linux-toradex.git/Documentation/gpio/driver.txt, branch v4.9.90

gpiolib: Make it possible to exclude GPIOs from IRQ domain

2016-09-23T12:49:50+00:00

When using GPIO irqchip helpers to setup irqchip for a gpiolib based
driver, it is not possible to select which GPIOs to add to the IRQ domain.
Instead it just adds all GPIOs which is not always desired. For example
there might be GPIOs that for some reason cannot generated normal
interrupts at all.

To support this we add a flag irq_need_valid_mask to struct gpio_chip. When
this flag is set the core allocates irq_valid_mask that holds one bit for
each GPIO the chip has. By default all bits are set but drivers can
manipulate this using set_bit() and clear_bit() accordingly.

Then when gpiochip_irqchip_add() is called, this mask is checked and all
GPIOs with bit is set are added to the IRQ domain created for the GPIO
chip.

Suggested-by: Linus Walleij 
Signed-off-by: Mika Westerberg 
Signed-off-by: Linus Walleij

gpio: clarify open drain/source docs

2016-04-27T08:23:44+00:00

Make the text clearer, remove reference to confusing "positive"
and "negative" and elaborate a bit.

Signed-off-by: Linus Walleij

gpio: document open drain/source behaviour

2016-04-09T18:14:26+00:00

This has been a totally undocumented feature for years so add some
generic concepts and documentation about open drain/source, include
some facts on how we now support for hardware.

Cc: Michael Hennerich 
Cc: Nicolas Saenz Julienne 
Cc: H. Nikolaus Schaller 
Signed-off-by: Linus Walleij

Doc: gpio: Fix typos in Documentation/gpio

2015-11-20T23:51:16+00:00

This patch fix some spelling typos found in Documentation/gpio.

Signed-off-by: Masanari Iida 
Acked-by: Randy Dunlap 
Signed-off-by: Jonathan Corbet

gpio: add a real time compliance notes

2015-10-27T10:13:42+00:00

Put in a compliance checklist.

Signed-off-by: Grygorii Strashko 
Signed-off-by: Linus Walleij

Revert "gpio: add a real time compliance checklist"

2015-10-27T10:13:18+00:00

This reverts commit 677b2ff4afd9996eabefc9472c701211b4b49e87.

gpio: add a real time compliance checklist

2015-10-20T08:17:35+00:00

Add some information about real time compliance to the driver document.
Inspired by Grygorii Strashko's real time compliance patches.

Cc: Grygorii Strashko 
Signed-off-by: Linus Walleij

gpio: rename gpio_lock_as_irq to gpiochip_lock_as_irq

2014-10-28T16:30:59+00:00

This function actually operates on a gpio_chip, so its prefix should
reflect that fact for consistency with other functions defined in
gpio/driver.h.

Signed-off-by: Alexandre Courbot 
Signed-off-by: Linus Walleij

gpio: handle also nested irqchips in the chained handler set-up

2014-09-26T12:39:08+00:00

To unify how we connect cascaded IRQ chips to parent IRQs, if
NULL us passed as handler to the gpiochip_set_chained_irqchip()
function, assume the chips is nested rather than chained, and
we still get the parent set up correctly by way of this function
call.

Alter the drivers for tc3589x and stmpe to use this to set up
their chained handlers as a demonstration of the usage.

Signed-off-by: Linus Walleij

gpio: change gpiochip_request_own_desc() prototype

2014-08-29T06:58:34+00:00

The current prototype of gpiochip_request_own_desc() requires to obtain
a pointer to a descriptor. This is in contradiction to all other GPIO
request schemes, and imposes an extra step of obtaining a descriptor to
drivers. Most drivers actually cannot even perform that step since the
function that does it (gpichip_get_desc()) is gpiolib-private.

Change gpiochip_request_own_desc() to return a descriptor from a
(chip, hwnum) tuple and update users of this function (currently
gpiolib-acpi only).

Signed-off-by: Alexandre Courbot 
Tested-by: Mika Westerberg 
Signed-off-by: Linus Walleij