Blackfin SPI Driver: Add GPIO controlled SPI Slave Select support
Add support for GPIO controlled SPI Chip Selects. To make use of this
feature, set chip_select = 0 and add a proper cs_gpio to your
controller_data.
struct spi_board_info
.chip_select = 0
struct bfin5xx_spi_chip
.cs_gpio = GPIO_P###
There are various SPI devices that require SPI MODE_0, and need to have
the Chip Selects asserted during the entire transfer. Consider using
SPI_MODE_3 (SPI_CPHA | SPI_CPOL) if your device allows it.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/blackfin/include/asm/bfin5xx_spi.h b/arch/blackfin/include/asm/bfin5xx_spi.h
index ea2d24a..8c5f8a9 100644
--- a/arch/blackfin/include/asm/bfin5xx_spi.h
+++ b/arch/blackfin/include/asm/bfin5xx_spi.h
@@ -124,6 +124,7 @@
u8 bits_per_word;
u8 cs_change_per_word;
u16 cs_chg_udelay; /* Some devices require 16-bit delays */
+ u32 cs_gpio;
};
#endif /* _SPI_CHANNEL_H_ */