spi/dw_spi: add DMA support

dw_spi driver in upstream only supports PIO mode, and this patch
will support it to cowork with the Designware dma controller used
on Intel Moorestown platform, at the same time it provides a general
framework to support dw_spi core to cowork with dma controllers on
other platforms

It has been tested with a Option GTM501L 3G modem and Infenion 60x60
modem. To use DMA mode, DMA controller 2 of Moorestown has to be enabled

Also change the dma interface suggested by Linus Walleij.

Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Feng Tang <feng.tang@intel.com>
[Typo fix and renames to match intel_mid_dma renaming]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 665d03d4e022..caa2e84cc0a6 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -382,6 +382,10 @@ config SPI_DW_PCI
         tristate "PCI interface driver for DW SPI core"
         depends on SPI_DESIGNWARE && PCI
 
+config SPI_DW_MID_DMA
+        bool "DMA support for DW SPI controller on Intel Moorestown platform"
+        depends on SPI_DW_PCI && INTEL_MID_DMAC
+
 config SPI_DW_MMIO
         tristate "Memory-mapped io interface driver for DW SPI core"
         depends on SPI_DESIGNWARE && HAVE_CLK