Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / spi / spi_bitbang.h

diff --git a/kernel/include/linux/spi/spi_bitbang.h b/kernel/include/linux/spi/spi_bitbang.h
new file mode 100644 (file)
index 0000000..85578d4
--- /dev/null
+++ b/kernel/include/linux/spi/spi_bitbang.h
@@ -0,0 +1,47 @@
+#ifndef        __SPI_BITBANG_H
+#define        __SPI_BITBANG_H
+
+#include <linux/workqueue.h>
+
+struct spi_bitbang {
+       spinlock_t              lock;
+       u8                      busy;
+       u8                      use_dma;
+       u8                      flags;          /* extra spi->mode support */
+
+       struct spi_master       *master;
+
+       /* setup_transfer() changes clock and/or wordsize to match settings
+        * for this transfer; zeroes restore defaults from spi_device.
+        */
+       int     (*setup_transfer)(struct spi_device *spi,
+                       struct spi_transfer *t);
+
+       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);
+};
+
+/* you can call these default bitbang->master methods from your custom
+ * methods, if you like.
+ */
+extern int spi_bitbang_setup(struct spi_device *spi);
+extern void spi_bitbang_cleanup(struct spi_device *spi);
+extern int spi_bitbang_setup_transfer(struct spi_device *spi,
+                                     struct spi_transfer *t);
+
+/* start or stop queue processing */
+extern int spi_bitbang_start(struct spi_bitbang *spi);
+extern void spi_bitbang_stop(struct spi_bitbang *spi);
+
+#endif /* __SPI_BITBANG_H */