Commit Graph

5 Commits

Author SHA1 Message Date
Mika Westerberg cfc507648c Documentation: gpio: Update ACPI part of the document to mention _DSD
With ACPI 5.1 _DSD (Device Specific Data) it is now possible to name
functions just like Device Tree is doing. Make sure that the documentation
mentions _DSD as the recommended way to describe GPIOs in ACPI systems.

Reported-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-04-04 15:20:27 +02:00
Fabio Estevam 4f7d45596e gpio: board.txt: Fix the gpio name example
As explained in this file:

"GPIOs mappings are defined in the consumer device's node, in a property named
<function>-gpios"

So fix the example to match the convention.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2015-01-28 11:14:00 -07:00
Linus Walleij 0a6d315827 gpio: split gpiod board registration into machine header
As per example from the regulator subsystem: put all defines and
functions related to registering board info for GPIO descriptors
into a separate <linux/gpio/machine.h> header.

Cc: Andrew Victor <linux@maxim.org.za>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Reviewed-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-28 12:23:35 +02:00
Alexandre Courbot ad824783fb gpio: better lookup method for platform GPIOs
Change the format of the platform GPIO lookup tables to make them less
confusing and improve lookup efficiency.

The previous format was a single linked-list that required to compare
the device name and function ID of every single GPIO defined for each
lookup. Switch that to a list of per-device tables, so that the lookup
can be done in two steps, omitting the GPIOs that are not relevant for a
particular device.

The matching rules are now defined as follows:
- The device name must match *exactly*, and can be NULL for GPIOs not
  assigned to a particular device,
- If the function ID in the lookup table is NULL, the con_id argument of
  gpiod_get() will not be used for lookup. However, if it is defined, it
  must match exactly.
- The index must always match.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-09 14:05:51 +01:00
Alexandre Courbot fd8e198cfc Documentation: gpiolib: document new interface
gpiolib now exports a new descriptor-based interface which deprecates
the older integer-based one. This patch documents this new interface and
also takes the opportunity to brush-up the GPIO documentation a little
bit.

The new descriptor-based interface follows the same consumer/driver
model as many other kernel subsystems (e.g. clock, regulator), so its
documentation has similarly been splitted into different files.

The content of the former documentation has been reused whenever it
made sense; however, some of its content did not apply to the new
interface anymore and have this been removed. Likewise, new sections
like the mapping of GPIOs to devices have been written from scratch.

The deprecated legacy-based documentation is still available, untouched,
under Documentation/gpio/gpio-legacy.txt.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-11-25 09:02:30 +01:00