1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __SPI_BITBANG_H
3 #define __SPI_BITBANG_H
5 #include <linux/workqueue.h>
11 u16 flags; /* extra spi->mode support */
13 struct spi_master *master;
15 /* setup_transfer() changes clock and/or wordsize to match settings
16 * for this transfer; zeroes restore defaults from spi_device.
18 int (*setup_transfer)(struct spi_device *spi,
19 struct spi_transfer *t);
21 void (*chipselect)(struct spi_device *spi, int is_on);
22 #define BITBANG_CS_ACTIVE 1 /* normally nCS, active low */
23 #define BITBANG_CS_INACTIVE 0
25 /* txrx_bufs() may handle dma mapping for transfers that don't
26 * already have one (transfer.{tx,rx}_dma is zero), or use PIO
28 int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
30 /* txrx_word[SPI_MODE_*]() just looks like a shift register */
31 u32 (*txrx_word[4])(struct spi_device *spi,
33 u32 word, u8 bits, unsigned flags);
34 int (*set_line_direction)(struct spi_device *spi, bool output);
37 /* you can call these default bitbang->master methods from your custom
38 * methods, if you like.
40 extern int spi_bitbang_setup(struct spi_device *spi);
41 extern void spi_bitbang_cleanup(struct spi_device *spi);
42 extern int spi_bitbang_setup_transfer(struct spi_device *spi,
43 struct spi_transfer *t);
45 /* start or stop queue processing */
46 extern int spi_bitbang_start(struct spi_bitbang *spi);
47 extern int spi_bitbang_init(struct spi_bitbang *spi);
48 extern void spi_bitbang_stop(struct spi_bitbang *spi);
50 #endif /* __SPI_BITBANG_H */