[PATCH v3 2/6] ALSA: hda/tegra: Reset hardware

Dmitry Osipenko
2021-01-20T00:37:28Z

Reset hardware on RPM-resume in order to bring it into a predictable
state.

Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30 audio works
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30 boot-tested
Tested-by: Nicolas Chauvet <kwizart@gmail.com> # TK1 boot-tested
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
sound/pci/hda/hda_tegra.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index a25bf7083c28..04dcd4cdfd9e 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -17,6 +17,7 @@
#include <linux/moduleparam.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
+#include <linux/reset.h>
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/string.h>
@@ -70,6 +71,7 @@
struct hda_tegra {
struct azx chip;
struct device *dev;
+ struct reset_control *reset;
struct clk_bulk_data clocks[3];
unsigned int nclocks;
void __iomem *regs;
@@ -167,6 +169,12 @@ static int __maybe_unused hda_tegra_runtime_resume(struct device *dev)
struct hda_tegra *hda = container_of(chip, struct hda_tegra, chip);
int rc;

+ if (!chip->running) {
+ rc = reset_control_assert(hda->reset);
+ if (rc)
+ return rc;
+ }
+
rc = clk_bulk_prepare_enable(hda->nclocks, hda->clocks);
if (rc != 0)
return rc;
@@ -176,6 +184,12 @@ static int __maybe_unused hda_tegra_runtime_resume(struct device *dev)
/* disable controller wake up event*/
azx_writew(chip, WAKEEN, azx_readw(chip, WAKEEN) &
~STATESTS_INT_MASK);
+ } else {
+ usleep_range(10, 100);
+
+ rc = reset_control_deassert(hda->reset);
+ if (rc)
+ return rc;
}

return 0;
@@ -441,6 +455,12 @@ static int hda_tegra_probe(struct platform_device *pdev)
return err;
}

+ hda->reset = devm_reset_control_array_get_exclusive(&pdev->dev);
+ if (IS_ERR(hda->reset)) {
+ err = PTR_ERR(hda->reset);
+ goto out_free;
+ }
+
hda->clocks[hda->nclocks++].id = "hda";
hda->clocks[hda->nclocks++].id = "hda2hdmi";
hda->clocks[hda->nclocks++].id = "hda2codec_2x";
--
2.29.2