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Diffstat (limited to 'include/linux/spi/spi_bitbang.h')
-rw-r--r--include/linux/spi/spi_bitbang.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index 8dfe61a445f..c961fe9bf3e 100644
--- a/include/linux/spi/spi_bitbang.h
+++ b/include/linux/spi/spi_bitbang.h
@@ -31,8 +31,15 @@ struct spi_bitbang {
struct spi_master *master;
void (*chipselect)(struct spi_device *spi, int is_on);
+#define BITBANG_CS_ACTIVE 1 /* normally nCS, active low */
+#define BITBANG_CS_INACTIVE 0
+ /* txrx_bufs() may handle dma mapping for transfers that don't
+ * already have one (transfer.{tx,rx}_dma is zero), or use PIO
+ */
int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
+
+ /* txrx_word[SPI_MODE_*]() just looks like a shift register */
u32 (*txrx_word[4])(struct spi_device *spi,
unsigned nsecs,
u32 word, u8 bits);