ASoC: add support for SSI asynchronous mode to the Freescale SSI drivers

Add a new device tree property for the SSI node: "fsl,ssi-asynchronous".  If
defined, the SSI is programmed into asynchronous mode, otherwise it is
programmed into synchronous mode.  In asynchronous mode, pin SRCK must be
connected to the same clock source as STFS, and pin SRFS must be connected to
the same signal as STFS.  Asynchronous mode allows playback and capture to
use different sample sizes.  It also technically allows different sample rates,
but the driver does not support that.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/sound/soc/fsl/fsl_ssi.h b/sound/soc/fsl/fsl_ssi.h
index 83b44d700e33..eade01feaab6 100644
--- a/sound/soc/fsl/fsl_ssi.h
+++ b/sound/soc/fsl/fsl_ssi.h
@@ -208,6 +208,7 @@ struct ccsr_ssi {
  * ssi_phys: physical address of the SSI registers
  * irq: IRQ of this SSI
  * dev: struct device, used to create the sysfs statistics file
+ * asynchronous: 0=synchronous mode, 1=asynchronous mode
 */
 struct fsl_ssi_info {
         unsigned int id;
@@ -215,6 +216,7 @@ struct fsl_ssi_info {
         dma_addr_t ssi_phys;
         unsigned int irq;
         struct device *dev;
+        int asynchronous;
 };
 
 struct snd_soc_dai *fsl_ssi_create_dai(struct fsl_ssi_info *ssi_info);