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/module.h>
16
17#include "internal.h"
18
19struct regmap_async_spi {
20	struct regmap_async core;
21	struct spi_message m;
22	struct spi_transfer t[2];
23};
24
25static void regmap_spi_complete(void *data)
26{
27	struct regmap_async_spi *async = data;
28
29	regmap_async_complete_cb(&async->core, async->m.status);
30}
31
32static int regmap_spi_write(void *context, const void *data, size_t count)
33{
34	struct device *dev = context;
35	struct spi_device *spi = to_spi_device(dev);
36
37	return spi_write(spi, data, count);
38}
39
40static int regmap_spi_gather_write(void *context,
41				   const void *reg, size_t reg_len,
42				   const void *val, size_t val_len)
43{
44	struct device *dev = context;
45	struct spi_device *spi = to_spi_device(dev);
46	struct spi_message m;
47	struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
48				     { .tx_buf = val, .len = val_len, }, };
49
50	spi_message_init(&m);
51	spi_message_add_tail(&t[0], &m);
52	spi_message_add_tail(&t[1], &m);
53
54	return spi_sync(spi, &m);
55}
56
57static int regmap_spi_async_write(void *context,
58				  const void *reg, size_t reg_len,
59				  const void *val, size_t val_len,
60				  struct regmap_async *a)
61{
62	struct regmap_async_spi *async = container_of(a,
63						      struct regmap_async_spi,
64						      core);
65	struct device *dev = context;
66	struct spi_device *spi = to_spi_device(dev);
67
68	async->t[0].tx_buf = reg;
69	async->t[0].len = reg_len;
70	async->t[1].tx_buf = val;
71	async->t[1].len = val_len;
72
73	spi_message_init(&async->m);
74	spi_message_add_tail(&async->t[0], &async->m);
75	if (val)
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	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
113	.val_format_endian_default = REGMAP_ENDIAN_BIG,
114};
115
116/**
117 * regmap_init_spi(): Initialise register map
118 *
119 * @spi: Device that will be interacted with
120 * @config: Configuration for register map
121 *
122 * The return value will be an ERR_PTR() on error or a valid pointer to
123 * a struct regmap.
124 */
125struct regmap *regmap_init_spi(struct spi_device *spi,
126			       const struct regmap_config *config)
127{
128	return regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
129}
130EXPORT_SYMBOL_GPL(regmap_init_spi);
131
132/**
133 * devm_regmap_init_spi(): Initialise register map
134 *
135 * @spi: Device that will be interacted with
136 * @config: Configuration for register map
137 *
138 * The return value will be an ERR_PTR() on error or a valid pointer
139 * to a struct regmap.  The map will be automatically freed by the
140 * device management code.
141 */
142struct regmap *devm_regmap_init_spi(struct spi_device *spi,
143				    const struct regmap_config *config)
144{
145	return devm_regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
146}
147EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
148
149MODULE_LICENSE("GPL");
150