alistair23-linux/include/linux/spi/spi_bitbang.h
Mark Brown 2025172e32 spi/bitbang: Use core message pump
Convert drivers using bitbang to use the core mesasge pump infrastructure,
saving some code and meaning that these drivers get to take advantage of
work done on improving the core implementation.

Signed-off-by: Mark Brown <broonie@linaro.org>
2013-07-17 18:13:01 +01:00

48 lines
1.4 KiB
C

#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 int spi_bitbang_stop(struct spi_bitbang *spi);
#endif /* __SPI_BITBANG_H */