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ASoC: simple-card: set cpu dai clk in hw_params

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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 clocks in cpu and codec dai sub-nodes will be set to
the calculated rate (stream rate * mclk_fs) in hw_params.

This allows platforms to pass tuneable clocks as phandle that will
automatically be set to the right rates.

Signed-off-by: Daniel Mack <daniel@zonque.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Daniel Mack 2018-05-30 21:45:56 +02:00 committed by Mark Brown
parent f9e0b4afd4
commit e9be4ffd4f
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2 changed files with 26 additions and 0 deletions
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5
Documentation/devicetree/bindings/sound/simple-card.txt
View file

@ -86,6 +86,11 @@ Optional CPU/CODEC subnodes properties:
in dai startup() and disabled with
clk_disable_unprepare() in dai
shutdown().
If a clock is specified and a
multiplication factor is given with
mclk-fs, the clock will be set to the
calculated mclk frequency when the
stream starts.
- system-clock-direction-out : specifies clock direction as 'out' on
initialization. It is useful for some aCPUs with
fixed clocks.

21
sound/soc/generic/simple-card.c
View file

@ -135,6 +135,18 @@ static void asoc_simple_card_shutdown(struct snd_pcm_substream *substream)
asoc_simple_card_clk_disable(&dai_props->codec_dai);
}
static int asoc_simple_set_clk_rate(struct asoc_simple_dai *simple_dai,
unsigned long rate)
{
if (!simple_dai->clk)
return 0;
if (clk_get_rate(simple_dai->clk) == rate)
return 0;
return clk_set_rate(simple_dai->clk, rate);
}
static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
@ -154,6 +166,15 @@ static int asoc_simple_card_hw_params(struct snd_pcm_substream *substream,
if (mclk_fs) {
mclk = params_rate(params) * mclk_fs;
ret = asoc_simple_set_clk_rate(&dai_props->codec_dai, mclk);
if (ret < 0)
return ret;
ret = asoc_simple_set_clk_rate(&dai_props->cpu_dai, mclk);
if (ret < 0)
return ret;
ret = snd_soc_dai_set_sysclk(codec_dai, 0, mclk,
SND_SOC_CLOCK_IN);
if (ret && ret != -ENOTSUPP)