Edit File: spi_bitbang.h
#ifndef __SPI_BITBANG_H #define __SPI_BITBANG_H #include <linux/workqueue.h> struct spi_bitbang { struct workqueue_struct *workqueue; struct work_struct work; spinlock_t lock; struct list_head queue; 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_transfer(struct spi_device *spi, struct spi_message *m); 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 */