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 	struct regmap_bus *bus;
117 
118 	if (max_size != SIZE_MAX) {
119 		bus = kmemdup(&regmap_spi, sizeof(*bus), GFP_KERNEL);
120 		if (!bus)
121 			return ERR_PTR(-ENOMEM);
122 
123 		bus->free_on_exit = true;
124 		bus->max_raw_read = max_size;
125 		bus->max_raw_write = max_size;
126 		return bus;
127 	}
128 
129 	return &regmap_spi;
130 }
131 
__regmap_init_spi(struct spi_device * spi,const struct regmap_config * config,struct lock_class_key * lock_key,const char * lock_name)132 struct regmap *__regmap_init_spi(struct spi_device *spi,
133 				 const struct regmap_config *config,
134 				 struct lock_class_key *lock_key,
135 				 const char *lock_name)
136 {
137 	const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
138 
139 	if (IS_ERR(bus))
140 		return ERR_CAST(bus);
141 
142 	return __regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
143 }
144 EXPORT_SYMBOL_GPL(__regmap_init_spi);
145 
__devm_regmap_init_spi(struct spi_device * spi,const struct regmap_config * config,struct lock_class_key * lock_key,const char * lock_name)146 struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
147 				      const struct regmap_config *config,
148 				      struct lock_class_key *lock_key,
149 				      const char *lock_name)
150 {
151 	const struct regmap_bus *bus = regmap_get_spi_bus(spi, config);
152 
153 	if (IS_ERR(bus))
154 		return ERR_CAST(bus);
155 
156 	return __devm_regmap_init(&spi->dev, bus, &spi->dev, config, lock_key, lock_name);
157 }
158 EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
159 
160 MODULE_LICENSE("GPL");
161