On Fri, Dec 02, 2011 at 03:08:37PM -0700, Stephen Warren wrote:
wm8903_platform_data.gpio_cfg[] was intended to be interpreted as follows: 0: Don't touch this GPIO's configuration register 1..7fff: Write that value to the GPIO's configuration register 8000: Write zero to the GPIO's configuration register other: Undefined (invalid)
The rationale is that platform data is usually global data, and a value of zero means that the field wasn't explicitly set to anything (e.g. because the field was new to the pdata type, and existing users weren't update to initialize it) and hence the value zero should be ignored. 0x8000 is an explicit way to get 0 in the register.
The code worked this way until commit 7cfe561 "ASoC: wm8903: Expose GPIOs through gpiolib", where the behaviour was changed due to my lack of awareness of the above rationale.
This patch reverts to the intended behaviour, and updates all in-tree users to use the correct scheme. This also makes WM8903 consistent with other devices that use a similar scheme.
WM8903_GPIO_NO_CONFIG is also renamed to WM8903_GPIO_CONFIG_ZERO so that its name accurately reflects its purpose.
Signed-off-by: Stephen Warren swarren@nvidia.com Cc: Olof Johansson olof@lixom.net Cc: Colin Cross ccross@android.com
Olof, Colin, could you please ack this so that Mark can apply it to the ASoC tree even though it touches Tegra code? Thanks.
Mark, since Stephen is a tegra maintainer, there's no real need to have an explicit ack from one of the others, IMHO. But here you have it. :)
Acked-by: Olof Johansson olof@lixom.net
-Olof