drivers/regulator/max1586.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * max1586.c  --  Voltage and current regulation for the Maxim 1586
0004  *
0005  * Copyright (C) 2008 Robert Jarzmik
0006  */
0007 #include <linux/module.h>
0008 #include <linux/err.h>
0009 #include <linux/i2c.h>
0010 #include <linux/platform_device.h>
0011 #include <linux/regulator/driver.h>
0012 #include <linux/slab.h>
0013 #include <linux/regulator/max1586.h>
0014 #include <linux/of_device.h>
0015 #include <linux/regulator/of_regulator.h>
0016
0017 #define MAX1586_V3_MAX_VSEL 31
0018 #define MAX1586_V6_MAX_VSEL 3
0019
0020 #define MAX1586_V3_MIN_UV   700000
0021 #define MAX1586_V3_MAX_UV  1475000
0022
0023 #define MAX1586_V6_MIN_UV        0
0024 #define MAX1586_V6_MAX_UV  3000000
0025
0026 #define I2C_V3_SELECT (0 << 5)
0027 #define I2C_V6_SELECT (1 << 5)
0028
0029 struct max1586_data {
0030     struct i2c_client *client;
0031
0032     /* min/max V3 voltage */
0033     unsigned int min_uV;
0034     unsigned int max_uV;
0035
0036     unsigned int v3_curr_sel;
0037     unsigned int v6_curr_sel;
0038 };
0039
0040 /*
0041  * V6 voltage
0042  * On I2C bus, sending a "x" byte to the max1586 means :
0043  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
0044  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
0045  */
0046 static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
0047
0048 /*
0049  * V3 voltage
0050  * On I2C bus, sending a "x" byte to the max1586 means :
0051  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
0052  * This voltage can be increased by external resistors
0053  * R24 and R25=100kOhm as described in the data sheet.
0054  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
0055  */
0056 static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
0057 {
0058     struct max1586_data *max1586 = rdev_get_drvdata(rdev);
0059
0060     return max1586->v3_curr_sel;
0061 }
0062
0063 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
0064                       unsigned selector)
0065 {
0066     struct max1586_data *max1586 = rdev_get_drvdata(rdev);
0067     struct i2c_client *client = max1586->client;
0068     int ret;
0069     u8 v3_prog;
0070
0071     dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
0072         regulator_list_voltage_linear(rdev, selector) / 1000);
0073
0074     v3_prog = I2C_V3_SELECT | (u8) selector;
0075     ret = i2c_smbus_write_byte(client, v3_prog);
0076     if (ret)
0077         return ret;
0078
0079     max1586->v3_curr_sel = selector;
0080
0081     return 0;
0082 }
0083
0084 static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
0085 {
0086     struct max1586_data *max1586 = rdev_get_drvdata(rdev);
0087
0088     return max1586->v6_curr_sel;
0089 }
0090
0091 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
0092                       unsigned int selector)
0093 {
0094     struct max1586_data *max1586 = rdev_get_drvdata(rdev);
0095     struct i2c_client *client = max1586->client;
0096     u8 v6_prog;
0097     int ret;
0098
0099     dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
0100         rdev->desc->volt_table[selector] / 1000);
0101
0102     v6_prog = I2C_V6_SELECT | (u8) selector;
0103     ret = i2c_smbus_write_byte(client, v6_prog);
0104     if (ret)
0105         return ret;
0106
0107     max1586->v6_curr_sel = selector;
0108
0109     return 0;
0110 }
0111
0112 /*
0113  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
0114  * the set up value.
0115  */
0116 static const struct regulator_ops max1586_v3_ops = {
0117     .get_voltage_sel = max1586_v3_get_voltage_sel,
0118     .set_voltage_sel = max1586_v3_set_voltage_sel,
0119     .list_voltage = regulator_list_voltage_linear,
0120     .map_voltage = regulator_map_voltage_linear,
0121 };
0122
0123 static const struct regulator_ops max1586_v6_ops = {
0124     .get_voltage_sel = max1586_v6_get_voltage_sel,
0125     .set_voltage_sel = max1586_v6_set_voltage_sel,
0126     .list_voltage = regulator_list_voltage_table,
0127 };
0128
0129 static struct regulator_desc max1586_reg[] = {
0130     {
0131         .name = "Output_V3",
0132         .id = MAX1586_V3,
0133         .ops = &max1586_v3_ops,
0134         .type = REGULATOR_VOLTAGE,
0135         .n_voltages = MAX1586_V3_MAX_VSEL + 1,
0136         .owner = THIS_MODULE,
0137     },
0138     {
0139         .name = "Output_V6",
0140         .id = MAX1586_V6,
0141         .ops = &max1586_v6_ops,
0142         .type = REGULATOR_VOLTAGE,
0143         .n_voltages = MAX1586_V6_MAX_VSEL + 1,
0144         .volt_table = v6_voltages_uv,
0145         .owner = THIS_MODULE,
0146     },
0147 };
0148
0149 static int of_get_max1586_platform_data(struct device *dev,
0150                  struct max1586_platform_data *pdata)
0151 {
0152     struct max1586_subdev_data *sub;
0153     struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { };
0154     struct device_node *np = dev->of_node;
0155     int i, matched;
0156
0157     if (of_property_read_u32(np, "v3-gain",
0158                  &pdata->v3_gain) < 0) {
0159         dev_err(dev, "%pOF has no 'v3-gain' property\n", np);
0160         return -EINVAL;
0161     }
0162
0163     np = of_get_child_by_name(np, "regulators");
0164     if (!np) {
0165         dev_err(dev, "missing 'regulators' subnode in DT\n");
0166         return -EINVAL;
0167     }
0168
0169     for (i = 0; i < ARRAY_SIZE(rmatch); i++)
0170         rmatch[i].name = max1586_reg[i].name;
0171
0172     matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
0173     of_node_put(np);
0174     /*
0175      * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found,
0176      * return 0, which signals the normal situation where no subregulator is
0177      * available. This is normal because the max1586 doesn't provide any
0178      * readback support, so the subregulators can't report any status
0179      * anyway.  If matched < 0, return the error.
0180      */
0181     if (matched <= 0)
0182         return matched;
0183
0184     pdata->subdevs = devm_kcalloc(dev,
0185                       matched,
0186                       sizeof(struct max1586_subdev_data),
0187                       GFP_KERNEL);
0188     if (!pdata->subdevs)
0189         return -ENOMEM;
0190
0191     pdata->num_subdevs = matched;
0192     sub = pdata->subdevs;
0193
0194     for (i = 0; i < matched; i++) {
0195         sub->id = i;
0196         sub->name = rmatch[i].of_node->name;
0197         sub->platform_data = rmatch[i].init_data;
0198         sub++;
0199     }
0200
0201     return 0;
0202 }
0203
0204 static const struct of_device_id __maybe_unused max1586_of_match[] = {
0205     { .compatible = "maxim,max1586", },
0206     {},
0207 };
0208 MODULE_DEVICE_TABLE(of, max1586_of_match);
0209
0210 static int max1586_pmic_probe(struct i2c_client *client,
0211                     const struct i2c_device_id *i2c_id)
0212 {
0213     struct max1586_platform_data *pdata, pdata_of;
0214     struct regulator_config config = { };
0215     struct max1586_data *max1586;
0216     int i, id, ret;
0217     const struct of_device_id *match;
0218
0219     pdata = dev_get_platdata(&client->dev);
0220     if (client->dev.of_node && !pdata) {
0221         match = of_match_device(of_match_ptr(max1586_of_match),
0222                     &client->dev);
0223         if (!match) {
0224             dev_err(&client->dev, "Error: No device match found\n");
0225             return -ENODEV;
0226         }
0227         ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
0228         if (ret < 0)
0229             return ret;
0230         pdata = &pdata_of;
0231     }
0232
0233     max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
0234             GFP_KERNEL);
0235     if (!max1586)
0236         return -ENOMEM;
0237
0238     max1586->client = client;
0239
0240     if (!pdata->v3_gain)
0241         return -EINVAL;
0242
0243     max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
0244     max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
0245
0246     /* Set curr_sel to default voltage on power-up */
0247     max1586->v3_curr_sel = 24; /* 1.3V */
0248     max1586->v6_curr_sel = 0;
0249
0250     for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
0251         struct regulator_dev *rdev;
0252
0253         id = pdata->subdevs[i].id;
0254         if (!pdata->subdevs[i].platform_data)
0255             continue;
0256         if (id < MAX1586_V3 || id > MAX1586_V6) {
0257             dev_err(&client->dev, "invalid regulator id %d\n", id);
0258             return -EINVAL;
0259         }
0260
0261         if (id == MAX1586_V3) {
0262             max1586_reg[id].min_uV = max1586->min_uV;
0263             max1586_reg[id].uV_step =
0264                     (max1586->max_uV - max1586->min_uV) /
0265                     MAX1586_V3_MAX_VSEL;
0266         }
0267
0268         config.dev = &client->dev;
0269         config.init_data = pdata->subdevs[i].platform_data;
0270         config.driver_data = max1586;
0271
0272         rdev = devm_regulator_register(&client->dev,
0273                           &max1586_reg[id], &config);
0274         if (IS_ERR(rdev)) {
0275             dev_err(&client->dev, "failed to register %s\n",
0276                 max1586_reg[id].name);
0277             return PTR_ERR(rdev);
0278         }
0279     }
0280
0281     i2c_set_clientdata(client, max1586);
0282     dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
0283     return 0;
0284 }
0285
0286 static const struct i2c_device_id max1586_id[] = {
0287     { "max1586", 0 },
0288     { }
0289 };
0290 MODULE_DEVICE_TABLE(i2c, max1586_id);
0291
0292 static struct i2c_driver max1586_pmic_driver = {
0293     .probe = max1586_pmic_probe,
0294     .driver     = {
0295         .name   = "max1586",
0296         .of_match_table = of_match_ptr(max1586_of_match),
0297     },
0298     .id_table   = max1586_id,
0299 };
0300
0301 static int __init max1586_pmic_init(void)
0302 {
0303     return i2c_add_driver(&max1586_pmic_driver);
0304 }
0305 subsys_initcall(max1586_pmic_init);
0306
0307 static void __exit max1586_pmic_exit(void)
0308 {
0309     i2c_del_driver(&max1586_pmic_driver);
0310 }
0311 module_exit(max1586_pmic_exit);
0312
0313 /* Module information */
0314 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
0315 MODULE_AUTHOR("Robert Jarzmik");
0316 MODULE_LICENSE("GPL");