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>
11 #include <linux/bitops.h>
13 struct ofnode_phandle_args;
16 * Generic GPIO API for U-Boot
19 * NB: This is deprecated. Please use the driver model functions instead:
21 * - gpio_request_by_name()
22 * - dm_gpio_get_value() etc.
24 * For now we need a dm_ prefix on some functions to avoid name collision.
27 * GPIOs are numbered from 0 to GPIO_COUNT-1 which value is defined
28 * by the SOC/architecture.
30 * Each GPIO can be an input or output. If an input then its value can
31 * be read as 0 or 1. If an output then its value can be set to 0 or 1.
32 * If you try to write an input then the value is undefined. If you try
33 * to read an output, barring something very unusual, you will get
34 * back the value of the output that you previously set.
36 * In some cases the operation may fail, for example if the GPIO number
37 * is out of range, or the GPIO is not available because its pin is
38 * being used by another function. In that case, functions may return
39 * an error value of -1.
43 * @deprecated Please use driver model instead
44 * Request a GPIO. This should be called before any of the other functions
45 * are used on this GPIO.
47 * Note: With driver model, the label is allocated so there is no need for
48 * the caller to preserve it.
50 * @param gpio GPIO number
51 * @param label User label for this GPIO
52 * @return 0 if ok, -1 on error
54 int gpio_request(unsigned gpio, const char *label);
57 * @deprecated Please use driver model instead
58 * Stop using the GPIO. This function should not alter pin configuration.
60 * @param gpio GPIO number
61 * @return 0 if ok, -1 on error
63 int gpio_free(unsigned gpio);
66 * @deprecated Please use driver model instead
67 * Make a GPIO an input.
69 * @param gpio GPIO number
70 * @return 0 if ok, -1 on error
72 int gpio_direction_input(unsigned gpio);
75 * @deprecated Please use driver model instead
76 * Make a GPIO an output, and set its value.
78 * @param gpio GPIO number
79 * @param value GPIO value (0 for low or 1 for high)
80 * @return 0 if ok, -1 on error
82 int gpio_direction_output(unsigned gpio, int value);
85 * @deprecated Please use driver model instead
86 * Get a GPIO's value. This will work whether the GPIO is an input
89 * @param gpio GPIO number
90 * @return 0 if low, 1 if high, -1 on error
92 int gpio_get_value(unsigned gpio);
95 * @deprecated Please use driver model instead
96 * Set an output GPIO's value. The GPIO must already be an output or
97 * this function may have no effect.
99 * @param gpio GPIO number
100 * @param value GPIO value (0 for low or 1 for high)
101 * @return 0 if ok, -1 on error
103 int gpio_set_value(unsigned gpio, int value);
105 /* State of a GPIO, as reported by get_function() */
109 GPIOF_UNUSED, /* Not claimed */
110 GPIOF_UNKNOWN, /* Not known */
111 GPIOF_FUNC, /* Not used as a GPIO */
119 struct udevice *dev; /* Device, NULL for invalid GPIO */
121 #define GPIOD_IS_OUT BIT(1) /* GPIO is an output */
122 #define GPIOD_IS_IN BIT(2) /* GPIO is an input */
123 #define GPIOD_ACTIVE_LOW BIT(3) /* GPIO is active when value is low */
124 #define GPIOD_IS_OUT_ACTIVE BIT(4) /* set output active */
125 #define GPIOD_OPEN_DRAIN BIT(5) /* GPIO is open drain type */
126 #define GPIOD_OPEN_SOURCE BIT(6) /* GPIO is open source type */
127 #define GPIOD_PULL_UP BIT(7) /* GPIO has pull-up enabled */
128 #define GPIOD_PULL_DOWN BIT(8) /* GPIO has pull-down enabled */
130 uint offset; /* GPIO offset within the device */
132 * We could consider adding the GPIO label in here. Possibly we could
133 * use this structure for internal GPIO information.
137 /* helper to compute the value of the gpio output */
138 #define GPIOD_FLAGS_OUTPUT_MASK (GPIOD_ACTIVE_LOW | GPIOD_IS_OUT_ACTIVE)
139 #define GPIOD_FLAGS_OUTPUT(flags) \
140 (((((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_IS_OUT_ACTIVE) || \
141 (((flags) & GPIOD_FLAGS_OUTPUT_MASK) == GPIOD_ACTIVE_LOW)))
144 * dm_gpio_is_valid() - Check if a GPIO is valid
146 * @desc: GPIO description containing device, offset and flags,
147 * previously returned by gpio_request_by_name()
148 * @return true if valid, false if not
150 static inline bool dm_gpio_is_valid(const struct gpio_desc *desc)
152 return desc->dev != NULL;
156 * gpio_get_status() - get the current GPIO status as a string
158 * Obtain the current GPIO status as a string which can be presented to the
159 * user. A typical string is:
161 * "b4: in: 1 [x] sdmmc_cd"
163 * which means this is GPIO bank b, offset 4, currently set to input, current
164 * value 1, [x] means that it is requested and the owner is 'sdmmc_cd'
166 * TODO(sjg@chromium.org): This should use struct gpio_desc
168 * @dev: Device to check
169 * @offset: Offset of device GPIO to check
170 * @buf: Place to put string
171 * @buffsize: Size of string including \0
173 int gpio_get_status(struct udevice *dev, int offset, char *buf, int buffsize);
176 * gpio_get_function() - get the current function for a GPIO pin
178 * Note this returns GPIOF_UNUSED if the GPIO is not requested.
180 * TODO(sjg@chromium.org): This should use struct gpio_desc
182 * @dev: Device to check
183 * @offset: Offset of device GPIO to check
184 * @namep: If non-NULL, this is set to the name given when the GPIO
185 * was requested, or -1 if it has not been requested
186 * @return -ENODATA if the driver returned an unknown function,
187 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
188 * GPIOF_UNUSED if the GPIO has not been requested. Otherwise returns the
189 * function from enum gpio_func_t.
191 int gpio_get_function(struct udevice *dev, int offset, const char **namep);
194 * gpio_get_raw_function() - get the current raw function for a GPIO pin
196 * Note this does not return GPIOF_UNUSED - it will always return the GPIO
197 * driver's view of a pin function, even if it is not correctly set up.
199 * TODO(sjg@chromium.org): This should use struct gpio_desc
201 * @dev: Device to check
202 * @offset: Offset of device GPIO to check
203 * @namep: If non-NULL, this is set to the name given when the GPIO
204 * was requested, or -1 if it has not been requested
205 * @return -ENODATA if the driver returned an unknown function,
206 * -ENODEV if the device is not active, -EINVAL if the offset is invalid.
207 * Otherwise returns the function from enum gpio_func_t.
209 int gpio_get_raw_function(struct udevice *dev, int offset, const char **namep);
212 * gpio_requestf() - request a GPIO using a format string for the owner
214 * This is a helper function for gpio_request(). It allows you to provide
215 * a printf()-format string for the GPIO owner. It calls gpio_request() with
216 * the string that is created
218 int gpio_requestf(unsigned gpio, const char *fmt, ...)
219 __attribute__ ((format (__printf__, 2, 3)));
221 struct fdtdec_phandle_args;
224 * gpio_xlate_offs_flags() - implementation for common use of dm_gpio_ops.xlate
226 * This routine sets the offset field to args[0] and the flags field to
227 * GPIOD_ACTIVE_LOW if the GPIO_ACTIVE_LOW flag is present in args[1].
229 int gpio_xlate_offs_flags(struct udevice *dev, struct gpio_desc *desc,
230 struct ofnode_phandle_args *args);
233 * struct struct dm_gpio_ops - Driver model GPIO operations
235 * Refer to functions above for description. These function largely copy
238 * This is trying to be close to Linux GPIO API. Once the U-Boot uses the
239 * new DM GPIO API, this should be really easy to flip over to the Linux
240 * GPIO API-alike interface.
242 * Also it would be useful to standardise additional functions like
243 * pullup, slew rate and drive strength.
245 * gpio_request() and gpio_free() are optional - if NULL then they will
248 * Note that @offset is the offset from the base GPIO of the device. So
249 * offset 0 is the device's first GPIO and offset o-1 is the last GPIO,
250 * where o is the number of GPIO lines controlled by the device. A device
251 * is typically used to control a single bank of GPIOs. Within complex
252 * SoCs there may be many banks and therefore many devices all referring
253 * to the different IO addresses within the SoC.
255 * The uclass combines all GPIO devices together to provide a consistent
256 * numbering from 0 to n-1, where n is the number of GPIOs in total across
257 * all devices. Be careful not to confuse offset with gpio in the parameters.
260 int (*request)(struct udevice *dev, unsigned offset, const char *label);
261 int (*rfree)(struct udevice *dev, unsigned int offset);
262 int (*direction_input)(struct udevice *dev, unsigned offset);
263 int (*direction_output)(struct udevice *dev, unsigned offset,
265 int (*get_value)(struct udevice *dev, unsigned offset);
266 int (*set_value)(struct udevice *dev, unsigned offset, int value);
268 * get_function() Get the GPIO function
270 * @dev: Device to check
271 * @offset: GPIO offset within that device
272 * @return current function - GPIOF_...
274 int (*get_function)(struct udevice *dev, unsigned offset);
277 * xlate() - Translate phandle arguments into a GPIO description
279 * This function should set up the fields in desc according to the
280 * information in the arguments. The uclass will have set up:
286 * This method is optional and defaults to gpio_xlate_offs_flags,
287 * which will parse offset and the GPIO_ACTIVE_LOW flag in the first
290 * Note that @dev is passed in as a parameter to follow driver model
291 * uclass conventions, even though it is already available as
295 * @desc: Place to put GPIO description
296 * @args: Arguments provided in description
297 * @return 0 if OK, -ve on error
299 int (*xlate)(struct udevice *dev, struct gpio_desc *desc,
300 struct ofnode_phandle_args *args);
303 * set_dir_flags() - Set GPIO dir flags
305 * This function should set up the GPIO configuration according to the
306 * information provide by the direction flags bitfield.
308 * This method is optional.
311 * @offset: GPIO offset within that device
312 * @flags: GPIO configuration to use
313 * @return 0 if OK, -ve on error
315 int (*set_dir_flags)(struct udevice *dev, unsigned int offset,
319 * get_dir_flags() - Get GPIO dir flags
321 * This function return the GPIO direction flags used.
323 * This method is optional.
326 * @offset: GPIO offset within that device
327 * @flags: place to put the used direction flags by GPIO
328 * @return 0 if OK, -ve on error
330 int (*get_dir_flags)(struct udevice *dev, unsigned int offset,
335 * struct gpio_dev_priv - information about a device used by the uclass
337 * The uclass combines all active GPIO devices into a unified numbering
338 * scheme. To do this it maintains some private information about each
341 * To implement driver model support in your GPIO driver, add a probe
342 * handler, and set @gpio_count and @bank_name correctly in that handler.
343 * This tells the uclass the name of the GPIO bank and the number of GPIOs
346 * @bank_name: Name of the GPIO device (e.g 'a' means GPIOs will be called
348 * @gpio_count: Number of GPIOs in this device
349 * @gpio_base: Base GPIO number for this device. For the first active device
350 * this will be 0; the numbering for others will follow sequentially so that
351 * @gpio_base for device 1 will equal the number of GPIOs in device 0.
352 * @name: Array of pointers to the name for each GPIO in this bank. The
353 * value of the pointer will be NULL if the GPIO has not been claimed.
355 struct gpio_dev_priv {
356 const char *bank_name;
362 /* Access the GPIO operations for a device */
363 #define gpio_get_ops(dev) ((struct dm_gpio_ops *)(dev)->driver->ops)
366 * gpio_get_bank_info - Return information about a GPIO bank/device
368 * This looks up a device and returns both its GPIO base name and the number
369 * of GPIOs it controls.
371 * @dev: Device to look up
372 * @offset_count: Returns number of GPIOs within this bank
373 * @return bank name of this device
375 const char *gpio_get_bank_info(struct udevice *dev, int *offset_count);
378 * dm_gpio_lookup_name() - Look up a named GPIO and return its description
380 * The name of a GPIO is typically its bank name followed by a number from 0.
381 * For example A0 is the first GPIO in bank A. Each bank is a separate driver
384 * @name: Name to look up
385 * @desc: Returns description, on success
386 * @return 0 if OK, -ve on error
388 int dm_gpio_lookup_name(const char *name, struct gpio_desc *desc);
391 * gpio_hog_lookup_name() - Look up a named GPIO and return the gpio descr.
393 * @name: Name to look up
394 * @desc: Returns GPIO description, on success, else NULL
395 * @return: Returns 0 if OK, else -ENODEV
397 int gpio_hog_lookup_name(const char *name, struct gpio_desc **desc);
400 * gpio_hog_probe_all() - probe all gpio devices with
403 * @return: Returns return value from device_probe()
405 int gpio_hog_probe_all(void);
408 * gpio_lookup_name - Look up a GPIO name and return its details
410 * This is used to convert a named GPIO into a device, offset and GPIO
413 * @name: GPIO name to look up
414 * @devp: Returns pointer to device which contains this GPIO
415 * @offsetp: Returns the offset number within this device
416 * @gpiop: Returns the absolute GPIO number, numbered from 0
418 int gpio_lookup_name(const char *name, struct udevice **devp,
419 unsigned int *offsetp, unsigned int *gpiop);
422 * gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
424 * This puts the value of the first GPIO into bit 0, the second into bit 1,
425 * etc. then returns the resulting integer.
427 * @gpio_list: List of GPIOs to collect
428 * @return resulting integer value, or -ve on error
430 int gpio_get_values_as_int(const int *gpio_list);
433 * dm_gpio_get_values_as_int() - Turn the values of a list of GPIOs into an int
435 * This puts the value of the first GPIO into bit 0, the second into bit 1,
436 * etc. then returns the resulting integer.
438 * @desc_list: List of GPIOs to collect
439 * @count: Number of GPIOs
440 * @return resulting integer value, or -ve on error
442 int dm_gpio_get_values_as_int(const struct gpio_desc *desc_list, int count);
445 * gpio_claim_vector() - claim a number of GPIOs for input
447 * @gpio_num_array: array of gpios to claim, terminated by -1
448 * @fmt: format string for GPIO names, e.g. "board_id%d"
449 * @return 0 if OK, -ve on error
451 int gpio_claim_vector(const int *gpio_num_array, const char *fmt);
454 * gpio_request_by_name() - Locate and request a GPIO by name
456 * This operates by looking up the given list name in the device (device
457 * tree property) and requesting the GPIO for use. The property must exist
460 * Use @flags to specify whether the GPIO should be an input or output. In
461 * principle this can also come from the device tree binding but most
462 * bindings don't provide this information. Specifically, when the GPIO uclass
463 * calls the xlate() method, it can return default flags, which are then
464 * ORed with this @flags.
466 * If we find that requesting the GPIO is not always needed we could add a
467 * new function or a new GPIOD_NO_REQUEST flag.
469 * At present driver model has no reference counting so if one device
470 * requests a GPIO which subsequently is unbound, the @desc->dev pointer
471 * will be invalid. However this will only happen if the GPIO device is
472 * unbound, not if it is removed, so this seems like a reasonable limitation
473 * for now. There is no real use case for unbinding drivers in normal
476 * The device tree binding is doc/device-tree-bindings/gpio/gpio.txt in
477 * generate terms and each specific device may add additional details in
478 * a binding file in the same directory.
480 * @dev: Device requesting the GPIO
481 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
482 * @index: Index number of the GPIO in that list use request (0=first)
483 * @desc: Returns GPIO description information. If there is no such
484 * GPIO, dev->dev will be NULL.
485 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
486 * @return 0 if OK, -ENOENT if the GPIO does not exist, -EINVAL if there is
487 * something wrong with the list, or other -ve for another error (e.g.
488 * -EBUSY if a GPIO was already requested)
490 int gpio_request_by_name(struct udevice *dev, const char *list_name,
491 int index, struct gpio_desc *desc, int flags);
494 * gpio_request_list_by_name() - Request a list of GPIOs
496 * Reads all the GPIOs from a list and requests them. See
497 * gpio_request_by_name() for additional details. Lists should not be
498 * misused to hold unrelated or optional GPIOs. They should only be used
499 * for things like parallel data lines. A zero phandle terminates the list
502 * This function will either succeed, and request all GPIOs in the list, or
503 * fail and request none (it will free already-requested GPIOs in case of
504 * an error part-way through).
506 * @dev: Device requesting the GPIO
507 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
508 * @desc_list: Returns a list of GPIO description information
509 * @max_count: Maximum number of GPIOs to return (@desc_list must be at least
511 * @flags: Indicates the GPIO input/output settings (GPIOD_...)
512 * @return number of GPIOs requested, or -ve on error
514 int gpio_request_list_by_name(struct udevice *dev, const char *list_name,
515 struct gpio_desc *desc_list, int max_count,
519 * dm_gpio_request() - manually request a GPIO
521 * Note: This function should only be used for testing / debugging. Instead.
522 * use gpio_request_by_name() to pull GPIOs from the device tree.
524 * @desc: GPIO description of GPIO to request (see dm_gpio_lookup_name())
525 * @label: Label to attach to the GPIO while claimed
526 * @return 0 if OK, -ve on error
528 int dm_gpio_request(struct gpio_desc *desc, const char *label);
531 * gpio_get_list_count() - Returns the number of GPIOs in a list
533 * Counts the GPIOs in a list. See gpio_request_by_name() for additional
536 * @dev: Device requesting the GPIO
537 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
538 * @return number of GPIOs (0 for an empty property) or -ENOENT if the list
541 int gpio_get_list_count(struct udevice *dev, const char *list_name);
544 * gpio_request_by_name_nodev() - request GPIOs without a device
546 * This is a version of gpio_request_list_by_name() that does not use a
547 * device. Avoid it unless the caller is not yet using driver model
549 int gpio_request_by_name_nodev(ofnode node, const char *list_name, int index,
550 struct gpio_desc *desc, int flags);
553 * gpio_request_list_by_name_nodev() - request GPIOs without a device
555 * This is a version of gpio_request_list_by_name() that does not use a
556 * device. Avoid it unless the caller is not yet using driver model
558 int gpio_request_list_by_name_nodev(ofnode node, const char *list_name,
559 struct gpio_desc *desc_list, int max_count,
563 * gpio_dev_request_index() - request single GPIO from gpio device
566 * @nodename: Name of node for which gpio gets requested, used
567 * for the gpio label name
568 * @list_name: Name of GPIO list (e.g. "board-id-gpios")
569 * @index: Index number of the GPIO in that list use request (0=first)
570 * @flags: GPIOD_* flags
571 * @dtflags: GPIO flags read from DT defined see GPIOD_*
572 * @desc: returns GPIO descriptor filled from this function
573 * @return: return value from gpio_request_tail()
575 int gpio_dev_request_index(struct udevice *dev, const char *nodename,
576 char *list_name, int index, int flags,
577 int dtflags, struct gpio_desc *desc);
580 * dm_gpio_free() - Free a single GPIO
582 * This frees a single GPIOs previously returned from gpio_request_by_name().
584 * @dev: Device which requested the GPIO
585 * @desc: GPIO to free
586 * @return 0 if OK, -ve on error
588 int dm_gpio_free(struct udevice *dev, struct gpio_desc *desc);
591 * gpio_free_list() - Free a list of GPIOs
593 * This frees a list of GPIOs previously returned from
594 * gpio_request_list_by_name().
596 * @dev: Device which requested the GPIOs
597 * @desc: List of GPIOs to free
598 * @count: Number of GPIOs in the list
599 * @return 0 if OK, -ve on error
601 int gpio_free_list(struct udevice *dev, struct gpio_desc *desc, int count);
604 * gpio_free_list_nodev() - free GPIOs without a device
606 * This is a version of gpio_free_list() that does not use a
607 * device. Avoid it unless the caller is not yet using driver model
609 int gpio_free_list_nodev(struct gpio_desc *desc, int count);
612 * dm_gpio_get_value() - Get the value of a GPIO
614 * This is the driver model version of the existing gpio_get_value() function
615 * and should be used instead of that.
617 * For now, these functions have a dm_ prefix since they conflict with
620 * @desc: GPIO description containing device, offset and flags,
621 * previously returned by gpio_request_by_name()
622 * @return GPIO value (0 for inactive, 1 for active) or -ve on error
624 int dm_gpio_get_value(const struct gpio_desc *desc);
626 int dm_gpio_set_value(const struct gpio_desc *desc, int value);
629 * dm_gpio_set_dir() - Set the direction for a GPIO
631 * This sets up the direction according to the GPIO flags: desc->flags.
633 * @desc: GPIO description containing device, offset and flags,
634 * previously returned by gpio_request_by_name()
635 * @return 0 if OK, -ve on error
637 int dm_gpio_set_dir(struct gpio_desc *desc);
640 * dm_gpio_set_dir_flags() - Set direction using description and added flags
642 * This sets up the direction according to the provided flags and the GPIO
643 * description (desc->flags) which include direction information.
644 * Note that desc->flags is updated by this function.
646 * @desc: GPIO description containing device, offset and flags,
647 * previously returned by gpio_request_by_name()
648 * @flags: New flags to use
649 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
651 int dm_gpio_set_dir_flags(struct gpio_desc *desc, ulong flags);
654 * dm_gpio_get_dir_flags() - Get direction flags
656 * read the current direction flags
658 * @desc: GPIO description containing device, offset and flags,
659 * previously returned by gpio_request_by_name()
660 * @flags: place to put the used flags
661 * @return 0 if OK, -ve on error, in which case desc->flags is not updated
663 int dm_gpio_get_dir_flags(struct gpio_desc *desc, ulong *flags);
666 * gpio_get_number() - Get the global GPIO number of a GPIO
668 * This should only be used for debugging or interest. It returns the number
669 * that should be used for gpio_get_value() etc. to access this GPIO.
671 * @desc: GPIO description containing device, offset and flags,
672 * previously returned by gpio_request_by_name()
673 * @return GPIO number, or -ve if not found
675 int gpio_get_number(const struct gpio_desc *desc);
677 #endif /* _ASM_GENERIC_GPIO_H_ */