[PATCH] ASoC: stm32: spdifrx: add power management

From: Olivier Moysan
Date: Wed Mar 06 2019 - 11:49:38 EST


Add suspend and resume sleep callbacks to STM32 SPDIFRX driver,
to support system low power modes.

Signed-off-by: Olivier Moysan <olivier.moysan@xxxxxx>
---
sound/soc/stm/stm32_spdifrx.c | 42 +++++++++++++++++++++++++++++++++++++++---
1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/sound/soc/stm/stm32_spdifrx.c b/sound/soc/stm/stm32_spdifrx.c
index 373df4f24be1..b4c3d983e195 100644
--- a/sound/soc/stm/stm32_spdifrx.c
+++ b/sound/soc/stm/stm32_spdifrx.c
@@ -21,6 +21,7 @@
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
#include <linux/regmap.h>
#include <linux/reset.h>

@@ -471,6 +472,8 @@ static int stm32_spdifrx_get_ctrl_data(struct stm32_spdifrx_data *spdifrx)
memset(spdifrx->cs, 0, SPDIFRX_CS_BYTES_NB);
memset(spdifrx->ub, 0, SPDIFRX_UB_BYTES_NB);

+ pinctrl_pm_select_default_state(&spdifrx->pdev->dev);
+
ret = stm32_spdifrx_dma_ctrl_start(spdifrx);
if (ret < 0)
return ret;
@@ -502,6 +505,7 @@ static int stm32_spdifrx_get_ctrl_data(struct stm32_spdifrx_data *spdifrx)

end:
clk_disable_unprepare(spdifrx->kclk);
+ pinctrl_pm_select_sleep_state(&spdifrx->pdev->dev);

return ret;
}
@@ -611,10 +615,15 @@ static bool stm32_spdifrx_readable_reg(struct device *dev, unsigned int reg)

static bool stm32_spdifrx_volatile_reg(struct device *dev, unsigned int reg)
{
- if (reg == STM32_SPDIFRX_DR)
+ switch (reg) {
+ case STM32_SPDIFRX_DR:
+ case STM32_SPDIFRX_CSR:
+ case STM32_SPDIFRX_SR:
+ case STM32_SPDIFRX_DIR:
return true;
-
- return false;
+ default:
+ return false;
+ }
}

static bool stm32_spdifrx_writeable_reg(struct device *dev, unsigned int reg)
@@ -638,6 +647,7 @@ static const struct regmap_config stm32_h7_spdifrx_regmap_conf = {
.volatile_reg = stm32_spdifrx_volatile_reg,
.writeable_reg = stm32_spdifrx_writeable_reg,
.fast_io = true,
+ .cache_type = REGCACHE_FLAT,
};

static irqreturn_t stm32_spdifrx_isr(int irq, void *devid)
@@ -983,10 +993,36 @@ static int stm32_spdifrx_remove(struct platform_device *pdev)

MODULE_DEVICE_TABLE(of, stm32_spdifrx_ids);

+#ifdef CONFIG_PM_SLEEP
+static int stm32_spdifrx_suspend(struct device *dev)
+{
+ struct stm32_spdifrx_data *spdifrx = dev_get_drvdata(dev);
+
+ regcache_cache_only(spdifrx->regmap, true);
+ regcache_mark_dirty(spdifrx->regmap);
+
+ return 0;
+}
+
+static int stm32_spdifrx_resume(struct device *dev)
+{
+ struct stm32_spdifrx_data *spdifrx = dev_get_drvdata(dev);
+
+ regcache_cache_only(spdifrx->regmap, false);
+
+ return regcache_sync(spdifrx->regmap);
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops stm32_spdifrx_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(stm32_spdifrx_suspend, stm32_spdifrx_resume)
+};
+
static struct platform_driver stm32_spdifrx_driver = {
.driver = {
.name = "st,stm32-spdifrx",
.of_match_table = stm32_spdifrx_ids,
+ .pm = &stm32_spdifrx_pm_ops,
},
.probe = stm32_spdifrx_probe,
.remove = stm32_spdifrx_remove,
--
2.7.4