[alsa-devel] [PATCH v2 1/5] ASoC: WM8903: Fix platform data gpio_cfg confusion

Olof Johansson olof at lixom.net
Thu Dec 8 00:49:27 CET 2011

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 at nvidia.com>
> Cc: Olof Johansson <olof at lixom.net>
> Cc: Colin Cross <ccross at 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 at lixom.net>


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