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 --- 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; }