ASoC: davinci-mcasp: Choose PCM driver based on configured DMA controller

Find the configured DMA controller by asking for a DMA channel in the
probe phase and releasing it right after. The controller device can be
found via the dma_chan struct and the controller is recognized from
the compatible property of its device node. The patch assumes EDMA if
there is no device node.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index 68356f2c78f8e091e3d9c30ddfd0f2becc1c1667..c744cb29c6bb50977e5b6e44753bd7177abf21e5 100644 (file)
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -1567,6 +1567,49 @@ static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp)
        return ret;
 }
 
+enum {
+       PCM_EDMA,
+       PCM_SDMA,
+};
+static const char *sdma_prefix = "ti,omap";
+
+static int davinci_mcasp_get_dma_type(struct davinci_mcasp *mcasp)
+{
+       struct dma_chan *chan;
+       const char *tmp;
+       int ret = PCM_EDMA;
+
+       if (!mcasp->dev->of_node)
+               return PCM_EDMA;
+
+       tmp = mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data;
+       chan = dma_request_slave_channel_reason(mcasp->dev, tmp);
+       if (IS_ERR(chan)) {
+               if (PTR_ERR(chan) != -EPROBE_DEFER)
+                       dev_err(mcasp->dev,
+                               "Can't verify DMA configuration (%ld)\n",
+                               PTR_ERR(chan));
+               return PTR_ERR(chan);
+       }
+       BUG_ON(!chan->device || !chan->device->dev);
+
+       if (chan->device->dev->of_node)
+               ret = of_property_read_string(chan->device->dev->of_node,
+                                             "compatible", &tmp);
+       else
+               dev_dbg(mcasp->dev, "DMA controller has no of-node\n");
+
+       dma_release_channel(chan);
+       if (ret)
+               return ret;
+
+       dev_dbg(mcasp->dev, "DMA controller compatible = \"%s\"\n", tmp);
+       if (!strncmp(tmp, sdma_prefix, strlen(sdma_prefix)))
+               return PCM_SDMA;
+
+       return PCM_EDMA;
+}
+
 static int davinci_mcasp_probe(struct platform_device *pdev)
 {
        struct snd_dmaengine_dai_dma_data *dma_data;
@@ -1765,27 +1808,34 @@ static int davinci_mcasp_probe(struct platform_device *pdev)
        if (ret != 0)
                goto err;
 
-       switch (mcasp->version) {
+       ret = davinci_mcasp_get_dma_type(mcasp);
+       switch (ret) {
+       case PCM_EDMA:
 #if IS_BUILTIN(CONFIG_SND_EDMA_SOC) || \
        (IS_MODULE(CONFIG_SND_DAVINCI_SOC_MCASP) && \
         IS_MODULE(CONFIG_SND_EDMA_SOC))
-       case MCASP_VERSION_1:
-       case MCASP_VERSION_2:
-       case MCASP_VERSION_3:
                ret = edma_pcm_platform_register(&pdev->dev);
-               break;
+#else
+               dev_err(&pdev->dev, "Missing SND_EDMA_SOC\n");
+               ret = -EINVAL;
+               goto err;
 #endif
+               break;
+       case PCM_SDMA:
 #if IS_BUILTIN(CONFIG_SND_OMAP_SOC) || \
        (IS_MODULE(CONFIG_SND_DAVINCI_SOC_MCASP) && \
         IS_MODULE(CONFIG_SND_OMAP_SOC))
-       case MCASP_VERSION_4:
                ret = omap_pcm_platform_register(&pdev->dev);
-               break;
+#else
+               dev_err(&pdev->dev, "Missing SND_SDMA_SOC\n");
+               ret = -EINVAL;
+               goto err;
 #endif
+               break;
        default:
-               dev_err(&pdev->dev, "Invalid McASP version: %d\n",
-                       mcasp->version);
-               ret = -EINVAL;
+               dev_err(&pdev->dev, "No DMA controller found (%d)\n", ret);
+       case -EPROBE_DEFER:
+               goto err;
                break;
        }