1#ifndef	__SPI_BITBANG_H
2#define	__SPI_BITBANG_H
3
4#include <linux/workqueue.h>
5
6struct spi_bitbang {
7	struct mutex		lock;
8	u8			busy;
9	u8			use_dma;
10	u8			flags;		/* extra spi->mode support */
11
12	struct spi_master	*master;
13
14	/* setup_transfer() changes clock and/or wordsize to match settings
15	 * for this transfer; zeroes restore defaults from spi_device.
16	 */
17	int	(*setup_transfer)(struct spi_device *spi,
18			struct spi_transfer *t);
19
20	void	(*chipselect)(struct spi_device *spi, int is_on);
21#define	BITBANG_CS_ACTIVE	1	/* normally nCS, active low */
22#define	BITBANG_CS_INACTIVE	0
23
24	/* txrx_bufs() may handle dma mapping for transfers that don't
25	 * already have one (transfer.{tx,rx}_dma is zero), or use PIO
26	 */
27	int	(*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
28
29	/* txrx_word[SPI_MODE_*]() just looks like a shift register */
30	u32	(*txrx_word[4])(struct spi_device *spi,
31			unsigned nsecs,
32			u32 word, u8 bits);
33};
34
35/* you can call these default bitbang->master methods from your custom
36 * methods, if you like.
37 */
38extern int spi_bitbang_setup(struct spi_device *spi);
39extern void spi_bitbang_cleanup(struct spi_device *spi);
40extern int spi_bitbang_setup_transfer(struct spi_device *spi,
41				      struct spi_transfer *t);
42
43/* start or stop queue processing */
44extern int spi_bitbang_start(struct spi_bitbang *spi);
45extern void spi_bitbang_stop(struct spi_bitbang *spi);
46
47#endif	/* __SPI_BITBANG_H */
48