[alsa-devel] [PATCH] ASoC: cs42888: Add codec driver support
Nicolin Chen
Guangyu.Chen at freescale.com
Mon Feb 24 17:06:49 CET 2014
On Mon, Feb 24, 2014 at 03:52:24PM +0000, Austin, Brian wrote:
> >> + if (!IS_ERR(cs42888->clk))
> >> + clk_disable_unprepare(cs42888->clk);
> >
> > Does the device work without MCLK?
> Yes, MCLK is required. If you can’t get the clock you should error out.
Wait...Regarding this clock part, I just forgot the reason I put the code:
385 cs42888->clk = devm_clk_get(&i2c->dev, "mclk");
386 if (IS_ERR(cs42888->clk))
387 dev_warn(&i2c->dev, "failed to get the clock: %ld\n",
388 PTR_ERR(cs42888->clk));
was because the MCLK might be provided from SoC (DAI master) so it could
be totally controlled by CPU DAI driver, ESAI for example has its own
dividers to derive the HCKT clock (MCLK for Tx) from ahb clock in SoC
clock tree, in which case we might not easily pass a valid clock phandle
via DT. (RFC to this thought.)
Thank you,
Nicolin Chen
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