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