1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __SPI_BITBANG_H |
3 | #define __SPI_BITBANG_H |
4 | |
5 | #include <linux/workqueue.h> |
6 | |
7 | struct spi_bitbang { |
8 | struct mutex lock; |
9 | u8 busy; |
10 | u8 use_dma; |
11 | u16 flags; /* extra spi->mode support */ |
12 | |
13 | struct spi_master *master; |
14 | |
15 | /* setup_transfer() changes clock and/or wordsize to match settings |
16 | * for this transfer; zeroes restore defaults from spi_device. |
17 | */ |
18 | int (*setup_transfer)(struct spi_device *spi, |
19 | struct spi_transfer *t); |
20 | |
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 |
24 | |
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 |
27 | */ |
28 | int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t); |
29 | |
30 | /* txrx_word[SPI_MODE_*]() just looks like a shift register */ |
31 | u32 (*txrx_word[4])(struct spi_device *spi, |
32 | unsigned nsecs, |
33 | u32 word, u8 bits, unsigned flags); |
34 | int (*set_line_direction)(struct spi_device *spi, bool output); |
35 | }; |
36 | |
37 | /* you can call these default bitbang->master methods from your custom |
38 | * methods, if you like. |
39 | */ |
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); |
44 | |
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); |
49 | |
50 | #endif /* __SPI_BITBANG_H */ |
51 | |