max1586.c revision bd88c9b285b76f329243d5c80960c23a04004043
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/regulator/max1586.h> 26 27#define MAX1586_V3_MAX_VSEL 31 28#define MAX1586_V6_MAX_VSEL 3 29 30#define MAX1586_V3_MIN_UV 700000 31#define MAX1586_V3_MAX_UV 1475000 32 33#define MAX1586_V6_MIN_UV 0 34#define MAX1586_V6_MAX_UV 3000000 35 36#define I2C_V3_SELECT (0 << 5) 37#define I2C_V6_SELECT (1 << 5) 38 39struct max1586_data { 40 struct i2c_client *client; 41 42 /* min/max V3 voltage */ 43 unsigned int min_uV; 44 unsigned int max_uV; 45 46 struct regulator_dev *rdev[0]; 47}; 48 49/* 50 * V3 voltage 51 * On I2C bus, sending a "x" byte to the max1586 means : 52 * set V3 to 0.700V + (x & 0x1f) * 0.025V 53 * This voltage can be increased by external resistors 54 * R24 and R25=100kOhm as described in the data sheet. 55 * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm 56 */ 57static int max1586_v3_calc_voltage(struct max1586_data *max1586, 58 unsigned selector) 59{ 60 unsigned range_uV = max1586->max_uV - max1586->min_uV; 61 62 return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL); 63} 64 65static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV) 66{ 67 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 68 struct i2c_client *client = max1586->client; 69 unsigned range_uV = max1586->max_uV - max1586->min_uV; 70 unsigned selector; 71 u8 v3_prog; 72 73 if (min_uV > max1586->max_uV || max_uV < max1586->min_uV) 74 return -EINVAL; 75 if (min_uV < max1586->min_uV) 76 min_uV = max1586->min_uV; 77 78 selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL + 79 range_uV - 1) / range_uV; 80 if (max1586_v3_calc_voltage(max1586, selector) > max_uV) 81 return -EINVAL; 82 83 dev_dbg(&client->dev, "changing voltage v3 to %dmv\n", 84 max1586_v3_calc_voltage(max1586, selector) / 1000); 85 86 v3_prog = I2C_V3_SELECT | (u8) selector; 87 return i2c_smbus_write_byte(client, v3_prog); 88} 89 90static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector) 91{ 92 struct max1586_data *max1586 = rdev_get_drvdata(rdev); 93 94 if (selector > MAX1586_V3_MAX_VSEL) 95 return -EINVAL; 96 return max1586_v3_calc_voltage(max1586, selector); 97} 98 99/* 100 * V6 voltage 101 * On I2C bus, sending a "x" byte to the max1586 means : 102 * set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3) 103 * As regulator framework doesn't accept voltages to be 0V, we use 1uV. 104 */ 105static int max1586_v6_calc_voltage(unsigned selector) 106{ 107 static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 }; 108 109 return voltages_uv[selector]; 110} 111 112static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV) 113{ 114 struct i2c_client *client = rdev_get_drvdata(rdev); 115 unsigned selector; 116 u8 v6_prog; 117 118 if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV) 119 return -EINVAL; 120 if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV) 121 return -EINVAL; 122 123 if (min_uV >= 3000000) 124 selector = 3; 125 if (min_uV < 3000000) 126 selector = 2; 127 if (min_uV < 2500000) 128 selector = 1; 129 if (min_uV < 1800000) 130 selector = 0; 131 132 if (max1586_v6_calc_voltage(selector) > max_uV) 133 return -EINVAL; 134 135 dev_dbg(&client->dev, "changing voltage v6 to %dmv\n", 136 max1586_v6_calc_voltage(selector) / 1000); 137 138 v6_prog = I2C_V6_SELECT | (u8) selector; 139 return i2c_smbus_write_byte(client, v6_prog); 140} 141 142static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector) 143{ 144 if (selector > MAX1586_V6_MAX_VSEL) 145 return -EINVAL; 146 return max1586_v6_calc_voltage(selector); 147} 148 149/* 150 * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back 151 * the set up value. 152 */ 153static struct regulator_ops max1586_v3_ops = { 154 .set_voltage = max1586_v3_set, 155 .list_voltage = max1586_v3_list, 156}; 157 158static struct regulator_ops max1586_v6_ops = { 159 .set_voltage = max1586_v6_set, 160 .list_voltage = max1586_v6_list, 161}; 162 163static struct regulator_desc max1586_reg[] = { 164 { 165 .name = "Output_V3", 166 .id = MAX1586_V3, 167 .ops = &max1586_v3_ops, 168 .type = REGULATOR_VOLTAGE, 169 .n_voltages = MAX1586_V3_MAX_VSEL + 1, 170 .owner = THIS_MODULE, 171 }, 172 { 173 .name = "Output_V6", 174 .id = MAX1586_V6, 175 .ops = &max1586_v6_ops, 176 .type = REGULATOR_VOLTAGE, 177 .n_voltages = MAX1586_V6_MAX_VSEL + 1, 178 .owner = THIS_MODULE, 179 }, 180}; 181 182static int __devinit max1586_pmic_probe(struct i2c_client *client, 183 const struct i2c_device_id *i2c_id) 184{ 185 struct regulator_dev **rdev; 186 struct max1586_platform_data *pdata = client->dev.platform_data; 187 struct max1586_data *max1586; 188 int i, id, ret = -ENOMEM; 189 190 max1586 = kzalloc(sizeof(struct max1586_data) + 191 sizeof(struct regulator_dev *) * (MAX1586_V6 + 1), 192 GFP_KERNEL); 193 if (!max1586) 194 goto out; 195 196 max1586->client = client; 197 198 if (!pdata->v3_gain) { 199 ret = -EINVAL; 200 goto out_unmap; 201 } 202 max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000; 203 max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000; 204 205 rdev = max1586->rdev; 206 for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) { 207 id = pdata->subdevs[i].id; 208 if (!pdata->subdevs[i].platform_data) 209 continue; 210 if (id < MAX1586_V3 || id > MAX1586_V6) { 211 dev_err(&client->dev, "invalid regulator id %d\n", id); 212 goto err; 213 } 214 rdev[i] = regulator_register(&max1586_reg[id], &client->dev, 215 pdata->subdevs[i].platform_data, 216 max1586); 217 if (IS_ERR(rdev[i])) { 218 ret = PTR_ERR(rdev[i]); 219 dev_err(&client->dev, "failed to register %s\n", 220 max1586_reg[id].name); 221 goto err; 222 } 223 } 224 225 i2c_set_clientdata(client, rdev); 226 dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n"); 227 return 0; 228 229err: 230 while (--i >= 0) 231 regulator_unregister(rdev[i]); 232out_unmap: 233 kfree(max1586); 234out: 235 return ret; 236} 237 238static int __devexit max1586_pmic_remove(struct i2c_client *client) 239{ 240 struct regulator_dev **rdev = i2c_get_clientdata(client); 241 int i; 242 243 for (i = 0; i <= MAX1586_V6; i++) 244 if (rdev[i]) 245 regulator_unregister(rdev[i]); 246 kfree(rdev); 247 i2c_set_clientdata(client, NULL); 248 249 return 0; 250} 251 252static const struct i2c_device_id max1586_id[] = { 253 { "max1586", 0 }, 254 { } 255}; 256MODULE_DEVICE_TABLE(i2c, max1586_id); 257 258static 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 268static int __init max1586_pmic_init(void) 269{ 270 return i2c_add_driver(&max1586_pmic_driver); 271} 272subsys_initcall(max1586_pmic_init); 273 274static void __exit max1586_pmic_exit(void) 275{ 276 i2c_del_driver(&max1586_pmic_driver); 277} 278module_exit(max1586_pmic_exit); 279 280/* Module information */ 281MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver"); 282MODULE_AUTHOR("Robert Jarzmik"); 283MODULE_LICENSE("GPL"); 284