1 /* 2 * max1586.c -- Voltage and current regulation for the Maxim 1586 3 * 4 * Copyright (C) 2008 Robert Jarzmik 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 */ 20 #include <linux/module.h> 21 #include <linux/err.h> 22 #include <linux/i2c.h> 23 #include <linux/platform_device.h> 24 #include <linux/regulator/driver.h> 25 #include <linux/slab.h> 26 #include <linux/regulator/max1586.h> 27 #include <linux/of_device.h> 28 #include <linux/regulator/of_regulator.h> 29 30 #define MAX1586_V3_MAX_VSEL 31 31 #define MAX1586_V6_MAX_VSEL 3 32 33 #define MAX1586_V3_MIN_UV 700000 34 #define MAX1586_V3_MAX_UV 1475000 35 36 #define MAX1586_V6_MIN_UV 0 37 #define MAX1586_V6_MAX_UV 3000000 38 39 #define I2C_V3_SELECT (0 << 5) 40 #define I2C_V6_SELECT (1 << 5) 41 42 struct max1586_data { 43 struct i2c_client *client; 44 45 /* min/max V3 voltage */ 46 unsigned int min_uV; 47 unsigned int max_uV; 48 49 unsigned int v3_curr_sel; 50 unsigned int v6_curr_sel; 51 }; 52 53 /* 54 * V6 voltage 55 * On I2C bus, sending a "x" byte to the max1586 means : 56 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) 57 * As regulator framework doesn't accept voltages to be 0V, we use 1uV. 58 */ 59 static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; 60 61 /* 62 * V3 voltage 63 * On I2C bus, sending a "x" byte to the max1586 means : 64 * set V3 to 0.700V + (x & 0x1f) * 0.025V 65 * This voltage can be increased by external resistors 66 * R24 and R25=100kOhm as described in the data sheet. 67 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm 68 */ 69 static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev) 70 { 71 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 72 73 return max1586->v3_curr_sel; 74 } 75 76 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev, 77 unsigned selector) 78 { 79 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 80 struct i2c_client *client = max1586->client; 81 int ret; 82 u8 v3_prog; 83 84 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", 85 regulator_list_voltage_linear(rdev, selector) / 1000); 86 87 v3_prog = I2C_V3_SELECT | (u8) selector; 88 ret = i2c_smbus_write_byte(client, v3_prog); 89 if (ret) 90 return ret; 91 92 max1586->v3_curr_sel = selector; 93 94 return 0; 95 } 96 97 static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev) 98 { 99 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 100 101 return max1586->v6_curr_sel; 102 } 103 104 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev, 105 unsigned int selector) 106 { 107 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 108 struct i2c_client *client = max1586->client; 109 u8 v6_prog; 110 int ret; 111 112 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", 113 rdev->desc->volt_table[selector] / 1000); 114 115 v6_prog = I2C_V6_SELECT | (u8) selector; 116 ret = i2c_smbus_write_byte(client, v6_prog); 117 if (ret) 118 return ret; 119 120 max1586->v6_curr_sel = selector; 121 122 return 0; 123 } 124 125 /* 126 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back 127 * the set up value. 128 */ 129 static const struct regulator_ops max1586_v3_ops = { 130 .get_voltage_sel = max1586_v3_get_voltage_sel, 131 .set_voltage_sel = max1586_v3_set_voltage_sel, 132 .list_voltage = regulator_list_voltage_linear, 133 .map_voltage = regulator_map_voltage_linear, 134 }; 135 136 static const struct regulator_ops max1586_v6_ops = { 137 .get_voltage_sel = max1586_v6_get_voltage_sel, 138 .set_voltage_sel = max1586_v6_set_voltage_sel, 139 .list_voltage = regulator_list_voltage_table, 140 }; 141 142 static struct regulator_desc max1586_reg[] = { 143 { 144 .name = "Output_V3", 145 .id = MAX1586_V3, 146 .ops = &max1586_v3_ops, 147 .type = REGULATOR_VOLTAGE, 148 .n_voltages = MAX1586_V3_MAX_VSEL + 1, 149 .owner = THIS_MODULE, 150 }, 151 { 152 .name = "Output_V6", 153 .id = MAX1586_V6, 154 .ops = &max1586_v6_ops, 155 .type = REGULATOR_VOLTAGE, 156 .n_voltages = MAX1586_V6_MAX_VSEL + 1, 157 .volt_table = v6_voltages_uv, 158 .owner = THIS_MODULE, 159 }, 160 }; 161 162 static int of_get_max1586_platform_data(struct device *dev, 163 struct max1586_platform_data *pdata) 164 { 165 struct max1586_subdev_data *sub; 166 struct of_regulator_match rmatch[ARRAY_SIZE(max1586_reg)] = { }; 167 struct device_node *np = dev->of_node; 168 int i, matched; 169 170 if (of_property_read_u32(np, "v3-gain", 171 &pdata->v3_gain) < 0) { 172 dev_err(dev, "%pOF has no 'v3-gain' property\n", np); 173 return -EINVAL; 174 } 175 176 np = of_get_child_by_name(np, "regulators"); 177 if (!np) { 178 dev_err(dev, "missing 'regulators' subnode in DT\n"); 179 return -EINVAL; 180 } 181 182 for (i = 0; i < ARRAY_SIZE(rmatch); i++) 183 rmatch[i].name = max1586_reg[i].name; 184 185 matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch)); 186 of_node_put(np); 187 /* 188 * If matched is 0, ie. neither Output_V3 nor Output_V6 have been found, 189 * return 0, which signals the normal situation where no subregulator is 190 * available. This is normal because the max1586 doesn't provide any 191 * readback support, so the subregulators can't report any status 192 * anyway. If matched < 0, return the error. 193 */ 194 if (matched <= 0) 195 return matched; 196 197 pdata->subdevs = devm_kcalloc(dev, 198 matched, 199 sizeof(struct max1586_subdev_data), 200 GFP_KERNEL); 201 if (!pdata->subdevs) 202 return -ENOMEM; 203 204 pdata->num_subdevs = matched; 205 sub = pdata->subdevs; 206 207 for (i = 0; i < matched; i++) { 208 sub->id = i; 209 sub->name = rmatch[i].of_node->name; 210 sub->platform_data = rmatch[i].init_data; 211 sub++; 212 } 213 214 return 0; 215 } 216 217 static const struct of_device_id max1586_of_match[] = { 218 { .compatible = "maxim,max1586", }, 219 {}, 220 }; 221 MODULE_DEVICE_TABLE(of, max1586_of_match); 222 223 static int max1586_pmic_probe(struct i2c_client *client, 224 const struct i2c_device_id *i2c_id) 225 { 226 struct max1586_platform_data *pdata, pdata_of; 227 struct regulator_config config = { }; 228 struct max1586_data *max1586; 229 int i, id, ret; 230 const struct of_device_id *match; 231 232 pdata = dev_get_platdata(&client->dev); 233 if (client->dev.of_node && !pdata) { 234 match = of_match_device(of_match_ptr(max1586_of_match), 235 &client->dev); 236 if (!match) { 237 dev_err(&client->dev, "Error: No device match found\n"); 238 return -ENODEV; 239 } 240 ret = of_get_max1586_platform_data(&client->dev, &pdata_of); 241 if (ret < 0) 242 return ret; 243 pdata = &pdata_of; 244 } 245 246 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data), 247 GFP_KERNEL); 248 if (!max1586) 249 return -ENOMEM; 250 251 max1586->client = client; 252 253 if (!pdata->v3_gain) 254 return -EINVAL; 255 256 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 257 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 258 259 /* Set curr_sel to default voltage on power-up */ 260 max1586->v3_curr_sel = 24; /* 1.3V */ 261 max1586->v6_curr_sel = 0; 262 263 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 264 struct regulator_dev *rdev; 265 266 id = pdata->subdevs[i].id; 267 if (!pdata->subdevs[i].platform_data) 268 continue; 269 if (id < MAX1586_V3 || id > MAX1586_V6) { 270 dev_err(&client->dev, "invalid regulator id %d\n", id); 271 return -EINVAL; 272 } 273 274 if (id == MAX1586_V3) { 275 max1586_reg[id].min_uV = max1586->min_uV; 276 max1586_reg[id].uV_step = 277 (max1586->max_uV - max1586->min_uV) / 278 MAX1586_V3_MAX_VSEL; 279 } 280 281 config.dev = &client->dev; 282 config.init_data = pdata->subdevs[i].platform_data; 283 config.driver_data = max1586; 284 285 rdev = devm_regulator_register(&client->dev, 286 &max1586_reg[id], &config); 287 if (IS_ERR(rdev)) { 288 dev_err(&client->dev, "failed to register %s\n", 289 max1586_reg[id].name); 290 return PTR_ERR(rdev); 291 } 292 } 293 294 i2c_set_clientdata(client, max1586); 295 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 296 return 0; 297 } 298 299 static const struct i2c_device_id max1586_id[] = { 300 { "max1586", 0 }, 301 { } 302 }; 303 MODULE_DEVICE_TABLE(i2c, max1586_id); 304 305 static struct i2c_driver max1586_pmic_driver = { 306 .probe = max1586_pmic_probe, 307 .driver = { 308 .name = "max1586", 309 .of_match_table = of_match_ptr(max1586_of_match), 310 }, 311 .id_table = max1586_id, 312 }; 313 314 static int __init max1586_pmic_init(void) 315 { 316 return i2c_add_driver(&max1586_pmic_driver); 317 } 318 subsys_initcall(max1586_pmic_init); 319 320 static void __exit max1586_pmic_exit(void) 321 { 322 i2c_del_driver(&max1586_pmic_driver); 323 } 324 module_exit(max1586_pmic_exit); 325 326 /* Module information */ 327 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 328 MODULE_AUTHOR("Robert Jarzmik"); 329 MODULE_LICENSE("GPL"); 330