Ok, I spent some time in debugging this again, and here are my findings.
Again, to summarize what this is all about - what I need the code to produce is the following output:
- syncronous LRCLK - 64fs on I2SCLK - I2S data on the first 16bits of each LRCLK edge -> http://caiaq.de/download/tmp/2.png
So I applied all three patches and added the following call to my board support code:
snd_soc_dai_set_tdm_slot(cpu_dai, 3, 3, 2, 16);
Which translates into "give me 2 slots with 16 bits each, and distribute them over the timeline as a 0-1-0-1 pattern". Which is exactly what I need, right?
But unfortunately, the code didn't make the SSP port do that. I ended up having a asynchronous clock and the data somewhere where I wouldn't have expected them: http://caiaq.de/download/tmp/1.png
I did some minor modifications to the patches 2/3 and 3/3 which made it work for me eventually - find them inline.
Not sure whether I got the theory about the API right, and of course I didn't test on any other hardware than the one I have.
On Thu, Aug 06, 2009 at 03:55:18PM +0100, Mark Brown wrote:
- Automatically sets TDM mode for frame_width larger than 32 bits, if the user doesn't setup the TDM slots with set_tdm_slot().
- Reset SSCR0_EDSS and SSCR0_DSS on pxa_ssp_set_dai_fmt.
- Makes SSCR0_MOD optional.
- Clears SSCR1_RWOT case SSCR0_MOD is set.
Signed-off-by: Daniel Ribeiro drwyrm@gmail.com Signed-off-by: Mark Brown broonie@opensource.wolfsonmicro.com
sound/soc/pxa/pxa-ssp.c | 92 +++++++++++++++++++++++++++-------------------- 1 files changed, 53 insertions(+), 39 deletions(-)
diff --git a/sound/soc/pxa/pxa-ssp.c b/sound/soc/pxa/pxa-ssp.c index 5b9ed64..d60492e 100644 --- a/sound/soc/pxa/pxa-ssp.c +++ b/sound/soc/pxa/pxa-ssp.c
[...]
@@ -532,48 +532,70 @@ static int pxa_ssp_hw_params(struct snd_pcm_substream *substream, struct ssp_priv *priv = cpu_dai->private_data; struct ssp_device *ssp = priv->dev.ssp; int chn = params_channels(params);
- u32 sscr0;
- u32 sspsp;
- u32 sscr0, sscr1, sspsp; int width = snd_pcm_format_physical_width(params_format(params));
- int ttsa = ssp_read_reg(ssp, SSTSA) & 0xf;
int slot_width, frame_width = 0;
/* check if the user explicitly set a slot_width */
sscr0 = ssp_read_reg(ssp, SSCR0);
if (sscr0 & (SSCR0_EDSS | SSCR0_DSS))
slot_width = (sscr0 & SSCR0_DSS) +(sscr0 & SSCR0_EDSS ? 17 : 1);else
frame_width = slot_width = width * chn;/* generate correct DMA params */ if (cpu_dai->dma_data) kfree(cpu_dai->dma_data);
- /* Network mode with one active slot (ttsa == 1) can be used
* to force 16-bit frame width on the wire (for S16_LE), even* with two channels. Use 16-bit DMA transfers for this case.*/- cpu_dai->dma_data = ssp_get_dma_params(ssp,
((chn == 2) && (ttsa != 1)) || (width == 32),
- cpu_dai->dma_data = ssp_get_dma_params(ssp, slot_width > 16, substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
The condition for the width4 parameter needs to be (slot_width * slots) > 16 for me. With that parameter set to 0, audio plays at half speed on my system.
And in patch 3/3,
diff --git a/sound/soc/pxa/pxa-ssp.c b/sound/soc/pxa/pxa-ssp.c index d60492e..aac85fe 100644 --- a/sound/soc/pxa/pxa-ssp.c +++ b/sound/soc/pxa/pxa-ssp.c
[...]
@@ -561,6 +543,59 @@ static int pxa_ssp_hw_params(struct snd_pcm_substream *substream, sscr0 |= SSCR0_FPCKE; #endif
- sspsp = ssp_read_reg(ssp, SSPSP);
- switch (priv->dai_fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
- case SND_SOC_DAIFMT_I2S:
/** I2S and LEFT_J are stereo only, we have to send data for* both channels.*/if (chn == 1)frame_width *= 2;/** If the user did not use network mode, we assume the codec* is I2S compliant.*/if (frame_width > 0) {sspsp |= SSPSP_SFRMWDTH(frame_width / 2);sspsp |= SSPSP_FSRT;} else {/** Otherwise we assume that it is a single TDM slot, and* the user is abusing set_tdm_slot to support an* out of spec codec.*/int slots = ((sscr0 & SSCR0_SlotsPerFrm(8)) >> 24) + 1;/* PXA2XX doesn't support DMYSTOP > 3 */if (slot_width != (width * 2) && !cpu_is_pxa3xx())return -EINVAL;sspsp |= SSPSP_DMYSTRT(1);sspsp |= SSPSP_DMYSTOP((slot_width * slots) / 2 - width - 1);sspsp |= SSPSP_SFRMWDTH((slot_width * slots) / 2);
These two calculations are wrong my case. What works here is
sspsp |= SSPSP_DMYSTOP( (slot_width * slots * chn) / 2 - width - 1); sspsp |= SSPSP_SFRMWDTH((slot_width * slots * chn) / 2);
... which is another multiplication by factor 2. But I'm not sure if I got the wrong variable with value 2 :)
I then end up having the following register contents:
SSCR0 0xa10003ff SSCR1 0x00601d08 SSPSP 0x31a00084 SSACD 0x00000060 SSTSA 0x00000003 SSRSA 0x00000003
Daniel