1// SPDX-License-Identifier: GPL-2.0
2
3#include <linux/errno.h>
4#include <linux/mdio.h>
5#include <linux/module.h>
6#include <linux/regmap.h>
7
8#define REGVAL_MASK		GENMASK(15, 0)
9#define REGNUM_C22_MASK		GENMASK(4, 0)
10/* Clause-45 mask includes the device type (5 bit) and actual register number (16 bit) */
11#define REGNUM_C45_MASK		GENMASK(20, 0)
12
13static int regmap_mdio_c22_read(void *context, unsigned int reg, unsigned int *val)
14{
15	struct mdio_device *mdio_dev = context;
16	int ret;
17
18	if (unlikely(reg & ~REGNUM_C22_MASK))
19		return -ENXIO;
20
21	ret = mdiodev_read(mdio_dev, reg);
22	if (ret < 0)
23		return ret;
24
25	*val = ret & REGVAL_MASK;
26
27	return 0;
28}
29
30static int regmap_mdio_c22_write(void *context, unsigned int reg, unsigned int val)
31{
32	struct mdio_device *mdio_dev = context;
33
34	if (unlikely(reg & ~REGNUM_C22_MASK))
35		return -ENXIO;
36
37	return mdiodev_write(mdio_dev, reg, val);
38}
39
40static const struct regmap_bus regmap_mdio_c22_bus = {
41	.reg_write = regmap_mdio_c22_write,
42	.reg_read = regmap_mdio_c22_read,
43};
44
45static int regmap_mdio_c45_read(void *context, unsigned int reg, unsigned int *val)
46{
47	struct mdio_device *mdio_dev = context;
48	unsigned int devad;
49	int ret;
50
51	if (unlikely(reg & ~REGNUM_C45_MASK))
52		return -ENXIO;
53
54	devad = reg >> REGMAP_MDIO_C45_DEVAD_SHIFT;
55	reg = reg & REGMAP_MDIO_C45_REGNUM_MASK;
56
57	ret = mdiodev_c45_read(mdio_dev, devad, reg);
58	if (ret < 0)
59		return ret;
60
61	*val = ret & REGVAL_MASK;
62
63	return 0;
64}
65
66static int regmap_mdio_c45_write(void *context, unsigned int reg, unsigned int val)
67{
68	struct mdio_device *mdio_dev = context;
69	unsigned int devad;
70
71	if (unlikely(reg & ~REGNUM_C45_MASK))
72		return -ENXIO;
73
74	devad = reg >> REGMAP_MDIO_C45_DEVAD_SHIFT;
75	reg = reg & REGMAP_MDIO_C45_REGNUM_MASK;
76
77	return mdiodev_c45_write(mdio_dev, devad, reg, val);
78}
79
80static const struct regmap_bus regmap_mdio_c45_bus = {
81	.reg_write = regmap_mdio_c45_write,
82	.reg_read = regmap_mdio_c45_read,
83};
84
85struct regmap *__regmap_init_mdio(struct mdio_device *mdio_dev,
86	const struct regmap_config *config, struct lock_class_key *lock_key,
87	const char *lock_name)
88{
89	const struct regmap_bus *bus;
90
91	if (config->reg_bits == 5 && config->val_bits == 16)
92		bus = &regmap_mdio_c22_bus;
93	else if (config->reg_bits == 21 && config->val_bits == 16)
94		bus = &regmap_mdio_c45_bus;
95	else
96		return ERR_PTR(-EOPNOTSUPP);
97
98	return __regmap_init(&mdio_dev->dev, bus, mdio_dev, config, lock_key, lock_name);
99}
100EXPORT_SYMBOL_GPL(__regmap_init_mdio);
101
102struct regmap *__devm_regmap_init_mdio(struct mdio_device *mdio_dev,
103	const struct regmap_config *config, struct lock_class_key *lock_key,
104	const char *lock_name)
105{
106	const struct regmap_bus *bus;
107
108	if (config->reg_bits == 5 && config->val_bits == 16)
109		bus = &regmap_mdio_c22_bus;
110	else if (config->reg_bits == 21 && config->val_bits == 16)
111		bus = &regmap_mdio_c45_bus;
112	else
113		return ERR_PTR(-EOPNOTSUPP);
114
115	return __devm_regmap_init(&mdio_dev->dev, bus, mdio_dev, config, lock_key, lock_name);
116}
117EXPORT_SYMBOL_GPL(__devm_regmap_init_mdio);
118
119MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
120MODULE_DESCRIPTION("Regmap MDIO Module");
121MODULE_LICENSE("GPL v2");
122