tree 491f4802a391e3bc04b80f2fbd6ddcd2d2bf7a94
parent 7d1311b93e58ed55f3a31cc8f94c4b8fe988a2b9
author Robin Gong <b38343@freescale.com> 1410398324 +0800
committer Mark Brown <broonie@kernel.org> 1410978971 -0700

spi: spi-imx: add DMA support

Enable DMA support on i.mx6. The read speed can increase from 600KB/s
to 1.2MB/s on i.mx6q. You can disable or enable dma function in dts.
If not set "dma-names" in dts, spi will use PIO mode. This patch only
validate on i.mx6, not i.mx5, but encourage ones to apply this patch
on i.mx5 since they share the same IP.

Note:
  Sometime, there is a weid data in rxfifo after one full tx/rx
transfer finish by DMA on i.mx6dl, so we disable dma functhion on
i.mx6dl.

Signed-off-by: Frank Li <Frank.Li@freescale.com>
Signed-off-by: Robin Gong <b38343@freescale.com>
Acked-by: Marek Vasut <marex@denx.de>
Signed-off-by: Mark Brown <broonie@kernel.org>