1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (c) 2019 five technologies GmbH
4 // Author: Markus Reichl <m.reichl@fivetechno.de>
5 
6 #include <linux/module.h>
7 #include <linux/i2c.h>
8 #include <linux/of.h>
9 #include <linux/regulator/driver.h>
10 #include <linux/regmap.h>
11 
12 
13 #define VOL_MIN_IDX			0x00
14 #define VOL_MAX_IDX			0x7ff
15 
16 /* Register definitions */
17 #define MP8859_VOUT_L_REG		0    //3 lo Bits
18 #define MP8859_VOUT_H_REG		1    //8 hi Bits
19 #define MP8859_VOUT_GO_REG		2
20 #define MP8859_IOUT_LIM_REG		3
21 #define MP8859_CTL1_REG			4
22 #define MP8859_CTL2_REG			5
23 #define MP8859_RESERVED1_REG		6
24 #define MP8859_RESERVED2_REG		7
25 #define MP8859_RESERVED3_REG		8
26 #define MP8859_STATUS_REG		9
27 #define MP8859_INTERRUPT_REG		0x0A
28 #define MP8859_MASK_REG			0x0B
29 #define MP8859_ID1_REG			0x0C
30 #define MP8859_MFR_ID_REG		0x27
31 #define MP8859_DEV_ID_REG		0x28
32 #define MP8859_IC_REV_REG		0x29
33 
34 #define MP8859_MAX_REG			0x29
35 
36 #define MP8859_GO_BIT			0x01
37 
38 
mp8859_set_voltage_sel(struct regulator_dev * rdev,unsigned int sel)39 static int mp8859_set_voltage_sel(struct regulator_dev *rdev, unsigned int sel)
40 {
41 	int ret;
42 
43 	ret = regmap_write(rdev->regmap, MP8859_VOUT_L_REG, sel & 0x7);
44 
45 	if (ret)
46 		return ret;
47 	ret = regmap_write(rdev->regmap, MP8859_VOUT_H_REG, sel >> 3);
48 
49 	if (ret)
50 		return ret;
51 	ret = regmap_update_bits(rdev->regmap, MP8859_VOUT_GO_REG,
52 					MP8859_GO_BIT, 1);
53 	return ret;
54 }
55 
mp8859_get_voltage_sel(struct regulator_dev * rdev)56 static int mp8859_get_voltage_sel(struct regulator_dev *rdev)
57 {
58 	unsigned int val_tmp;
59 	unsigned int val;
60 	int ret;
61 
62 	ret = regmap_read(rdev->regmap, MP8859_VOUT_H_REG, &val_tmp);
63 
64 	if (ret)
65 		return ret;
66 	val = val_tmp << 3;
67 
68 	ret = regmap_read(rdev->regmap, MP8859_VOUT_L_REG, &val_tmp);
69 
70 	if (ret)
71 		return ret;
72 	val |= val_tmp & 0x07;
73 	return val;
74 }
75 
76 static const struct linear_range mp8859_dcdc_ranges[] = {
77 	REGULATOR_LINEAR_RANGE(0, VOL_MIN_IDX, VOL_MAX_IDX, 10000),
78 };
79 
80 static const struct regmap_config mp8859_regmap = {
81 	.reg_bits = 8,
82 	.val_bits = 8,
83 	.max_register = MP8859_MAX_REG,
84 	.cache_type = REGCACHE_RBTREE,
85 };
86 
87 static const struct regulator_ops mp8859_ops = {
88 	.set_voltage_sel = mp8859_set_voltage_sel,
89 	.get_voltage_sel = mp8859_get_voltage_sel,
90 	.list_voltage = regulator_list_voltage_linear_range,
91 };
92 
93 static const struct regulator_desc mp8859_regulators[] = {
94 	{
95 		.id = 0,
96 		.type = REGULATOR_VOLTAGE,
97 		.name = "mp8859_dcdc",
98 		.supply_name = "vin",
99 		.of_match = of_match_ptr("mp8859_dcdc"),
100 		.n_voltages = VOL_MAX_IDX + 1,
101 		.linear_ranges = mp8859_dcdc_ranges,
102 		.n_linear_ranges = 1,
103 		.ops = &mp8859_ops,
104 		.owner = THIS_MODULE,
105 	},
106 };
107 
mp8859_i2c_probe(struct i2c_client * i2c)108 static int mp8859_i2c_probe(struct i2c_client *i2c)
109 {
110 	int ret;
111 	struct regulator_config config = {.dev = &i2c->dev};
112 	struct regmap *regmap = devm_regmap_init_i2c(i2c, &mp8859_regmap);
113 	struct regulator_dev *rdev;
114 
115 	if (IS_ERR(regmap)) {
116 		ret = PTR_ERR(regmap);
117 		dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
118 		return ret;
119 	}
120 	rdev = devm_regulator_register(&i2c->dev, &mp8859_regulators[0],
121 					&config);
122 
123 	if (IS_ERR(rdev)) {
124 		ret = PTR_ERR(rdev);
125 		dev_err(&i2c->dev, "failed to register %s: %d\n",
126 			mp8859_regulators[0].name, ret);
127 		return ret;
128 	}
129 	return 0;
130 }
131 
132 static const struct of_device_id mp8859_dt_id[] = {
133 	{.compatible =  "mps,mp8859"},
134 	{},
135 };
136 MODULE_DEVICE_TABLE(of, mp8859_dt_id);
137 
138 static const struct i2c_device_id mp8859_i2c_id[] = {
139 	{ "mp8859", },
140 	{  },
141 };
142 MODULE_DEVICE_TABLE(i2c, mp8859_i2c_id);
143 
144 static struct i2c_driver mp8859_regulator_driver = {
145 	.driver = {
146 		.name = "mp8859",
147 		.of_match_table = of_match_ptr(mp8859_dt_id),
148 	},
149 	.probe_new = mp8859_i2c_probe,
150 	.id_table = mp8859_i2c_id,
151 };
152 
153 module_i2c_driver(mp8859_regulator_driver);
154 
155 MODULE_DESCRIPTION("Monolithic Power Systems MP8859 voltage regulator driver");
156 MODULE_AUTHOR("Markus Reichl <m.reichl@fivetechno.de>");
157 MODULE_LICENSE("GPL v2");
158