tree 52761ad5f2229d0b176ca36b7107a0ec43e1168f
parent 04bb2a031cf95b34b7432dd47b318a932a895b4c
author Marek Szyprowski <m.szyprowski@samsung.com> 1277929657 -0600
committer Grant Likely <grant.likely@secretlab.ca> 1278218744 -0600

spi/spi-gpio: add support for controllers without MISO or MOSI pin

There are some boards that do not strictly follow SPI standard and use
only 3 wires (SCLK, MOSI or MISO, SS) for connecting some simple auxiliary
chips and controls them with GPIO based 'spi controller'. In this
configuration the MISO or MOSI line is missing (it is not required if the
chip does not transfer any data back to host or host only reads data from
chip).

This patch adds support for such non-standard configuration in GPIO-based
SPI controller. It has been tested in configuration without MISO pin.

Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>