drivers/regulator/max1586.c

   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_device.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
  29 struct 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  */
  46 static 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  */
  56 static 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
  63 static 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
  84 static 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
  91 static 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  */
 116 static 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
 123 static 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
 129 static 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
 149 static 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
 204 static const struct of_device_id max1586_of_match[] = {
 205         { .compatible = "maxim,max1586", },
 206         {},
 207 };
 208 MODULE_DEVICE_TABLE(of, max1586_of_match);
 209
 210 static int max1586_pmic_probe(struct i2c_client *client,
 211                                         const struct i2c_device_id *i2c_id)
 212 {
 213         struct max1586_platform_data *pdata, pdata_of;
 214         struct regulator_config config = { };
 215         struct max1586_data *max1586;
 216         int i, id, ret;
 217         const struct of_device_id *match;
 218
 219         pdata = dev_get_platdata(&client->dev);
 220         if (client->dev.of_node && !pdata) {
 221                 match = of_match_device(of_match_ptr(max1586_of_match),
 222                                         &client->dev);
 223                 if (!match) {
 224                         dev_err(&client->dev, "Error: No device match found\n");
 225                         return -ENODEV;
 226                 }
 227                 ret = of_get_max1586_platform_data(&client->dev, &pdata_of);
 228                 if (ret < 0)
 229                         return ret;
 230                 pdata = &pdata_of;
 231         }
 232
 233         max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data),
 234                         GFP_KERNEL);
 235         if (!max1586)
 236                 return -ENOMEM;
 237
 238         max1586->client = client;
 239
 240         if (!pdata->v3_gain)
 241                 return -EINVAL;
 242
 243         max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 244         max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 245
 246         /* Set curr_sel to default voltage on power-up */
 247         max1586->v3_curr_sel = 24; /* 1.3V */
 248         max1586->v6_curr_sel = 0;
 249
 250         for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 251                 struct regulator_dev *rdev;
 252
 253                 id = pdata->subdevs[i].id;
 254                 if (!pdata->subdevs[i].platform_data)
 255                         continue;
 256                 if (id < MAX1586_V3 || id > MAX1586_V6) {
 257                         dev_err(&client->dev, "invalid regulator id %d\n", id);
 258                         return -EINVAL;
 259                 }
 260
 261                 if (id == MAX1586_V3) {
 262                         max1586_reg[id].min_uV = max1586->min_uV;
 263                         max1586_reg[id].uV_step =
 264                                         (max1586->max_uV - max1586->min_uV) /
 265                                         MAX1586_V3_MAX_VSEL;
 266                 }
 267
 268                 config.dev = &client->dev;
 269                 config.init_data = pdata->subdevs[i].platform_data;
 270                 config.driver_data = max1586;
 271
 272                 rdev = devm_regulator_register(&client->dev,
 273                                                   &max1586_reg[id], &config);
 274                 if (IS_ERR(rdev)) {
 275                         dev_err(&client->dev, "failed to register %s\n",
 276                                 max1586_reg[id].name);
 277                         return PTR_ERR(rdev);
 278                 }
 279         }
 280
 281         i2c_set_clientdata(client, max1586);
 282         dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 283         return 0;
 284 }
 285
 286 static const struct i2c_device_id max1586_id[] = {
 287         { "max1586", 0 },
 288         { }
 289 };
 290 MODULE_DEVICE_TABLE(i2c, max1586_id);
 291
 292 static struct i2c_driver max1586_pmic_driver = {
 293         .probe = max1586_pmic_probe,
 294         .driver         = {
 295                 .name   = "max1586",
 296                 .of_match_table = of_match_ptr(max1586_of_match),
 297         },
 298         .id_table       = max1586_id,
 299 };
 300
 301 static int __init max1586_pmic_init(void)
 302 {
 303         return i2c_add_driver(&max1586_pmic_driver);
 304 }
 305 subsys_initcall(max1586_pmic_init);
 306
 307 static void __exit max1586_pmic_exit(void)
 308 {
 309         i2c_del_driver(&max1586_pmic_driver);
 310 }
 311 module_exit(max1586_pmic_exit);
 312
 313 /* Module information */
 314 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 315 MODULE_AUTHOR("Robert Jarzmik");
 316 MODULE_LICENSE("GPL");