[PATCH v2 2/4] ASoC: mchp-pdmc: use runtime pm for clock power saving
Claudiu Beznea
claudiu.beznea at microchip.com
Mon Dec 12 08:41:51 PST 2022
Implement clock power saving taking advantage of runtime PM infrastructure.
This simplifies the code and allow using the same infrastructure for
suspend to RAM functionalities.
Signed-off-by: Claudiu Beznea <claudiu.beznea at microchip.com>
---
sound/soc/atmel/mchp-pdmc.c | 126 ++++++++++++++++++++++++------------
1 file changed, 84 insertions(+), 42 deletions(-)
diff --git a/sound/soc/atmel/mchp-pdmc.c b/sound/soc/atmel/mchp-pdmc.c
index 44aefbd5b62c..f184404e74e5 100644
--- a/sound/soc/atmel/mchp-pdmc.c
+++ b/sound/soc/atmel/mchp-pdmc.c
@@ -11,6 +11,7 @@
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of.h>
+#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <sound/core.h>
@@ -115,7 +116,6 @@ struct mchp_pdmc {
int mic_no;
int sinc_order;
bool audio_filter_en;
- u8 gclk_enabled:1;
};
static const char *const mchp_pdmc_sinc_filter_order_text[] = {
@@ -454,13 +454,6 @@ static int mchp_pdmc_startup(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
- int ret;
-
- ret = clk_prepare_enable(dd->pclk);
- if (ret) {
- dev_err(dd->dev, "failed to enable the peripheral clock: %d\n", ret);
- return ret;
- }
regmap_write(dd->regmap, MCHP_PDMC_CR, MCHP_PDMC_CR_SWRST);
@@ -470,14 +463,6 @@ static int mchp_pdmc_startup(struct snd_pcm_substream *substream,
return 0;
}
-static void mchp_pdmc_shutdown(struct snd_pcm_substream *substream,
- struct snd_soc_dai *dai)
-{
- struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
-
- clk_disable_unprepare(dd->pclk);
-}
-
static int mchp_pdmc_dai_probe(struct snd_soc_dai *dai)
{
struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
@@ -594,11 +579,6 @@ static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
cfgr_val |= MCHP_PDMC_CFGR_BSSEL(i);
}
- if (dd->gclk_enabled) {
- clk_disable_unprepare(dd->gclk);
- dd->gclk_enabled = 0;
- }
-
for (osr_start = dd->audio_filter_en ? 64 : 8;
osr_start <= 256 && best_diff_rate; osr_start *= 2) {
long round_rate;
@@ -620,8 +600,12 @@ static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
return -EINVAL;
}
+ /* CLK is enabled by runtime PM. */
+ clk_disable_unprepare(dd->gclk);
+
/* set the rate */
ret = clk_set_rate(dd->gclk, gclk_rate);
+ clk_prepare_enable(dd->gclk);
if (ret) {
dev_err(comp->dev, "unable to set rate %lu to GCLK: %d\n",
gclk_rate, ret);
@@ -636,9 +620,6 @@ static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
mr_val |= MCHP_PDMC_MR_CHUNK(dd->addr.maxburst);
dev_dbg(comp->dev, "maxburst set to %d\n", dd->addr.maxburst);
- clk_prepare_enable(dd->gclk);
- dd->gclk_enabled = 1;
-
snd_soc_component_update_bits(comp, MCHP_PDMC_MR,
MCHP_PDMC_MR_OSR_MASK |
MCHP_PDMC_MR_SINCORDER_MASK |
@@ -650,19 +631,6 @@ static int mchp_pdmc_hw_params(struct snd_pcm_substream *substream,
return 0;
}
-static int mchp_pdmc_hw_free(struct snd_pcm_substream *substream,
- struct snd_soc_dai *dai)
-{
- struct mchp_pdmc *dd = snd_soc_dai_get_drvdata(dai);
-
- if (dd->gclk_enabled) {
- clk_disable_unprepare(dd->gclk);
- dd->gclk_enabled = 0;
- }
-
- return 0;
-}
-
static int mchp_pdmc_trigger(struct snd_pcm_substream *substream,
int cmd, struct snd_soc_dai *dai)
{
@@ -711,9 +679,7 @@ static int mchp_pdmc_trigger(struct snd_pcm_substream *substream,
static const struct snd_soc_dai_ops mchp_pdmc_dai_ops = {
.set_fmt = mchp_pdmc_set_fmt,
.startup = mchp_pdmc_startup,
- .shutdown = mchp_pdmc_shutdown,
.hw_params = mchp_pdmc_hw_params,
- .hw_free = mchp_pdmc_hw_free,
.trigger = mchp_pdmc_trigger,
};
@@ -864,6 +830,7 @@ static const struct regmap_config mchp_pdmc_regmap_config = {
.readable_reg = mchp_pdmc_readable_reg,
.writeable_reg = mchp_pdmc_writeable_reg,
.precious_reg = mchp_pdmc_precious_reg,
+ .cache_type = REGCACHE_FLAT,
};
static int mchp_pdmc_dt_init(struct mchp_pdmc *dd)
@@ -970,6 +937,49 @@ static struct snd_dmaengine_pcm_config mchp_pdmc_config = {
.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
};
+static int mchp_pdmc_runtime_suspend(struct device *dev)
+{
+ struct mchp_pdmc *dd = dev_get_drvdata(dev);
+
+ regcache_cache_only(dd->regmap, true);
+
+ clk_disable_unprepare(dd->gclk);
+ clk_disable_unprepare(dd->pclk);
+
+ return 0;
+}
+
+static int mchp_pdmc_runtime_resume(struct device *dev)
+{
+ struct mchp_pdmc *dd = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(dd->pclk);
+ if (ret) {
+ dev_err(dd->dev,
+ "failed to enable the peripheral clock: %d\n", ret);
+ return ret;
+ }
+ ret = clk_prepare_enable(dd->gclk);
+ if (ret) {
+ dev_err(dd->dev,
+ "failed to enable generic clock: %d\n", ret);
+ goto disable_pclk;
+ }
+
+ regcache_cache_only(dd->regmap, false);
+ regcache_mark_dirty(dd->regmap);
+ ret = regcache_sync(dd->regmap);
+ if (ret) {
+ regcache_cache_only(dd->regmap, true);
+ clk_disable_unprepare(dd->gclk);
+disable_pclk:
+ clk_disable_unprepare(dd->pclk);
+ }
+
+ return ret;
+}
+
static int mchp_pdmc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
@@ -1039,18 +1049,25 @@ static int mchp_pdmc_probe(struct platform_device *pdev)
dd->addr.addr = (dma_addr_t)res->start + MCHP_PDMC_RHR;
platform_set_drvdata(pdev, dd);
+ pm_runtime_enable(dd->dev);
+ if (!pm_runtime_enabled(dd->dev)) {
+ ret = mchp_pdmc_runtime_resume(dd->dev);
+ if (ret)
+ return ret;
+ }
+
/* register platform */
ret = devm_snd_dmaengine_pcm_register(dev, &mchp_pdmc_config, 0);
if (ret) {
dev_err(dev, "could not register platform: %d\n", ret);
- return ret;
+ goto pm_runtime_suspend;
}
ret = devm_snd_soc_register_component(dev, &mchp_pdmc_dai_component,
&mchp_pdmc_dai, 1);
if (ret) {
dev_err(dev, "could not register CPU DAI: %d\n", ret);
- return ret;
+ goto pm_runtime_suspend;
}
/* print IP version */
@@ -1059,6 +1076,25 @@ static int mchp_pdmc_probe(struct platform_device *pdev)
version & MCHP_PDMC_VER_VERSION);
return 0;
+
+pm_runtime_suspend:
+ if (!pm_runtime_status_suspended(dd->dev))
+ mchp_pdmc_runtime_suspend(dd->dev);
+ pm_runtime_disable(dd->dev);
+
+ return ret;
+}
+
+static int mchp_pdmc_remove(struct platform_device *pdev)
+{
+ struct mchp_pdmc *dd = platform_get_drvdata(pdev);
+
+ if (!pm_runtime_status_suspended(dd->dev))
+ mchp_pdmc_runtime_suspend(dd->dev);
+
+ pm_runtime_disable(dd->dev);
+
+ return 0;
}
static const struct of_device_id mchp_pdmc_of_match[] = {
@@ -1070,13 +1106,19 @@ static const struct of_device_id mchp_pdmc_of_match[] = {
};
MODULE_DEVICE_TABLE(of, mchp_pdmc_of_match);
+static const struct dev_pm_ops mchp_pdmc_pm_ops = {
+ RUNTIME_PM_OPS(mchp_pdmc_runtime_suspend, mchp_pdmc_runtime_resume,
+ NULL)
+};
+
static struct platform_driver mchp_pdmc_driver = {
.driver = {
.name = "mchp-pdmc",
.of_match_table = of_match_ptr(mchp_pdmc_of_match),
- .pm = &snd_soc_pm_ops,
+ .pm = pm_ptr(&mchp_pdmc_pm_ops),
},
.probe = mchp_pdmc_probe,
+ .remove = mchp_pdmc_remove,
};
module_platform_driver(mchp_pdmc_driver);
--
2.34.1
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