Hi Daniel,
On Du, 2019-04-21 at 19:39 +0000, Daniel Baluta wrote:
> From: Shengjiu Wang <shengjiu.wang@xxxxxxx>
>
> Turn off/on clocks when device enters suspend/resume. This
> can help saving power.
>
> As a further optimization, we turn off/on mclk only when SAI
> is in master mode because otherwise mclk is externally provided.
>
> Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
> ---
> sound/soc/fsl/fsl_sai.c | 60 ++++++++++++++++++++++++++++++++++-------
> 1 file changed, 50 insertions(+), 10 deletions(-)
>
> diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> index 8623b7f882b9..13a462360ed3 100644
> --- a/sound/soc/fsl/fsl_sai.c
> +++ b/sound/soc/fsl/fsl_sai.c
> @@ -596,15 +596,8 @@ 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);
>
> @@ -621,8 +614,6 @@ 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 = {
> @@ -932,6 +923,16 @@ static int fsl_sai_runtime_suspend(struct device *dev)
> {
> struct fsl_sai *sai = dev_get_drvdata(dev);
>
> + if (!sai->is_slave_mode) {
This check is redundant as the bits in sai->mclk_streams are set/unset for master
mode only, please check fsl_sai_hw_params and fsl_sai_hw_free functions.
> + 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);
>
> @@ -941,6 +942,27 @@ 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->is_slave_mode) {
> + 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);
> @@ -948,7 +970,25 @@ 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->is_slave_mode &&
> + (sai->mclk_streams & BIT(SNDRV_PCM_STREAM_CAPTURE)))
> + clk_disable_unprepare(sai->mclk_clk[sai->mclk_id[0]]);
> +disable_tx_clk:
> + if (!sai->is_slave_mode &&
> + (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
>
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