linux_dsm_epyc7002/include/linux/spi/spi_bitbang.h
Andrey Smirnov 45beec3519
spi: bitbang: Introduce spi_bitbang_init()
Move all of the code doing struct spi_bitbang initialization, so that
it can be paired with devm_spi_register_master() in order to avoid
having to call spi_bitbang_stop() explicitly.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Chris Healy <cphealy@gmail.com>
Cc: linux-spi@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-04-08 14:10:39 +07:00

51 lines
1.6 KiB
C

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