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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __SPI_BITBANG_H
#define __SPI_BITBANG_H
#include <linux/workqueue.h>
struct spi_bitbang {
struct mutex lock;
u8 busy;
u8 use_dma;
u16 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, unsigned flags);
int (*set_line_direction)(struct spi_device *spi, bool output);
};
/* 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 */
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