diff options
Diffstat (limited to 'sound/soc/davinci/davinci-i2s.c')
| -rw-r--r-- | sound/soc/davinci/davinci-i2s.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c index bf5ec4b2f7f5..dd44167a90f0 100644 --- a/sound/soc/davinci/davinci-i2s.c +++ b/sound/soc/davinci/davinci-i2s.c @@ -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); |