Re: [alsa-devel] [PATCH 1/3] ASoC: simple-card: set cpu dai clk in hw_params

29 May 2018


      Hi Daniel
...
The simple-card driver currently accepts a clock node in the cpu dai
sub-node and only uses it as an alternative to the
'system-clock-frequency' property to get the current frequency.
This patch adds another use of the passed clock node. If mclk-fs is
specified, the clock will be set to the calculated rate (stream rate *
mclk_fs) in hw_params. This allows platforms to pass a tuneable clock
as phandle that will automatically be set to the right rates.
Signed-off-by: Daniel Mack daniel@zonque.org
(snip)
...
if (mclk_fs) {
   	mclk = params_rate(params) * mclk_fs;


if (dai_props->cpu_dai.clk)


	clk_set_rate(dai_props->cpu_dai.clk, mclk);


ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
  			     SND_SOC_CLOCK_IN);
  if (ret && ret != -ENOTSUPP)

Having codec is nice balance ?
Best regards
---
Kuninori Morimoto