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

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>

diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index f403f399808afc1431b6ad8a52a377329536707f..b1cc2a4a7fc0ec3c08a597e58ef5bc9e94d68d61 100644 (file)
--- a/sound/soc/atmel/atmel_ssc_dai.c
+++ b/sound/soc/atmel/atmel_ssc_dai.c
@@ -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)