On Sun, Apr 07, 2013 at 07:18:50PM -0500, Timur Tabi wrote:
Markus Pargmann wrote:
Add support for non-dma pcm for imx platforms with imx-pcm-fiq support. Instead of imx-pcm-audio, in this case imx-pcm-fiq-audio device is added and the SIER flags are set differently.
So just to be clear, this is interrupt-driven SSI audio? So you're generating an interrupt every time the transmit FIFO goes below the threshold?
Yes
I wonder if it makes sense to enable both FIFOs, so that you take half as many interrupts per second.
It looks like imx-pcm-fiq and ssi-fiq.s do not support transmitting through two FIFOs at the moment.
Signed-off-by: Markus Pargmann mpa@pengutronix.de
sound/soc/fsl/fsl_ssi.c | 70 ++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 58 insertions(+), 12 deletions(-)
diff --git a/sound/soc/fsl/fsl_ssi.c b/sound/soc/fsl/fsl_ssi.c index 7decbd9..afb5a23 100644 --- a/sound/soc/fsl/fsl_ssi.c +++ b/sound/soc/fsl/fsl_ssi.c @@ -120,10 +120,12 @@ struct fsl_ssi_private {
bool new_binding; bool ssi_on_imx;
- bool dma;
Can you rename this to "use_dma" or something like that?
Done.
struct clk *clk; struct platform_device *imx_pcm_pdev; struct imx_pcm_dma_params dma_params_tx; struct imx_pcm_dma_params dma_params_rx;
struct imx_pcm_fiq_params fiq_params;
struct { unsigned int rfrc;
@@ -353,7 +355,8 @@ static int fsl_ssi_startup(struct snd_pcm_substream *substream, */
/* Enable the interrupts and DMA requests */
write_ssi(SIER_FLAGS, &ssi->sier);
if (ssi_private->dma)write_ssi(SIER_FLAGS, &ssi->sier);/*
- Set the watermark for transmit FIFI 0 and receive FIFO 0. We
@@ -520,6 +523,18 @@ static int fsl_ssi_trigger(struct snd_pcm_substream *substream, int cmd, return -EINVAL; }
- if (!ssi_private->dma) {
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {write_ssi(CCSR_SSI_SOR_TX_CLR, &ssi->sor);write_ssi(CCSR_SSI_SIER_TIE | CCSR_SSI_SIER_TFE0_EN,&ssi->sier);} else {write_ssi(CCSR_SSI_SOR_RX_CLR, &ssi->sor);write_ssi(CCSR_SSI_SIER_RIE | CCSR_SSI_SIER_RFF0_EN,&ssi->sier);}- }
- return 0;
}
@@ -680,6 +695,8 @@ static int fsl_ssi_probe(struct platform_device *pdev) sizeof(fsl_ssi_dai_template)); ssi_private->cpu_dai_drv.name = ssi_private->name;
- ssi_private->dma = !of_property_read_bool(np, "fsl,imx-fiq");
Instead of looking for the FIQ property, maybe you should just look for the absence of a DMA property/node, and then default to interrupts if there is no DMA. That would make it more generic, and even work on non-IMX systems.
I do not think it is possible. For example imx27 ssi does support DMA but for specific boards we have to use fiq instead (phycore-ac97). So I would prefer to define the DMA in the chip dtsi file and choose fiq, if necessary, in the board dts.
Regards,
Markus