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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-07 12:27:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-07 12:27:27 -0700 |
commit | 5e6a5845dd651b00754a62edec2f0a439182024d (patch) | |
tree | d93d10b5dc505b64b62ce42cee2bf926d6b42051 /Documentation/driver-api | |
parent | 75b96f0ec5faf730128c32187e3e28441c27a094 (diff) | |
parent | 889a1b3f35db6ba5ba6a0c23a3a55594570b6a17 (diff) | |
download | linux-5e6a5845dd651b00754a62edec2f0a439182024d.tar.bz2 |
Merge tag 'gpio-updates-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio updates from Bartosz Golaszewski:
"We mostly have various improvements and refactoring all over the place
but also some interesting new features - like the virtio GPIO driver
that allows guest VMs to use host's GPIOs. We also have a new/old GPIO
driver for rockchip - this one has been split out of the pinctrl
driver.
Summary:
- new driver: gpio-virtio allowing a guest VM running linux to access
GPIO lines provided by the host
- split the GPIO driver out of the rockchip pin control driver
- add support for a new model to gpio-aspeed-sgpio, refactor the
driver and use generic device property interfaces, improve property
sanitization
- add ACPI support to gpio-tegra186
- improve the code setting the line names to support multiple GPIO
banks per device
- constify a bunch of OF functions in the core GPIO code and make the
declaration for one of the core OF functions we use consistent
within its header
- use software nodes in intel_quark_i2c_gpio
- add support for the gpio-line-names property in gpio-mt7621
- use the standard GPIO function for setting the GPIO names in
gpio-brcmstb
- fix a bunch of leaks and other bugs in gpio-mpc8xxx
- use generic pm callbacks in gpio-ml-ioh
- improve resource management and PM handling in gpio-mlxbf2
- modernize and improve the gpio-dwapb driver
- coding style improvements in gpio-rcar
- documentation fixes and improvements
- update the MAINTAINERS entry for gpio-zynq
- minor tweaks in several drivers"
* tag 'gpio-updates-for-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux: (35 commits)
gpio: mpc8xxx: Use 'devm_gpiochip_add_data()' to simplify the code and avoid a leak
gpio: mpc8xxx: Fix a potential double iounmap call in 'mpc8xxx_probe()'
gpio: mpc8xxx: Fix a resources leak in the error handling path of 'mpc8xxx_probe()'
gpio: viperboard: remove platform_set_drvdata() call in probe
gpio: virtio: Add missing mailings lists in MAINTAINERS entry
gpio: virtio: Fix sparse warnings
gpio: remove the obsolete MX35 3DS BOARD MC9S08DZ60 GPIO functions
gpio: max730x: Use the right include
gpio: Add virtio-gpio driver
gpio: mlxbf2: Use DEFINE_RES_MEM_NAMED() helper macro
gpio: mlxbf2: Use devm_platform_ioremap_resource()
gpio: mlxbf2: Drop wrong use of ACPI_PTR()
gpio: mlxbf2: Convert to device PM ops
gpio: dwapb: Get rid of legacy platform data
mfd: intel_quark_i2c_gpio: Convert GPIO to use software nodes
gpio: dwapb: Read GPIO base from gpio-base property
gpio: dwapb: Unify ACPI enumeration checks in get_irq() and configure_irqs()
gpiolib: Deduplicate forward declaration in the consumer.h header
MAINTAINERS: update gpio-zynq.yaml reference
gpio: tegra186: Add ACPI support
...
Diffstat (limited to 'Documentation/driver-api')
-rw-r--r-- | Documentation/driver-api/gpio/consumer.rst | 10 | ||||
-rw-r--r-- | Documentation/driver-api/gpio/driver.rst | 11 |
2 files changed, 13 insertions, 8 deletions
diff --git a/Documentation/driver-api/gpio/consumer.rst b/Documentation/driver-api/gpio/consumer.rst index 3366a991b4aa..47869ca8ccf0 100644 --- a/Documentation/driver-api/gpio/consumer.rst +++ b/Documentation/driver-api/gpio/consumer.rst @@ -72,6 +72,10 @@ for the GPIO. Values can be: * GPIOD_OUT_HIGH_OPEN_DRAIN same as GPIOD_OUT_HIGH but also enforce the line to be electrically used with open drain. +Note that the initial value is *logical* and the physical line level depends on +whether the line is configured active high or active low (see +:ref:`active_low_semantics`). + The two last flags are used for use cases where open drain is mandatory, such as I2C: if the line is not already configured as open drain in the mappings (see board.txt), then open drain will be enforced anyway and a warning will be @@ -252,6 +256,8 @@ that can't be accessed from hardIRQ handlers, these calls act the same as the spinlock-safe calls. +.. _active_low_semantics: + The active low and open drain semantics --------------------------------------- As a consumer should not have to care about the physical line level, all of the @@ -309,9 +315,11 @@ work on the raw line value:: void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) int gpiod_direction_output_raw(struct gpio_desc *desc, int value) -The active low state of a GPIO can also be queried using the following call:: +The active low state of a GPIO can also be queried and toggled using the +following calls:: int gpiod_is_active_low(const struct gpio_desc *desc) + void gpiod_toggle_active_low(struct gpio_desc *desc) Note that these functions should only be used with great moderation; a driver should not have to care about the physical line level or open drain semantics. diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst index d6b0d779859b..bbc53920d4dd 100644 --- a/Documentation/driver-api/gpio/driver.rst +++ b/Documentation/driver-api/gpio/driver.rst @@ -547,13 +547,10 @@ To use the helpers please keep the following in mind: the irqchip can initialize. E.g. .dev and .can_sleep shall be set up properly. -- Nominally set all handlers to handle_bad_irq() in the setup call and pass - handle_bad_irq() as flow handler parameter in gpiochip_irqchip_add() if it is - expected for GPIO driver that irqchip .set_type() callback will be called - before using/enabling each GPIO IRQ. Then set the handler to - handle_level_irq() and/or handle_edge_irq() in the irqchip .set_type() - callback depending on what your controller supports and what is requested - by the consumer. +- Nominally set gpio_irq_chip.handler to handle_bad_irq. Then, if your irqchip + is cascaded, set the handler to handle_level_irq() and/or handle_edge_irq() + in the irqchip .set_type() callback depending on what your controller + supports and what is requested by the consumer. Locking IRQ usage |