Commit graph

5 commits

Author SHA1 Message Date
Simon Glass
bb4e4a5d96 rockchip: rk3288: Add pinctrl driver
Add a driver which supports pin multiplexing setup for the most commonly
used peripherals.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:24 -06:00
Simon Glass
c5acf4a2b3 pinctrl: Add the concept of peripheral IDs
My original pinctrl patch operating using a peripheral ID enum. This was
shared between pinmux and clock and provides an easy way to specify a device
that needs to be controlled, even it is does not (yet) have a driver within
driver model.

Masahiro's new simple pinctrl gets around this by providing a
set_state_simple() pinctrl method. By passing a device to that call the
peripheral ID becomes unnecessary. If the driver needs it, it can calculate
it itself and use it internally.

However this does not solve the problem for peripheral clocks. The 'pure'
solution would be to pass a driver to the clock uclass also. But this
requires that all devices should have a driver, and a struct udevide. Also
a key optimisation of the clock uclass is allowing a peripheral clock to
be set even when there is no device for that clock.

There may be a better way to achive the same goal, but for now it seems
expedient to add in peripheral ID to the pinctrl uclass. Two methods are
added - one to get the peripheral ID and one to select it. The existing
set_state_simple() is effectively the union of these.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:22 -06:00
Simon Glass
458a070076 pinctrl: Add help text to Kconfig
The pinctrl Kconfig options should have help messages. Add this to a few
options.

Signed-off-by: Simon Glass <sjg@chromium.org>
2015-09-02 21:28:22 -06:00
Masahiro Yamada
9c6a3c6772 pinctrl: sandbox: add sandbox pinctrl driver
This driver actually does nothing but test pinctrl uclass, and
demonstrate how things work.

To try this driver, uncomment /* #define DEBUG */ in the
drivers/pinctrl/pinctrl-sandbox.c, and debug messages will be
displayed.

  DRAM:  128 MiB
  sandbox pinmux: group = 1 (serial_a), function = 1 (serial)
  Using default environment

  In:    cros-ec-keyb
  Out:   lcd
  Err:   lcd
  Net:   Net Initialization Skipped
  eth0: eth@10002000, eth1: eth@80000000, eth5: eth@90000000
  => i2c dev 0
  Setting bus to 0
  sandbox pinmux: group = 0 (i2c), function = 0 (i2c)
  sandbox pinconf: group = 0 (i2c), param = 3, arg = 1

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-08-31 07:57:29 -06:00
Masahiro Yamada
d90a5a30de pinctrl: add pin control uclass support
This creates a new framework for handling of pin control devices,
i.e. devices that control different aspects of package pins.

This uclass handles pinmuxing and pin configuration; pinmuxing
controls switching among silicon blocks that share certain physical
pins, pin configuration handles electronic properties such as pin-
biasing, load capacitance etc.

This framework can support the same device tree bindings, but if you
do not need full interface support, you can disable some features to
reduce memory foot print.  Typically around 1.5KB is necessary to
include full-featured uclass support on ARM board (CONFIG_PINCTRL +
CONFIG_PINCTRL_FULL + CONFIG_PINCTRL_GENERIC + CONFIG_PINCTRL_PINMUX),
for example.

We are often limited on code size for SPL.  Besides, we still have
many boards that do not support device tree configuration.  The full
pinctrl, which requires OF_CONTROL, does not make sense for those
boards.  So, this framework also has a Do-It-Yourself (let's say
simple pinctrl) interface.  With CONFIG_PINCTRL_FULL disabled, the
uclass itself provides no systematic mechanism for identifying the
peripheral device, applying pinctrl settings, etc.  They must be
done in each low-level driver.  In return, you can save much memory
footprint and it might be useful especially for SPL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-08-31 07:57:29 -06:00