1 #ifndef __SPI_BITBANG_H 2 #define __SPI_BITBANG_H 3 4 #include <linux/workqueue.h> 5 6 struct spi_bitbang { 7 struct workqueue_struct *workqueue; 8 struct work_struct work; 9 10 spinlock_t lock; 11 struct list_head queue; 12 u8 busy; 13 u8 use_dma; 14 u8 flags; /* extra spi->mode support */ 15 16 struct spi_master *master; 17 18 /* setup_transfer() changes clock and/or wordsize to match settings 19 * for this transfer; zeroes restore defaults from spi_device. 20 */ 21 int (*setup_transfer)(struct spi_device *spi, 22 struct spi_transfer *t); 23 24 void (*chipselect)(struct spi_device *spi, int is_on); 25 #define BITBANG_CS_ACTIVE 1 /* normally nCS, active low */ 26 #define BITBANG_CS_INACTIVE 0 27 28 /* txrx_bufs() may handle dma mapping for transfers that don't 29 * already have one (transfer.{tx,rx}_dma is zero), or use PIO 30 */ 31 int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t); 32 33 /* txrx_word[SPI_MODE_*]() just looks like a shift register */ 34 u32 (*txrx_word[4])(struct spi_device *spi, 35 unsigned nsecs, 36 u32 word, u8 bits); 37 }; 38 39 /* you can call these default bitbang->master methods from your custom 40 * methods, if you like. 41 */ 42 extern int spi_bitbang_setup(struct spi_device *spi); 43 extern void spi_bitbang_cleanup(struct spi_device *spi); 44 extern int spi_bitbang_transfer(struct spi_device *spi, struct spi_message *m); 45 extern int spi_bitbang_setup_transfer(struct spi_device *spi, 46 struct spi_transfer *t); 47 48 /* start or stop queue processing */ 49 extern int spi_bitbang_start(struct spi_bitbang *spi); 50 extern int spi_bitbang_stop(struct spi_bitbang *spi); 51 52 #endif /* __SPI_BITBANG_H */ 53