[PATCH v4 10/22] ASoC: tegra20: spdif: Reset hardware

Dmitry Osipenko
2021-12-04T14:38:01Z

Reset S/PDIF controller on runtime PM suspend/resume to ensure that we
always have a consistent hardware state.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
sound/soc/tegra/tegra20_spdif.c | 32 ++++++++++++++++++++++++++++++++
sound/soc/tegra/tegra20_spdif.h | 1 +
2 files changed, 33 insertions(+)

diff --git a/sound/soc/tegra/tegra20_spdif.c b/sound/soc/tegra/tegra20_spdif.c
index 7dd263721c2c..bc45a0a8afab 100644
--- a/sound/soc/tegra/tegra20_spdif.c
+++ b/sound/soc/tegra/tegra20_spdif.c
@@ -7,6 +7,7 @@
*/

#include <linux/clk.h>
+#include <linux/delay.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
@@ -14,6 +15,7 @@
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <sound/core.h>
#include <sound/pcm.h>
@@ -27,6 +29,8 @@ static __maybe_unused int tegra20_spdif_runtime_suspend(struct device *dev)
{
struct tegra20_spdif *spdif = dev_get_drvdata(dev);

+ regcache_cache_only(spdif->regmap, true);
+
clk_disable_unprepare(spdif->clk_spdif_out);

return 0;
@@ -37,13 +41,35 @@ static __maybe_unused int tegra20_spdif_runtime_resume(struct device *dev)
struct tegra20_spdif *spdif = dev_get_drvdata(dev);
int ret;

+ ret = reset_control_assert(spdif->reset);
+ if (ret)
+ return ret;
+
ret = clk_prepare_enable(spdif->clk_spdif_out);
if (ret) {
dev_err(dev, "clk_enable failed: %d\n", ret);
return ret;
}

+ usleep_range(10, 100);
+
+ ret = reset_control_deassert(spdif->reset);
+ if (ret)
+ goto disable_clocks;
+
+ regcache_cache_only(spdif->regmap, false);
+ regcache_mark_dirty(spdif->regmap);
+
+ ret = regcache_sync(spdif->regmap);
+ if (ret)
+ goto disable_clocks;
+
return 0;
+
+disable_clocks:
+ clk_disable_unprepare(spdif->clk_spdif_out);
+
+ return ret;
}

static int tegra20_spdif_hw_params(struct snd_pcm_substream *substream,
@@ -268,6 +294,12 @@ static int tegra20_spdif_platform_probe(struct platform_device *pdev)

dev_set_drvdata(&pdev->dev, spdif);

+ spdif->reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (IS_ERR(spdif->reset)) {
+ dev_err(&pdev->dev, "Can't retrieve spdif reset\n");
+ return PTR_ERR(spdif->reset);
+ }
+
spdif->clk_spdif_out = devm_clk_get(&pdev->dev, "out");
if (IS_ERR(spdif->clk_spdif_out)) {
dev_err(&pdev->dev, "Could not retrieve spdif clock\n");
diff --git a/sound/soc/tegra/tegra20_spdif.h b/sound/soc/tegra/tegra20_spdif.h
index 1973ffc2d5c7..ff4b79e2052f 100644
--- a/sound/soc/tegra/tegra20_spdif.h
+++ b/sound/soc/tegra/tegra20_spdif.h
@@ -451,6 +451,7 @@ struct tegra20_spdif {
struct snd_dmaengine_dai_dma_data capture_dma_data;
struct snd_dmaengine_dai_dma_data playback_dma_data;
struct regmap *regmap;
+ struct reset_control *reset;
};

#endif
--
2.33.1