Lines Matching +full:led +full:- +full:open +full:- +full:drain
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.
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
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
60 see Documentation/driver-api/gpio/board.rst
71 to be electrically used with open drain.
73 to be electrically used with open drain.
75 The two last flags are used for use cases where open drain is mandatory, such
76 as I2C: if the line is not already configured as open drain in the mappings
77 (see board.txt), then open drain will be enforced anyway and a warning will be
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::
102 -ENOSYS return codes. System integrators should however be careful to enable
121 The following function returns NULL instead of -ENOENT if no GPIOs have been
128 Device-managed variants of these functions are also defined::
167 The device-managed variants are, unsurprisingly::
178 -----------------
180 direction-setting flags have been given to gpiod_get*(), this is done by
189 for spinlock-safe GPIOs it is OK to use them before tasking is enabled, as part
206 Spinlock-Safe GPIO Access
207 -------------------------
209 don't need to sleep, and can safely be done from inside hard (non-threaded) IRQ
220 open-drain signaling and output latencies.
230 --------------------------
247 IRQ handler, and those accessors must be used instead of spinlock-safe
252 spinlock-safe calls.
255 The active low and open drain semantics
256 ---------------------------------------
264 The same is applicable for open drain or open source output lines: those do not
265 actively drive their output high (open drain) or low (open source), they just
267 care. (For details read about open drain in driver.txt.)
270 parameter "value" as "asserted" ("1") or "de-asserted" ("0"). The physical line
286 gpiod_set_value(desc, 0); open drain low
287 gpiod_set_value(desc, 1); open drain high impedance
288 gpiod_set_value(desc, 0); open source high impedance
289 gpiod_set_value(desc, 1); open source high
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
317 should not have to care about the physical line level or open drain semantics.
321 -------------------------------------------------
365 * array_size - the number of array elements
366 * desc_array - an array of GPIO descriptors
367 * array_info - optional information obtained from gpiod_get_array()
368 * value_bitmap - a bitmap to store the GPIOs' values (get) or
377 gpiod_set_array_value(my_gpio_descs->ndescs, my_gpio_descs->desc,
378 my_gpio_descs->info, my_gpio_value_bitmap);
404 --------------------
416 Non-error values returned from gpiod_to_irq() can be passed to request_irq() or
418 by the board-specific initialization code. Note that IRQ trigger options are
438 For details refer to Documentation/firmware-guide/acpi/gpio-properties.rst
443 Many kernel subsystems still handle GPIOs using the legacy integer-based
445 descriptor-based API, the following two functions allow you to convert a GPIO
446 descriptor into the GPIO integer namespace and vice-versa::