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 * V3 voltage 52 * On I2C bus, sending a "x" byte to the max1586 means : 53 * set V3 to 0.700V + (x & 0x1f) * 0.025V 54 * This voltage can be increased by external resistors 55 * R24 and R25=100kOhm as described in the data sheet. 56 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm 57 */ 58 static int max1586_v3_calc_voltage(struct max1586_data *max1586, 59 unsigned selector) 60 { 61 unsigned range_uV = max1586->max_uV - max1586->min_uV; 62 63 return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL); 64 } 65 66 static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV, 67 unsigned *selector) 68 { 69 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 70 struct i2c_client *client = max1586->client; 71 unsigned range_uV = max1586->max_uV - max1586->min_uV; 72 u8 v3_prog; 73 74 if (min_uV > max1586->max_uV || max_uV < max1586->min_uV) 75 return -EINVAL; 76 if (min_uV < max1586->min_uV) 77 min_uV = max1586->min_uV; 78 79 *selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL + 80 range_uV - 1) / range_uV; 81 if (max1586_v3_calc_voltage(max1586, *selector) > max_uV) 82 return -EINVAL; 83 84 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", 85 max1586_v3_calc_voltage(max1586, *selector) / 1000); 86 87 v3_prog = I2C_V3_SELECT | (u8) *selector; 88 return i2c_smbus_write_byte(client, v3_prog); 89 } 90 91 static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector) 92 { 93 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 94 95 if (selector > MAX1586_V3_MAX_VSEL) 96 return -EINVAL; 97 return max1586_v3_calc_voltage(max1586, selector); 98 } 99 100 /* 101 * V6 voltage 102 * On I2C bus, sending a "x" byte to the max1586 means : 103 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) 104 * As regulator framework doesn't accept voltages to be 0V, we use 1uV. 105 */ 106 static int max1586_v6_calc_voltage(unsigned selector) 107 { 108 static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; 109 110 return voltages_uv[selector]; 111 } 112 113 static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV, 114 unsigned int *selector) 115 { 116 struct i2c_client *client = rdev_get_drvdata(rdev); 117 u8 v6_prog; 118 119 if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV) 120 return -EINVAL; 121 if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV) 122 return -EINVAL; 123 124 if (min_uV < 1800000) 125 *selector = 0; 126 else if (min_uV < 2500000) 127 *selector = 1; 128 else if (min_uV < 3000000) 129 *selector = 2; 130 else if (min_uV >= 3000000) 131 *selector = 3; 132 133 if (max1586_v6_calc_voltage(*selector) > max_uV) 134 return -EINVAL; 135 136 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", 137 max1586_v6_calc_voltage(*selector) / 1000); 138 139 v6_prog = I2C_V6_SELECT | (u8) *selector; 140 return i2c_smbus_write_byte(client, v6_prog); 141 } 142 143 static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector) 144 { 145 if (selector > MAX1586_V6_MAX_VSEL) 146 return -EINVAL; 147 return max1586_v6_calc_voltage(selector); 148 } 149 150 /* 151 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back 152 * the set up value. 153 */ 154 static struct regulator_ops max1586_v3_ops = { 155 .set_voltage = max1586_v3_set, 156 .list_voltage = max1586_v3_list, 157 }; 158 159 static struct regulator_ops max1586_v6_ops = { 160 .set_voltage = max1586_v6_set, 161 .list_voltage = max1586_v6_list, 162 }; 163 164 static struct regulator_desc max1586_reg[] = { 165 { 166 .name = "Output_V3", 167 .id = MAX1586_V3, 168 .ops = &max1586_v3_ops, 169 .type = REGULATOR_VOLTAGE, 170 .n_voltages = MAX1586_V3_MAX_VSEL + 1, 171 .owner = THIS_MODULE, 172 }, 173 { 174 .name = "Output_V6", 175 .id = MAX1586_V6, 176 .ops = &max1586_v6_ops, 177 .type = REGULATOR_VOLTAGE, 178 .n_voltages = MAX1586_V6_MAX_VSEL + 1, 179 .owner = THIS_MODULE, 180 }, 181 }; 182 183 static int __devinit max1586_pmic_probe(struct i2c_client *client, 184 const struct i2c_device_id *i2c_id) 185 { 186 struct regulator_dev **rdev; 187 struct max1586_platform_data *pdata = client->dev.platform_data; 188 struct max1586_data *max1586; 189 int i, id, ret = -ENOMEM; 190 191 max1586 = kzalloc(sizeof(struct max1586_data) + 192 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1), 193 GFP_KERNEL); 194 if (!max1586) 195 goto out; 196 197 max1586->client = client; 198 199 if (!pdata->v3_gain) { 200 ret = -EINVAL; 201 goto out_unmap; 202 } 203 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 204 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 205 206 rdev = max1586->rdev; 207 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 208 id = pdata->subdevs[i].id; 209 if (!pdata->subdevs[i].platform_data) 210 continue; 211 if (id < MAX1586_V3 || id > MAX1586_V6) { 212 dev_err(&client->dev, "invalid regulator id %d\n", id); 213 goto err; 214 } 215 rdev[i] = regulator_register(&max1586_reg[id], &client->dev, 216 pdata->subdevs[i].platform_data, 217 max1586); 218 if (IS_ERR(rdev[i])) { 219 ret = PTR_ERR(rdev[i]); 220 dev_err(&client->dev, "failed to register %s\n", 221 max1586_reg[id].name); 222 goto err; 223 } 224 } 225 226 i2c_set_clientdata(client, max1586); 227 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 228 return 0; 229 230 err: 231 while (--i >= 0) 232 regulator_unregister(rdev[i]); 233 out_unmap: 234 kfree(max1586); 235 out: 236 return ret; 237 } 238 239 static int __devexit max1586_pmic_remove(struct i2c_client *client) 240 { 241 struct max1586_data *max1586 = i2c_get_clientdata(client); 242 int i; 243 244 for (i = 0; i <= MAX1586_V6; i++) 245 if (max1586->rdev[i]) 246 regulator_unregister(max1586->rdev[i]); 247 kfree(max1586); 248 249 return 0; 250 } 251 252 static const struct i2c_device_id max1586_id[] = { 253 { "max1586", 0 }, 254 { } 255 }; 256 MODULE_DEVICE_TABLE(i2c, max1586_id); 257 258 static struct i2c_driver max1586_pmic_driver = { 259 .probe = max1586_pmic_probe, 260 .remove = __devexit_p(max1586_pmic_remove), 261 .driver = { 262 .name = "max1586", 263 .owner = THIS_MODULE, 264 }, 265 .id_table = max1586_id, 266 }; 267 268 static int __init max1586_pmic_init(void) 269 { 270 return i2c_add_driver(&max1586_pmic_driver); 271 } 272 subsys_initcall(max1586_pmic_init); 273 274 static void __exit max1586_pmic_exit(void) 275 { 276 i2c_del_driver(&max1586_pmic_driver); 277 } 278 module_exit(max1586_pmic_exit); 279 280 /* Module information */ 281 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 282 MODULE_AUTHOR("Robert Jarzmik"); 283 MODULE_LICENSE("GPL"); 284