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 <broonie@opensource.wolfsonmicro.com>
8
9 #include <linux/regmap.h>
10 #include <linux/spi/spi.h>
11 #include <linux/module.h>
12
13 #include "internal.h"
14
15 struct regmap_async_spi {
16 struct regmap_async core;
17 struct spi_message m;
18 struct spi_transfer t[2];
19 };
20
regmap_spi_complete(void * data)21 static 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
regmap_spi_write(void * context,const void * data,size_t count)28 static 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
regmap_spi_gather_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len)36 static 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
regmap_spi_async_write(void * context,const void * reg,size_t reg_len,const void * val,size_t val_len,struct regmap_async * a)53 static 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
regmap_spi_async_alloc(void)80 static struct regmap_async *regmap_spi_async_alloc(void)
81 {
82 struct regmap_async_spi *async_spi;
83
84 async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
85 if (!async_spi)
86 return NULL;
87
88 return &async_spi->core;
89 }
90
regmap_spi_read(void * context,const void * reg,size_t reg_size,void * val,size_t val_size)91 static 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
101 static 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
regmap_get_spi_bus(struct spi_device * spi,const struct regmap_config * config)112 static 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(®map_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 / BITS_PER_BYTE
126 + config->pad_bits / BITS_PER_BYTE;
127 if (max_size + reg_reserve_size > max_msg_size)
128 max_size -= reg_reserve_size;
129
130 bus->free_on_exit = true;
131 bus->max_raw_read = max_size;
132 bus->max_raw_write = max_size;
133
134 return bus;
135 }
136
137 return ®map_spi;
138 }
139
__regmap_init_spi(struct spi_device * spi,const struct regmap_config * config,struct lock_class_key * lock_key,const char * lock_name)140 struct regmap *__regmap_init_spi(struct spi_device *spi,
141 const struct regmap_config *config,
142 struct lock_class_key *lock_key,
143 const char *lock_name)
144 {
145 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
146
147 if (IS_ERR(bus))
148 return ERR_CAST(bus);
149
150 return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
151 }
152 EXPORT_SYMBOL_GPL(__regmap_init_spi);
153
__devm_regmap_init_spi(struct spi_device * spi,const struct regmap_config * config,struct lock_class_key * lock_key,const char * lock_name)154 struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
155 const struct regmap_config *config,
156 struct lock_class_key *lock_key,
157 const char *lock_name)
158 {
159 const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
160
161 if (IS_ERR(bus))
162 return ERR_CAST(bus);
163
164 return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
165 }
166 EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
167
168 MODULE_DESCRIPTION("regmap SPI Module");
169 MODULE_LICENSE("GPL");
170