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1// SPDX-License-Identifier: GPL-2.0
2//
3// Register map access API - SPI support
4//
5// Copyright 2011 Wolfson Microelectronics plc
6//
7// Author: Mark Brown <[email protected]>
8
9#include <linux/regmap.h>
10#include <linux/spi/spi.h>
11#include <linux/module.h>
12
13#include "internal.h"
14
15struct regmap_async_spi {
16 struct regmap_async core;
17 struct spi_message m;
18 struct spi_transfer t[2];
19};
20
21static void regmap_spi_complete(void *data)
22{
23 struct regmap_async_spi *async = data;
24
25 regmap_async_complete_cb(&async->core, async->m.status);
26}
27
28static int regmap_spi_write(void *context, const void *data, size_t count)
29{
30 struct device *dev = context;
31 struct spi_device *spi = to_spi_device(dev);
32
33 return spi_write(spi, data, count);
34}
35
36static int regmap_spi_gather_write(void *context,
37 const void *reg, size_t reg_len,
38 const void *val, size_t val_len)
39{
40 struct device *dev = context;
41 struct spi_device *spi = to_spi_device(dev);
42 struct spi_message m;
43 struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
44 { .tx_buf = val, .len = val_len, }, };
45
46 spi_message_init(&m);
47 spi_message_add_tail(&t[0], &m);
48 spi_message_add_tail(&t[1], &m);
49
50 return spi_sync(spi, &m);
51}
52
53static int regmap_spi_async_write(void *context,
54 const void *reg, size_t reg_len,
55 const void *val, size_t val_len,
56 struct regmap_async *a)
57{
58 struct regmap_async_spi *async = container_of(a,
59 struct regmap_async_spi,
60 core);
61 struct device *dev = context;
62 struct spi_device *spi = to_spi_device(dev);
63
64 async->t[0].tx_buf = reg;
65 async->t[0].len = reg_len;
66 async->t[1].tx_buf = val;
67 async->t[1].len = val_len;
68
69 spi_message_init(&async->m);
70 spi_message_add_tail(&async->t[0], &async->m);
71 if (val)
72 spi_message_add_tail(&async->t[1], &async->m);
73
74 async->m.complete = regmap_spi_complete;
75 async->m.context = async;
76
77 return spi_async(spi, &async->m);
78}
79
80static struct regmap_async *regmap_spi_async_alloc(void)
81{
82 struct regmap_async_spi *async_spi;
83
84 async_spi = kzalloc_obj(*async_spi);
85 if (!async_spi)
86 return NULL;
87
88 return &async_spi->core;
89}
90
91static int regmap_spi_read(void *context,
92 const void *reg, size_t reg_size,
93 void *val, size_t val_size)
94{
95 struct device *dev = context;
96 struct spi_device *spi = to_spi_device(dev);
97
98 return spi_write_then_read(spi, reg, reg_size, val, val_size);
99}
100
101static const struct regmap_bus regmap_spi = {
102 .write = regmap_spi_write,
103 .gather_write = regmap_spi_gather_write,
104 .async_write = regmap_spi_async_write,
105 .async_alloc = regmap_spi_async_alloc,
106 .read = regmap_spi_read,
107 .read_flag_mask = 0x80,
108 .reg_format_endian_default = REGMAP_ENDIAN_BIG,
109 .val_format_endian_default = REGMAP_ENDIAN_BIG,
110};
111
112static const struct regmap_bus *regmap_get_spi_bus(struct spi_device *spi,
113 const struct regmap_config *config)
114{
115 size_t max_size = spi_max_transfer_size(spi);
116 size_t max_msg_size, reg_reserve_size;
117 struct regmap_bus *bus;
118
119 if (max_size != SIZE_MAX) {
120 bus = kmemdup(&regmap_spi, sizeof(*bus), GFP_KERNEL);
121 if (!bus)
122 return ERR_PTR(-ENOMEM);
123
124 max_msg_size = spi_max_message_size(spi);
125 reg_reserve_size = (config->reg_bits + config->pad_bits) / BITS_PER_BYTE;
126 if (max_size + reg_reserve_size > max_msg_size)
127 max_size -= reg_reserve_size;
128
129 bus->free_on_exit = true;
130 bus->max_raw_read = max_size;
131 bus->max_raw_write = max_size;
132
133 return bus;
134 }
135
136 return &regmap_spi;
137}
138
139struct regmap *__regmap_init_spi(struct spi_device *spi,
140 const struct regmap_config *config,
141 struct lock_class_key *lock_key,
142 const char *lock_name)
143{
144 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
145
146 if (IS_ERR(bus))
147 return ERR_CAST(bus);
148
149 return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
150}
151EXPORT_SYMBOL_GPL(__regmap_init_spi);
152
153struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
154 const struct regmap_config *config,
155 struct lock_class_key *lock_key,
156 const char *lock_name)
157{
158 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
159
160 if (IS_ERR(bus))
161 return ERR_CAST(bus);
162
163 return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
164}
165EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
166
167MODULE_DESCRIPTION("regmap SPI Module");
168MODULE_LICENSE("GPL");