[alsa-devel] [PATCH 5/8] ASoC : dwc : reconfigure dwc in 'resume' from 'suspend'

[Alex Deucher]

From: Maruthi Srinivas Bayyavarapu <Maruthi.Bayyavarapu at amd.com>

dwc IP can be powered off during system suspend in some platforms
(Ex: AMD CZ) as per design. After system is resumed, dwc needs to be
programmed again to continue audio use case.

Signed-off-by: Maruthi Bayyavarapu <maruthi.bayyavarapu at amd.com>
---
 sound/soc/dwc/designware_i2s.c | 71 ++++++++++++++++++++++++++----------------
 1 file changed, 44 insertions(+), 27 deletions(-)

diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index a16b725..f7f38cb 100644
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -98,6 +98,8 @@ struct dw_i2s_dev {
 	unsigned int i2s_reg_comp1;
 	unsigned int i2s_reg_comp2;
 	struct device *dev;
+	u32 ccr;
+	u32 xfer_resolution;
 
 	/* data related to DMA transfers b/w i2s and DMAC */
 	union dw_i2s_snd_dma_data play_dma_data;
@@ -220,31 +222,58 @@ static int dw_i2s_startup(struct snd_pcm_substream *substream,
 	return 0;
 }
 
+static void dw_i2s_config(struct dw_i2s_dev *dev, int stream)
+{
+	u32 ch_reg, irq;
+	struct i2s_clk_config_data *config = &dev->config;
+
+
+	i2s_disable_channels(dev, stream);
+
+	for (ch_reg = 0; ch_reg < (config->chan_nr / 2); ch_reg++) {
+		if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+			i2s_write_reg(dev->i2s_pbase, TCR(ch_reg),
+				      dev->xfer_resolution);
+			i2s_write_reg(dev->i2s_pbase, TFCR(ch_reg), 0x02);
+			irq = i2s_read_reg(dev->i2s_pbase, IMR(ch_reg));
+			i2s_write_reg(dev->i2s_pbase, IMR(ch_reg), irq & ~0x30);
+			i2s_write_reg(dev->i2s_pbase, TER(ch_reg), 1);
+		} else {
+			i2s_write_reg(dev->i2s_cbase, RCR(ch_reg),
+				      dev->xfer_resolution);
+			i2s_write_reg(dev->i2s_cbase, RFCR(ch_reg), 0x07);
+			irq = i2s_read_reg(dev->i2s_cbase, IMR(ch_reg));
+			i2s_write_reg(dev->i2s_cbase, IMR(ch_reg), irq & ~0x03);
+			i2s_write_reg(dev->i2s_cbase, RER(ch_reg), 1);
+		}
+
+	}
+}
+
 static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 		struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
 {
 	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
 	struct i2s_clk_config_data *config = &dev->config;
-	u32 ccr, xfer_resolution, ch_reg, irq;
 	int ret;
 
 	switch (params_format(params)) {
 	case SNDRV_PCM_FORMAT_S16_LE:
 		config->data_width = 16;
-		ccr = 0x00;
-		xfer_resolution = 0x02;
+		dev->ccr = 0x00;
+		dev->xfer_resolution = 0x02;
 		break;
 
 	case SNDRV_PCM_FORMAT_S24_LE:
 		config->data_width = 24;
-		ccr = 0x08;
-		xfer_resolution = 0x04;
+		dev->ccr = 0x08;
+		dev->xfer_resolution = 0x04;
 		break;
 
 	case SNDRV_PCM_FORMAT_S32_LE:
 		config->data_width = 32;
-		ccr = 0x10;
-		xfer_resolution = 0x05;
+		dev->ccr = 0x10;
+		dev->xfer_resolution = 0x05;
 		break;
 
 	default:
@@ -265,27 +294,9 @@ static int dw_i2s_hw_params(struct snd_pcm_substream *substream,
 		return -EINVAL;
 	}
 
-	i2s_disable_channels(dev, substream->stream);
-
-	for (ch_reg = 0; ch_reg < (config->chan_nr / 2); ch_reg++) {
-		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
-			i2s_write_reg(dev->i2s_pbase, TCR(ch_reg),
-				      xfer_resolution);
-			i2s_write_reg(dev->i2s_pbase, TFCR(ch_reg), 0x02);
-			irq = i2s_read_reg(dev->i2s_pbase, IMR(ch_reg));
-			i2s_write_reg(dev->i2s_pbase, IMR(ch_reg), irq & ~0x30);
-			i2s_write_reg(dev->i2s_pbase, TER(ch_reg), 1);
-		} else {
-			i2s_write_reg(dev->i2s_cbase, RCR(ch_reg),
-				      xfer_resolution);
-			i2s_write_reg(dev->i2s_cbase, RFCR(ch_reg), 0x07);
-			irq = i2s_read_reg(dev->i2s_cbase, IMR(ch_reg));
-			i2s_write_reg(dev->i2s_cbase, IMR(ch_reg), irq & ~0x03);
-			i2s_write_reg(dev->i2s_cbase, RER(ch_reg), 1);
-		}
-	}
+	i2s_write_reg(dev->i2s_pbase, CCR, dev->ccr);
 
-	i2s_write_reg(dev->i2s_pbase, CCR, ccr);
+	dw_i2s_config(dev, substream->stream);
 
 	config->sample_rate = params_rate(params);
 
@@ -417,6 +428,12 @@ static int dw_i2s_resume(struct snd_soc_dai *dai)
 
 	if (dev->capability & DW_I2S_MASTER)
 		clk_enable(dev->clk);
+
+	if (dai->playback_active)
+		dw_i2s_config(dev, SNDRV_PCM_STREAM_PLAYBACK);
+	if (dai->capture_active)
+		dw_i2s_config(dev, SNDRV_PCM_STREAM_CAPTURE);
+
 	return 0;
 }
 
-- 
1.8.3.1