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 struct regulator_dev *rdev[0]; 48 }; 49 50 /* 51 * V6 voltage 52 * On I2C bus, sending a "x" byte to the max1586 means : 53 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) 54 * As regulator framework doesn't accept voltages to be 0V, we use 1uV. 55 */ 56 static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; 57 58 /* 59 * V3 voltage 60 * On I2C bus, sending a "x" byte to the max1586 means : 61 * set V3 to 0.700V + (x & 0x1f) * 0.025V 62 * This voltage can be increased by external resistors 63 * R24 and R25=100kOhm as described in the data sheet. 64 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm 65 */ 66 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev, 67 unsigned selector) 68 { 69 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 70 struct i2c_client *client = max1586->client; 71 u8 v3_prog; 72 73 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", 74 regulator_list_voltage_linear(rdev, selector) / 1000); 75 76 v3_prog = I2C_V3_SELECT | (u8) selector; 77 return i2c_smbus_write_byte(client, v3_prog); 78 } 79 80 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev, 81 unsigned int selector) 82 { 83 struct i2c_client *client = rdev_get_drvdata(rdev); 84 u8 v6_prog; 85 86 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", 87 rdev->desc->volt_table[selector] / 1000); 88 89 v6_prog = I2C_V6_SELECT | (u8) selector; 90 return i2c_smbus_write_byte(client, v6_prog); 91 } 92 93 /* 94 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back 95 * the set up value. 96 */ 97 static struct regulator_ops max1586_v3_ops = { 98 .set_voltage_sel = max1586_v3_set_voltage_sel, 99 .list_voltage = regulator_list_voltage_linear, 100 .map_voltage = regulator_map_voltage_linear, 101 }; 102 103 static struct regulator_ops max1586_v6_ops = { 104 .set_voltage_sel = max1586_v6_set_voltage_sel, 105 .list_voltage = regulator_list_voltage_table, 106 }; 107 108 static struct regulator_desc max1586_reg[] = { 109 { 110 .name = "Output_V3", 111 .id = MAX1586_V3, 112 .ops = &max1586_v3_ops, 113 .type = REGULATOR_VOLTAGE, 114 .n_voltages = MAX1586_V3_MAX_VSEL + 1, 115 .owner = THIS_MODULE, 116 }, 117 { 118 .name = "Output_V6", 119 .id = MAX1586_V6, 120 .ops = &max1586_v6_ops, 121 .type = REGULATOR_VOLTAGE, 122 .n_voltages = MAX1586_V6_MAX_VSEL + 1, 123 .volt_table = v6_voltages_uv, 124 .owner = THIS_MODULE, 125 }, 126 }; 127 128 static int __devinit max1586_pmic_probe(struct i2c_client *client, 129 const struct i2c_device_id *i2c_id) 130 { 131 struct regulator_dev **rdev; 132 struct max1586_platform_data *pdata = client->dev.platform_data; 133 struct regulator_config config = { }; 134 struct max1586_data *max1586; 135 int i, id, ret = -ENOMEM; 136 137 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) + 138 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1), 139 GFP_KERNEL); 140 if (!max1586) 141 return -ENOMEM; 142 143 max1586->client = client; 144 145 if (!pdata->v3_gain) 146 return -EINVAL; 147 148 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 149 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 150 151 rdev = max1586->rdev; 152 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 153 id = pdata->subdevs[i].id; 154 if (!pdata->subdevs[i].platform_data) 155 continue; 156 if (id < MAX1586_V3 || id > MAX1586_V6) { 157 dev_err(&client->dev, "invalid regulator id %d\n", id); 158 goto err; 159 } 160 161 if (id == MAX1586_V3) { 162 max1586_reg[id].min_uV = max1586->min_uV; 163 max1586_reg[id].uV_step = 164 (max1586->max_uV - max1586->min_uV) / 165 MAX1586_V3_MAX_VSEL; 166 } 167 168 config.dev = &client->dev; 169 config.init_data = pdata->subdevs[i].platform_data; 170 config.driver_data = max1586; 171 172 rdev[i] = regulator_register(&max1586_reg[id], &config); 173 if (IS_ERR(rdev[i])) { 174 ret = PTR_ERR(rdev[i]); 175 dev_err(&client->dev, "failed to register %s\n", 176 max1586_reg[id].name); 177 goto err; 178 } 179 } 180 181 i2c_set_clientdata(client, max1586); 182 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 183 return 0; 184 185 err: 186 while (--i >= 0) 187 regulator_unregister(rdev[i]); 188 return ret; 189 } 190 191 static int __devexit max1586_pmic_remove(struct i2c_client *client) 192 { 193 struct max1586_data *max1586 = i2c_get_clientdata(client); 194 int i; 195 196 for (i = 0; i <= MAX1586_V6; i++) 197 if (max1586->rdev[i]) 198 regulator_unregister(max1586->rdev[i]); 199 return 0; 200 } 201 202 static const struct i2c_device_id max1586_id[] = { 203 { "max1586", 0 }, 204 { } 205 }; 206 MODULE_DEVICE_TABLE(i2c, max1586_id); 207 208 static struct i2c_driver max1586_pmic_driver = { 209 .probe = max1586_pmic_probe, 210 .remove = __devexit_p(max1586_pmic_remove), 211 .driver = { 212 .name = "max1586", 213 .owner = THIS_MODULE, 214 }, 215 .id_table = max1586_id, 216 }; 217 218 static int __init max1586_pmic_init(void) 219 { 220 return i2c_add_driver(&max1586_pmic_driver); 221 } 222 subsys_initcall(max1586_pmic_init); 223 224 static void __exit max1586_pmic_exit(void) 225 { 226 i2c_del_driver(&max1586_pmic_driver); 227 } 228 module_exit(max1586_pmic_exit); 229 230 /* Module information */ 231 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 232 MODULE_AUTHOR("Robert Jarzmik"); 233 MODULE_LICENSE("GPL"); 234