DMA: of: Constant names

No DMA of-function alters the name, so this patch changes the name arguments
to be constant. Most drivers will probably request DMA channels using a
constant name.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
ASoC: dmaengine-pcm: Make requesting the DMA channel at PCM open optional

Refactor the dmaengine PCM library to allow the DMA channel to be requested
before opening a PCM substream. snd_dmaengine_pcm_open() now expects a DMA
channel instead of a filter function and filter parameter as its parameters.
snd_dmaengine_pcm_close() is updated to not release the DMA channel. This allows
a dmaengine based PCM driver to request its channels before the substream is
opened.

The patch also introduces two new functions, snd_dmaengine_pcm_open_request_chan()
and snd_dmaengine_pcm_close_release_chan(), which have the same signature and
behaviour of the old snd_dmaengine_pcm_{open,close}() and internally use the new
variants of these functions. All users of snd_dmaengine_pcm_{open,close}() are
updated to use snd_dmaengine_pcm_open_request_chan() and
snd_dmaengine_pcm_close_release_chan().

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: Add snd_soc_{add,remove}_platform

snd_soc_{add,remove}_platform are similar to snd_soc_register_platform and
snd_soc_unregister_platform with the difference that they won't allocate and
free the snd_soc_platform structure.

Also add snd_soc_lookup_platform which looks up a platform by the device it has
been registered for.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: Add a generic dmaengine_pcm driver

This patch adds a generic dmaengine PCM driver. It builds on top of the
dmaengine PCM library and adds the missing pieces like DMA channel management,
buffer management and channel configuration. It will be able to replace the
majority of the existing platform specific dmaengine based PCM drivers.
Devicetree is used to map the DMA channels to the PCM device.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: dmaengine_pcm: Add support for compat platforms

Add support for platforms which don't use devicetree yet or have to optionally
support a non-devicetree way to request the DMA channel. The patch adds the
compat_request_channel and compat_filter_fn callbacks to the
snd_dmaengine_pcm_config struct. If the compat_request_channel is implemented it
will be used to request the DMA channel. If not dma_request_channel with
compat_filter_fn as the filter function will be used to request the channel.

The patch also exports the snd_dmaengine_pcm_request_chan() function, since
compat platforms will want to use it to request their DMA channel.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: tegra: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: spear: Setup dma data in DAI probe

This allows us to access the DAI DMA data when we create the PCM. We'll use
this when converting spear to generic DMA engine PCM driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: spear: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: dmaengine-pcm: Add support for platforms which can't report residue

Unfortunately there are still quite a few platforms with a dmaengine driver
which do not support reporting the number of bytes left to transfer. If we want
to support these platforms in the generic dmaengine PCM driver we have.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: mxs: Setup dma data in DAI probe

This allows us to access the DAI DMA data when we create the PCM. We'll use
this when converting mxs to generic DMA engine PCM driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: mxs: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: imx: Setup dma data in DAI probe

This allows us to access the DAI DMA data when we create the PCM. We'll use
this when converting imx to generic DMA engine PCM driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: imx: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: omap: Setup dma data in DAI probe

This allows us to access the DAI DMA data when we create the PCM. We'll use
this when converting omap to generic DMA engine PCM driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: omap: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: ep93xx: Setup dma data in DAI probe

This allows us to access the DAI DMA data when we create the PCM. We'll use
this when converting ep39xx to generic DMA engine PCM driver.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: ep93xx: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implementation.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
ASoC: ux500: Use generic dmaengine PCM

Use the generic dmaengine PCM driver instead of a custom implemention.  There is
a minor functional change, the ux500 PCM driver did not preallocate the audio
buffer, while the generic dmaengine PCM driver will do this.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>