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@xxxxxx>
---
Changes since v2:
- Print only one error message if DMA "probing" fails
and none in case of -EPROBE_DEFER
Changes since first patch version:
- Change enum names from MCASP_?DMA to PCM_?DMA
- Return PCM_EDMA if !mcasp->dev->of_node
- Do not ignore possible error code returned by
davinci_mcasp_get_dma_type()
sound/soc/davinci/davinci-mcasp.c | 70 +++++++++++++++++++++++++++++++++------
1 file changed, 60 insertions(+), 10 deletions(-)
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index d793494..a73cd57 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -1565,6 +1565,49 @@ 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;
@@ -1763,27 +1806,34 @@ 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;
}
--
1.9.1
--
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