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| author | Ben Dooks <ben-linux@fluff.org> | 2009-09-22 16:48:56 +0100 |
|---|---|---|
| committer | Ben Dooks <ben-linux@fluff.org> | 2009-10-28 18:22:57 +0000 |
| commit | e3d8024891dbfec6cf36c9b76177650f48118462 (patch) | |
| tree | 2046fa2ec4259e32b02ef29107fa6ace142e8f8f /sound | |
| parent | 964fe080d94db82a3268443e9b9ece4c60246414 (diff) | |
| download | linux-e3d8024891dbfec6cf36c9b76177650f48118462.tar.gz linux-e3d8024891dbfec6cf36c9b76177650f48118462.tar.bz2 linux-e3d8024891dbfec6cf36c9b76177650f48118462.zip | |
ARM: S3C: Add info for supporting circular DMA buffers
The S3C64XX DMA implementation will work a lot better with the ability
to enqueue circular buffers as the hardware can do it's own linked-list
management.
Add a function s3c_dma_has_circular() to show that the system can do this
and a flag for the channel.
Update the s3c24xx/s3c64xx I2S DMA code to deal with this.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Mark Brown <broonie@@opensource.wolfsonmicro.com>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/soc/s3c24xx/s3c24xx-pcm.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/sound/soc/s3c24xx/s3c24xx-pcm.c b/sound/soc/s3c24xx/s3c24xx-pcm.c index 5cbbdc80fde3..1f35c6fcf5fd 100644 --- a/sound/soc/s3c24xx/s3c24xx-pcm.c +++ b/sound/soc/s3c24xx/s3c24xx-pcm.c @@ -75,11 +75,19 @@ static void s3c24xx_pcm_enqueue(struct snd_pcm_substream *substream) { struct s3c24xx_runtime_data *prtd = substream->runtime->private_data; dma_addr_t pos = prtd->dma_pos; + unsigned int limit; int ret; pr_debug("Entered %s\n", __func__); - while (prtd->dma_loaded < prtd->dma_limit) { + if (s3c_dma_has_circular()) { + limit = (prtd->dma_end - prtd->dma_start) / prtd->dma_period; + } else + limit = prtd->dma_limit; + + pr_debug("%s: loaded %d, limit %d\n", __func__, prtd->dma_loaded, limit); + + while (prtd->dma_loaded < limit) { unsigned long len = prtd->dma_period; pr_debug("dma_loaded: %d\n", prtd->dma_loaded); @@ -123,7 +131,7 @@ static void s3c24xx_audio_buffdone(struct s3c2410_dma_chan *channel, snd_pcm_period_elapsed(substream); spin_lock(&prtd->lock); - if (prtd->state & ST_RUNNING) { + if (prtd->state & ST_RUNNING && !s3c_dma_has_circular()) { prtd->dma_loaded--; s3c24xx_pcm_enqueue(substream); } @@ -164,6 +172,11 @@ static int s3c24xx_pcm_hw_params(struct snd_pcm_substream *substream, printk(KERN_ERR "failed to get dma channel\n"); return ret; } + + /* use the circular buffering if we have it available. */ + if (s3c_dma_has_circular()) + s3c2410_dma_setflags(prtd->params->channel, + S3C2410_DMAF_CIRCULAR); } s3c2410_dma_set_buffdone_fn(prtd->params->channel, |