ASoC: DaVinci: Update suspend/resume support for McASP driver

Add clock enable and disable calls to resume and suspend respectively.
Also add a member to the audio device data structure which tracks the clock
status.

Tested on DA850/OMAP-L138 EVM. For the purpose of testing, the patches[1] which
add suspend-to-RAM support to DA850/OMAP-L138 SoC were applied.

[1] http://linux.davincidsp.com/pipermail/davinci-linux-open-source/
2009-November/016958.html

Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

3 files changed, 18 insertions, 3 deletions

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index 0a302e1080d9..a613bbb0bc91 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -767,14 +767,27 @@ static int davinci_mcasp_trigger(struct snd_pcm_substream *substream,
         int ret = 0;
 
         switch (cmd) {
-        case SNDRV_PCM_TRIGGER_START:
         case SNDRV_PCM_TRIGGER_RESUME:
+                if (!dev->clk_active) {
+                        clk_enable(dev->clk);
+                        dev->clk_active = 1;
+                }
+                /* Fall through */
+        case SNDRV_PCM_TRIGGER_START:
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                 davinci_mcasp_start(dev, substream->stream);
                 break;
 
-        case SNDRV_PCM_TRIGGER_STOP:
         case SNDRV_PCM_TRIGGER_SUSPEND:
+                davinci_mcasp_stop(dev, substream->stream);
+                if (dev->clk_active) {
+                        clk_disable(dev->clk);
+                        dev->clk_active = 0;
+                }
+
+                break;
+
+        case SNDRV_PCM_TRIGGER_STOP:
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                 davinci_mcasp_stop(dev, substream->stream);
                 break;
@@ -866,6 +879,7 @@ static int davinci_mcasp_probe(struct platform_device *pdev)
         }
 
         clk_enable(dev->clk);
+        dev->clk_active = 1;
 
         dev->base = (void __iomem *)IO_ADDRESS(mem->start);
         dev->op_mode = pdata->op_mode;
diff --git a/sound/soc/davinci/davinci-mcasp.h b/sound/soc/davinci/davinci-mcasp.h
index 582c9249ef09..e755b5121ec7 100644
--- a/sound/soc/davinci/davinci-mcasp.h
+++ b/sound/soc/davinci/davinci-mcasp.h
@@ -44,6 +44,7 @@ struct davinci_audio_dev {
         int sample_rate;
         struct clk *clk;
         unsigned int codec_fmt;
+        u8 clk_active;
 
         /* McASP specific data */
         int     tdm_slots;
diff --git a/sound/soc/davinci/davinci-pcm.c b/sound/soc/davinci/davinci-pcm.c
index ad4d7f47a86b..80c7fdf2f521 100644
--- a/sound/soc/davinci/davinci-pcm.c
+++ b/sound/soc/davinci/davinci-pcm.c
@@ -49,7 +49,7 @@ static void print_buf_info(int slot, char *name)
 static struct snd_pcm_hardware pcm_hardware_playback = {
         .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
                  SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
-                 SNDRV_PCM_INFO_PAUSE),
+                 SNDRV_PCM_INFO_PAUSE | SNDRV_PCM_INFO_RESUME),
         .formats = (SNDRV_PCM_FMTBIT_S16_LE),
         .rates = (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_16000 |
                   SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_32000 |