Lines Matching +full:int +full:- +full:gpios
8 Guidelines for GPIOs consumers
13 obtain and use GPIOs are available by including the following file::
21 - Simple compile coverage with e.g. COMPILE_TEST - it does not matter that
25 - Truly optional GPIOLIB support - where the driver does not really make use
26 of the GPIOs on certain compile-time configurations for certain systems, but
27 will use it under other compile-time configurations. In this case the
35 All the functions that work with the descriptor-based GPIO interface are
42 Obtaining and Disposing GPIOs
45 With the descriptor-based interface, GPIOs are identified with an opaque,
46 non-forgeable handler that must be obtained through a call to one of the
54 If a function is implemented by using several GPIOs together (e.g. a simple LED
58 const char *con_id, unsigned int idx,
62 see Documentation/driver-api/gpio/board.rst
87 with IS_ERR() (they will never return a NULL pointer). -ENOENT will be returned
94 instead of -ENOENT if no GPIO has been assigned to the requested function::
102 unsigned int index,
108 -ENOSYS return codes. System integrators should however be careful to enable
111 For a function using multiple GPIOs all of those can be obtained with one call::
123 unsigned int ndescs;
127 The following function returns NULL instead of -ENOENT if no GPIOs have been
134 Device-managed variants of these functions are also defined::
141 unsigned int idx,
150 unsigned int index,
165 For an array of GPIOs this function can be used::
173 The device-managed variants are, unsurprisingly::
180 Using GPIOs
184 -----------------
186 direction-setting flags have been given to gpiod_get*(), this is done by
189 int gpiod_direction_input(struct gpio_desc *desc)
190 int gpiod_direction_output(struct gpio_desc *desc, int value)
195 for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part
198 For output GPIOs, the value provided becomes the initial output value. This
203 int gpiod_get_direction(const struct gpio_desc *desc)
207 Be aware that there is no default direction for GPIOs. Therefore, **using a GPIO
212 Spinlock-Safe GPIO Access
213 -------------------------
215 don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ
218 Use the following calls to access GPIOs from an atomic context::
220 int gpiod_get_value(const struct gpio_desc *desc);
221 void gpiod_set_value(struct gpio_desc *desc, int value);
226 open-drain signaling and output latencies.
231 Also, using these calls for GPIOs that can't safely be accessed without sleeping
236 --------------------------
242 Platforms that support this type of GPIO distinguish them from other GPIOs by
245 int gpiod_cansleep(const struct gpio_desc *desc)
247 To access such GPIOs, a different set of accessors is defined::
249 int gpiod_get_value_cansleep(const struct gpio_desc *desc)
250 void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
252 Accessing such GPIOs requires a context which may sleep, for example a threaded
253 IRQ handler, and those accessors must be used instead of spinlock-safe
256 Other than the fact that these accessors might sleep, and will work on GPIOs
258 spinlock-safe calls.
264 ---------------------------------------
300 but it should be avoided as much as possible, especially by system-agnostic drivers
306 -------------------------
311 The following set of calls ignore the active-low or open drain property of a GPIO and
314 int gpiod_get_raw_value(const struct gpio_desc *desc)
315 void gpiod_set_raw_value(struct gpio_desc *desc, int value)
316 int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
317 void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
318 int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
323 int gpiod_is_active_low(const struct gpio_desc *desc)
330 Access multiple GPIOs with a single function call
331 -------------------------------------------------
332 The following functions get or set the values of an array of GPIOs::
334 int gpiod_get_array_value(unsigned int array_size,
338 int gpiod_get_raw_array_value(unsigned int array_size,
342 int gpiod_get_array_value_cansleep(unsigned int array_size,
346 int gpiod_get_raw_array_value_cansleep(unsigned int array_size,
351 int gpiod_set_array_value(unsigned int array_size,
355 int gpiod_set_raw_array_value(unsigned int array_size,
359 int gpiod_set_array_value_cansleep(unsigned int array_size,
363 int gpiod_set_raw_array_value_cansleep(unsigned int array_size,
368 The array can be an arbitrary set of GPIOs. The functions will try to access
369 GPIOs belonging to the same bank or chip simultaneously if supported by the
371 can be expected. If simultaneous access is not possible the GPIOs will be
376 * array_size - the number of array elements
377 * desc_array - an array of GPIO descriptors
378 * array_info - optional information obtained from gpiod_get_array()
379 * value_bitmap - a bitmap to store the GPIOs' values (get) or
380 a bitmap of values to assign to the GPIOs (set)
384 matches the desired group of GPIOs, those GPIOs can be accessed by simply using
388 gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
389 my_gpio_descs->info, my_gpio_value_bitmap);
397 Note that for optimal performance GPIOs belonging to the same chip should be
414 GPIOs mapped to IRQs
415 --------------------
419 int gpiod_to_irq(const struct gpio_desc *desc)
427 Non-error values returned from gpiod_to_irq() can be passed to request_irq() or
429 by the board-specific initialization code. Note that IRQ trigger options are
434 GPIOs and ACPI
437 On ACPI systems, GPIOs are described by GpioIo()/GpioInt() resources listed by
439 connection IDs (names) for GPIOs, so it is necessary to use an additional
444 GPIOs described by the GpioIo()/GpioInt() resources in _CRS. If that is the
449 For details refer to Documentation/firmware-guide/acpi/gpio-properties.rst
454 Many kernel subsystems and drivers still handle GPIOs using the legacy
455 integer-based interface. It is strongly recommended to update these to the new
458 and vice-versa::
460 int desc_to_gpio(const struct gpio_desc *desc)