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.
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/soundcard.h>
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 <p...@axentia.se>
---
sound/soc/atmel/atmel_ssc_dai.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sound/soc/atmel/atmel_ssc_dai.c b/sound/soc/atmel/atmel_ssc_dai.c
index f403f39..b1cc2a4 100644
--- 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)
--
2.1.1
--
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