spi: davinci: enable GPIO lines to be used as chip selects

Sometimes, the chip selects provided by SPI module are
muxed with other functionality and cannot be used in
some designs. In such cases, it becomes convenient to use
an available GPIO line as chip select.

This patch enables the DaVinci SPI driver to treat specific
GPIO lines as chip selects based on information provided in
platform data.

Signed-off-by: Brian Niebuhr <bniebuhr@efjohnson.com>
Tested-By: Michael Williamson <michael.williamson@criticallink.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/include/mach/spi.h b/arch/arm/mach-davinci/include/mach/spi.h
index 2cb326e536bb..734d1fb99614 100644
--- a/arch/arm/mach-davinci/include/mach/spi.h
+++ b/arch/arm/mach-davinci/include/mach/spi.h
@@ -19,6 +19,8 @@
 #ifndef __ARCH_ARM_DAVINCI_SPI_H
 #define __ARCH_ARM_DAVINCI_SPI_H
 
+#define SPI_INTERN_CS   0xFF
+
 enum {
         SPI_VERSION_1, /* For DM355/DM365/DM6467 */
         SPI_VERSION_2, /* For DA8xx */
@@ -38,6 +40,7 @@ struct davinci_spi_platform_data {
         u8      use_dma;
         u8      c2tdelay;
         u8      t2cdelay;
+        u8      *chip_sel;
 };
 
 #endif  /* __ARCH_ARM_DAVINCI_SPI_H */