mirror of
https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git
synced 2026-10-30 11:41:38 -04:00
Bulk GPIO changes for the v4.10 kernel cycle:
Core changes:
- Simplify threaded interrupt handling: instead of passing
numbed parameters to gpiochip_irqchip_add_chained() we
create a new call: gpiochip_irqchip_add_nested() so the two
types are clearly semantically different. Also make sure
that all nested chips call gpiochip_set_nested_irqchip()
which is necessary for IRQ resend to work properly if
it happens.
- Return error on seek operations for the chardev.
- Clamp values set as part of gpio[d]_direction_output() so
that anything != 0 will be send down to the driver as "1"
not the value passed in.
- ACPI can now support naming of GPIO lines, hogs and holes
in the GPIO lists.
New drivers:
- The SX150x driver was deemed unfit for the GPIO subsystem
and was moved over to a combined GPIO+pinctrl driver in the
pinctrl subsystem.
New features:
- Various cleanups to various drivers.
-----BEGIN PGP SIGNATURE-----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=2UpT
-----END PGP SIGNATURE-----
Merge tag 'gpio-v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio
Pull GPIO updates from Luinus Walleij:
"Bulk GPIO changes for the v4.10 kernel cycle:
Core changes:
- Simplify threaded interrupt handling: instead of passing numbed
parameters to gpiochip_irqchip_add_chained() we create a new call:
gpiochip_irqchip_add_nested() so the two types are clearly
semantically different. Also make sure that all nested chips call
gpiochip_set_nested_irqchip() which is necessary for IRQ resend to
work properly if it happens.
- Return error on seek operations for the chardev.
- Clamp values set as part of gpio[d]_direction_output() so that
anything != 0 will be send down to the driver as "1" not the value
passed in.
- ACPI can now support naming of GPIO lines, hogs and holes in the
GPIO lists.
New drivers:
- The SX150x driver was deemed unfit for the GPIO subsystem and was
moved over to a combined GPIO+pinctrl driver in the pinctrl
subsystem.
New features:
- Various cleanups to various drivers"
* tag 'gpio-v4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (49 commits)
gpio: merrifield: Implement gpio_get_direction callback
gpio: merrifield: Add support for hardware debouncer
gpio: chardev: Return error for seek operations
gpio: arizona: Tidy up probe error path
gpio: arizona: Remove pointless set of platform drvdata
gpio: pl061: delete platform data handling
gpio: pl061: move platform data into driver
gpio: pl061: rename variable from chip to pl061
gpio: pl061: rename state container struct
gpio: pl061: use local state for parent IRQ storage
gpio: set explicit nesting on drivers
gpio: simplify adding threaded interrupts
gpio: vf610: use builtin_platform_driver
gpio: axp209: use correct register for GPIO input status
gpio: stmpe: fix interrupt handling bug
gpio: em: depnd on ARCH_SHMOBILE
gpio: zx: depend on ARCH_ZX
gpio: x86: update config dependencies for x86 specific hardware
gpio: mb86s7x: use builtin_platform_driver
gpio: etraxfs: use builtin_platform_driver
...
This commit is contained in:
Linus Torvalds
commit
061ad5038c
44 changed files with 2228 additions and 1295 deletions
|
|
@ -175,8 +175,8 @@ The IRQ portions of the GPIO block are implemented using an irqchip, using
|
|||
the header <linux/irq.h>. So basically such a driver is utilizing two sub-
|
||||
systems simultaneously: gpio and irq.
|
||||
|
||||
RT_FULL: GPIO driver should not use spinlock_t or any sleepable APIs
|
||||
(like PM runtime) as part of its irq_chip implementation on -RT.
|
||||
RT_FULL: a realtime compliant GPIO driver should not use spinlock_t or any
|
||||
sleepable APIs (like PM runtime) as part of its irq_chip implementation.
|
||||
- spinlock_t should be replaced with raw_spinlock_t [1].
|
||||
- If sleepable APIs have to be used, these can be done from the .irq_bus_lock()
|
||||
and .irq_bus_unlock() callbacks, as these are the only slowpath callbacks
|
||||
|
|
@ -185,33 +185,32 @@ RT_FULL: GPIO driver should not use spinlock_t or any sleepable APIs
|
|||
GPIO irqchips usually fall in one of two categories:
|
||||
|
||||
* CHAINED GPIO irqchips: these are usually the type that is embedded on
|
||||
an SoC. This means that there is a fast IRQ handler for the GPIOs that
|
||||
an SoC. This means that there is a fast IRQ flow handler for the GPIOs that
|
||||
gets called in a chain from the parent IRQ handler, most typically the
|
||||
system interrupt controller. This means the GPIO irqchip is registered
|
||||
using irq_set_chained_handler() or the corresponding
|
||||
gpiochip_set_chained_irqchip() helper function, and the GPIO irqchip
|
||||
handler will be called immediately from the parent irqchip, while
|
||||
holding the IRQs disabled. The GPIO irqchip will then end up calling
|
||||
something like this sequence in its interrupt handler:
|
||||
system interrupt controller. This means that the GPIO irqchip handler will
|
||||
be called immediately from the parent irqchip, while holding the IRQs
|
||||
disabled. The GPIO irqchip will then end up calling something like this
|
||||
sequence in its interrupt handler:
|
||||
|
||||
static irqreturn_t tc3589x_gpio_irq(int irq, void *data)
|
||||
static irqreturn_t foo_gpio_irq(int irq, void *data)
|
||||
chained_irq_enter(...);
|
||||
generic_handle_irq(...);
|
||||
chained_irq_exit(...);
|
||||
|
||||
Chained GPIO irqchips typically can NOT set the .can_sleep flag on
|
||||
struct gpio_chip, as everything happens directly in the callbacks.
|
||||
struct gpio_chip, as everything happens directly in the callbacks: no
|
||||
slow bus traffic like I2C can be used.
|
||||
|
||||
RT_FULL: Note, chained IRQ handlers will not be forced threaded on -RT.
|
||||
As result, spinlock_t or any sleepable APIs (like PM runtime) can't be used
|
||||
in chained IRQ handler.
|
||||
if required (and if it can't be converted to the nested threaded GPIO irqchip)
|
||||
- chained IRQ handler can be converted to generic irq handler and this way
|
||||
it will be threaded IRQ handler on -RT and hard IRQ handler on non-RT
|
||||
If required (and if it can't be converted to the nested threaded GPIO irqchip)
|
||||
a chained IRQ handler can be converted to generic irq handler and this way
|
||||
it will be a threaded IRQ handler on -RT and a hard IRQ handler on non-RT
|
||||
(for example, see [3]).
|
||||
Know W/A: The generic_handle_irq() is expected to be called with IRQ disabled,
|
||||
so IRQ core will complain if it will be called from IRQ handler which is
|
||||
forced thread. The "fake?" raw lock can be used to W/A this problem:
|
||||
so the IRQ core will complain if it is called from an IRQ handler which is
|
||||
forced to a thread. The "fake?" raw lock can be used to W/A this problem:
|
||||
|
||||
raw_spinlock_t wa_lock;
|
||||
static irqreturn_t omap_gpio_irq_handler(int irq, void *gpiobank)
|
||||
|
|
@ -243,7 +242,7 @@ GPIO irqchips usually fall in one of two categories:
|
|||
by the driver. The hallmark of this driver is to call something like
|
||||
this in its interrupt handler:
|
||||
|
||||
static irqreturn_t tc3589x_gpio_irq(int irq, void *data)
|
||||
static irqreturn_t foo_gpio_irq(int irq, void *data)
|
||||
...
|
||||
handle_nested_irq(irq);
|
||||
|
||||
|
|
@ -256,23 +255,31 @@ associated irqdomain and resource allocation callbacks, the gpiolib has
|
|||
some helpers that can be enabled by selecting the GPIOLIB_IRQCHIP Kconfig
|
||||
symbol:
|
||||
|
||||
* gpiochip_irqchip_add(): adds an irqchip to a gpiochip. It will pass
|
||||
* gpiochip_irqchip_add(): adds a chained irqchip to a gpiochip. It will pass
|
||||
the struct gpio_chip* for the chip to all IRQ callbacks, so the callbacks
|
||||
need to embed the gpio_chip in its state container and obtain a pointer
|
||||
to the container using container_of().
|
||||
(See Documentation/driver-model/design-patterns.txt)
|
||||
|
||||
If there is a need to exclude certain GPIOs from the IRQ domain, one can
|
||||
set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
|
||||
called. This allocates .irq_valid_mask with as many bits set as there are
|
||||
GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
|
||||
mask. The mask must be filled in before gpiochip_irqchip_add() is called.
|
||||
* gpiochip_irqchip_add_nested(): adds a nested irqchip to a gpiochip.
|
||||
Apart from that it works exactly like the chained irqchip.
|
||||
|
||||
* gpiochip_set_chained_irqchip(): sets up a chained irq handler for a
|
||||
gpio_chip from a parent IRQ and passes the struct gpio_chip* as handler
|
||||
data. (Notice handler data, since the irqchip data is likely used by the
|
||||
parent irqchip!) This is for the chained type of chip. This is also used
|
||||
to set up a nested irqchip if NULL is passed as handler.
|
||||
parent irqchip!).
|
||||
|
||||
* gpiochip_set_nested_irqchip(): sets up a nested irq handler for a
|
||||
gpio_chip from a parent IRQ. As the parent IRQ has usually been
|
||||
explicitly requested by the driver, this does very little more than
|
||||
mark all the child IRQs as having the other IRQ as parent.
|
||||
|
||||
If there is a need to exclude certain GPIOs from the IRQ domain, you can
|
||||
set .irq_need_valid_mask of the gpiochip before gpiochip_add_data() is
|
||||
called. This allocates an .irq_valid_mask with as many bits set as there
|
||||
are GPIOs in the chip. Drivers can exclude GPIOs by clearing bits from this
|
||||
mask. The mask must be filled in before gpiochip_irqchip_add() or
|
||||
gpiochip_irqchip_add_nested() is called.
|
||||
|
||||
To use the helpers please keep the following in mind:
|
||||
|
||||
|
|
@ -323,6 +330,9 @@ When implementing an irqchip inside a GPIO driver, these two functions should
|
|||
typically be called in the .startup() and .shutdown() callbacks from the
|
||||
irqchip.
|
||||
|
||||
When using the gpiolib irqchip helpers, these callback are automatically
|
||||
assigned.
|
||||
|
||||
Real-Time compliance for GPIO IRQ chips
|
||||
---------------------------------------
|
||||
|
||||
|
|
|
|||
Loading…
Reference in a new issue