Re: [PATCH 09/18] ASoC: sti: Update DT example to match the driver code
From: Arnd Bergmann
Date: Tue Apr 26 2016 - 07:44:47 EST
On Tuesday 26 April 2016 12:15:32 Peter Griffin wrote:
> >
> > > If not what would you recommend instead?
> >
> > It's still not clear to me what that bit in the syscfg register
> > is for. Given the error message about "sti-audio-clk-glue",
> > I suspect that this is actually a clock controller and that
> > it should be using the clock binding with a separate driver
> > instead of manipulating the regmap directly from the audio driver.
>
> Luckily I do have the datasheet for the audio-glue sysconf register.
>
> It says: -
>
> [11:8] PCM_CLK_SEL: Selects the frequency synthesizer clock or the external
> PCM clock for each channel.
>
> The driver only ever sets this to 1 which selects the frequency synthesizer
> clock. So the bitfield of the register which the driver is using (PCM_CLK_SEL)
> is a clock mux.
Ok, that sounds like it could be either a really simple clock driver
with just a few lines, or integrated into an existing clock driver
if you already have one for this syscon node.
Arnd