From 701a6ec3a3f8d30bdb45ee025fb61f7a934b6cad Mon Sep 17 00:00:00 2001 From: olivier moysan Date: Fri, 16 Jun 2017 14:15:34 +0200 Subject: ASoC: stm32: sai: manage master clock Disable master clock by default, and activate it only when requested. Signed-off-by: olivier moysan Signed-off-by: Mark Brown --- 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 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; } -- cgit v1.2.3