1 /* 2 * max8952.c - Voltage and current regulation for the Maxim 8952 3 * 4 * Copyright (C) 2010 Samsung Electronics 5 * MyungJoo Ham <myungjoo.ham@samsung.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 */ 21 22 #include <linux/module.h> 23 #include <linux/init.h> 24 #include <linux/i2c.h> 25 #include <linux/err.h> 26 #include <linux/platform_device.h> 27 #include <linux/regulator/driver.h> 28 #include <linux/regulator/max8952.h> 29 #include <linux/gpio.h> 30 #include <linux/io.h> 31 #include <linux/slab.h> 32 33 /* Registers */ 34 enum { 35 MAX8952_REG_MODE0, 36 MAX8952_REG_MODE1, 37 MAX8952_REG_MODE2, 38 MAX8952_REG_MODE3, 39 MAX8952_REG_CONTROL, 40 MAX8952_REG_SYNC, 41 MAX8952_REG_RAMP, 42 MAX8952_REG_CHIP_ID1, 43 MAX8952_REG_CHIP_ID2, 44 }; 45 46 struct max8952_data { 47 struct i2c_client *client; 48 struct device *dev; 49 struct max8952_platform_data *pdata; 50 struct regulator_dev *rdev; 51 52 bool vid0; 53 bool vid1; 54 }; 55 56 static int max8952_read_reg(struct max8952_data *max8952, u8 reg) 57 { 58 int ret = i2c_smbus_read_byte_data(max8952->client, reg); 59 if (ret > 0) 60 ret &= 0xff; 61 62 return ret; 63 } 64 65 static int max8952_write_reg(struct max8952_data *max8952, 66 u8 reg, u8 value) 67 { 68 return i2c_smbus_write_byte_data(max8952->client, reg, value); 69 } 70 71 static int max8952_list_voltage(struct regulator_dev *rdev, 72 unsigned int selector) 73 { 74 struct max8952_data *max8952 = rdev_get_drvdata(rdev); 75 76 if (rdev_get_id(rdev) != 0) 77 return -EINVAL; 78 79 return (max8952->pdata->dvs_mode[selector] * 10 + 770) * 1000; 80 } 81 82 static int max8952_get_voltage_sel(struct regulator_dev *rdev) 83 { 84 struct max8952_data *max8952 = rdev_get_drvdata(rdev); 85 u8 vid = 0; 86 87 if (max8952->vid0) 88 vid += 1; 89 if (max8952->vid1) 90 vid += 2; 91 92 return vid; 93 } 94 95 static int max8952_set_voltage_sel(struct regulator_dev *rdev, 96 unsigned selector) 97 { 98 struct max8952_data *max8952 = rdev_get_drvdata(rdev); 99 100 if (!gpio_is_valid(max8952->pdata->gpio_vid0) || 101 !gpio_is_valid(max8952->pdata->gpio_vid1)) { 102 /* DVS not supported */ 103 return -EPERM; 104 } 105 106 max8952->vid0 = selector & 0x1; 107 max8952->vid1 = (selector >> 1) & 0x1; 108 gpio_set_value(max8952->pdata->gpio_vid0, max8952->vid0); 109 gpio_set_value(max8952->pdata->gpio_vid1, max8952->vid1); 110 111 return 0; 112 } 113 114 static struct regulator_ops max8952_ops = { 115 .list_voltage = max8952_list_voltage, 116 .get_voltage_sel = max8952_get_voltage_sel, 117 .set_voltage_sel = max8952_set_voltage_sel, 118 }; 119 120 static const struct regulator_desc regulator = { 121 .name = "MAX8952_VOUT", 122 .id = 0, 123 .n_voltages = MAX8952_NUM_DVS_MODE, 124 .ops = &max8952_ops, 125 .type = REGULATOR_VOLTAGE, 126 .owner = THIS_MODULE, 127 }; 128 129 static int max8952_pmic_probe(struct i2c_client *client, 130 const struct i2c_device_id *i2c_id) 131 { 132 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); 133 struct max8952_platform_data *pdata = client->dev.platform_data; 134 struct regulator_config config = { }; 135 struct max8952_data *max8952; 136 137 int ret = 0, err = 0; 138 139 if (!pdata) { 140 dev_err(&client->dev, "Require the platform data\n"); 141 return -EINVAL; 142 } 143 144 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE)) 145 return -EIO; 146 147 max8952 = devm_kzalloc(&client->dev, sizeof(struct max8952_data), 148 GFP_KERNEL); 149 if (!max8952) 150 return -ENOMEM; 151 152 max8952->client = client; 153 max8952->dev = &client->dev; 154 max8952->pdata = pdata; 155 156 config.dev = max8952->dev; 157 config.init_data = &pdata->reg_data; 158 config.driver_data = max8952; 159 160 config.ena_gpio = pdata->gpio_en; 161 if (pdata->reg_data.constraints.boot_on) 162 config.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH; 163 164 max8952->rdev = regulator_register(®ulator, &config); 165 166 if (IS_ERR(max8952->rdev)) { 167 ret = PTR_ERR(max8952->rdev); 168 dev_err(max8952->dev, "regulator init failed (%d)\n", ret); 169 return ret; 170 } 171 172 max8952->vid0 = pdata->default_mode & 0x1; 173 max8952->vid1 = (pdata->default_mode >> 1) & 0x1; 174 175 if (gpio_is_valid(pdata->gpio_vid0) && 176 gpio_is_valid(pdata->gpio_vid1)) { 177 if (!gpio_request(pdata->gpio_vid0, "MAX8952 VID0")) 178 gpio_direction_output(pdata->gpio_vid0, 179 (pdata->default_mode) & 0x1); 180 else 181 err = 1; 182 183 if (!gpio_request(pdata->gpio_vid1, "MAX8952 VID1")) 184 gpio_direction_output(pdata->gpio_vid1, 185 (pdata->default_mode >> 1) & 0x1); 186 else { 187 if (!err) 188 gpio_free(pdata->gpio_vid0); 189 err = 2; 190 } 191 192 } else 193 err = 3; 194 195 if (err) { 196 dev_warn(max8952->dev, "VID0/1 gpio invalid: " 197 "DVS not available.\n"); 198 max8952->vid0 = 0; 199 max8952->vid1 = 0; 200 /* Mark invalid */ 201 pdata->gpio_vid0 = -1; 202 pdata->gpio_vid1 = -1; 203 204 /* Disable Pulldown of EN only */ 205 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x60); 206 207 dev_err(max8952->dev, "DVS modes disabled because VID0 and VID1" 208 " do not have proper controls.\n"); 209 } else { 210 /* 211 * Disable Pulldown on EN, VID0, VID1 to reduce 212 * leakage current of MAX8952 assuming that MAX8952 213 * is turned on (EN==1). Note that without having VID0/1 214 * properly connected, turning pulldown off can be 215 * problematic. Thus, turn this off only when they are 216 * controllable by GPIO. 217 */ 218 max8952_write_reg(max8952, MAX8952_REG_CONTROL, 0x0); 219 } 220 221 max8952_write_reg(max8952, MAX8952_REG_MODE0, 222 (max8952_read_reg(max8952, 223 MAX8952_REG_MODE0) & 0xC0) | 224 (pdata->dvs_mode[0] & 0x3F)); 225 max8952_write_reg(max8952, MAX8952_REG_MODE1, 226 (max8952_read_reg(max8952, 227 MAX8952_REG_MODE1) & 0xC0) | 228 (pdata->dvs_mode[1] & 0x3F)); 229 max8952_write_reg(max8952, MAX8952_REG_MODE2, 230 (max8952_read_reg(max8952, 231 MAX8952_REG_MODE2) & 0xC0) | 232 (pdata->dvs_mode[2] & 0x3F)); 233 max8952_write_reg(max8952, MAX8952_REG_MODE3, 234 (max8952_read_reg(max8952, 235 MAX8952_REG_MODE3) & 0xC0) | 236 (pdata->dvs_mode[3] & 0x3F)); 237 238 max8952_write_reg(max8952, MAX8952_REG_SYNC, 239 (max8952_read_reg(max8952, MAX8952_REG_SYNC) & 0x3F) | 240 ((pdata->sync_freq & 0x3) << 6)); 241 max8952_write_reg(max8952, MAX8952_REG_RAMP, 242 (max8952_read_reg(max8952, MAX8952_REG_RAMP) & 0x1F) | 243 ((pdata->ramp_speed & 0x7) << 5)); 244 245 i2c_set_clientdata(client, max8952); 246 247 return 0; 248 } 249 250 static int max8952_pmic_remove(struct i2c_client *client) 251 { 252 struct max8952_data *max8952 = i2c_get_clientdata(client); 253 struct max8952_platform_data *pdata = max8952->pdata; 254 struct regulator_dev *rdev = max8952->rdev; 255 256 regulator_unregister(rdev); 257 258 gpio_free(pdata->gpio_vid0); 259 gpio_free(pdata->gpio_vid1); 260 return 0; 261 } 262 263 static const struct i2c_device_id max8952_ids[] = { 264 { "max8952", 0 }, 265 { }, 266 }; 267 MODULE_DEVICE_TABLE(i2c, max8952_ids); 268 269 static struct i2c_driver max8952_pmic_driver = { 270 .probe = max8952_pmic_probe, 271 .remove = max8952_pmic_remove, 272 .driver = { 273 .name = "max8952", 274 }, 275 .id_table = max8952_ids, 276 }; 277 278 static int __init max8952_pmic_init(void) 279 { 280 return i2c_add_driver(&max8952_pmic_driver); 281 } 282 subsys_initcall(max8952_pmic_init); 283 284 static void __exit max8952_pmic_exit(void) 285 { 286 i2c_del_driver(&max8952_pmic_driver); 287 } 288 module_exit(max8952_pmic_exit); 289 290 MODULE_DESCRIPTION("MAXIM 8952 voltage regulator driver"); 291 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); 292 MODULE_LICENSE("GPL"); 293