1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Copyright (c) 2011 The Chromium OS Authors.
4 * Copyright (c) 2011, NVIDIA Corp. All rights reserved.
7 #ifndef _ASM_GENERIC_GPIO_H_
8 #define _ASM_GENERIC_GPIO_H_
10 #include <dm/ofnode.h>
12 struct ofnode_phandle_args;
15 * Generic GPIO API for U-Boot
18 * NB: This is deprecated. Please use the driver model functions instead:
20 * - gpio_request_by_name()
21 * - dm_gpio_get_value() etc.
23 * For now we need a dm_ prefix on some functions to avoid name collision.
26 * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
27 * by the SOC/architecture.
29 * Each GPIO can be an input or output. If an input then its value can
30 * be read as 0 or 1. If an output then its value can be set to 0 or 1.
31 * If you try to write an input then the value is undefined. If you try
32 * to read an output, barring something very unusual, you will get
33 * back the value of the output that you previously set.
35 * In some cases the operation may fail, for example if the GPIO number
36 * is out of range, or the GPIO is not available because its pin is
37 * being used by another function. In that case, functions may return
38 * an error value of -1.
42 * @deprecated Please use driver model instead
43 * Request a GPIO. This should be called before any of the other functions
44 * are used on this GPIO.
46 * Note: With driver model, the label is allocated so there is no need for
47 * the caller to preserve it.
49 * @param gpio GPIO number
50 * @param label User label for this GPIO
51 * @return 0 if ok, -1 on error
53 int gpio_request(unsigned gpio, const char *label);
56 * @deprecated Please use driver model instead
57 * Stop using the GPIO. This function should not alter pin configuration.
59 * @param gpio GPIO number
60 * @return 0 if ok, -1 on error
62 int gpio_free(unsigned gpio);
65 * @deprecated Please use driver model instead
66 * Make a GPIO an input.
68 * @param gpio GPIO number
69 * @return 0 if ok, -1 on error
71 int gpio_direction_input(unsigned gpio);
74 * @deprecated Please use driver model instead
75 * Make a GPIO an output, and set its value.
77 * @param gpio GPIO number
78 * @param value GPIO value (0 for low or 1 for high)
79 * @return 0 if ok, -1 on error
81 int gpio_direction_output(unsigned gpio, int value);
84 * @deprecated Please use driver model instead
85 * Get a GPIO's value. This will work whether the GPIO is an input
88 * @param gpio GPIO number
89 * @return 0 if low, 1 if high, -1 on error
91 int gpio_get_value(unsigned gpio);
94 * @deprecated Please use driver model instead
95 * Set an output GPIO's value. The GPIO must already be an output or
96 * this function may have no effect.
98 * @param gpio GPIO number
99 * @param value GPIO value (0 for low or 1 for high)
100 * @return 0 if ok, -1 on error
102 int gpio_set_value(unsigned gpio, int value);
104 /* State of a GPIO, as reported by get_function() */
108 GPIOF_UNUSED, /* Not claimed */
109 GPIOF_UNKNOWN, /* Not known */
110 GPIOF_FUNC, /* Not used as a GPIO */
118 struct udevice *dev; /* Device, NULL for invalid GPIO */
120 #define GPIOD_IS_OUT BIT(1) /* GPIO is an output */
121 #define GPIOD_IS_IN BIT(2) /* GPIO is an input */
122 #define GPIOD_ACTIVE_LOW BIT(3) /* GPIO is active when value is low */
123 #define GPIOD_IS_OUT_ACTIVE BIT(4) /* set output active */
124 #define GPIOD_OPEN_DRAIN BIT(5) /* GPIO is open drain type */
125 #define GPIOD_OPEN_SOURCE BIT(6) /* GPIO is open source type */
126 #define GPIOD_PULL_UP BIT(7) /* GPIO has pull-up enabled */
127 #define GPIOD_PULL_DOWN BIT(8) /* GPIO has pull-down enabled */
129 uint offset; /* GPIO offset within the device */
131 * We could consider adding the GPIO label in here. Possibly we could
132 * use this structure for internal GPIO information.
136 /* helper to compute the value of the gpio output */
137 #define GPIOD_FLAGS_OUTPUT_MASK (GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE)
138 #define GPIOD_FLAGS_OUTPUT(flags) \
139 (((((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_IS_OUT_ACTIVE) || \
140 (((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_ACTIVE_LOW)))
143 * dm_gpio_is_valid() - Check if a GPIO is valid
145 * @desc: GPIO description containing device, offset and flags,
146 * previously returned by gpio_request_by_name()
147 * @return true if valid, false if not
149 static inline bool dm_gpio_is_valid(const struct gpio_desc *desc)
151 return desc->dev != NULL;
155 * gpio_get_status() - get the current GPIO status as a string
157 * Obtain the current GPIO status as a string which can be presented to the
158 * user. A typical string is:
160 * "b4: in: 1 [x] sdmmc_cd"
162 * which means this is GPIO bank b, offset 4, currently set to input, current
163 * value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
165 * TODO(sjg@chromium.org): This should use struct gpio_desc
167 * @dev: Device to check
168 * @offset: Offset of device GPIO to check
169 * @buf: Place to put string
170 * @buffsize: Size of string including \0
172 int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);
175 * gpio_get_function() - get the current function for a GPIO pin
177 * Note this returns GPIOF_UNUSED if the GPIO is not requested.
179 * TODO(sjg@chromium.org): This should use struct gpio_desc
181 * @dev: Device to check
182 * @offset: Offset of device GPIO to check
183 * @namep: If non-NULL, this is set to the name given when the GPIO
184 * was requested, or -1 if it has not been requested
185 * @return -ENODATA if the driver returned an unknown function,
186 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
187 * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
188 * function from enum gpio_func_t.
190 int gpio_get_function(struct udevice *dev, int offset, const char **namep);
193 * gpio_get_raw_function() - get the current raw function for a GPIO pin
195 * Note this does not return GPIOF_UNUSED - it will always return the GPIO
196 * driver's view of a pin function, even if it is not correctly set up.
198 * TODO(sjg@chromium.org): This should use struct gpio_desc
200 * @dev: Device to check
201 * @offset: Offset of device GPIO to check
202 * @namep: If non-NULL, this is set to the name given when the GPIO
203 * was requested, or -1 if it has not been requested
204 * @return -ENODATA if the driver returned an unknown function,
205 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
206 * Otherwise returns the function from enum gpio_func_t.
208 int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
211 * gpio_requestf() - request a GPIO using a format string for the owner
213 * This is a helper function for gpio_request(). It allows you to provide
214 * a printf()-format string for the GPIO owner. It calls gpio_request() with
215 * the string that is created
217 int gpio_requestf(unsigned gpio, const char *fmt, ...)
218 __attribute__ ((format (__printf__, 2, 3)));
220 struct fdtdec_phandle_args;
223 * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
225 * This routine sets the offset field to args[0] and the flags field to
226 * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
228 int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
229 struct ofnode_phandle_args *args);
232 * struct struct dm_gpio_ops - Driver model GPIO operations
234 * Refer to functions above for description. These function largely copy
237 * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
238 * new DM GPIO API, this should be really easy to flip over to the Linux
239 * GPIO API-alike interface.
241 * Also it would be useful to standardise additional functions like
242 * pullup, slew rate and drive strength.
244 * gpio_request() and gpio_free() are optional - if NULL then they will
247 * Note that @offset is the offset from the base GPIO of the device. So
248 * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
249 * where o is the number of GPIO lines controlled by the device. A device
250 * is typically used to control a single bank of GPIOs. Within complex
251 * SoCs there may be many banks and therefore many devices all referring
252 * to the different IO addresses within the SoC.
254 * The uclass combines all GPIO devices together to provide a consistent
255 * numbering from 0 to n-1, where n is the number of GPIOs in total across
256 * all devices. Be careful not to confuse offset with gpio in the parameters.
259 int (*request)(struct udevice *dev, unsigned offset, const char *label);
260 int (*rfree)(struct udevice *dev, unsigned int offset);
261 int (*direction_input)(struct udevice *dev, unsigned offset);
262 int (*direction_output)(struct udevice *dev, unsigned offset,
264 int (*get_value)(struct udevice *dev, unsigned offset);
265 int (*set_value)(struct udevice *dev, unsigned offset, int value);
267 * get_function() Get the GPIO function
269 * @dev: Device to check
270 * @offset: GPIO offset within that device
271 * @return current function - GPIOF_...
273 int (*get_function)(struct udevice *dev, unsigned offset);
276 * xlate() - Translate phandle arguments into a GPIO description
278 * This function should set up the fields in desc according to the
279 * information in the arguments. The uclass will have set up:
285 * This method is optional and defaults to gpio_xlate_offs_flags,
286 * which will parse offset and the GPIO_ACTIVE_LOW flag in the first
289 * Note that @dev is passed in as a parameter to follow driver model
290 * uclass conventions, even though it is already available as
294 * @desc: Place to put GPIO description
295 * @args: Arguments provided in description
296 * @return 0 if OK, -ve on error
298 int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
299 struct ofnode_phandle_args *args);
302 * get_dir_flags() - Get GPIO dir flags
304 * This function return the GPIO direction flags used.
306 * This method is optional.
309 * @offset: GPIO offset within that device
310 * @flags: place to put the used direction flags by GPIO
311 * @return 0 if OK, -ve on error
313 int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
318 * struct gpio_dev_priv - information about a device used by the uclass
320 * The uclass combines all active GPIO devices into a unified numbering
321 * scheme. To do this it maintains some private information about each
324 * To implement driver model support in your GPIO driver, add a probe
325 * handler, and set @gpio_count and @bank_name correctly in that handler.
326 * This tells the uclass the name of the GPIO bank and the number of GPIOs
329 * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
331 * @gpio_count: Number of GPIOs in this device
332 * @gpio_base: Base GPIO number for this device. For the first active device
333 * this will be 0; the numbering for others will follow sequentially so that
334 * @gpio_base for device 1 will equal the number of GPIOs in device 0.
335 * @name: Array of pointers to the name for each GPIO in this bank. The
336 * value of the pointer will be NULL if the GPIO has not been claimed.
338 struct gpio_dev_priv {
339 const char *bank_name;
345 /* Access the GPIO operations for a device */
346 #define gpio_get_ops(dev) ((struct dm_gpio_ops *)(dev)->driver->ops)
349 * gpio_get_bank_info - Return information about a GPIO bank/device
351 * This looks up a device and returns both its GPIO base name and the number
352 * of GPIOs it controls.
354 * @dev: Device to look up
355 * @offset_count: Returns number of GPIOs within this bank
356 * @return bank name of this device
358 const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
361 * dm_gpio_lookup_name() - Look up a named GPIO and return its description
363 * The name of a GPIO is typically its bank name followed by a number from 0.
364 * For example A0 is the first GPIO in bank A. Each bank is a separate driver
367 * @name: Name to look up
368 * @desc: Returns description, on success
369 * @return 0 if OK, -ve on error
371 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
374 * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
376 * @name: Name to look up
377 * @desc: Returns GPIO description, on success, else NULL
378 * @return: Returns 0 if OK, else -ENODEV
380 int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);
383 * gpio_hog_probe_all() - probe all gpio devices with
386 * @return: Returns return value from device_probe()
388 int gpio_hog_probe_all(void);
391 * gpio_lookup_name - Look up a GPIO name and return its details
393 * This is used to convert a named GPIO into a device, offset and GPIO
396 * @name: GPIO name to look up
397 * @devp: Returns pointer to device which contains this GPIO
398 * @offsetp: Returns the offset number within this device
399 * @gpiop: Returns the absolute GPIO number, numbered from 0
401 int gpio_lookup_name(const char *name, struct udevice **devp,
402 unsigned int *offsetp, unsigned int *gpiop);
405 * gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
407 * This puts the value of the first GPIO into bit 0, the second into bit 1,
408 * etc. then returns the resulting integer.
410 * @gpio_list: List of GPIOs to collect
411 * @return resulting integer value, or -ve on error
413 int gpio_get_values_as_int(const int *gpio_list);
416 * dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
418 * This puts the value of the first GPIO into bit 0, the second into bit 1,
419 * etc. then returns the resulting integer.
421 * @desc_list: List of GPIOs to collect
422 * @count: Number of GPIOs
423 * @return resulting integer value, or -ve on error
425 int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count);
428 * gpio_claim_vector() - claim a number of GPIOs for input
430 * @gpio_num_array: array of gpios to claim, terminated by -1
431 * @fmt: format string for GPIO names, e.g. "board_id%d"
432 * @return 0 if OK, -ve on error
434 int gpio_claim_vector(const int *gpio_num_array, const char *fmt);
437 * gpio_request_by_name() - Locate and request a GPIO by name
439 * This operates by looking up the given list name in the device (device
440 * tree property) and requesting the GPIO for use. The property must exist
443 * Use @flags to specify whether the GPIO should be an input or output. In
444 * principle this can also come from the device tree binding but most
445 * bindings don't provide this information. Specifically, when the GPIO uclass
446 * calls the xlate() method, it can return default flags, which are then
447 * ORed with this @flags.
449 * If we find that requesting the GPIO is not always needed we could add a
450 * new function or a new GPIOD_NO_REQUEST flag.
452 * At present driver model has no reference counting so if one device
453 * requests a GPIO which subsequently is unbound, the @desc->dev pointer
454 * will be invalid. However this will only happen if the GPIO device is
455 * unbound, not if it is removed, so this seems like a reasonable limitation
456 * for now. There is no real use case for unbinding drivers in normal
459 * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
460 * generate terms and each specific device may add additional details in
461 * a binding file in the same directory.
463 * @dev: Device requesting the GPIO
464 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
465 * @index: Index number of the GPIO in that list use request (0=first)
466 * @desc: Returns GPIO description information. If there is no such
467 * GPIO, dev->dev will be NULL.
468 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
469 * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
470 * something wrong with the list, or other -ve for another error (e.g.
471 * -EBUSY if a GPIO was already requested)
473 int gpio_request_by_name(struct udevice *dev, const char *list_name,
474 int index, struct gpio_desc *desc, int flags);
477 * gpio_request_list_by_name() - Request a list of GPIOs
479 * Reads all the GPIOs from a list and requests them. See
480 * gpio_request_by_name() for additional details. Lists should not be
481 * misused to hold unrelated or optional GPIOs. They should only be used
482 * for things like parallel data lines. A zero phandle terminates the list
485 * This function will either succeed, and request all GPIOs in the list, or
486 * fail and request none (it will free already-requested GPIOs in case of
487 * an error part-way through).
489 * @dev: Device requesting the GPIO
490 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
491 * @desc_list: Returns a list of GPIO description information
492 * @max_count: Maximum number of GPIOs to return (@desc_list must be at least
494 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
495 * @return number of GPIOs requested, or -ve on error
497 int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
498 struct gpio_desc *desc_list, int max_count,
502 * dm_gpio_request() - manually request a GPIO
504 * Note: This function should only be used for testing / debugging. Instead.
505 * use gpio_request_by_name() to pull GPIOs from the device tree.
507 * @desc: GPIO description of GPIO to request (see dm_gpio_lookup_name())
508 * @label: Label to attach to the GPIO while claimed
509 * @return 0 if OK, -ve on error
511 int dm_gpio_request(struct gpio_desc *desc, const char *label);
514 * gpio_get_list_count() - Returns the number of GPIOs in a list
516 * Counts the GPIOs in a list. See gpio_request_by_name() for additional
519 * @dev: Device requesting the GPIO
520 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
521 * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
524 int gpio_get_list_count(struct udevice *dev, const char *list_name);
527 * gpio_request_by_name_nodev() - request GPIOs without a device
529 * This is a version of gpio_request_list_by_name() that does not use a
530 * device. Avoid it unless the caller is not yet using driver model
532 int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
533 struct gpio_desc *desc, int flags);
536 * gpio_request_list_by_name_nodev() - request GPIOs without a device
538 * This is a version of gpio_request_list_by_name() that does not use a
539 * device. Avoid it unless the caller is not yet using driver model
541 int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
542 struct gpio_desc *desc_list, int max_count,
546 * gpio_dev_request_index() - request single GPIO from gpio device
549 * @nodename: Name of node for which gpio gets requested, used
550 * for the gpio label name
551 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
552 * @index: Index number of the GPIO in that list use request (0=first)
553 * @flags: GPIOD_* flags
554 * @dtflags: GPIO flags read from DT defined see GPIOD_*
555 * @desc: returns GPIO descriptor filled from this function
556 * @return: return value from gpio_request_tail()
558 int gpio_dev_request_index(struct udevice *dev, const char *nodename,
559 char *list_name, int index, int flags,
560 int dtflags, struct gpio_desc *desc);
563 * dm_gpio_free() - Free a single GPIO
565 * This frees a single GPIOs previously returned from gpio_request_by_name().
567 * @dev: Device which requested the GPIO
568 * @desc: GPIO to free
569 * @return 0 if OK, -ve on error
571 int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
574 * gpio_free_list() - Free a list of GPIOs
576 * This frees a list of GPIOs previously returned from
577 * gpio_request_list_by_name().
579 * @dev: Device which requested the GPIOs
580 * @desc: List of GPIOs to free
581 * @count: Number of GPIOs in the list
582 * @return 0 if OK, -ve on error
584 int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
587 * gpio_free_list_nodev() - free GPIOs without a device
589 * This is a version of gpio_free_list() that does not use a
590 * device. Avoid it unless the caller is not yet using driver model
592 int gpio_free_list_nodev(struct gpio_desc *desc, int count);
595 * dm_gpio_get_value() - Get the value of a GPIO
597 * This is the driver model version of the existing gpio_get_value() function
598 * and should be used instead of that.
600 * For now, these functions have a dm_ prefix since they conflict with
603 * @desc: GPIO description containing device, offset and flags,
604 * previously returned by gpio_request_by_name()
605 * @return GPIO value (0 for inactive, 1 for active) or -ve on error
607 int dm_gpio_get_value(const struct gpio_desc *desc);
609 int dm_gpio_set_value(const struct gpio_desc *desc, int value);
612 * dm_gpio_set_dir() - Set the direction for a GPIO
614 * This sets up the direction according to the GPIO flags: desc->flags.
616 * @desc: GPIO description containing device, offset and flags,
617 * previously returned by gpio_request_by_name()
618 * @return 0 if OK, -ve on error
620 int dm_gpio_set_dir(struct gpio_desc *desc);
623 * dm_gpio_set_dir_flags() - Set direction using description and added flags
625 * This sets up the direction according to the provided flags and the GPIO
626 * description (desc->flags) which include direction information.
627 * Note that desc->flags is updated by this function.
629 * @desc: GPIO description containing device, offset and flags,
630 * previously returned by gpio_request_by_name()
631 * @flags: New flags to use
632 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
634 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
637 * dm_gpio_get_dir_flags() - Get direction flags
639 * read the current direction flags
641 * @desc: GPIO description containing device, offset and flags,
642 * previously returned by gpio_request_by_name()
643 * @flags: place to put the used flags
644 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
646 int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags);
649 * gpio_get_number() - Get the global GPIO number of a GPIO
651 * This should only be used for debugging or interest. It returns the number
652 * that should be used for gpio_get_value() etc. to access this GPIO.
654 * @desc: GPIO description containing device, offset and flags,
655 * previously returned by gpio_request_by_name()
656 * @return GPIO number, or -ve if not found
658 int gpio_get_number(const struct gpio_desc *desc);
660 #endif /* _ASM_GENERIC_GPIO_H_ */