ASoC: stm32: sai: manage master clock

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

Signed-off-by: olivier moysan <olivier.moysan@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/sound/soc/stm/stm32_sai_sub.c b/sound/soc/stm/stm32_sai_sub.c
index 2466af0343db..ce48c02db051 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;
 }