xref: /openbmc/linux/drivers/base/regmap/regmap-sdw.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0
2 // Copyright(c) 2015-17 Intel Corporation.
3 
4 #include <linux/device.h>
5 #include <linux/mod_devicetable.h>
6 #include <linux/module.h>
7 #include <linux/soundwire/sdw.h>
8 #include "internal.h"
9 
10 static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val)
11 {
12 	struct device *dev = context;
13 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
14 
15 	return sdw_write(slave, reg, val);
16 }
17 
18 static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
19 {
20 	struct device *dev = context;
21 	struct sdw_slave *slave = dev_to_sdw_dev(dev);
22 	int read;
23 
24 	read = sdw_read(slave, reg);
25 	if (read < 0)
26 		return read;
27 
28 	*val = read;
29 	return 0;
30 }
31 
32 static struct regmap_bus regmap_sdw = {
33 	.reg_read = regmap_sdw_read,
34 	.reg_write = regmap_sdw_write,
35 	.reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
36 	.val_format_endian_default = REGMAP_ENDIAN_LITTLE,
37 };
38 
39 static int regmap_sdw_config_check(const struct regmap_config *config)
40 {
41 	/* All register are 8-bits wide as per MIPI Soundwire 1.0 Spec */
42 	if (config->val_bits != 8)
43 		return -ENOTSUPP;
44 
45 	/* Registers are 32 bits wide */
46 	if (config->reg_bits != 32)
47 		return -ENOTSUPP;
48 
49 	if (config->pad_bits != 0)
50 		return -ENOTSUPP;
51 
52 	return 0;
53 }
54 
55 struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
56 				 const struct regmap_config *config,
57 				 struct lock_class_key *lock_key,
58 				 const char *lock_name)
59 {
60 	int ret;
61 
62 	ret = regmap_sdw_config_check(config);
63 	if (ret)
64 		return ERR_PTR(ret);
65 
66 	return __regmap_init(&sdw->dev, &regmap_sdw,
67 			&sdw->dev, config, lock_key, lock_name);
68 }
69 EXPORT_SYMBOL_GPL(__regmap_init_sdw);
70 
71 struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
72 				      const struct regmap_config *config,
73 				      struct lock_class_key *lock_key,
74 				      const char *lock_name)
75 {
76 	int ret;
77 
78 	ret = regmap_sdw_config_check(config);
79 	if (ret)
80 		return ERR_PTR(ret);
81 
82 	return __devm_regmap_init(&sdw->dev, &regmap_sdw,
83 			&sdw->dev, config, lock_key, lock_name);
84 }
85 EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw);
86 
87 MODULE_DESCRIPTION("Regmap SoundWire Module");
88 MODULE_LICENSE("GPL v2");
89