Root/drivers/base/regmap/regmap-spi.c

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
18#include "internal.h"
19
20struct regmap_async_spi {
21    struct regmap_async core;
22    struct spi_message m;
23    struct spi_transfer t[2];
24};
25
26static void regmap_spi_complete(void *data)
27{
28    struct regmap_async_spi *async = data;
29
30    regmap_async_complete_cb(&async->core, async->m.status);
31}
32
33static int regmap_spi_write(void *context, const void *data, size_t count)
34{
35    struct device *dev = context;
36    struct spi_device *spi = to_spi_device(dev);
37
38    return spi_write(spi, data, count);
39}
40
41static int regmap_spi_gather_write(void *context,
42                   const void *reg, size_t reg_len,
43                   const void *val, size_t val_len)
44{
45    struct device *dev = context;
46    struct spi_device *spi = to_spi_device(dev);
47    struct spi_message m;
48    struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
49                     { .tx_buf = val, .len = val_len, }, };
50
51    spi_message_init(&m);
52    spi_message_add_tail(&t[0], &m);
53    spi_message_add_tail(&t[1], &m);
54
55    return spi_sync(spi, &m);
56}
57
58static int regmap_spi_async_write(void *context,
59                  const void *reg, size_t reg_len,
60                  const void *val, size_t val_len,
61                  struct regmap_async *a)
62{
63    struct regmap_async_spi *async = container_of(a,
64                              struct regmap_async_spi,
65                              core);
66    struct device *dev = context;
67    struct spi_device *spi = to_spi_device(dev);
68
69    async->t[0].tx_buf = reg;
70    async->t[0].len = reg_len;
71    async->t[1].tx_buf = val;
72    async->t[1].len = val_len;
73
74    spi_message_init(&async->m);
75    spi_message_add_tail(&async->t[0], &async->m);
76    spi_message_add_tail(&async->t[1], &async->m);
77
78    async->m.complete = regmap_spi_complete;
79    async->m.context = async;
80
81    return spi_async(spi, &async->m);
82}
83
84static struct regmap_async *regmap_spi_async_alloc(void)
85{
86    struct regmap_async_spi *async_spi;
87
88    async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
89    if (!async_spi)
90        return NULL;
91
92    return &async_spi->core;
93}
94
95static int regmap_spi_read(void *context,
96               const void *reg, size_t reg_size,
97               void *val, size_t val_size)
98{
99    struct device *dev = context;
100    struct spi_device *spi = to_spi_device(dev);
101
102    return spi_write_then_read(spi, reg, reg_size, val, val_size);
103}
104
105static struct regmap_bus regmap_spi = {
106    .write = regmap_spi_write,
107    .gather_write = regmap_spi_gather_write,
108    .async_write = regmap_spi_async_write,
109    .async_alloc = regmap_spi_async_alloc,
110    .read = regmap_spi_read,
111    .read_flag_mask = 0x80,
112};
113
114/**
115 * regmap_init_spi(): Initialise register map
116 *
117 * @spi: Device that will be interacted with
118 * @config: Configuration for register map
119 *
120 * The return value will be an ERR_PTR() on error or a valid pointer to
121 * a struct regmap.
122 */
123struct regmap *regmap_init_spi(struct spi_device *spi,
124                   const struct regmap_config *config)
125{
126    return regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
127}
128EXPORT_SYMBOL_GPL(regmap_init_spi);
129
130/**
131 * devm_regmap_init_spi(): Initialise register map
132 *
133 * @spi: Device that will be interacted with
134 * @config: Configuration for register map
135 *
136 * The return value will be an ERR_PTR() on error or a valid pointer
137 * to a struct regmap. The map will be automatically freed by the
138 * device management code.
139 */
140struct regmap *devm_regmap_init_spi(struct spi_device *spi,
141                    const struct regmap_config *config)
142{
143    return devm_regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
144}
145EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
146
147MODULE_LICENSE("GPL");
148

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