summaryrefslogtreecommitdiff
path: root/Documentation/driver-api
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2023-04-26 03:18:18 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2023-04-26 03:18:18 +0300
commit2c96606a0f8b7900387dbeb6532b59527999834d (patch)
tree84772d9aa6951ca93d27b3ddc9bcb7c79bd7b554 /Documentation/driver-api
parentd84955790e16588774c4365ba0d449e8a2aa46d8 (diff)
parent8a4adcf67a39b3f308bb8cf686e41c0e26aa12e8 (diff)
downloadlinux-2c96606a0f8b7900387dbeb6532b59527999834d.tar.xz
Merge tag 'gpio-updates-for-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski: "We have some new drivers, significant refactoring of existing intel platforms, lots of improvements all around, mass conversion to using immutable irqchips by drivers that had not been converted individually yet and some changes in the core library code. Summary: New drivers: - add a driver for the Loongson GPIO controller - add a driver for the fxl6408 I2C GPIO expander - add a GPIO module containing code common for Intel Elkhart Lake and Merrifield platforms - add a driver for the Intel Elkhart Lake platform reusing the code from the intel tangier library GPIOLIB core: - GPIO ACPI improvements - simplify gpiochip_add_data_with_keys() fwnode handling - cleanup header inclusions (remove unneeded ones, order the rest alphabetically) - remove duplicate code (reuse krealloc() instead of open-coding it, drop a duplicated check in gpiod_find_and_request()) - reshuffle the code to remove unnecessary forward declarations - coding style cleanups and improvements - add a helper for accessing device fwnodes - small updates in docs Driver improvements: - convert all remaining GPIO irqchip drivers to using immutable irqchips - drop unnecessary of_match_ptr() macro expansions - shrink the code in gpio-merrifield significantly by reusing the code from gpio-tangier + minor tweaks to the driver code - remove MODULE_LICENSE() from drivers that can only be built-in - add device-tree support to gpio-loongson1 - use new regmap features in gpio-104-dio-48e and gpio-pcie-idio-24 - minor tweaks and fixes to gpio-xra1403, gpio-sim, gpio-tegra194, gpio-omap, gpio-aspeed, gpio-raspberrypi-exp - shrink code in gpio-ich and gpio-pxa - Kconfig tweak for gpio-pmic-eic-sprd" * tag 'gpio-updates-for-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (99 commits) gpio: gpiolib: Simplify gpiochip_add_data_with_key() fwnode gpiolib: Add gpiochip_set_data() helper gpiolib: Move gpiochip_get_data() higher in the code gpiolib: Check array_info for NULL only once in gpiod_get_array() gpiolib: Replace open coded krealloc() gpiolib: acpi: Add a ignore wakeup quirk for Clevo NL5xNU gpiolib: acpi: Move ACPI device NULL check to acpi_get_driver_gpio_data() gpiolib: acpi: use the fwnode in acpi_gpiochip_find() gpio: mm-lantiq: Fix typo in the newly added header filename sh: mach-x3proto: Add missing #include <linux/gpio/driver.h> powerpc/40x: Add missing select OF_GPIO_MM_GPIOCHIP gpio: xlp: Convert to immutable irq_chip gpio: xilinx: Convert to immutable irq_chip gpio: xgs-iproc: Convert to immutable irq_chip gpio: visconti: Convert to immutable irq_chip gpio: tqmx86: Convert to immutable irq_chip gpio: thunderx: Convert to immutable irq_chip gpio: stmpe: Convert to immutable irq_chip gpio: siox: Convert to immutable irq_chip gpio: rda: Convert to immutable irq_chip ...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r--Documentation/driver-api/gpio/driver.rst8
-rw-r--r--Documentation/driver-api/gpio/legacy.rst23
2 files changed, 4 insertions, 27 deletions
diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst
index 6baaeab79534..bf6319cc531b 100644
--- a/Documentation/driver-api/gpio/driver.rst
+++ b/Documentation/driver-api/gpio/driver.rst
@@ -218,10 +218,10 @@ not support open drain/open source in hardware, the GPIO library will instead
use a trick: when a line is set as output, if the line is flagged as open
drain, and the IN output value is low, it will be driven low as usual. But
if the IN output value is set to high, it will instead *NOT* be driven high,
-instead it will be switched to input, as input mode is high impedance, thus
-achieving an "open drain emulation" of sorts: electrically the behaviour will
-be identical, with the exception of possible hardware glitches when switching
-the mode of the line.
+instead it will be switched to input, as input mode is an equivalent to
+high impedance, thus achieving an "open drain emulation" of sorts: electrically
+the behaviour will be identical, with the exception of possible hardware glitches
+when switching the mode of the line.
For open source configuration the same principle is used, just that instead
of actively driving the line low, it is set to input.
diff --git a/Documentation/driver-api/gpio/legacy.rst b/Documentation/driver-api/gpio/legacy.rst
index a0559d93efd1..78372853c6d4 100644
--- a/Documentation/driver-api/gpio/legacy.rst
+++ b/Documentation/driver-api/gpio/legacy.rst
@@ -238,8 +238,6 @@ setup or driver probe/teardown code, so this is an easy constraint.)::
## gpio_free_array()
gpio_free()
- gpio_set_debounce()
-
Claiming and Releasing GPIOs
@@ -716,27 +714,6 @@ gpiochip nodes (possibly in conjunction with schematics) to determine
the correct GPIO number to use for a given signal.
-Exporting from Kernel code
---------------------------
-Kernel code can explicitly manage exports of GPIOs which have already been
-requested using gpio_request()::
-
- /* export the GPIO to userspace */
- int gpio_export(unsigned gpio, bool direction_may_change);
-
- /* reverse gpio_export() */
- void gpio_unexport();
-
-After a kernel driver requests a GPIO, it may only be made available in
-the sysfs interface by gpio_export(). The driver can control whether the
-signal direction may change. This helps drivers prevent userspace code
-from accidentally clobbering important system state.
-
-This explicit exporting can help with debugging (by making some kinds
-of experiments easier), or can provide an always-there interface that's
-suitable for documenting as part of a board support package.
-
-
API Reference
=============