ASoC: DaVinci: i2s toggle clock to complete reset
Add toggle_clock function to complete i2s reset earlier.
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c
index bf5ec4b..dd44167 100644
--- a/sound/soc/davinci/davinci-i2s.c
+++ b/sound/soc/davinci/davinci-i2s.c
@@ -104,6 +104,7 @@
struct davinci_mcbsp_dev {
void __iomem *base;
+ u32 pcr;
struct clk *clk;
struct davinci_pcm_dma_params *dma_params[2];
};
@@ -119,17 +120,34 @@
return __raw_readl(dev->base + reg);
}
+static void toggle_clock(struct davinci_mcbsp_dev *dev, int playback)
+{
+ u32 m = playback ? DAVINCI_MCBSP_PCR_CLKXP : DAVINCI_MCBSP_PCR_CLKRP;
+ /* The clock needs to toggle to complete reset.
+ * So, fake it by toggling the clk polarity.
+ */
+ davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr ^ m);
+ davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, dev->pcr);
+}
+
static void davinci_mcbsp_start(struct snd_pcm_substream *substream)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct davinci_mcbsp_dev *dev = rtd->dai->cpu_dai->private_data;
struct snd_soc_device *socdev = rtd->socdev;
struct snd_soc_platform *platform = socdev->card->platform;
+ int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
u32 spcr;
int ret;
-
- /* Start the sample generator and enable transmitter/receiver */
+ u32 mask = playback ? DAVINCI_MCBSP_SPCR_XRST : DAVINCI_MCBSP_SPCR_RRST;
spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
+ if (spcr & mask) {
+ /* start off disabled */
+ davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG,
+ spcr & ~mask);
+ toggle_clock(dev, playback);
+ }
+ /* Start the sample generator and enable transmitter/receiver */
spcr |= DAVINCI_MCBSP_SPCR_GRST;
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
@@ -155,6 +173,7 @@
spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
spcr &= ~DAVINCI_MCBSP_SPCR_XRST;
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
+ toggle_clock(dev, playback);
/* Restart the DMA */
if (platform->pcm_ops->trigger) {
@@ -188,15 +207,14 @@
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct davinci_mcbsp_dev *dev = rtd->dai->cpu_dai->private_data;
u32 spcr;
+ int playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
/* Reset transmitter/receiver and sample rate/frame sync generators */
spcr = davinci_mcbsp_read_reg(dev, DAVINCI_MCBSP_SPCR_REG);
spcr &= ~(DAVINCI_MCBSP_SPCR_GRST | DAVINCI_MCBSP_SPCR_FRST);
- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
- spcr &= ~DAVINCI_MCBSP_SPCR_XRST;
- else
- spcr &= ~DAVINCI_MCBSP_SPCR_RRST;
+ spcr &= playback ? ~DAVINCI_MCBSP_SPCR_XRST : ~DAVINCI_MCBSP_SPCR_RRST;
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SPCR_REG, spcr);
+ toggle_clock(dev, playback);
}
static int davinci_i2s_startup(struct snd_pcm_substream *substream,
@@ -334,6 +352,7 @@
return -EINVAL;
}
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_SRGR_REG, srgr);
+ dev->pcr = pcr;
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_PCR_REG, pcr);
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_RCR_REG, rcr);
davinci_mcbsp_write_reg(dev, DAVINCI_MCBSP_XCR_REG, xcr);