tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Register map access API - SPI support
3 *
4 * Copyright 2011 Wolfson Microelectronics plc
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/regmap.h>
14#include <linux/spi/spi.h>
15#include <linux/init.h>
16#include <linux/module.h>
17
18static int regmap_spi_write(struct device *dev, const void *data, size_t count)
19{
20 struct spi_device *spi = to_spi_device(dev);
21
22 return spi_write(spi, data, count);
23}
24
25static int regmap_spi_gather_write(struct device *dev,
26 const void *reg, size_t reg_len,
27 const void *val, size_t val_len)
28{
29 struct spi_device *spi = to_spi_device(dev);
30 struct spi_message m;
31 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
32 { .tx_buf = val, .len = val_len, }, };
33
34 spi_message_init(&m);
35 spi_message_add_tail(&t[0], &m);
36 spi_message_add_tail(&t[1], &m);
37
38 return spi_sync(spi, &m);
39}
40
41static int regmap_spi_read(struct device *dev,
42 const void *reg, size_t reg_size,
43 void *val, size_t val_size)
44{
45 struct spi_device *spi = to_spi_device(dev);
46
47 return spi_write_then_read(spi, reg, reg_size, val, val_size);
48}
49
50static struct regmap_bus regmap_spi = {
51 .write = regmap_spi_write,
52 .gather_write = regmap_spi_gather_write,
53 .read = regmap_spi_read,
54 .read_flag_mask = 0x80,
55};
56
57/**
58 * regmap_init_spi(): Initialise register map
59 *
60 * @spi: Device that will be interacted with
61 * @config: Configuration for register map
62 *
63 * The return value will be an ERR_PTR() on error or a valid pointer to
64 * a struct regmap.
65 */
66struct regmap *regmap_init_spi(struct spi_device *spi,
67 const struct regmap_config *config)
68{
69 return regmap_init(&spi->dev, ®map_spi, config);
70}
71EXPORT_SYMBOL_GPL(regmap_init_spi);
72
73MODULE_LICENSE("GPL");