We need channel 0 of the sdma engine for internal purposes. We
accomplished this by calling dma_request_channel() in the probe
function. This does not work when multiple dma engines are
present which is the case when IPU support for i.MX31/35 is
compiled in. So instead of registering channel 0 and reserving
it afterwards simply do not register it in the first place.
With this the dmaengine channel counting does not match sdma
channel counting anymore, so we have to use sdma channel counting
in the driver.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

The capabilities are device specific fields, not channel specific fields.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

This is bogus as the dmaengine core will overwrite this field.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

This patch lets sdma_prep_slave_sg fail if the entries of an
sg list do not start on multiples of the word size or if the
lengths are not multiple of the word size.
Also, catch the previously unhandled DMA_SLAVE_BUSWIDTH_8_BYTES
and DMA_SLAVE_BUSWIDTH_UNDEFINED cases.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>

The firmware framework gets initialized during fs_initcall time, so
we are not allowed to call request_firmware earlier.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

Currently while submitting scatterlists with more than one SG
entry the DMA buffer address from the first SG entry is inserted
into all initialized DMA buffer descriptors. This is due to the
typo in the for_each_sg() loop where the scatterlist pointer is
used for obtaining the DMA buffer address and _not_ the SG list
iterator.

As a result all received data will be written only into the first
DMA buffer while reading. While writing the data from the first
DMA buffer is send to the device multiple times. This caused
the filesystem destruction on the MMC card when using DMA in
mxcmmc driver.
Signed-off-by: NAnatolij Gustschin <agust@denx.de>
Acked-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>

The SDMA firmware consists of a ROM part and a RAM part.
The ROM part is always present in the SDMA engine and
is sufficient for many cases.
This patch allows to pass in platform data containing
the script addresses in ROM, so loading a firmware is
optional now.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NDan Williams <dan.j.williams@intel.com>

This patch adds support for the Freescale i.MX SDMA engine.

The SDMA engine is a scatter/gather DMA engine which is implemented
as a seperate coprocessor. SDMA needs its own firmware which is
requested using the standard request_firmware mechanism. The firmware
has different entry points for each peripheral type, so drivers
have to pass the peripheral type to the DMA engine which in turn
picks the correct firmware entry point from a table contained in
the firmware image itself.
The original Freescale code also supports support for transfering
data to the internal SRAM which needs different entry points to
the firmware. Support for this is currently not implemented. Also,
support for the ASRC (asymmetric sample rate converter) is skipped.

I took a very simple approach to implement dmaengine support. Only
a single descriptor is statically assigned to a each channel. This
means that transfers can't be queued up but only a single transfer
is in progress. This simplifies implementation a lot and is sufficient
for the usual device/memory transfers.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: NLinus Walleij <linus.ml.walleij@gmail.com>
Signed-off-by: NDan Williams <dan.j.williams@intel.com>