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>

1 files changed, 16 insertions, 2 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;