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 gpio-legacy.txt.
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
81 with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned
88 instead of -ENOENT if no GPIO has been assigned to the requested function::
96 unsigned int index,
102 -ENOSYS return codes. System integrators should however be careful to enable
105 For a function using multiple GPIOs all of those can be obtained with one call::
115 unsigned int ndescs;
119 The following function returns NULL instead of -ENOENT if no GPIOs have been
126 Device-managed variants of these functions are also defined::
133 unsigned int idx,
142 unsigned int index,
157 For an array of GPIOs this function can be used::
165 The device-managed variants are, unsurprisingly::
172 Using GPIOs
176 -----------------
178 direction-setting flags have been given to gpiod_get*(), this is done by
181 int gpiod_direction_input(struct gpio_desc *desc)
182 int gpiod_direction_output(struct gpio_desc *desc, int value)
187 for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part
190 For output GPIOs, the value provided becomes the initial output value. This
195 int gpiod_get_direction(const struct gpio_desc *desc)
199 Be aware that there is no default direction for GPIOs. Therefore, **using a GPIO
204 Spinlock-Safe GPIO Access
205 -------------------------
207 don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ
210 Use the following calls to access GPIOs from an atomic context::
212 int gpiod_get_value(const struct gpio_desc *desc);
213 void gpiod_set_value(struct gpio_desc *desc, int value);
218 open-drain signaling and output latencies.
223 Also, using these calls for GPIOs that can't safely be accessed without sleeping
228 --------------------------
234 Platforms that support this type of GPIO distinguish them from other GPIOs by
237 int gpiod_cansleep(const struct gpio_desc *desc)
239 To access such GPIOs, a different set of accessors is defined::
241 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
242 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
244 Accessing such GPIOs requires a context which may sleep, for example a threaded
245 IRQ handler, and those accessors must be used instead of spinlock-safe
248 Other than the fact that these accessors might sleep, and will work on GPIOs
250 spinlock-safe calls.
254 ---------------------------------------
268 parameter "value" as "asserted" ("1") or "de-asserted" ("0"). The physical line
292 but it should be avoided as much as possible, especially by system-agnostic drivers
298 -------------------------
303 The following set of calls ignore the active-low or open drain property of a GPIO and
306 int gpiod_get_raw_value(const struct gpio_desc *desc)
307 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
308 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
309 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
310 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
314 int gpiod_is_active_low(const struct gpio_desc *desc)
320 Access multiple GPIOs with a single function call
321 -------------------------------------------------
322 The following functions get or set the values of an array of GPIOs::
324 int gpiod_get_array_value(unsigned int array_size,
326 int *value_array);
327 int gpiod_get_raw_array_value(unsigned int array_size,
329 int *value_array);
330 int gpiod_get_array_value_cansleep(unsigned int array_size,
332 int *value_array);
333 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
335 int *value_array);
337 void gpiod_set_array_value(unsigned int array_size,
339 int *value_array)
340 void gpiod_set_raw_array_value(unsigned int array_size,
342 int *value_array)
343 void gpiod_set_array_value_cansleep(unsigned int array_size,
345 int *value_array)
346 void gpiod_set_raw_array_value_cansleep(unsigned int array_size,
348 int *value_array)
350 The array can be an arbitrary set of GPIOs. The functions will try to access
351 GPIOs belonging to the same bank or chip simultaneously if supported by the
353 can be expected. If simultaneous access is not possible the GPIOs will be
357 * array_size - the number of array elements
358 * desc_array - an array of GPIO descriptors
359 * value_array - an array to store the GPIOs' values (get) or
360 an array of values to assign to the GPIOs (set)
364 matches the desired group of GPIOs, those GPIOs can be accessed by simply using
368 gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
376 Note that for optimal performance GPIOs belonging to the same chip should be
385 GPIOs mapped to IRQs
386 --------------------
390 int gpiod_to_irq(const struct gpio_desc *desc)
398 Non-error values returned from gpiod_to_irq() can be passed to request_irq() or
400 by the board-specific initialization code. Note that IRQ trigger options are
405 GPIOs and ACPI
408 On ACPI systems, GPIOs are described by GpioIo()/GpioInt() resources listed by
410 connection IDs (names) for GPIOs, so it is necessary to use an additional
415 GPIOs described by the GpioIo()/GpioInt() resources in _CRS. If that is the
420 For details refer to Documentation/acpi/gpio-properties.txt
425 Many kernel subsystems still handle GPIOs using the legacy integer-based
427 descriptor-based API, the following two functions allow you to convert a GPIO
428 descriptor into the GPIO integer namespace and vice-versa::
430 int desc_to_gpio(const struct gpio_desc *desc)