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ASoC: DaVinci: i2s toggle clock to complete reset

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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>
tirimbino
Troy Kisky 16 years ago committed by Mark Brown
parent 35cf63583d
commit c392bec716
1 changed files with 25 additions and 6 deletions
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  1. 31
      sound/soc/davinci/davinci-i2s.c

31
sound/soc/davinci/davinci-i2s.c
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@ -104,6 +104,7 @@ static struct davinci_pcm_dma_params davinci_i2s_pcm_in = {
struct davinci_mcbsp_dev {
void __iomem *base;
u32 pcr;
struct clk *clk;
struct davinci_pcm_dma_params *dma_params[2];
};
@ -119,17 +120,34 @@ static inline u32 davinci_mcbsp_read_reg(struct davinci_mcbsp_dev *dev, int reg)
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 @@ static void davinci_mcbsp_start(struct snd_pcm_substream *substream)
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 @@ static void davinci_mcbsp_stop(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;
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 @@ static int davinci_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
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);

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