[PATCH 7/7] ASoC: stm32: sai: manage master clock

olivier moysan
2017-06-16T12:15:34Z

Disable master clock by default, and activate
it only when requested.

Signed-off-by: olivier moysan <olivier.moysan@st.com>
---
sound/soc/stm/stm32_sai_sub.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
index 2466af0..ce48c02 100644
--- a/sound/soc/stm/stm32_sai_sub.c
+++ b/sound/soc/stm/stm32_sai_sub.c
@@ -220,8 +220,15 @@ static int stm32_sai_set_sysclk(struct snd_soc_dai *cpu_dai,
int clk_id, unsigned int freq, int dir)
{
struct stm32_sai_sub_data *sai = snd_soc_dai_get_drvdata(cpu_dai);
+ int ret;

if ((dir == SND_SOC_CLOCK_OUT) && sai->master) {
+ ret = regmap_update_bits(sai->regmap, STM_SAI_CR1_REGX,
+ SAI_XCR1_NODIV,
+ (unsigned int)~SAI_XCR1_NODIV);
+ if (ret < 0)
+ return ret;
+
sai->mclk_rate = freq;
dev_dbg(cpu_dai->dev, "SAI MCLK frequency is %uHz\n", freq);
}
@@ -356,6 +363,10 @@ static int stm32_sai_set_dai_fmt(struct snd_soc_dai *cpu_dai, unsigned int fmt)
}
cr1_mask |= SAI_XCR1_SLAVE;

+ /* do not generate master by default */
+ cr1 |= SAI_XCR1_NODIV;
+ cr1_mask |= SAI_XCR1_NODIV;
+
ret = regmap_update_bits(sai->regmap, STM_SAI_CR1_REGX, cr1_mask, cr1);
if (ret < 0) {
dev_err(cpu_dai->dev, "Failed to update CR1 register\n");
@@ -652,6 +663,9 @@ static void stm32_sai_shutdown(struct snd_pcm_substream *substream,

regmap_update_bits(sai->regmap, STM_SAI_IMR_REGX, SAI_XIMR_MASK, 0);

+ regmap_update_bits(sai->regmap, STM_SAI_CR1_REGX, SAI_XCR1_NODIV,
+ SAI_XCR1_NODIV);
+
clk_disable_unprepare(sai->sai_ck);
sai->substream = NULL;
}
--
1.9.1