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
20 struct regmap_async_spi {
21 struct regmap_async core;
22 struct spi_message m;
23 struct spi_transfer t[2];
24 };
25
regmap_spi_complete(void * data)26 static 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
regmap_spi_write(void * context,const void * data,size_t count)33 static 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
regmap_spi_gather_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len)41 static 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
regmap_spi_async_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len,struct regmap_async * a)58 static 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
regmap_spi_async_alloc(void)84 static 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
regmap_spi_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)95 static 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
105 static 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 */
regmap_init_spi(struct spi_device * spi,const struct regmap_config * config)123 struct regmap *regmap_init_spi(struct spi_device *spi,
124 const struct regmap_config *config)
125 {
126 return regmap_init(&spi->dev, ®map_spi, &spi->dev, config);
127 }
128 EXPORT_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 */
devm_regmap_init_spi(struct spi_device * spi,const struct regmap_config * config)140 struct regmap *devm_regmap_init_spi(struct spi_device *spi,
141 const struct regmap_config *config)
142 {
143 return devm_regmap_init(&spi->dev, ®map_spi, &spi->dev, config);
144 }
145 EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
146
147 MODULE_LICENSE("GPL");
148