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@xxxxxxxxxx>
---
This is the only patch that's left from the series of three that I
posted earlier.
v1 → v2:
* Apply the setting to both the codec and the cpu dai
* Check for errors from clk_set_rate() and avoid unnecessary rate
changes.
.../devicetree/bindings/sound/simple-card.txt | 5 +++++
sound/soc/generic/simple-card.c | 21 +++++++++++++++++++++
2 files changed, 26 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
index 17c13e74667d..a4c72d09cd45 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.txt
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt
@@ -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.
diff --git a/sound/soc/generic/simple-card.c b/sound/soc/generic/simple-card.c
index 6959a74a6f49..4a516c428b3d 100644
--- a/sound/soc/generic/simple-card.c
+++ b/sound/soc/generic/simple-card.c
@@ -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)
--
2.14.3
--
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