Lines Matching +full:int +full:- +full:gpios
6 it describes the new descriptor-based interface. For a description of the
7 deprecated integer-based GPIO interface please refer to legacy.rst.
10 Guidelines for GPIOs consumers
15 obtain and use GPIOs are available by including the following file::
23 - Simple compile coverage with e.g. COMPILE_TEST - it does not matter that
27 - Truly optional GPIOLIB support - where the driver does not really make use
28 of the GPIOs on certain compile-time configurations for certain systems, but
29 will use it under other compile-time configurations. In this case the
33 All the functions that work with the descriptor-based GPIO interface are
40 Obtaining and Disposing GPIOs
43 With the descriptor-based interface, GPIOs are identified with an opaque,
44 non-forgeable handler that must be obtained through a call to one of the
52 If a function is implemented by using several GPIOs together (e.g. a simple LED
56 const char *con_id, unsigned int idx,
60 see Documentation/driver-api/gpio/board.rst
85 with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned
92 instead of -ENOENT if no GPIO has been assigned to the requested function::
100 unsigned int index,
106 -ENOSYS return codes. System integrators should however be careful to enable
109 For a function using multiple GPIOs all of those can be obtained with one call::
121 unsigned int ndescs;
125 The following function returns NULL instead of -ENOENT if no GPIOs have been
132 Device-managed variants of these functions are also defined::
139 unsigned int idx,
148 unsigned int index,
163 For an array of GPIOs this function can be used::
171 The device-managed variants are, unsurprisingly::
178 Using GPIOs
182 -----------------
184 direction-setting flags have been given to gpiod_get*(), this is done by
187 int gpiod_direction_input(struct gpio_desc *desc)
188 int gpiod_direction_output(struct gpio_desc *desc, int value)
193 for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part
196 For output GPIOs, the value provided becomes the initial output value. This
201 int gpiod_get_direction(const struct gpio_desc *desc)
205 Be aware that there is no default direction for GPIOs. Therefore, **using a GPIO
210 Spinlock-Safe GPIO Access
211 -------------------------
213 don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ
216 Use the following calls to access GPIOs from an atomic context::
218 int gpiod_get_value(const struct gpio_desc *desc);
219 void gpiod_set_value(struct gpio_desc *desc, int value);
224 open-drain signaling and output latencies.
229 Also, using these calls for GPIOs that can't safely be accessed without sleeping
234 --------------------------
240 Platforms that support this type of GPIO distinguish them from other GPIOs by
243 int gpiod_cansleep(const struct gpio_desc *desc)
245 To access such GPIOs, a different set of accessors is defined::
247 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
248 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
250 Accessing such GPIOs requires a context which may sleep, for example a threaded
251 IRQ handler, and those accessors must be used instead of spinlock-safe
254 Other than the fact that these accessors might sleep, and will work on GPIOs
256 spinlock-safe calls.
262 ---------------------------------------
276 parameter "value" as "asserted" ("1") or "de-asserted" ("0"). The physical line
298 but it should be avoided as much as possible, especially by system-agnostic drivers
304 -------------------------
309 The following set of calls ignore the active-low or open drain property of a GPIO and
312 int gpiod_get_raw_value(const struct gpio_desc *desc)
313 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
314 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
315 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
316 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
321 int gpiod_is_active_low(const struct gpio_desc *desc)
328 Access multiple GPIOs with a single function call
329 -------------------------------------------------
330 The following functions get or set the values of an array of GPIOs::
332 int gpiod_get_array_value(unsigned int array_size,
336 int gpiod_get_raw_array_value(unsigned int array_size,
340 int gpiod_get_array_value_cansleep(unsigned int array_size,
344 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
349 int gpiod_set_array_value(unsigned int array_size,
353 int gpiod_set_raw_array_value(unsigned int array_size,
357 int gpiod_set_array_value_cansleep(unsigned int array_size,
361 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
366 The array can be an arbitrary set of GPIOs. The functions will try to access
367 GPIOs belonging to the same bank or chip simultaneously if supported by the
369 can be expected. If simultaneous access is not possible the GPIOs will be
374 * array_size - the number of array elements
375 * desc_array - an array of GPIO descriptors
376 * array_info - optional information obtained from gpiod_get_array()
377 * value_bitmap - a bitmap to store the GPIOs' values (get) or
378 a bitmap of values to assign to the GPIOs (set)
382 matches the desired group of GPIOs, those GPIOs can be accessed by simply using
386 gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
387 my_gpio_descs->info, my_gpio_value_bitmap);
395 Note that for optimal performance GPIOs belonging to the same chip should be
412 GPIOs mapped to IRQs
413 --------------------
417 int gpiod_to_irq(const struct gpio_desc *desc)
425 Non-error values returned from gpiod_to_irq() can be passed to request_irq() or
427 by the board-specific initialization code. Note that IRQ trigger options are
432 GPIOs and ACPI
435 On ACPI systems, GPIOs are described by GpioIo()/GpioInt() resources listed by
437 connection IDs (names) for GPIOs, so it is necessary to use an additional
442 GPIOs described by the GpioIo()/GpioInt() resources in _CRS. If that is the
447 For details refer to Documentation/firmware-guide/acpi/gpio-properties.rst
452 Many kernel subsystems and drivers still handle GPIOs using the legacy
453 integer-based interface. It is strongly recommended to update these to the new
456 and vice-versa::
458 int desc_to_gpio(const struct gpio_desc *desc)