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-rw-r--r--sound/soc/renesas/rcar/msiof.c39
1 files changed, 38 insertions, 1 deletions
diff --git a/sound/soc/renesas/rcar/msiof.c b/sound/soc/renesas/rcar/msiof.c
index 6819471fb5b2..87bec248d5c1 100644
--- a/sound/soc/renesas/rcar/msiof.c
+++ b/sound/soc/renesas/rcar/msiof.c
@@ -24,12 +24,25 @@
* Clock/Frame Consumer Mode.
*/
+/*
+ * [NOTE-RESET]
+ *
+ * MSIOF has TXRST/RXRST to reset FIFO, but it shouldn't be used during SYNC signal was asserted,
+ * because it will be cause of HW issue.
+ *
+ * When MSIOF is used as Sound driver, this driver is assuming it is used as clock consumer mode
+ * (= Codec is clock provider). This means, it can't control SYNC signal by itself.
+ *
+ * We need to use SW reset (= reset_control_xxx()) instead of TXRST/RXRST.
+ */
+
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/of_graph.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/spi/sh_msiof.h>
#include <sound/dmaengine_pcm.h>
#include <sound/soc.h>
@@ -60,10 +73,13 @@
struct msiof_priv {
struct device *dev;
struct snd_pcm_substream *substream[SNDRV_PCM_STREAM_LAST + 1];
+ struct reset_control *reset;
spinlock_t lock;
void __iomem *base;
resource_size_t phy_addr;
+ int count;
+
/* for error */
int err_syc[SNDRV_PCM_STREAM_LAST + 1];
int err_ovf[SNDRV_PCM_STREAM_LAST + 1];
@@ -131,6 +147,16 @@ static int msiof_hw_start(struct snd_soc_component *component,
* RX: Fig 109.15
*/
+ /*
+ * Use reset_control_xx() instead of TXRST/RXRST.
+ * see
+ * [NOTE-RESET]
+ */
+ if (!priv->count)
+ reset_control_deassert(priv->reset);
+
+ priv->count++;
+
/* reset errors */
priv->err_syc[substream->stream] =
priv->err_ovf[substream->stream] =
@@ -152,7 +178,6 @@ static int msiof_hw_start(struct snd_soc_component *component,
val = FIELD_PREP(SIMDR2_BITLEN1, width - 1);
msiof_write(priv, SITMDR2, val | FIELD_PREP(SIMDR2_GRP, 1));
msiof_write(priv, SITMDR3, val);
-
}
/* SIRMDRx */
else {
@@ -227,6 +252,11 @@ static int msiof_hw_stop(struct snd_soc_component *component,
priv->err_ovf[substream->stream],
priv->err_udf[substream->stream]);
+ priv->count--;
+
+ if (!priv->count)
+ reset_control_assert(priv->reset);
+
return 0;
}
@@ -490,12 +520,19 @@ static int msiof_probe(struct platform_device *pdev)
if (IS_ERR(priv->base))
return PTR_ERR(priv->base);
+ priv->reset = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(priv->reset))
+ return PTR_ERR(priv->reset);
+
+ reset_control_assert(priv->reset);
+
ret = devm_request_irq(dev, irq, msiof_interrupt, 0, dev_name(dev), priv);
if (ret)
return ret;
priv->dev = dev;
priv->phy_addr = res->start;
+ priv->count = 0;
spin_lock_init(&priv->lock);
platform_set_drvdata(pdev, priv);