ASoC: tegra_alt: Fix I2S shutdown sequence

1. Soft reset APBIF and wait for tx/rx fifo to be disabled/empty
2. Soft reset I2S post the DAPM widget power down

Bug 1492370

Change-Id: Iadbfa86a6e1937e33c7bc920e0ea4847e18aa7c0
Signed-off-by: Arun Shamanna Lakshmi <aruns@nvidia.com>
Signed-off-by: Songhee Baek <sbaek@nvidia.com>
Reviewed-on: http://git-master/r/391633
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Tested-by: Sonny Jamuar <sjamuar@nvidia.com>
Reviewed-by: Gajanan Bhat <gbhat@nvidia.com>
Reviewed-by: Bharat Nihalani <bnihalani@nvidia.com>

3 files changed, 160 insertions, 5 deletions

diff --git a/sound/soc/tegra-alt/tegra30_apbif_alt.c b/sound/soc/tegra-alt/tegra30_apbif_alt.c
index 08ce186ba10b..5413f2355fd5 100644
--- a/sound/soc/tegra-alt/tegra30_apbif_alt.c
+++ b/sound/soc/tegra-alt/tegra30_apbif_alt.c
@@ -34,6 +34,8 @@
 
 #define DRV_NAME "tegra30-ahub-apbif"
 
+struct tegra30_apbif *apbif;
+
 #define FIFOS_IN_FIRST_REG_BLOCK 4
 
 #define LAST_REG(name) \
@@ -178,6 +180,54 @@ static int tegra30_apbif_runtime_resume(struct device *dev)
 	return 0;
 }
 
+int tegra30_apbif_i2s_rx_fifo_is_enabled(int i2s_id)
+{
+	int val;
+
+	regmap_read(apbif->regmap[0], TEGRA_AHUB_I2S_LIVE_STATUS, &val);
+	val &= (TEGRA_AHUB_I2S_LIVE_STATUS_I2S0_RX_FIFO_ENABLED <<
+			(i2s_id * 2));
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(tegra30_apbif_i2s_rx_fifo_is_enabled);
+
+int tegra30_apbif_i2s_tx_fifo_is_enabled(int i2s_id)
+{
+	int val;
+
+	regmap_read(apbif->regmap[0], TEGRA_AHUB_I2S_LIVE_STATUS, &val);
+	val &= (TEGRA_AHUB_I2S_LIVE_STATUS_I2S0_TX_FIFO_ENABLED <<
+			(i2s_id * 2));
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(tegra30_apbif_i2s_tx_fifo_is_enabled);
+
+int tegra30_apbif_i2s_rx_fifo_is_empty(int i2s_id)
+{
+	int val;
+
+	regmap_read(apbif->regmap[0], TEGRA_AHUB_I2S_LIVE_STATUS, &val);
+	val &= (TEGRA_AHUB_I2S_LIVE_STATUS_I2S0_RX_FIFO_EMPTY <<
+			(i2s_id * 2));
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(tegra30_apbif_i2s_rx_fifo_is_empty);
+
+int tegra30_apbif_i2s_tx_fifo_is_empty(int i2s_id)
+{
+	int val;
+
+	regmap_read(apbif->regmap[0], TEGRA_AHUB_I2S_LIVE_STATUS, &val);
+	val &= (TEGRA_AHUB_I2S_LIVE_STATUS_I2S0_TX_FIFO_EMPTY <<
+			(i2s_id * 2));
+
+	return val;
+}
+EXPORT_SYMBOL_GPL(tegra30_apbif_i2s_tx_fifo_is_empty);
+
 static int tegra30_apbif_hw_params(struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *params,
 				 struct snd_soc_dai *dai)
@@ -308,6 +358,12 @@ static void tegra30_apbif_stop_playback(struct snd_soc_dai *dai)
 	reg = TEGRA_AHUB_CHANNEL_CTRL +
 		((dai->id - base_ch) * TEGRA_AHUB_CHANNEL_CTRL_STRIDE);
 	regmap_update_bits(regmap, reg, TEGRA_AHUB_CHANNEL_CTRL_TX_EN, 0);
+
+	/* soft reset APBIF TX */
+	reg = TEGRA_AHUB_CHANNEL_CLEAR +
+		((dai->id - base_ch) * TEGRA_AHUB_CHANNEL_CTRL_STRIDE);
+	regmap_update_bits(regmap, reg,
+		TEGRA_AHUB_CHANNEL_CLEAR_TX_SOFT_RESET, 1);
 }
 
 static void tegra30_apbif_start_capture(struct snd_soc_dai *dai)
@@ -347,6 +403,12 @@ static void tegra30_apbif_stop_capture(struct snd_soc_dai *dai)
 	reg = TEGRA_AHUB_CHANNEL_CTRL +
 		((dai->id - base_ch) * TEGRA_AHUB_CHANNEL_CTRL_STRIDE);
 	regmap_update_bits(regmap, reg, TEGRA_AHUB_CHANNEL_CTRL_RX_EN, 0);
+
+	/* soft reset APBIF RX */
+	reg = TEGRA_AHUB_CHANNEL_CLEAR +
+		((dai->id - base_ch) * TEGRA_AHUB_CHANNEL_CTRL_STRIDE);
+	regmap_update_bits(regmap, reg,
+		TEGRA_AHUB_CHANNEL_CLEAR_RX_SOFT_RESET, 1);
 }
 
 static int tegra30_apbif_trigger(struct snd_pcm_substream *substream, int cmd,
@@ -527,7 +589,6 @@ static int tegra30_apbif_probe(struct platform_device *pdev)
 	int i;
 	struct clk *clk;
 	int ret;
-	struct tegra30_apbif *apbif;
 	void __iomem *regs;
 	struct resource *res[2];
 	u32 of_dma[10][2];
diff --git a/sound/soc/tegra-alt/tegra30_apbif_alt.h b/sound/soc/tegra-alt/tegra30_apbif_alt.h
index 62a835fb8ecf..c46c114d5dcc 100644
--- a/sound/soc/tegra-alt/tegra30_apbif_alt.h
+++ b/sound/soc/tegra-alt/tegra30_apbif_alt.h
@@ -302,6 +302,11 @@
 /* TEGRA_AHUB_CIF_RX9_CTRL */
 #define TEGRA_AHUB_CIF_RX9_CTRL				0xb8
 
+int tegra30_apbif_i2s_rx_fifo_is_enabled(int i2s_id);
+int tegra30_apbif_i2s_tx_fifo_is_enabled(int i2s_id);
+int tegra30_apbif_i2s_rx_fifo_is_empty(int i2s_id);
+int tegra30_apbif_i2s_tx_fifo_is_empty(int i2s_id);
+
 struct tegra30_apbif_soc_data {
 	unsigned int num_ch;
 	unsigned int clk_list_mask;
diff --git a/sound/soc/tegra-alt/tegra30_i2s_alt.c b/sound/soc/tegra-alt/tegra30_i2s_alt.c
index c1aac76599b7..dc045e5359a4 100644
--- a/sound/soc/tegra-alt/tegra30_i2s_alt.c
+++ b/sound/soc/tegra-alt/tegra30_i2s_alt.c
@@ -25,6 +25,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/delay.h>
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/io.h>
@@ -43,6 +44,7 @@
 
 #include "tegra30_xbar_alt.h"
 #include "tegra30_i2s_alt.h"
+#include "tegra30_apbif_alt.h"
 
 #define DRV_NAME "tegra30-i2s"
 
@@ -355,6 +357,83 @@ static int tegra30_i2s_hw_params(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+static int tegra30_i2s_soft_reset(struct tegra30_i2s *i2s)
+{
+	int dcnt = 10;
+	unsigned int val, ctrl_val;
+
+	regmap_read(i2s->regmap, TEGRA30_I2S_CTRL, &ctrl_val);
+
+	regmap_update_bits(i2s->regmap, TEGRA30_I2S_CTRL,
+		TEGRA30_I2S_CTRL_SOFT_RESET, TEGRA30_I2S_CTRL_SOFT_RESET);
+
+	do {
+		udelay(100);
+		regmap_read(i2s->regmap, TEGRA30_I2S_CTRL, &val);
+	} while ((val & TEGRA30_I2S_CTRL_SOFT_RESET) && dcnt--);
+
+	/* Restore reg_ctrl to ensure if a concurrent playback/capture
+	   session was active it continues after SOFT_RESET */
+	regmap_update_bits(i2s->regmap, TEGRA30_I2S_CTRL,
+		TEGRA30_I2S_CTRL_SOFT_RESET, 0);
+
+	regmap_write(i2s->regmap, TEGRA30_I2S_CTRL, ctrl_val);
+
+	return (dcnt < 0) ? -ETIMEDOUT : 0;
+}
+
+static int tegra30_i2s_rx_stop(struct snd_soc_dapm_widget *w,
+				struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_codec *codec = w->codec;
+	struct device *dev = codec->dev;
+	struct tegra30_i2s *i2s = dev_get_drvdata(dev);
+	int dcnt = 10;
+
+	/* wait until rx fifo is disabled */
+	while (tegra30_apbif_i2s_rx_fifo_is_enabled(dev->id) && dcnt--)
+		udelay(100);
+
+	dcnt = 10;
+	while (!tegra30_apbif_i2s_rx_fifo_is_empty(dev->id) && dcnt--)
+		udelay(100);
+
+	if (dcnt < 0) {
+		dcnt = 10;
+		tegra30_i2s_soft_reset(i2s);
+		while (!tegra30_apbif_i2s_rx_fifo_is_empty(dev->id) &&
+		       dcnt--)
+			udelay(100);
+	}
+	return 0;
+}
+
+static int tegra30_i2s_tx_stop(struct snd_soc_dapm_widget *w,
+				struct snd_kcontrol *kcontrol, int event)
+{
+	struct snd_soc_codec *codec = w->codec;
+	struct device *dev = codec->dev;
+	struct tegra30_i2s *i2s = dev_get_drvdata(dev);
+	int dcnt = 10;
+
+	/* wait until tx fifo is disabled */
+	while (tegra30_apbif_i2s_tx_fifo_is_enabled(dev->id) && dcnt--)
+		udelay(100);
+
+	dcnt = 10;
+	while (!tegra30_apbif_i2s_tx_fifo_is_empty(dev->id) && dcnt--)
+		udelay(100);
+
+	if (dcnt < 0) {
+		dcnt = 10;
+		tegra30_i2s_soft_reset(i2s);
+		while (!tegra30_apbif_i2s_tx_fifo_is_empty(dev->id) &&
+		       dcnt--)
+			udelay(100);
+	}
+	return 0;
+}
+
 static int tegra30_i2s_codec_probe(struct snd_soc_codec *codec)
 {
 	struct tegra30_i2s *i2s = snd_soc_codec_get_drvdata(codec);
@@ -432,10 +511,12 @@ static const struct snd_soc_dapm_widget tegra30_i2s_widgets[] = {
 				0, 0),
 	SND_SOC_DAPM_AIF_OUT("CIF TX", NULL, 0, SND_SOC_NOPM,
 				0, 0),
-	SND_SOC_DAPM_AIF_IN("DAP RX", NULL, 0, TEGRA30_I2S_CTRL,
-				TEGRA30_I2S_CTRL_XFER_EN_RX_SHIFT, 0),
-	SND_SOC_DAPM_AIF_OUT("DAP TX", NULL, 0, TEGRA30_I2S_CTRL,
-				TEGRA30_I2S_CTRL_XFER_EN_TX_SHIFT, 0),
+	SND_SOC_DAPM_AIF_IN_E("DAP RX", NULL, 0, TEGRA30_I2S_CTRL,
+				TEGRA30_I2S_CTRL_XFER_EN_RX_SHIFT, 0,
+				tegra30_i2s_rx_stop, SND_SOC_DAPM_POST_PMD),
+	SND_SOC_DAPM_AIF_OUT_E("DAP TX", NULL, 0, TEGRA30_I2S_CTRL,
+				TEGRA30_I2S_CTRL_XFER_EN_TX_SHIFT, 0,
+				tegra30_i2s_tx_stop, SND_SOC_DAPM_POST_PMD),
 };
 
 static const struct snd_soc_dapm_route tegra30_i2s_routes[] = {
@@ -491,6 +572,7 @@ static bool tegra30_i2s_wr_rd_reg(struct device *dev, unsigned int reg)
 static bool tegra30_i2s_volatile_reg(struct device *dev, unsigned int reg)
 {
 	switch (reg) {
+	case TEGRA30_I2S_CTRL:
 	case TEGRA30_I2S_FLOW_STATUS:
 	case TEGRA30_I2S_FLOW_TOTAL:
 	case TEGRA30_I2S_FLOW_OVER:
@@ -623,6 +705,13 @@ static int tegra30_i2s_platform_probe(struct platform_device *pdev)
 	}
 	regcache_cache_only(i2s->regmap, true);
 
+	if (of_property_read_u32(pdev->dev.of_node,
+		"nvidia,ahub-i2s-id", &pdev->dev.id) < 0) {
+		dev_err(&pdev->dev, "Missing property nvidia,ahub-i2s-id\n");
+		ret = -ENODEV;
+		goto err;
+	}
+
 	pm_runtime_enable(&pdev->dev);
 	if (!pm_runtime_enabled(&pdev->dev)) {
 		ret = tegra30_i2s_runtime_resume(&pdev->dev);