drivers/regulator/max8649.c

   1 /*
   2  * Regulators driver for Maxim max8649
   3  *
   4  * Copyright (C) 2009-2010 Marvell International Ltd.
   5  *      Haojian Zhuang <haojian.zhuang@marvell.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 version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/err.h>
  14 #include <linux/i2c.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/regulator/driver.h>
  17 #include <linux/slab.h>
  18 #include <linux/regulator/max8649.h>
  19 #include <linux/regmap.h>
  20
  21 #define MAX8649_DCDC_VMIN       750000          /* uV */
  22 #define MAX8649_DCDC_VMAX       1380000         /* uV */
  23 #define MAX8649_DCDC_STEP       10000           /* uV */
  24 #define MAX8649_VOL_MASK        0x3f
  25
  26 /* Registers */
  27 #define MAX8649_MODE0           0x00
  28 #define MAX8649_MODE1           0x01
  29 #define MAX8649_MODE2           0x02
  30 #define MAX8649_MODE3           0x03
  31 #define MAX8649_CONTROL         0x04
  32 #define MAX8649_SYNC            0x05
  33 #define MAX8649_RAMP            0x06
  34 #define MAX8649_CHIP_ID1        0x08
  35 #define MAX8649_CHIP_ID2        0x09
  36
  37 /* Bits */
  38 #define MAX8649_EN_PD           (1 << 7)
  39 #define MAX8649_VID0_PD         (1 << 6)
  40 #define MAX8649_VID1_PD         (1 << 5)
  41 #define MAX8649_VID_MASK        (3 << 5)
  42
  43 #define MAX8649_FORCE_PWM       (1 << 7)
  44 #define MAX8649_SYNC_EXTCLK     (1 << 6)
  45
  46 #define MAX8649_EXT_MASK        (3 << 6)
  47
  48 #define MAX8649_RAMP_MASK       (7 << 5)
  49 #define MAX8649_RAMP_DOWN       (1 << 1)
  50
  51 struct max8649_regulator_info {
  52         struct regulator_dev    *regulator;
  53         struct device           *dev;
  54         struct regmap           *regmap;
  55
  56         int             vol_reg;
  57         unsigned        mode:2; /* bit[1:0] = VID1, VID0 */
  58         unsigned        extclk_freq:2;
  59         unsigned        extclk:1;
  60         unsigned        ramp_timing:3;
  61         unsigned        ramp_down:1;
  62 };
  63
  64 /* I2C operations */
  65
  66 static inline int check_range(int min_uV, int max_uV)
  67 {
  68         if ((min_uV < MAX8649_DCDC_VMIN) || (max_uV > MAX8649_DCDC_VMAX)
  69                 || (min_uV > max_uV))
  70                 return -EINVAL;
  71         return 0;
  72 }
  73
  74 static int max8649_list_voltage(struct regulator_dev *rdev, unsigned index)
  75 {
  76         return (MAX8649_DCDC_VMIN + index * MAX8649_DCDC_STEP);
  77 }
  78
  79 static int max8649_get_voltage(struct regulator_dev *rdev)
  80 {
  81         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  82         unsigned int val;
  83         unsigned char data;
  84         int ret;
  85
  86         ret = regmap_read(info->regmap, info->vol_reg, &val);
  87         if (ret != 0)
  88                 return ret;
  89         data = (unsigned char)val & MAX8649_VOL_MASK;
  90         return max8649_list_voltage(rdev, data);
  91 }
  92
  93 static int max8649_set_voltage(struct regulator_dev *rdev,
  94                                int min_uV, int max_uV, unsigned *selector)
  95 {
  96         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  97         unsigned char data, mask;
  98
  99         if (check_range(min_uV, max_uV)) {
 100                 dev_err(info->dev, "invalid voltage range (%d, %d) uV\n",
 101                         min_uV, max_uV);
 102                 return -EINVAL;
 103         }
 104         data = (min_uV - MAX8649_DCDC_VMIN + MAX8649_DCDC_STEP - 1)
 105                 / MAX8649_DCDC_STEP;
 106         mask = MAX8649_VOL_MASK;
 107         *selector = data & mask;
 108
 109         return regmap_update_bits(info->regmap, info->vol_reg, mask, data);
 110 }
 111
 112 /* EN_PD means pulldown on EN input */
 113 static int max8649_enable(struct regulator_dev *rdev)
 114 {
 115         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 116         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD, 0);
 117 }
 118
 119 /*
 120  * Applied internal pulldown resistor on EN input pin.
 121  * If pulldown EN pin outside, it would be better.
 122  */
 123 static int max8649_disable(struct regulator_dev *rdev)
 124 {
 125         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 126         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD,
 127                                 MAX8649_EN_PD);
 128 }
 129
 130 static int max8649_is_enabled(struct regulator_dev *rdev)
 131 {
 132         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 133         unsigned int val;
 134         int ret;
 135
 136         ret = regmap_read(info->regmap, MAX8649_CONTROL, &val);
 137         if (ret != 0)
 138                 return ret;
 139         return !((unsigned char)val & MAX8649_EN_PD);
 140 }
 141
 142 static int max8649_enable_time(struct regulator_dev *rdev)
 143 {
 144         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 145         int voltage, rate, ret;
 146         unsigned int val;
 147
 148         /* get voltage */
 149         ret = regmap_read(info->regmap, info->vol_reg, &val);
 150         if (ret != 0)
 151                 return ret;
 152         val &= MAX8649_VOL_MASK;
 153         voltage = max8649_list_voltage(rdev, (unsigned char)val); /* uV */
 154
 155         /* get rate */
 156         ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
 157         if (ret != 0)
 158                 return ret;
 159         ret = (val & MAX8649_RAMP_MASK) >> 5;
 160         rate = (32 * 1000) >> ret;      /* uV/uS */
 161
 162         return DIV_ROUND_UP(voltage, rate);
 163 }
 164
 165 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
 166 {
 167         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 168
 169         switch (mode) {
 170         case REGULATOR_MODE_FAST:
 171                 regmap_update_bits(info->regmap, info->vol_reg, MAX8649_FORCE_PWM,
 172                                    MAX8649_FORCE_PWM);
 173                 break;
 174         case REGULATOR_MODE_NORMAL:
 175                 regmap_update_bits(info->regmap, info->vol_reg,
 176                                    MAX8649_FORCE_PWM, 0);
 177                 break;
 178         default:
 179                 return -EINVAL;
 180         }
 181         return 0;
 182 }
 183
 184 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
 185 {
 186         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 187         unsigned int val;
 188         int ret;
 189
 190         ret = regmap_read(info->regmap, info->vol_reg, &val);
 191         if (ret != 0)
 192                 return ret;
 193         if (val & MAX8649_FORCE_PWM)
 194                 return REGULATOR_MODE_FAST;
 195         return REGULATOR_MODE_NORMAL;
 196 }
 197
 198 static struct regulator_ops max8649_dcdc_ops = {
 199         .set_voltage    = max8649_set_voltage,
 200         .get_voltage    = max8649_get_voltage,
 201         .list_voltage   = max8649_list_voltage,
 202         .enable         = max8649_enable,
 203         .disable        = max8649_disable,
 204         .is_enabled     = max8649_is_enabled,
 205         .enable_time    = max8649_enable_time,
 206         .set_mode       = max8649_set_mode,
 207         .get_mode       = max8649_get_mode,
 208
 209 };
 210
 211 static struct regulator_desc dcdc_desc = {
 212         .name           = "max8649",
 213         .ops            = &max8649_dcdc_ops,
 214         .type           = REGULATOR_VOLTAGE,
 215         .n_voltages     = 1 << 6,
 216         .owner          = THIS_MODULE,
 217 };
 218
 219 static struct regmap_config max8649_regmap_config = {
 220         .reg_bits = 8,
 221         .val_bits = 8,
 222 };
 223
 224 static int __devinit max8649_regulator_probe(struct i2c_client *client,
 225                                              const struct i2c_device_id *id)
 226 {
 227         struct max8649_platform_data *pdata = client->dev.platform_data;
 228         struct max8649_regulator_info *info = NULL;
 229         unsigned int val;
 230         unsigned char data;
 231         int ret;
 232
 233         info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
 234         if (!info) {
 235                 dev_err(&client->dev, "No enough memory\n");
 236                 return -ENOMEM;
 237         }
 238
 239         info->regmap = regmap_init_i2c(client, &max8649_regmap_config);
 240         if (IS_ERR(info->regmap)) {
 241                 ret = PTR_ERR(info->regmap);
 242                 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
 243                 goto fail;
 244         }
 245
 246         info->dev = &client->dev;
 247         i2c_set_clientdata(client, info);
 248
 249         info->mode = pdata->mode;
 250         switch (info->mode) {
 251         case 0:
 252                 info->vol_reg = MAX8649_MODE0;
 253                 break;
 254         case 1:
 255                 info->vol_reg = MAX8649_MODE1;
 256                 break;
 257         case 2:
 258                 info->vol_reg = MAX8649_MODE2;
 259                 break;
 260         case 3:
 261                 info->vol_reg = MAX8649_MODE3;
 262                 break;
 263         default:
 264                 break;
 265         }
 266
 267         ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
 268         if (ret != 0) {
 269                 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
 270                         ret);
 271                 goto out;
 272         }
 273         dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", ret);
 274
 275         /* enable VID0 & VID1 */
 276         regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
 277
 278         /* enable/disable external clock synchronization */
 279         info->extclk = pdata->extclk;
 280         data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
 281         regmap_update_bits(info->regmap, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
 282         if (info->extclk) {
 283                 /* set external clock frequency */
 284                 info->extclk_freq = pdata->extclk_freq;
 285                 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
 286                                    info->extclk_freq << 6);
 287         }
 288
 289         if (pdata->ramp_timing) {
 290                 info->ramp_timing = pdata->ramp_timing;
 291                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
 292                                    info->ramp_timing << 5);
 293         }
 294
 295         info->ramp_down = pdata->ramp_down;
 296         if (info->ramp_down) {
 297                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
 298                                    MAX8649_RAMP_DOWN);
 299         }
 300
 301         info->regulator = regulator_register(&dcdc_desc, &client->dev,
 302                                              pdata->regulator, info, NULL);
 303         if (IS_ERR(info->regulator)) {
 304                 dev_err(info->dev, "failed to register regulator %s\n",
 305                         dcdc_desc.name);
 306                 ret = PTR_ERR(info->regulator);
 307                 goto out;
 308         }
 309
 310         dev_info(info->dev, "Max8649 regulator device is detected.\n");
 311         return 0;
 312 out:
 313         regmap_exit(info->regmap);
 314 fail:
 315         kfree(info);
 316         return ret;
 317 }
 318
 319 static int __devexit max8649_regulator_remove(struct i2c_client *client)
 320 {
 321         struct max8649_regulator_info *info = i2c_get_clientdata(client);
 322
 323         if (info) {
 324                 if (info->regulator)
 325                         regulator_unregister(info->regulator);
 326                 regmap_exit(info->regmap);
 327                 kfree(info);
 328         }
 329
 330         return 0;
 331 }
 332
 333 static const struct i2c_device_id max8649_id[] = {
 334         { "max8649", 0 },
 335         { }
 336 };
 337 MODULE_DEVICE_TABLE(i2c, max8649_id);
 338
 339 static struct i2c_driver max8649_driver = {
 340         .probe          = max8649_regulator_probe,
 341         .remove         = __devexit_p(max8649_regulator_remove),
 342         .driver         = {
 343                 .name   = "max8649",
 344         },
 345         .id_table       = max8649_id,
 346 };
 347
 348 static int __init max8649_init(void)
 349 {
 350         return i2c_add_driver(&max8649_driver);
 351 }
 352 subsys_initcall(max8649_init);
 353
 354 static void __exit max8649_exit(void)
 355 {
 356         i2c_del_driver(&max8649_driver);
 357 }
 358 module_exit(max8649_exit);
 359
 360 /* Module information */
 361 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
 362 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 363 MODULE_LICENSE("GPL");
 364