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 28 #define MAX1586_V3_MAX_VSEL 31 29 #define MAX1586_V6_MAX_VSEL 3 30 31 #define MAX1586_V3_MIN_UV 700000 32 #define MAX1586_V3_MAX_UV 1475000 33 34 #define MAX1586_V6_MIN_UV 0 35 #define MAX1586_V6_MAX_UV 3000000 36 37 #define I2C_V3_SELECT (0 << 5) 38 #define I2C_V6_SELECT (1 << 5) 39 40 struct max1586_data { 41 struct i2c_client *client; 42 43 /* min/max V3 voltage */ 44 unsigned int min_uV; 45 unsigned int max_uV; 46 47 unsigned int v3_curr_sel; 48 unsigned int v6_curr_sel; 49 50 struct regulator_dev *rdev[0]; 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 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 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 max1586_pmic_probe(struct i2c_client *client, 163 const struct i2c_device_id *i2c_id) 164 { 165 struct regulator_dev **rdev; 166 struct max1586_platform_data *pdata = dev_get_platdata(&client->dev); 167 struct regulator_config config = { }; 168 struct max1586_data *max1586; 169 int i, id; 170 171 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) + 172 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1), 173 GFP_KERNEL); 174 if (!max1586) 175 return -ENOMEM; 176 177 max1586->client = client; 178 179 if (!pdata->v3_gain) 180 return -EINVAL; 181 182 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 183 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 184 185 /* Set curr_sel to default voltage on power-up */ 186 max1586->v3_curr_sel = 24; /* 1.3V */ 187 max1586->v6_curr_sel = 0; 188 189 rdev = max1586->rdev; 190 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 191 id = pdata->subdevs[i].id; 192 if (!pdata->subdevs[i].platform_data) 193 continue; 194 if (id < MAX1586_V3 || id > MAX1586_V6) { 195 dev_err(&client->dev, "invalid regulator id %d\n", id); 196 return -EINVAL; 197 } 198 199 if (id == MAX1586_V3) { 200 max1586_reg[id].min_uV = max1586->min_uV; 201 max1586_reg[id].uV_step = 202 (max1586->max_uV - max1586->min_uV) / 203 MAX1586_V3_MAX_VSEL; 204 } 205 206 config.dev = &client->dev; 207 config.init_data = pdata->subdevs[i].platform_data; 208 config.driver_data = max1586; 209 210 rdev[i] = devm_regulator_register(&client->dev, 211 &max1586_reg[id], &config); 212 if (IS_ERR(rdev[i])) { 213 dev_err(&client->dev, "failed to register %s\n", 214 max1586_reg[id].name); 215 return PTR_ERR(rdev[i]); 216 } 217 } 218 219 i2c_set_clientdata(client, max1586); 220 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 221 return 0; 222 } 223 224 static const struct i2c_device_id max1586_id[] = { 225 { "max1586", 0 }, 226 { } 227 }; 228 MODULE_DEVICE_TABLE(i2c, max1586_id); 229 230 static struct i2c_driver max1586_pmic_driver = { 231 .probe = max1586_pmic_probe, 232 .driver = { 233 .name = "max1586", 234 .owner = THIS_MODULE, 235 }, 236 .id_table = max1586_id, 237 }; 238 239 static int __init max1586_pmic_init(void) 240 { 241 return i2c_add_driver(&max1586_pmic_driver); 242 } 243 subsys_initcall(max1586_pmic_init); 244 245 static void __exit max1586_pmic_exit(void) 246 { 247 i2c_del_driver(&max1586_pmic_driver); 248 } 249 module_exit(max1586_pmic_exit); 250 251 /* Module information */ 252 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 253 MODULE_AUTHOR("Robert Jarzmik"); 254 MODULE_LICENSE("GPL"); 255