[PATCH] spi: use linked lists rather than an array

[linux-beck.git] / include / linux / spi / spi_bitbang.h

diff --git a/include/linux/spi/spi_bitbang.h b/include/linux/spi/spi_bitbang.h
index 8dfe61a445f44e08cc9d56c7007cdc2dbffd6bb3..c961fe9bf3eb48f3576035a7ec62bc5c743bc008 100644 (file)
--- 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);