u-boot.git/include/asm-generic/gpio.h, branch v2016.01

dm: gpio: Add dm_gpio_request() to manually request a GPIO

2015-07-21T23:39:23+00:00

This function can be used for testing to manually request a GPIO for use,
without resorting to the legacy GPIO API.

Signed-off-by: Simon Glass

dm: gpio: Add dm_gpio_lookup_name() to look up a GPIO name

2015-07-21T23:39:23+00:00

Provide a driver-model function to look up a GPIO name. Make the standard
function use it.

Signed-off-by: Simon Glass

gpio: fix typos in GPIO header

2015-06-04T09:38:05+00:00

Signed-off-by: Masahiro Yamada

dm: gpio: Fix comment typo in GPIOD_IS_IN

2015-05-15T00:49:34+00:00

This should say 'in', not 'out'.

Signed-off-by: Simon Glass

dm: gpio: Add error handling and a function to claim vector GPIOs

2015-05-13T16:24:06+00:00

gpio_get_values_as_int() should return an error if something goes wrong.
Also provide gpio_claim_vector(), a function to request the GPIOs and set
them to input mode. Otherwise callers have to do this themselves.

Signed-off-by: Simon Glass 
Signed-off-by: Tom Warren

dm: gpio: Mark the old GPIO API deprecated

2015-01-30T00:09:51+00:00

Add a deprecation notice to each function so that it is more obvious that we
are moving GPIOs to driver model.

Signed-off-by: Simon Glass

dm: gpio: Add better functions to request GPIOs

2015-01-30T00:09:51+00:00

At present U-Boot sort-of supports the standard way of reading GPIOs from
device tree nodes, but the support is incomplete, a bit clunky and only
works for GPIO bindings where #gpio-cells is 2.

Add new functions to request GPIOs, taking full account of the device
tree binding. These permit requesting a GPIO with a simple call like:

   gpio_request_by_name(dev, "cd-gpios", 0, &desc, GPIOD_IS_IN);

This will request the GPIO, looking at the device's node which might be
this, for example:

   cd-gpios = <&gpio TEGRA_GPIO(B, 3) GPIO_ACTIVE_LOW>;

The GPIO will be set to input mode in this case and polarity will be
honoured by the GPIO calls.

It is also possible to request and free a list of GPIOs.

Signed-off-by: Simon Glass

dm: gpio: Add a driver GPIO translation method

2015-01-30T00:09:50+00:00

Only the GPIO driver knows about the full GPIO device tree binding used by
a device. Add a method to allow the driver to provide this information to the
uclass, including the GPIO offset within the device and flags such as the
polarity.

Signed-off-by: Simon Glass

dm: gpio: Add a native driver model API

2015-01-30T00:09:50+00:00

So far driver model's GPIO uclass just implements the existing GPIO API.
This has some limitations:

- it requires manual device tree munging to support GPIOs in device tree
    (fdtdec_get_gpio() and friends)
- it does not understand polarity
- it is somewhat slower since we must scan for the GPIO device each time
- Global GPIO numbering can change if other GPIO drivers are probed
- it requires extra steps to set the GPIO direction and value

The new functions have a dm_ prefix where necessary to avoid name conflicts
but we can remove that when it is no-longer needed. The new struct gpio_desc
holds all required information about the GPIO. For now this is intended to
be stored by the client requesting the GPIO, but in future it might be
brought into the uclass in some way.

With these changes the old GPIO API still works, and uses the driver model
API underneath.

Signed-off-by: Simon Glass

dm: gpio: Add a function to read an ID from a list of GPIOs

2014-11-21T06:24:11+00:00

For board IDs a common approach is to set aside several GPIOs for use in
determining the board ID. This can provide information about board features
and the revision.

Add a function that turns a list of GPIOs into an integer by assigning
each GPIO to a single bit.

Signed-off-by: Simon Glass