This patch adds dma support for Freescale MXS-based SoC i.MX23/28,
including apbh-dma and apbx-dma.
* apbh-dma and apbx-dma are supported in the driver as two mxs-dma
instances.
* apbh-dma is different between mx23 and mx28, hardware version
register is used to differentiate.
* mxs-dma supports pio function besides data transfer. The driver
uses dma_data_direction DMA_NONE to identify the pio mode, and
steals sgl and sg_len to get pio words and numbers from clients.
* mxs dmaengine has some very specific features, like sense function
and the special NAND support (nand_lock, nand_wait4ready). These
are too specific to implemented in generic dmaengine driver.
* The driver refers to imx-sdma and only a single descriptor is
statically assigned to each channel.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
