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 51 /* 52 * V6 voltage 53 * On I2C bus, sending a "x" byte to the max1586 means : 54 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) 55 * As regulator framework doesn't accept voltages to be 0V, we use 1uV. 56 */ 57 static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; 58 59 /* 60 * V3 voltage 61 * On I2C bus, sending a "x" byte to the max1586 means : 62 * set V3 to 0.700V + (x & 0x1f) * 0.025V 63 * This voltage can be increased by external resistors 64 * R24 and R25=100kOhm as described in the data sheet. 65 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm 66 */ 67 static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev) 68 { 69 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 70 71 return max1586->v3_curr_sel; 72 } 73 74 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev, 75 unsigned selector) 76 { 77 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 78 struct i2c_client *client = max1586->client; 79 int ret; 80 u8 v3_prog; 81 82 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", 83 regulator_list_voltage_linear(rdev, selector) / 1000); 84 85 v3_prog = I2C_V3_SELECT | (u8) selector; 86 ret = i2c_smbus_write_byte(client, v3_prog); 87 if (ret) 88 return ret; 89 90 max1586->v3_curr_sel = selector; 91 92 return 0; 93 } 94 95 static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev) 96 { 97 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 98 99 return max1586->v6_curr_sel; 100 } 101 102 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev, 103 unsigned int selector) 104 { 105 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 106 struct i2c_client *client = max1586->client; 107 u8 v6_prog; 108 int ret; 109 110 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", 111 rdev->desc->volt_table[selector] / 1000); 112 113 v6_prog = I2C_V6_SELECT | (u8) selector; 114 ret = i2c_smbus_write_byte(client, v6_prog); 115 if (ret) 116 return ret; 117 118 max1586->v6_curr_sel = selector; 119 120 return 0; 121 } 122 123 /* 124 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back 125 * the set up value. 126 */ 127 static struct regulator_ops max1586_v3_ops = { 128 .get_voltage_sel = max1586_v3_get_voltage_sel, 129 .set_voltage_sel = max1586_v3_set_voltage_sel, 130 .list_voltage = regulator_list_voltage_linear, 131 .map_voltage = regulator_map_voltage_linear, 132 }; 133 134 static struct regulator_ops max1586_v6_ops = { 135 .get_voltage_sel = max1586_v6_get_voltage_sel, 136 .set_voltage_sel = max1586_v6_set_voltage_sel, 137 .list_voltage = regulator_list_voltage_table, 138 }; 139 140 static struct regulator_desc max1586_reg[] = { 141 { 142 .name = "Output_V3", 143 .id = MAX1586_V3, 144 .ops = &max1586_v3_ops, 145 .type = REGULATOR_VOLTAGE, 146 .n_voltages = MAX1586_V3_MAX_VSEL + 1, 147 .owner = THIS_MODULE, 148 }, 149 { 150 .name = "Output_V6", 151 .id = MAX1586_V6, 152 .ops = &max1586_v6_ops, 153 .type = REGULATOR_VOLTAGE, 154 .n_voltages = MAX1586_V6_MAX_VSEL + 1, 155 .volt_table = v6_voltages_uv, 156 .owner = THIS_MODULE, 157 }, 158 }; 159 160 static int max1586_pmic_probe(struct i2c_client *client, 161 const struct i2c_device_id *i2c_id) 162 { 163 struct max1586_platform_data *pdata = dev_get_platdata(&client->dev); 164 struct regulator_config config = { }; 165 struct max1586_data *max1586; 166 int i, id; 167 168 max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data), 169 GFP_KERNEL); 170 if (!max1586) 171 return -ENOMEM; 172 173 max1586->client = client; 174 175 if (!pdata->v3_gain) 176 return -EINVAL; 177 178 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 179 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 180 181 /* Set curr_sel to default voltage on power-up */ 182 max1586->v3_curr_sel = 24; /* 1.3V */ 183 max1586->v6_curr_sel = 0; 184 185 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 186 struct regulator_dev *rdev; 187 188 id = pdata->subdevs[i].id; 189 if (!pdata->subdevs[i].platform_data) 190 continue; 191 if (id < MAX1586_V3 || id > MAX1586_V6) { 192 dev_err(&client->dev, "invalid regulator id %d\n", id); 193 return -EINVAL; 194 } 195 196 if (id == MAX1586_V3) { 197 max1586_reg[id].min_uV = max1586->min_uV; 198 max1586_reg[id].uV_step = 199 (max1586->max_uV - max1586->min_uV) / 200 MAX1586_V3_MAX_VSEL; 201 } 202 203 config.dev = &client->dev; 204 config.init_data = pdata->subdevs[i].platform_data; 205 config.driver_data = max1586; 206 207 rdev = devm_regulator_register(&client->dev, 208 &max1586_reg[id], &config); 209 if (IS_ERR(rdev)) { 210 dev_err(&client->dev, "failed to register %s\n", 211 max1586_reg[id].name); 212 return PTR_ERR(rdev); 213 } 214 } 215 216 i2c_set_clientdata(client, max1586); 217 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 218 return 0; 219 } 220 221 static const struct i2c_device_id max1586_id[] = { 222 { "max1586", 0 }, 223 { } 224 }; 225 MODULE_DEVICE_TABLE(i2c, max1586_id); 226 227 static struct i2c_driver max1586_pmic_driver = { 228 .probe = max1586_pmic_probe, 229 .driver = { 230 .name = "max1586", 231 .owner = THIS_MODULE, 232 }, 233 .id_table = max1586_id, 234 }; 235 236 static int __init max1586_pmic_init(void) 237 { 238 return i2c_add_driver(&max1586_pmic_driver); 239 } 240 subsys_initcall(max1586_pmic_init); 241 242 static void __exit max1586_pmic_exit(void) 243 { 244 i2c_del_driver(&max1586_pmic_driver); 245 } 246 module_exit(max1586_pmic_exit); 247 248 /* Module information */ 249 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 250 MODULE_AUTHOR("Robert Jarzmik"); 251 MODULE_LICENSE("GPL"); 252