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ASoC: atmel_ssc_dai: Match the CMR divider only in full duplex.

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The CMR divider register is shared by playback and capture. The SSC driver
therefore tries to enforce rules so that the needed register content do
not conflict during simultaneous playback/capture. However, the
implementation also prevents changing the register content in
half-duplex scenarios, which is needed when using the OSS API.

Thus, only lock the divider if there is a stream in the other direction.

Fixes the below program to not fail with the atmel ssc dai in master mode.

int
main(void)
{
	int fd;
	int format;
	int channels;
	int speed;

	if ((fd = open("/dev/dsp", O_WRONLY, 0)) == -1) {
		perror("open");
		return 1;
	}
	format = AFMT_S16_LE;
	if (ioctl(fd, SNDCTL_DSP_SETFMT, &format) == -1) {
		perror("SNDCTL_DSP_SETFMT");
		return 1;
	}
	channels = 2;
	if (ioctl(fd, SNDCTL_DSP_CHANNELS, &channels) == -1) {
		perror("SNDCTL_DSP_CHANNELS");
		return 1;
	}
	speed = 22025;
	if (ioctl(fd, SNDCTL_DSP_SPEED, &speed) == -1) {
		perror("SNDCTL_DSP_SPEED");
		return 1;
	}
	return 0;
}

Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Peter Rosin 2014-10-24 21:25:59 +02:00 • committed by Mark Brown
commit eb58960e9e
1 changed files with 4 additions and 1 deletions
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5
sound/soc/atmel/atmel_ssc_dai.c
View file

@ -310,7 +310,10 @@ static int atmel_ssc_set_dai_clkdiv(struct snd_soc_dai *cpu_dai,
* transmit and receive, so if a value has already
* been set, it must match this value.
*/
if (ssc_p->cmr_div == 0)
if (ssc_p->dir_mask !=
(SSC_DIR_MASK_PLAYBACK | SSC_DIR_MASK_CAPTURE))
ssc_p->cmr_div = div;
else if (ssc_p->cmr_div == 0)
ssc_p->cmr_div = div;
else
if (div != ssc_p->cmr_div)