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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * max1586.c -- Voltage and current regulation for the Maxim 1586
4 *
5 * Copyright (C) 2008 Robert Jarzmik
6 */
7#include <linux/module.h>
8#include <linux/err.h>
9#include <linux/i2c.h>
10#include <linux/platform_device.h>
11#include <linux/regulator/driver.h>
12#include <linux/slab.h>
13#include <linux/regulator/max1586.h>
14#include <linux/of.h>
15#include <linux/regulator/of_regulator.h>
16
17#define MAX1586_V3_MAX_VSEL 31
18#define MAX1586_V6_MAX_VSEL 3
19
20#define MAX1586_V3_MIN_UV 700000
21#define MAX1586_V3_MAX_UV 1475000
22
23#define MAX1586_V6_MIN_UV 0
24#define MAX1586_V6_MAX_UV 3000000
25
26#define I2C_V3_SELECT (0 << 5)
27#define I2C_V6_SELECT (1 << 5)
28
29struct max1586_data {
30 struct i2c_client *client;
31
32 /* min/max V3 voltage */
33 unsigned int min_uV;
34 unsigned int max_uV;
35
36 unsigned int v3_curr_sel;
37 unsigned int v6_curr_sel;
38};
39
40/*
41 * V6 voltage
42 * On I2C bus, sending a "x" byte to the max1586 means :
43 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
44 * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
45 */
46static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
47
48/*
49 * V3 voltage
50 * On I2C bus, sending a "x" byte to the max1586 means :
51 * set V3 to 0.700V + (x & 0x1f) * 0.025V
52 * This voltage can be increased by external resistors
53 * R24 and R25=100kOhm as described in the data sheet.
54 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
55 */
56static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
57{
58 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
59
60 return max1586->v3_curr_sel;
61}
62
63static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
64 unsigned selector)
65{
66 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
67 struct i2c_client *client = max1586->client;
68 int ret;
69 u8 v3_prog;
70
71 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
72 regulator_list_voltage_linear(rdev, selector) / 1000);
73
74 v3_prog = I2C_V3_SELECT | (u8) selector;
75 ret = i2c_smbus_write_byte(client, v3_prog);
76 if (ret)
77 return ret;
78
79 max1586->v3_curr_sel = selector;
80
81 return 0;
82}
83
84static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
85{
86 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
87
88 return max1586->v6_curr_sel;
89}
90
91static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
92 unsigned int selector)
93{
94 struct max1586_data *max1586 = rdev_get_drvdata(rdev);
95 struct i2c_client *client = max1586->client;
96 u8 v6_prog;
97 int ret;
98
99 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
100 rdev->desc->volt_table[selector] / 1000);
101
102 v6_prog = I2C_V6_SELECT | (u8) selector;
103 ret = i2c_smbus_write_byte(client, v6_prog);
104 if (ret)
105 return ret;
106
107 max1586->v6_curr_sel = selector;
108
109 return 0;
110}
111
112/*
113 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
114 * the set up value.
115 */
116static const struct regulator_ops max1586_v3_ops = {
117 .get_voltage_sel = max1586_v3_get_voltage_sel,
118 .set_voltage_sel = max1586_v3_set_voltage_sel,
119 .list_voltage = regulator_list_voltage_linear,
120 .map_voltage = regulator_map_voltage_linear,
121};
122
123static const struct regulator_ops max1586_v6_ops = {
124 .get_voltage_sel = max1586_v6_get_voltage_sel,
125 .set_voltage_sel = max1586_v6_set_voltage_sel,
126 .list_voltage = regulator_list_voltage_table,
127};
128
129static struct regulator_desc max1586_reg[] = {
130 {
131 .name = "Output_V3",
132 .id = MAX1586_V3,
133 .ops = &max1586_v3_ops,
134 .type = REGULATOR_VOLTAGE,
135 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
136 .owner = THIS_MODULE,
137 },
138 {
139 .name = "Output_V6",
140 .id = MAX1586_V6,
141 .ops = &max1586_v6_ops,
142 .type = REGULATOR_VOLTAGE,
143 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
144 .volt_table = v6_voltages_uv,
145 .owner = THIS_MODULE,
146 },
147};
148
149static int of_get_max1586_platform_data(struct device *dev,
150 struct max1586_platform_data *pdata)
151{
152 struct max1586_subdev_data *sub;
153 struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
154 struct device_node *np = dev->of_node;
155 int i, matched;
156
157 if (of_property_read_u32(np, "v3-gain",
158 &pdata->v3_gain) < 0) {
159 dev_err(dev, "%pOF has no 'v3-gain' property\n", np);
160 return -EINVAL;
161 }
162
163 np = of_get_child_by_name(np, "regulators");
164 if (!np) {
165 dev_err(dev, "missing 'regulators' subnode in DT\n");
166 return -EINVAL;
167 }
168
169 for (i = 0; i < ARRAY_SIZE(rmatch); i++)
170 rmatch[i].name = max1586_reg[i].name;
171
172 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
173 of_node_put(np);
174 /*
175 * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
176 * return 0, which signals the normal situation where no subregulator is
177 * available. This is normal because the max1586 doesn't provide any
178 * readback support, so the subregulators can't report any status
179 * anyway. If matched < 0, return the error.
180 */
181 if (matched <= 0)
182 return matched;
183
184 pdata->subdevs = devm_kcalloc(dev,
185 matched,
186 sizeof(struct max1586_subdev_data),
187 GFP_KERNEL);
188 if (!pdata->subdevs)
189 return -ENOMEM;
190
191 pdata->num_subdevs = matched;
192 sub = pdata->subdevs;
193
194 for (i = 0; i < matched; i++) {
195 sub->id = i;
196 sub->name = rmatch[i].of_node->name;
197 sub->platform_data = rmatch[i].init_data;
198 sub++;
199 }
200
201 return 0;
202}
203
204static const struct of_device_id __maybe_unused max1586_of_match[] = {
205 { .compatible = "maxim,max1586", },
206 {},
207};
208MODULE_DEVICE_TABLE(of, max1586_of_match);
209
210static int max1586_pmic_probe(struct i2c_client *client)
211{
212 struct max1586_platform_data *pdata, pdata_of;
213 struct regulator_config config = { };
214 struct max1586_data *max1586;
215 int i, id, ret;
216
217 pdata = dev_get_platdata(&client->dev);
218 if (client->dev.of_node && !pdata) {
219 ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
220 if (ret < 0)
221 return ret;
222 pdata = &pdata_of;
223 }
224
225 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
226 GFP_KERNEL);
227 if (!max1586)
228 return -ENOMEM;
229
230 max1586->client = client;
231
232 if (!pdata->v3_gain)
233 return -EINVAL;
234
235 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
236 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
237
238 /* Set curr_sel to default voltage on power-up */
239 max1586->v3_curr_sel = 24; /* 1.3V */
240 max1586->v6_curr_sel = 0;
241
242 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
243 struct regulator_dev *rdev;
244
245 id = pdata->subdevs[i].id;
246 if (!pdata->subdevs[i].platform_data)
247 continue;
248 if (id < MAX1586_V3 || id > MAX1586_V6) {
249 dev_err(&client->dev, "invalid regulator id %d\n", id);
250 return -EINVAL;
251 }
252
253 if (id == MAX1586_V3) {
254 max1586_reg[id].min_uV = max1586->min_uV;
255 max1586_reg[id].uV_step =
256 (max1586->max_uV - max1586->min_uV) /
257 MAX1586_V3_MAX_VSEL;
258 }
259
260 config.dev = &client->dev;
261 config.init_data = pdata->subdevs[i].platform_data;
262 config.driver_data = max1586;
263
264 rdev = devm_regulator_register(&client->dev,
265 &max1586_reg[id], &config);
266 if (IS_ERR(rdev)) {
267 dev_err(&client->dev, "failed to register %s\n",
268 max1586_reg[id].name);
269 return PTR_ERR(rdev);
270 }
271 }
272
273 i2c_set_clientdata(client, max1586);
274 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
275 return 0;
276}
277
278static const struct i2c_device_id max1586_id[] = {
279 { .name = "max1586" },
280 { }
281};
282MODULE_DEVICE_TABLE(i2c, max1586_id);
283
284static struct i2c_driver max1586_pmic_driver = {
285 .probe = max1586_pmic_probe,
286 .driver = {
287 .name = "max1586",
288 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
289 .of_match_table = of_match_ptr(max1586_of_match),
290 },
291 .id_table = max1586_id,
292};
293
294static int __init max1586_pmic_init(void)
295{
296 return i2c_add_driver(&max1586_pmic_driver);
297}
298subsys_initcall(max1586_pmic_init);
299
300static void __exit max1586_pmic_exit(void)
301{
302 i2c_del_driver(&max1586_pmic_driver);
303}
304module_exit(max1586_pmic_exit);
305
306/* Module information */
307MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
308MODULE_AUTHOR("Robert Jarzmik");
309MODULE_LICENSE("GPL");