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
19 struct regmap_async_spi {
20 struct regmap_async core;
21 struct spi_message m;
22 struct spi_transfer t[2];
23 };
24
regmap_spi_complete(void * data)25 static 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
regmap_spi_write(void * context,const void * data,size_t count)32 static 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
regmap_spi_gather_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len)40 static 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
regmap_spi_async_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len,struct regmap_async * a)57 static 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
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 .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 */
regmap_init_spi(struct spi_device * spi,const struct regmap_config * config)125 struct regmap *regmap_init_spi(struct spi_device *spi,
126 const struct regmap_config *config)
127 {
128 return regmap_init(&spi->dev, ®map_spi, &spi->dev, config);
129 }
130 EXPORT_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 */
devm_regmap_init_spi(struct spi_device * spi,const struct regmap_config * config)142 struct regmap *devm_regmap_init_spi(struct spi_device *spi,
143 const struct regmap_config *config)
144 {
145 return devm_regmap_init(&spi->dev, ®map_spi, &spi->dev, config);
146 }
147 EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
148
149 MODULE_LICENSE("GPL");
150