spi: spi-gpio: store chipselect information in private structure

The spi-gpio driver currently assumes the chipselect gpio number is
stored in ->controller_data of the device's static board information.

In devicetree environments, this information is unavailable and has to
be derived from the DT node.

This patch moves the gpio storage to the controller's private data so
the DT bindings can easily build upon the driver.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
spi: spi-gpio: Add DT bindings

This patch adds DT bindings to the spi-gpio driver and some
documentation about how to use it.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
spi/gpio: Fix stub for spi_gpio_probe_dt()

The gpio_ was missing from the name.  Add a name for the parameter while
we're at it since GCC warns.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
staging:iio: trigger: Add hrtimer trigger

This patch adds a IIO trigger driver which uses a highres timer to provide a
frequency based trigger.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>