTED (1 << 0) /* Requested/claimed */
102#define GPIOD_IS_OUT (1 << 1) /* GPIO is an output */
103#define GPIOD_IS_IN (1 << 2) /* GPIO is an output */
104#define GPIOD_ACTIVE_LOW (1 << 3) /* value has active low */
105#define GPIOD_IS_OUT_ACTIVE (1 << 4) /* set output active */
106
107 uint offset; /* GPIO offset within the device */
108 /*
109 * We could consider adding the GPIO label in here. Possibly we could
110 * use this structure for internal GPIO information.
111 */
112};
113
Simon Glass96495d92014-02-26 15:59:24 -0700114/**
Simon Glass3669e0e2015-01-05 20:05:29 -0700115 * dm_gpio_is_valid() - Check if a GPIO is gpio_is_valie
116 *
117 * @desc: GPIO description containing device, offset and flags,
118 * previously returned by gpio_request_by_name()
119 * @return true if valid, false if not
120 */
121static inline bool dm_gpio_is_valid(struct gpio_desc *desc)
122{
123 return desc->dev != NULL;
124}
125
126/**
Simon Glass07575352014-10-04 11:29:44 -0600127 * gpio_get_status() - get the current GPIO status as a string
128 *
129 * Obtain the current GPIO status as a string which can be presented to the
130 * user. A typical string is:
131 *
132 * "b4: in: 1 [x] sdmmc_cd"
133 *
134 * which means this is GPIO bank b, offset 4, currently set to input, current
135 * value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
136 *
137 * @dev: Device to check
138 * @offset: Offset of device GPIO to check
139 * @buf: Place to put string
140 * @buffsize: Size of string including \0
141 */
142int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);
143
144/**
Simon Glass6449a502014-10-04 11:29:43 -0600145 * gpio_get_function() - get the current function for a GPIO pin
146 *
147 * Note this returns GPIOF_UNUSED if the GPIO is not requested.
148 *
149 * @dev: Device to check
150 * @offset: Offset of device GPIO to check
151 * @namep: If non-NULL, this is set to the nane given when the GPIO
152 * was requested, or -1 if it has not been requested
153 * @return -ENODATA if the driver returned an unknown function,
154 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
155 * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
156 * function from enum gpio_func_t.
157 */
158int gpio_get_function(struct udevice *dev, int offset, const char **namep);
159
160/**
161 * gpio_get_raw_function() - get the current raw function for a GPIO pin
162 *
163 * Note this does not return GPIOF_UNUSED - it will always return the GPIO
164 * driver's view of a pin function, even if it is not correctly set up.
165 *
166 * @dev: Device to check
167 * @offset: Offset of device GPIO to check
168 * @namep: If non-NULL, this is set to the nane given when the GPIO
169 * was requested, or -1 if it has not been requested
170 * @return -ENODATA if the driver returned an unknown function,
171 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
172 * Otherwise returns the function from enum gpio_func_t.
173 */
174int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
175
176/**
Simon Glassd44f5972014-10-04 11:29:49 -0600177 * gpio_requestf() - request a GPIO using a format string for the owner
178 *
179 * This is a helper function for gpio_request(). It allows you to provide
180 * a printf()-format string for the GPIO owner. It calls gpio_request() with
181 * the string that is created
182 */
183int gpio_requestf(unsigned gpio, const char *fmt, ...)
184 __attribute__ ((format (__printf__, 2, 3)));
185
Simon Glass0dac4d52015-01-05 20:05:28 -0700186struct fdtdec_phandle_args;
187
Simon Glassd44f5972014-10-04 11:29:49 -0600188/**
Simon Glass96495d92014-02-26 15:59:24 -0700189 * struct struct dm_gpio_ops - Driver model GPIO operations
190 *
191 * Refer to functions above for description. These function largely copy
192 * the old API.
193 *
194 * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
195 * new DM GPIO API, this should be really easy to flip over to the Linux
196 * GPIO API-alike interface.
197 *
Marcel Ziswiler25ca3852014-10-10 17:31:41 +0200198 * Also it would be useful to standardise additional functions like
Simon Glass96495d92014-02-26 15:59:24 -0700199 * pullup, slew rate and drive strength.
200 *
201 * gpio_request)( and gpio_free() are optional - if NULL then they will
202 * not be called.
203 *
204 * Note that @offset is the offset from the base GPIO of the device. So
205 * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
206 * where o is the number of GPIO lines controlled by the device. A device
207 * is typically used to control a single bank of GPIOs. Within complex
208 * SoCs there may be many banks and therefore many devices all referring
209 * to the different IO addresses within the SoC.
210 *
Marcel Ziswiler25ca3852014-10-10 17:31:41 +0200211 * The uclass combines all GPIO devices together to provide a consistent
Simon Glass96495d92014-02-26 15:59:24 -0700212 * numbering from 0 to n-1, where n is the number of GPIOs in total across
213 * all devices. Be careful not to confuse offset with gpio in the parameters.
214 */
215struct dm_gpio_ops {
Heiko Schocher54c5d082014-05-22 12:43:05 +0200216 int (*request)(struct udevice *dev, unsigned offset, const char *label);
217 int (*free)(struct udevice *dev, unsigned offset);
218 int (*direction_input)(struct udevice *dev, unsigned offset);
219 int (*direction_output)(struct udevice *dev, unsigned offset,
Simon Glass96495d92014-02-26 15:59:24 -0700220 int value);
Heiko Schocher54c5d082014-05-22 12:43:05 +0200221 int (*get_value)(struct udevice *dev, unsigned offset);
222 int (*set_value)(struct udevice *dev, unsigned offset, int value);
Simon Glass89e64052014-08-11 09:23:52 -0600223 /**
224 * get_function() Get the GPIO function
225 *
226 * @dev: Device to check
227 * @offset: GPIO offset within that device
228 * @return current function - GPIOF_...
229 */
Heiko Schocher54c5d082014-05-22 12:43:05 +0200230 int (*get_function)(struct udevice *dev, unsigned offset);
Simon Glass0dac4d52015-01-05 20:05:28 -0700231
232 /**
233 * xlate() - Translate phandle arguments into a GPIO description
234 *
235 * This function should set up the fields in desc according to the
236 * information in the arguments. The uclass will have set up:
237 *
238 * @desc->dev to @dev
239 * @desc->flags to 0
240 * @desc->offset to the value of the first argument in args, if any,
241 * otherwise -1 (which is invalid)
242 *
243 * This method is optional so if the above defaults suit it can be
244 * omitted. Typical behaviour is to set up the GPIOD_ACTIVE_LOW flag
245 * in desc->flags.
246 *
247 * Note that @dev is passed in as a parameter to follow driver model
248 * uclass conventions, even though it is already available as
249 * desc->dev.
250 *
251 * @dev: GPIO device
252 * @desc: Place to put GPIO description
253 * @args: Arguments provided in descripion
254 * @return 0 if OK, -ve on error
255 */
256 int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
257 struct fdtdec_phandle_args *args);
Simon Glass96495d92014-02-26 15:59:24 -0700258};
259
260/**
261 * struct gpio_dev_priv - information about a device used by the uclass
262 *
263 * The uclass combines all active GPIO devices into a unified numbering
Marcel Ziswiler25ca3852014-10-10 17:31:41 +0200264 * scheme. To do this it maintains some private information about each
Simon Glass96495d92014-02-26 15:59:24 -0700265 * device.
266 *
267 * To implement driver model support in your GPIO driver, add a probe
268 * handler, and set @gpio_count and @bank_name correctly in that handler.
269 * This tells the uclass the name of the GPIO bank and the number of GPIOs
270 * it contains.
271 *
272 * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
273 * 'A0', 'A1', etc.
274 * @gpio_count: Number of GPIOs in this device
275 * @gpio_base: Base GPIO number for this device. For the first active device
276 * this will be 0; the numbering for others will follow sequentially so that
277 * @gpio_base for device 1 will equal the number of GPIOs in device 0.
Simon Glassb892d122014-10-04 11:29:42 -0600278 * @name: Array of pointers to the name for each GPIO in this bank. The
279 * value of the pointer will be NULL if the GPIO has not been claimed.
Simon Glass96495d92014-02-26 15:59:24 -0700280 */
281struct gpio_dev_priv {
282 const char *bank_name;
283 unsigned gpio_count;
284 unsigned gpio_base;
Simon Glassb892d122014-10-04 11:29:42 -0600285 char **name;
Simon Glass96495d92014-02-26 15:59:24 -0700286};
287
288/* Access the GPIO operations for a device */
289#define gpio_get_ops(dev) ((struct dm_gpio_ops *)(dev)->driver->ops)
290
291/**
292 * gpio_get_bank_info - Return information about a GPIO bank/device
293 *
294 * This looks up a device and returns both its GPIO base name and the number
295 * of GPIOs it controls.
296 *
297 * @dev: Device to look up
298 * @offset_count: Returns number of GPIOs within this bank
299 * @return bank name of this device
300 */
Heiko Schocher54c5d082014-05-22 12:43:05 +0200301const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
Simon Glass96495d92014-02-26 15:59:24 -0700302
303/**
304 * gpio_lookup_name - Look up a GPIO name and return its details
305 *
306 * This is used to convert a named GPIO into a device, offset and GPIO
307 * number.
308 *
309 * @name: GPIO name to look up
310 * @devp: Returns pointer to device which contains this GPIO
311 * @offsetp: Returns the offset number within this device
312 * @gpiop: Returns the absolute GPIO number, numbered from 0
313 */
Heiko Schocher54c5d082014-05-22 12:43:05 +0200314int gpio_lookup_name(const char *name, struct udevice **devp,
Simon Glass96495d92014-02-26 15:59:24 -0700315 unsigned int *offsetp, unsigned int *gpiop);
316
Simon Glasse5901c92014-11-10 18:00:21 -0700317/**
318 * get_gpios() - Turn the values of a list of GPIOs into an integer
319 *
320 * This puts the value of the first GPIO into bit 0, the second into bit 1,
321 * etc. then returns the resulting integer.
322 *
323 * @gpio_list: List of GPIOs to collect
324 * @return resulting integer value
325 */
326unsigned gpio_get_values_as_int(const int *gpio_list);
Jeroen Hofstee5b5ac642014-10-08 22:58:03 +0200327
Simon Glass3669e0e2015-01-05 20:05:29 -0700328/**
329 * gpio_request_by_name() - Locate and request a GPIO by name
330 *
331 * This operates by looking up the given list name in the device (device
332 * tree property) and requesting the GPIO for use. The property must exist
333 * in @dev's node.
334 *
335 * Use @flags to specify whether the GPIO should be an input or output. In
336 * principle this can also come from the device tree binding but most
337 * bindings don't provide this information. Specifically, when the GPIO uclass
338 * calls the xlate() method, it can return default flags, which are then
339 * ORed with this @flags.
340 *
341 * If we find that requesting the GPIO is not always needed we could add a
342 * new function or a new GPIOD_NO_REQUEST flag.
343 *
344 * At present driver model has no reference counting so if one device
345 * requests a GPIO which subsequently is unbound, the @desc->dev pointer
346 * will be invalid. However this will only happen if the GPIO device is
347 * unbound, not if it is removed, so this seems like a reasonable limitation
348 * for now. There is no real use case for unbinding drivers in normal
349 * operation.
350 *
351 * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
352 * generate terms and each specific device may add additional details in
353 * a binding file in the same directory.
354 *
355 * @dev: Device requesting the GPIO
356 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
357 * @index: Index number of the GPIO in that list use request (0=first)
358 * @desc: Returns GPIO description information. If there is no such
359 * GPIO, dev->dev will be NULL.
360 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
361 * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
362 * something wrong with the list, or other -ve for another error (e.g.
363 * -EBUSY if a GPIO was already requested)
364 */
365int gpio_request_by_name(struct udevice *dev, const char *list_name,
366 int index, struct gpio_desc *desc, int flags);
367
368/**
369 * gpio_request_list_by_name() - Request a list of GPIOs
370 *
371 * Reads all the GPIOs from a list and requetss them. See
372 * gpio_request_by_name() for additional details. Lists should not be
373 * misused to hold unrelated or optional GPIOs. They should only be used
374 * for things like parallel data lines. A zero phandle terminates the list
375 * the list.
376 *
377 * This function will either succeed, and request all GPIOs in the list, or
378 * fail and request none (it will free already-requested GPIOs in case of
379 * an error part-way through).
380 *
381 * @dev: Device requesting the GPIO
382 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
383 * @desc_list: Returns a list of GPIO description information
384 * @max_count: Maximum number of GPIOs to return (@desc_list must be at least
385 * this big)
386 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
387 * @return number of GPIOs requested, or -ve on error
388 */
389int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
390 struct gpio_desc *desc_list, int max_count,
391 int flags);
392
393/**
394 * gpio_get_list_count() - Returns the number of GPIOs in a list
395 *
396 * Counts the GPIOs in a list. See gpio_request_by_name() for additional
397 * details.
398 *
399 * @dev: Device requesting the GPIO
400 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
401 * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
402 * does not exist
403 */
404int gpio_get_list_count(struct udevice *dev, const char *list_name);
405
406/**
407 * gpio_request_by_name_nodev() - request GPIOs without a device
408 *
409 * This is a version of gpio_request_list_by_name() that does not use a
410 * device. Avoid it unless the caller is not yet using driver model
411 */
412int gpio_request_by_name_nodev(const void *blob, int node,
413 const char *list_name,
414 int index, struct gpio_desc *desc, int flags);
415
416/**
417 * gpio_request_list_by_name_nodev() - request GPIOs without a device
418 *
419 * This is a version of gpio_request_list_by_name() that does not use a
420 * device. Avoid it unless the caller is not yet using driver model
421 */
422int gpio_request_list_by_name_nodev(const void *blob, int node,
423 const char *list_name,
424 struct gpio_desc *desc_list, int max_count,
425 int flags);
426
427/**
428 * dm_gpio_free() - Free a single GPIO
429 *
430 * This frees a single GPIOs previously returned from gpio_request_by_name().
431 *
432 * @dev: Device which requested the GPIO
433 * @desc: GPIO to free
434 * @return 0 if OK, -ve on error
435 */
436int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
437
438/**
439 * gpio_free_list() - Free a list of GPIOs
440 *
441 * This frees a list of GPIOs previously returned from
442 * gpio_request_list_by_name().
443 *
444 * @dev: Device which requested the GPIOs
445 * @desc: List of GPIOs to free
446 * @count: Number of GPIOs in the list
447 * @return 0 if OK, -ve on error
448 */
449int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
450
451/**
452 * gpio_free_list_nodev() - free GPIOs without a device
453 *
454 * This is a version of gpio_free_list() that does not use a
455 * device. Avoid it unless the caller is not yet using driver model
456 */
457int gpio_free_list_nodev(struct gpio_desc *desc, int count);
458
459/**
460 * dm_gpio_get_value() - Get the value of a GPIO
461 *
462 * This is the driver model version of the existing gpio_get_value() function
463 * and should be used instead of that.
464 *
465 * For now, these functions have a dm_ prefix since they conflict with
466 * existing names.
467 *
468 * @desc: GPIO description containing device, offset and flags,
469 * previously returned by gpio_request_by_name()
470 * @return GPIO value (0 for inactive, 1 for active) or -ve on error
471 */
472int dm_gpio_get_value(struct gpio_desc *desc);
473
474int dm_gpio_set_value(struct gpio_desc *desc, int value);
475
476/**
477 * dm_gpio_set_dir() - Set the direction for a GPIO
478 *
479 * This sets up the direction according tot the provided flags. It will do
480 * nothing unless the direction is actually specified.
481 *
482 * @desc: GPIO description containing device, offset and flags,
483 * previously returned by gpio_request_by_name()
484 * @return 0 if OK, -ve on error
485 */
486int dm_gpio_set_dir(struct gpio_desc *desc);
487
488/**
489 * dm_gpio_set_dir_flags() - Set direction using specific flags
490 *
491 * This is like dm_gpio_set_dir() except that the flags value is provided
492 * instead of being used from desc->flags. This is needed because in many
493 * cases the GPIO description does not include direction information.
494 * Note that desc->flags is updated by this function.
495 *
496 * @desc: GPIO description containing device, offset and flags,
497 * previously returned by gpio_request_by_name()
498 * @flags: New flags to use
499 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
500 */
501int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
502
503/**
504 * gpio_get_number() - Get the global GPIO number of a GPIO
505 *
506 * This should only be used for debugging or interest. It returns the nummber
507 * that should be used for gpio_get_value() etc. to access this GPIO.
508 *
509 * @desc: GPIO description containing device, offset and flags,
510 * previously returned by gpio_request_by_name()
511 * @return GPIO number, or -ve if not found
512 */
513int gpio_get_number(struct gpio_desc *desc);
514
Joe Hershberger5f533ae2011-11-11 15:55:35 -0600515#endif /* _ASM_GENERIC_GPIO_H_ */