3 files changed, 39 insertions, 25 deletions

diff --git a/arch/arm/plat-omap/include/mach/mcbsp.h b/arch/arm/plat-omap/include/mach/mcbsp.h
index bb154ea76769..57249bb1e9bc 100644
--- a/arch/arm/plat-omap/include/mach/mcbsp.h
+++ b/arch/arm/plat-omap/include/mach/mcbsp.h
@@ -387,8 +387,8 @@ void omap_mcbsp_register_board_cfg(struct omap_mcbsp_platform_data *config,
 void omap_mcbsp_config(unsigned int id, const struct omap_mcbsp_reg_cfg * config);
 int omap_mcbsp_request(unsigned int id);
 void omap_mcbsp_free(unsigned int id);
-void omap_mcbsp_start(unsigned int id);
-void omap_mcbsp_stop(unsigned int id);
+void omap_mcbsp_start(unsigned int id, int tx, int rx);
+void omap_mcbsp_stop(unsigned int id, int tx, int rx);
 void omap_mcbsp_xmit_word(unsigned int id, u32 word);
 u32 omap_mcbsp_recv_word(unsigned int id);
 
diff --git a/arch/arm/plat-omap/mcbsp.c b/arch/arm/plat-omap/mcbsp.c
index efa0e0111f38..a3d2313460b3 100644
--- a/arch/arm/plat-omap/mcbsp.c
+++ b/arch/arm/plat-omap/mcbsp.c
@@ -328,14 +328,15 @@ void omap_mcbsp_free(unsigned int id)
 EXPORT_SYMBOL(omap_mcbsp_free);
 
 /*
- * Here we start the McBSP, by enabling the sample
- * generator, both transmitter and receivers,
- * and the frame sync.
+ * Here we start the McBSP, by enabling transmitter, receiver or both.
+ * If no transmitter or receiver is active prior calling, then sample-rate
+ * generator and frame sync are started.
  */
-void omap_mcbsp_start(unsigned int id)
+void omap_mcbsp_start(unsigned int id, int tx, int rx)
 {
         struct omap_mcbsp *mcbsp;
         void __iomem *io_base;
+        int idle;
         u16 w;
 
         if (!omap_mcbsp_check_valid_id(id)) {
@@ -348,32 +349,40 @@ void omap_mcbsp_start(unsigned int id)
         mcbsp->rx_word_length = (OMAP_MCBSP_READ(io_base, RCR1) >> 5) & 0x7;
         mcbsp->tx_word_length = (OMAP_MCBSP_READ(io_base, XCR1) >> 5) & 0x7;
 
-        /* Start the sample generator */
-        w = OMAP_MCBSP_READ(io_base, SPCR2);
-        OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
+        idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
+                  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
+
+        if (idle) {
+                /* Start the sample generator */
+                w = OMAP_MCBSP_READ(io_base, SPCR2);
+                OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 6));
+        }
 
         /* Enable transmitter and receiver */
         w = OMAP_MCBSP_READ(io_base, SPCR2);
-        OMAP_MCBSP_WRITE(io_base, SPCR2, w | 1);
+        OMAP_MCBSP_WRITE(io_base, SPCR2, w | (tx & 1));
 
         w = OMAP_MCBSP_READ(io_base, SPCR1);
-        OMAP_MCBSP_WRITE(io_base, SPCR1, w | 1);
+        OMAP_MCBSP_WRITE(io_base, SPCR1, w | (rx & 1));
 
         udelay(100);
 
-        /* Start frame sync */
-        w = OMAP_MCBSP_READ(io_base, SPCR2);
-        OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
+        if (idle) {
+                /* Start frame sync */
+                w = OMAP_MCBSP_READ(io_base, SPCR2);
+                OMAP_MCBSP_WRITE(io_base, SPCR2, w | (1 << 7));
+        }
 
         /* Dump McBSP Regs */
         omap_mcbsp_dump_reg(id);
 }
 EXPORT_SYMBOL(omap_mcbsp_start);
 
-void omap_mcbsp_stop(unsigned int id)
+void omap_mcbsp_stop(unsigned int id, int tx, int rx)
 {
         struct omap_mcbsp *mcbsp;
         void __iomem *io_base;
+        int idle;
         u16 w;
 
         if (!omap_mcbsp_check_valid_id(id)) {
@@ -386,15 +395,20 @@ void omap_mcbsp_stop(unsigned int id)
 
         /* Reset transmitter */
         w = OMAP_MCBSP_READ(io_base, SPCR2);
-        OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1));
+        OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(tx & 1));
 
         /* Reset receiver */
         w = OMAP_MCBSP_READ(io_base, SPCR1);
-        OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(1));
+        OMAP_MCBSP_WRITE(io_base, SPCR1, w & ~(rx & 1));
 
-        /* Reset the sample rate generator */
-        w = OMAP_MCBSP_READ(io_base, SPCR2);
-        OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
+        idle = !((OMAP_MCBSP_READ(io_base, SPCR2) |
+                  OMAP_MCBSP_READ(io_base, SPCR1)) & 1);
+
+        if (idle) {
+                /* Reset the sample rate generator */
+                w = OMAP_MCBSP_READ(io_base, SPCR2);
+                OMAP_MCBSP_WRITE(io_base, SPCR2, w & ~(1 << 6));
+        }
 }
 EXPORT_SYMBOL(omap_mcbsp_stop);
 
diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index a5d46a7b196a..6a837ffd5d0b 100644
--- a/sound/soc/omap/omap-mcbsp.c
+++ b/sound/soc/omap/omap-mcbsp.c
@@ -183,21 +183,21 @@ static int omap_mcbsp_dai_trigger(struct snd_pcm_substream *substream, int cmd,
         struct snd_soc_pcm_runtime *rtd = substream->private_data;
         struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
         struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data);
-        int err = 0;
+        int err = 0, play = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 
         switch (cmd) {
         case SNDRV_PCM_TRIGGER_START:
         case SNDRV_PCM_TRIGGER_RESUME:
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
-                if (!mcbsp_data->active++)
-                        omap_mcbsp_start(mcbsp_data->bus_id);
+                mcbsp_data->active++;
+                omap_mcbsp_start(mcbsp_data->bus_id, play, !play);
                 break;
 
         case SNDRV_PCM_TRIGGER_STOP:
         case SNDRV_PCM_TRIGGER_SUSPEND:
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
-                if (!--mcbsp_data->active)
-                        omap_mcbsp_stop(mcbsp_data->bus_id);
+                omap_mcbsp_stop(mcbsp_data->bus_id, play, !play);
+                mcbsp_data->active--;
                 break;
         default:
                 err = -EINVAL;