[PATCH 2/2] ASoC: fsl: Move clock operation to PM runtime

Daniel Baluta
2019-04-20T15:59:24Z

From: Shengjiu Wang <shengjiu.wang@nxp.com>

Turn off/on clocks when device enters suspend/resume. This
helps saving power.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
sound/soc/fsl/fsl_sai.c | 54 +++++++++++++++++++++++++++++++++--------
1 file changed, 44 insertions(+), 10 deletions(-)

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index aeeb07b74177..a224c07ce31f 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -594,15 +594,8 @@ static int fsl_sai_startup(struct snd_pcm_substream *substream,
{
struct fsl_sai *sai = snd_soc_dai_get_drvdata(cpu_dai);
bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
- struct device *dev = &sai->pdev->dev;
int ret;

- ret = clk_prepare_enable(sai->bus_clk);
- if (ret) {
- dev_err(dev, "failed to enable bus clock: %d\n", ret);
- return ret;
- }
-
regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE,
FSL_SAI_CR3_TRCE);

@@ -619,8 +612,6 @@ static void fsl_sai_shutdown(struct snd_pcm_substream *substream,
bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;

regmap_update_bits(sai->regmap, FSL_SAI_xCR3(tx), FSL_SAI_CR3_TRCE, 0);
-
- clk_disable_unprepare(sai->bus_clk);
}

static const struct snd_soc_dai_ops fsl_sai_pcm_dai_ops = {
@@ -925,6 +916,14 @@ static int fsl_sai_runtime_suspend(struct device *dev)
{
struct fsl_sai *sai = dev_get_drvdata(dev);

+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE))
+ clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
+
+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK))
+ clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
+
+ clk_disable_unprepare(sai->bus_clk);
+
regcache_cache_only(sai->regmap, true);
regcache_mark_dirty(sai->regmap);

@@ -934,6 +933,25 @@ static int fsl_sai_runtime_suspend(struct device *dev)
static int fsl_sai_runtime_resume(struct device *dev)
{
struct fsl_sai *sai = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(sai->bus_clk);
+ if (ret) {
+ dev_err(dev, "failed to enable bus clock: %d\n", ret);
+ return ret;
+ }
+
+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK)) {
+ ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[1]]);
+ if (ret)
+ goto disable_bus_clk;
+ }
+
+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)) {
+ ret = clk_prepare_enable(sai->mclk_clk[sai->mclk_id[0]]);
+ if (ret)
+ goto disable_tx_clk;
+ }

regcache_cache_only(sai->regmap, false);
regmap_write(sai->regmap, FSL_SAI_TCSR, FSL_SAI_CSR_SR);
@@ -941,7 +959,23 @@ static int fsl_sai_runtime_resume(struct device *dev)
usleep_range(1000, 2000);
regmap_write(sai->regmap, FSL_SAI_TCSR, 0);
regmap_write(sai->regmap, FSL_SAI_RCSR, 0);
- return regcache_sync(sai->regmap);
+
+ ret = regcache_sync(sai->regmap);
+ if (ret)
+ goto disable_rx_clk;
+
+ return 0;
+
+disable_rx_clk:
+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE))
+ clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
+disable_tx_clk:
+ if (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_PLAYBACK))
+ clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[1]]);
+disable_bus_clk:
+ clk_disable_unprepare(sai->bus_clk);
+
+ return ret;
}
#endif /* CONFIG_PM */

--
2.17.1