The tegra GPIO controller has two ways of reading the value of a GPIO. It
can supply the 'input' value (which is the value read from the pin) and the
'output' value (which is the value being driven from the pin. With a GPIO
set to output mode, the 'input' value is always low which is not very
useful.
This has the unfortunate result that setting a GPIO high still leaves it
showing as low in the 'gpio status' command.
Adjust the driver to check which direction the GPIO is set to, then read
the value from the appropriate register: 'input' for input GPIOs, 'output'
for output GPIOs.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
In order to make it clear what the parameters to set_config() and
set_direction() mean, and similarly for the return values from the
respective get_*(), define named constants for these values.
Disassembly shows no diff in the generated code, except that the
order of the code in the branches of tegra_gpio_get_function() gets
modified without affecting behaviour.
Suggested-by: Tom Warren <twarren@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
These enum values aren't used anywhere. Remove them.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Tegra's GPIO driver currently enables pins as GPIO as soon as they're
requested. This is not safe, since the desired direction and output value
are not yet known. This could cause a glitch on the output pins between
gpio_request() and gpio_direction_*(), depending on what values happen to
be in the GPIO controller's in/out and out-value registers vs. the final
desired configuration.
To solve this, defer enabling pins as GPIOs until some gpio_direction_*()
is invoked, and the desired configuration is explicitly programmed.
In theory this change could cause regressions, if code exists that claims
a GPIO, never explicitly sets a direction, and then gets/sets the GPIO
value based on that assumption. However, I've read through all the Tegra-
related board files and device drivers that touch GPIOs and I do not see
such buggy code anywhere.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
Tegra's gpio_config_table() currently uses common GPIO APIs. These used
to work without requesting the GPIO, but since commit 2fccd2d96b "tegra:
Convert tegra GPIO driver to use driver model" no longer do so. This
prevents any of the GPIO initialization table from being applied to HW.
Fix gpio_config_table() to directly program the HW to solve this.
Fixes: 2fccd2d96b ("tegra: Convert tegra GPIO driver to use driver model")
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This is a convenient way for a driver to get the hardware address of a
device, when regmap or syscon are not being used. Change existing callers
to use it as an example to others.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Joe Hershberger <joe.hershberger@ni.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Add a convenience function to access the private data that a uclass stores
for each of its devices. Convert over most existing uses for consistency
and to provide an example for others.
Signed-off-by: Simon Glass <sjg@chromium.org>
Use the full driver model GPIO and serial drivers in SPL now that these are
supported. Since device tree is not available they will use platform data.
Remove the special SPL GPIO function as it is no longer needed.
This is all in one commit to maintain bisectability.
Signed-off-by: Simon Glass <sjg@chromium.org>
Now that the uclass supports gpio_request/free() there is no need for the
driver to implement it too. Drop this unnecessary code.
Signed-off-by: Simon Glass <sjg@chromium.org>
Fix Tegra GPIO driver to not crash resp. misbehave upon requesting
GPIOs with an empty aka NULL label. As the driver uses exclusively the
label to check for reservation status actually supplying one is
mandatory!
This fixes a regression introduced by commit:
2fccd2d96b
tegra: Convert tegra GPIO driver to use driver model
Signed-off-by: Marcel Ziswiler <marcel@ziswiler.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
This is an implementation of GPIOs for Tegra that uses driver model. It has
been tested on trimslice and also using the new iotrace feature.
The implementation uses a top-level GPIO device (which has no actual GPIOS).
Under this all the banks are created as separate GPIO devices.
The GPIOs are named as per the Tegra datasheet/header files: A0..A7, B0..B7,
..., Z0..Z7, AA0..AA7, etc.
Since driver model is not yet available before relocation, or in SPL, a
special function is provided for seaboard's SPL code.
Signed-off-by: Simon Glass <sjg@chromium.org>
The HW-defined procedure for booting Tegra requires that some pins be
set up as GPIOs immediately at boot in order to avoid glitches on those
pins, when the pinmux is programmed. Add a feature to the GPIO driver
which executes a GPIO configuration table. Board files will use this to
implement the correct HW initialization procedure.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
The move is pretty straight-forward. ap20.h and tegra20.h were renamed to ap.h and tegra.h.
Some files remain in arch-tegra20 but 'include' a file in 'arch-tegra' with #defines & structs
that will be common between T20 and T30 HW. HW-specific #defines, etc. stay in the 'arch-tegra20'
'root' file.
All boards build OK w/MAKEALL -s tegra20. Checkpatch.pl runs clean. Seaboard works OK.
Signed-off-by: Tom Warren <twarren@nvidia.com>
Convert TEGRA20_ defines to either TEGRA_ or NV_PA_ where appropriate.
Convert tegra20_ source file and function names to tegra_, also.
Upcoming Tegra30 port will use common code/defines/names where possible.
Signed-off-by: Tom Warren <twarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
This is make naming consistent with the kernel and devicetree and in
preparation of pulling out the common tegra20 code.
Signed-off-by: Allen Martin <amartin@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Tested-by: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: Tom Warren <twarren@nvidia.com>
In anticipation of Tegra3 support, continue removing/renaming
Tegra2-specific files. No functional changes (yet).
Updated copyrights to 2012.
Signed-off-by: Tom Warren <twarren@nvidia.com>
2012-07-07 14:07:20 +02:00
Renamed from drivers/gpio/tegra2_gpio.c (Browse further)
