[alsa-devel] [PATCH] ASoC: core: Configure pin muxing via pinctrl when registering a DAI

Stephen Warren swarren at wwwdotorg.org
Mon Sep 24 17:38:43 CEST 2012

On 09/24/2012 02:34 AM, Linus Walleij wrote:
> On Fri, Sep 21, 2012 at 6:23 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>> On 09/21/2012 07:16 AM, Peter Ujfalusi wrote:
>>> pinctrl_get_select() returns with a pointer to struct pinctrl. If the platform
>>> does not have CONFIG_PINCTRL enabled it will return with NULL.
>>> If no pinctrl has been specified for the device it will return with error
>>> (-ENODEV).
>>> Neither of these cases should be considered as error. We do print out with
>>> dev_info() to notify the developer, but having pinctrl mux should not be
>>> mandatory.
>> Indeed - what about a platform like Tegra which has pinctrl enabled, yet
>> doesn't specify any pinctrl configuration for any device other than the
>> pin controller itself?
> It would be fixed by calling pinctrl_provide_dummies() right?
> Not that it's elegant or anything ...

Right - calling pinctrl_provide_dummies() ends up telling the pinctrl
core never to return an error even when it "should". I don't think it's
appropriate to use that API at all except to help out transitioning a
particular SoC to use pinctrl.

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