| Message ID | bcd986aa18bf41643f1d190739381a890313ac61.1433235274.git.jsarha@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 06/02/2015 11:58 AM, Jyri Sarha wrote: > 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> > --- > sound/soc/davinci/davinci-mcasp.c | 61 ++++++++++++++++++++++++++++++++------- > 1 file changed, 51 insertions(+), 10 deletions(-) > > diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c > index d793494..5bc2712 100644 > --- a/sound/soc/davinci/davinci-mcasp.c > +++ b/sound/soc/davinci/davinci-mcasp.c > @@ -1565,6 +1565,46 @@ static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp) > return ret; > } > > +enum { > + MCASP_EDMA = 1, Why start from 1? I'm not sure about the name. It somehow implies that McASP has something to do with the dma engine. MCASP_SERVICED_BY_E/SDMA PLATFORM_USES_E/SDMA I can not come up with a decent name :( > + MCASP_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 = MCASP_EDMA; > + > + tmp = mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data; > + chan = dma_request_slave_channel_reason(mcasp->dev, tmp); this will return with error in case of !dev->of_node. The first check should be: if (!mcasp->dev->of_node) return MCASP_EDMA; since we can only boot in legacy mode with daVinci devices and they are using eDMA. > + 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"); Now this is not likely to happen... > + > + 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 MCASP_SDMA; > + > + return MCASP_EDMA; > +} > + > static int davinci_mcasp_probe(struct platform_device *pdev) > { > struct snd_dmaengine_dai_dma_data *dma_data; > @@ -1763,27 +1803,28 @@ static int davinci_mcasp_probe(struct platform_device *pdev) > if (ret != 0) > goto err; > > - switch (mcasp->version) { > + ret = -EINVAL; Why? What was the problem with setting the ret in the default case? > + switch (davinci_mcasp_get_dma_type(mcasp)) { > + case MCASP_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"); > #endif > + break; > + case MCASP_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"); > #endif > + break; > default: > - dev_err(&pdev->dev, "Invalid McASP version: %d\n", > - mcasp->version); > - ret = -EINVAL; > + dev_err(&pdev->dev, "No DMA controller found\n"); > break; > } > >
On 06/02/15 13:31, Peter Ujfalusi wrote: > On 06/02/2015 11:58 AM, Jyri Sarha wrote: >> 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> >> --- >> sound/soc/davinci/davinci-mcasp.c | 61 ++++++++++++++++++++++++++++++++------- >> 1 file changed, 51 insertions(+), 10 deletions(-) >> >> diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c >> index d793494..5bc2712 100644 >> --- a/sound/soc/davinci/davinci-mcasp.c >> +++ b/sound/soc/davinci/davinci-mcasp.c >> @@ -1565,6 +1565,46 @@ static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp) >> return ret; >> } >> >> +enum { >> + MCASP_EDMA = 1, > > Why start from 1? This is just an implementation detail, for "if" statement below. Maybe I should restucture for better readability. > I'm not sure about the name. It somehow implies that McASP has something to do > with the dma engine. > MCASP_SERVICED_BY_E/SDMA > PLATFORM_USES_E/SDMA > > I can not come up with a decent name :( > What about PCM_EDMA/PCM_SDMA? This is a local definition after all. > >> + MCASP_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 = MCASP_EDMA; >> + >> + tmp = mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data; >> + chan = dma_request_slave_channel_reason(mcasp->dev, tmp); > > this will return with error in case of !dev->of_node. > The first check should be: > if (!mcasp->dev->of_node) > return MCASP_EDMA; > > since we can only boot in legacy mode with daVinci devices and they are using > eDMA. > >> + 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"); > > Now this is not likely to happen... > Not having of_node happens on am335x, but not having compatible property is unlikely... >> + >> + 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 MCASP_SDMA; >> + >> + return MCASP_EDMA; >> +} >> + >> static int davinci_mcasp_probe(struct platform_device *pdev) >> { >> struct snd_dmaengine_dai_dma_data *dma_data; >> @@ -1763,27 +1803,28 @@ static int davinci_mcasp_probe(struct platform_device *pdev) >> if (ret != 0) >> goto err; >> >> - switch (mcasp->version) { >> + ret = -EINVAL; > > Why? What was the problem with setting the ret in the default case? > >> + switch (davinci_mcasp_get_dma_type(mcasp)) { >> + case MCASP_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"); >> #endif >> + break; >> + case MCASP_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"); >> #endif >> + break; >> default: >> - dev_err(&pdev->dev, "Invalid McASP version: %d\n", >> - mcasp->version); >> - ret = -EINVAL; >> + dev_err(&pdev->dev, "No DMA controller found\n"); >> break; >> } >> >> > >
On Tue, Jun 02, 2015 at 01:31:28PM +0300, Peter Ujfalusi wrote: > On 06/02/2015 11:58 AM, Jyri Sarha wrote: > > +enum { > > + MCASP_EDMA = 1, > Why start from 1? It's a fairly common style to ensure that zero initialised structures don't have a default value. Don't know if that's the intent here or not.
On 06/02/2015 01:40 PM, Jyri Sarha wrote: >>> +enum { >>> + MCASP_EDMA = 1, >> >> Why start from 1? > > This is just an implementation detail, for "if" statement below. Maybe I > should restucture for better readability. No need to change if it makes the code flow better. I was just asking. >> I'm not sure about the name. It somehow implies that McASP has something to do >> with the dma engine. >> MCASP_SERVICED_BY_E/SDMA >> PLATFORM_USES_E/SDMA >> >> I can not come up with a decent name :( >> > > What about PCM_EDMA/PCM_SDMA? This is a local definition after all. Sounds much better! >>> + MCASP_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 = MCASP_EDMA; >>> + >>> + tmp = mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data; >>> + chan = dma_request_slave_channel_reason(mcasp->dev, tmp); >> >> this will return with error in case of !dev->of_node. >> The first check should be: >> if (!mcasp->dev->of_node) >> return MCASP_EDMA; >> >> since we can only boot in legacy mode with daVinci devices and they are using >> eDMA. >> >>> + 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"); >> >> Now this is not likely to happen... >> > > Not having of_node happens on am335x, but not having compatible property is > unlikely... Yes, you are right. The edma dmaengine driver is not probed via DT, but the arch/arm/common/edma.c will create a platform device for it to load, so it does not have of_node. On the other hand omap-dma is probed via DT. > >>> + >>> + 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 MCASP_SDMA; >>> + >>> + return MCASP_EDMA; >>> +} >>> + >>> static int davinci_mcasp_probe(struct platform_device *pdev) >>> { >>> struct snd_dmaengine_dai_dma_data *dma_data; >>> @@ -1763,27 +1803,28 @@ static int davinci_mcasp_probe(struct >>> platform_device *pdev) >>> if (ret != 0) >>> goto err; >>> >>> - switch (mcasp->version) { >>> + ret = -EINVAL; >> >> Why? What was the problem with setting the ret in the default case? >> >>> + switch (davinci_mcasp_get_dma_type(mcasp)) { >>> + case MCASP_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"); >>> #endif >>> + break; >>> + case MCASP_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"); >>> #endif >>> + break; >>> default: >>> - dev_err(&pdev->dev, "Invalid McASP version: %d\n", >>> - mcasp->version); >>> - ret = -EINVAL; >>> + dev_err(&pdev->dev, "No DMA controller found\n"); >>> break; >>> } >>> >>> >> >> >
I missed two comments first time around... On 06/02/15 13:31, Peter Ujfalusi wrote: > On 06/02/2015 11:58 AM, Jyri Sarha wrote: >> 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> >> --- >> sound/soc/davinci/davinci-mcasp.c | 61 ++++++++++++++++++++++++++++++++------- >> 1 file changed, 51 insertions(+), 10 deletions(-) >> >> diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c >> index d793494..5bc2712 100644 >> --- a/sound/soc/davinci/davinci-mcasp.c >> +++ b/sound/soc/davinci/davinci-mcasp.c >> @@ -1565,6 +1565,46 @@ static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp) >> return ret; >> } >> >> +enum { >> + MCASP_EDMA = 1, > > Why start from 1? > I'm not sure about the name. It somehow implies that McASP has something to do > with the dma engine. > MCASP_SERVICED_BY_E/SDMA > PLATFORM_USES_E/SDMA > > I can not come up with a decent name :( > > >> + MCASP_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 = MCASP_EDMA; >> + >> + tmp = mcasp->dma_data[SNDRV_PCM_STREAM_PLAYBACK].filter_data; >> + chan = dma_request_slave_channel_reason(mcasp->dev, tmp); > > this will return with error in case of !dev->of_node. > The first check should be: > if (!mcasp->dev->of_node) > return MCASP_EDMA; > > since we can only boot in legacy mode with daVinci devices and they are using > eDMA. > Yep, I'll add that back. I tought that I would not need it, but am not so familiar with the generic dmaengine pcm... >> + 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"); > > Now this is not likely to happen... > >> + >> + 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 MCASP_SDMA; >> + >> + return MCASP_EDMA; >> +} >> + >> static int davinci_mcasp_probe(struct platform_device *pdev) >> { >> struct snd_dmaengine_dai_dma_data *dma_data; >> @@ -1763,27 +1803,28 @@ static int davinci_mcasp_probe(struct platform_device *pdev) >> if (ret != 0) >> goto err; >> >> - switch (mcasp->version) { >> + ret = -EINVAL; > > Why? What was the problem with setting the ret in the default case? > I would need to have that I three places now for the #else cases, when devicetree tries to configure pcm driver that has not been compiled. >> + switch (davinci_mcasp_get_dma_type(mcasp)) { >> + case MCASP_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"); >> #endif >> + break; >> + case MCASP_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"); >> #endif >> + break; >> default: >> - dev_err(&pdev->dev, "Invalid McASP version: %d\n", >> - mcasp->version); >> - ret = -EINVAL; >> + dev_err(&pdev->dev, "No DMA controller found\n"); >> break; >> } >> >> > >
On 06/02/2015 02:11 PM, Jyri Sarha wrote: >>> - switch (mcasp->version) { >>> + ret = -EINVAL; >> >> Why? What was the problem with setting the ret in the default case? >> > > I would need to have that I three places now for the #else cases, when > devicetree tries to configure pcm driver that has not been compiled. I see now, thanks for pointing out ;) >>> + switch (davinci_mcasp_get_dma_type(mcasp)) { >>> + case MCASP_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"); >>> #endif >>> + break; >>> + case MCASP_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"); >>> #endif >>> + break; >>> default: >>> - dev_err(&pdev->dev, "Invalid McASP version: %d\n", >>> - mcasp->version); >>> - ret = -EINVAL; >>> + dev_err(&pdev->dev, "No DMA controller found\n"); >>> break; >>> }
diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c index d793494..5bc2712 100644 --- a/sound/soc/davinci/davinci-mcasp.c +++ b/sound/soc/davinci/davinci-mcasp.c @@ -1565,6 +1565,46 @@ static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp) return ret; } +enum { + MCASP_EDMA = 1, + MCASP_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 = MCASP_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 MCASP_SDMA; + + return MCASP_EDMA; +} + static int davinci_mcasp_probe(struct platform_device *pdev) { struct snd_dmaengine_dai_dma_data *dma_data; @@ -1763,27 +1803,28 @@ static int davinci_mcasp_probe(struct platform_device *pdev) if (ret != 0) goto err; - switch (mcasp->version) { + ret = -EINVAL; + switch (davinci_mcasp_get_dma_type(mcasp)) { + case MCASP_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"); #endif + break; + case MCASP_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"); #endif + break; default: - dev_err(&pdev->dev, "Invalid McASP version: %d\n", - mcasp->version); - ret = -EINVAL; + dev_err(&pdev->dev, "No DMA controller found\n"); break; }
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> --- sound/soc/davinci/davinci-mcasp.c | 61 ++++++++++++++++++++++++++++++++------- 1 file changed, 51 insertions(+), 10 deletions(-)