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 = DIV_ROUND_UP(min_uV - MAX8649_DCDC_VMIN, MAX8649_DCDC_STEP);
 105         mask = MAX8649_VOL_MASK;
 106         *selector = data & mask;
 107
 108         return regmap_update_bits(info->regmap, info->vol_reg, mask, data);
 109 }
 110
 111 /* EN_PD means pulldown on EN input */
 112 static int max8649_enable(struct regulator_dev *rdev)
 113 {
 114         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 115         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD, 0);
 116 }
 117
 118 /*
 119  * Applied internal pulldown resistor on EN input pin.
 120  * If pulldown EN pin outside, it would be better.
 121  */
 122 static int max8649_disable(struct regulator_dev *rdev)
 123 {
 124         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 125         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD,
 126                                 MAX8649_EN_PD);
 127 }
 128
 129 static int max8649_is_enabled(struct regulator_dev *rdev)
 130 {
 131         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 132         unsigned int val;
 133         int ret;
 134
 135         ret = regmap_read(info->regmap, MAX8649_CONTROL, &val);
 136         if (ret != 0)
 137                 return ret;
 138         return !((unsigned char)val & MAX8649_EN_PD);
 139 }
 140
 141 static int max8649_enable_time(struct regulator_dev *rdev)
 142 {
 143         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 144         int voltage, rate, ret;
 145         unsigned int val;
 146
 147         /* get voltage */
 148         ret = regmap_read(info->regmap, info->vol_reg, &val);
 149         if (ret != 0)
 150                 return ret;
 151         val &= MAX8649_VOL_MASK;
 152         voltage = max8649_list_voltage(rdev, (unsigned char)val); /* uV */
 153
 154         /* get rate */
 155         ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
 156         if (ret != 0)
 157                 return ret;
 158         ret = (val & MAX8649_RAMP_MASK) >> 5;
 159         rate = (32 * 1000) >> ret;      /* uV/uS */
 160
 161         return DIV_ROUND_UP(voltage, rate);
 162 }
 163
 164 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
 165 {
 166         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 167
 168         switch (mode) {
 169         case REGULATOR_MODE_FAST:
 170                 regmap_update_bits(info->regmap, info->vol_reg, MAX8649_FORCE_PWM,
 171                                    MAX8649_FORCE_PWM);
 172                 break;
 173         case REGULATOR_MODE_NORMAL:
 174                 regmap_update_bits(info->regmap, info->vol_reg,
 175                                    MAX8649_FORCE_PWM, 0);
 176                 break;
 177         default:
 178                 return -EINVAL;
 179         }
 180         return 0;
 181 }
 182
 183 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
 184 {
 185         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 186         unsigned int val;
 187         int ret;
 188
 189         ret = regmap_read(info->regmap, info->vol_reg, &val);
 190         if (ret != 0)
 191                 return ret;
 192         if (val & MAX8649_FORCE_PWM)
 193                 return REGULATOR_MODE_FAST;
 194         return REGULATOR_MODE_NORMAL;
 195 }
 196
 197 static struct regulator_ops max8649_dcdc_ops = {
 198         .set_voltage    = max8649_set_voltage,
 199         .get_voltage    = max8649_get_voltage,
 200         .list_voltage   = max8649_list_voltage,
 201         .enable         = max8649_enable,
 202         .disable        = max8649_disable,
 203         .is_enabled     = max8649_is_enabled,
 204         .enable_time    = max8649_enable_time,
 205         .set_mode       = max8649_set_mode,
 206         .get_mode       = max8649_get_mode,
 207
 208 };
 209
 210 static struct regulator_desc dcdc_desc = {
 211         .name           = "max8649",
 212         .ops            = &max8649_dcdc_ops,
 213         .type           = REGULATOR_VOLTAGE,
 214         .n_voltages     = 1 << 6,
 215         .owner          = THIS_MODULE,
 216 };
 217
 218 static struct regmap_config max8649_regmap_config = {
 219         .reg_bits = 8,
 220         .val_bits = 8,
 221 };
 222
 223 static int __devinit max8649_regulator_probe(struct i2c_client *client,
 224                                              const struct i2c_device_id *id)
 225 {
 226         struct max8649_platform_data *pdata = client->dev.platform_data;
 227         struct max8649_regulator_info *info = NULL;
 228         unsigned int val;
 229         unsigned char data;
 230         int ret;
 231
 232         info = kzalloc(sizeof(struct max8649_regulator_info), GFP_KERNEL);
 233         if (!info) {
 234                 dev_err(&client->dev, "No enough memory\n");
 235                 return -ENOMEM;
 236         }
 237
 238         info->regmap = regmap_init_i2c(client, &max8649_regmap_config);
 239         if (IS_ERR(info->regmap)) {
 240                 ret = PTR_ERR(info->regmap);
 241                 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
 242                 goto fail;
 243         }
 244
 245         info->dev = &client->dev;
 246         i2c_set_clientdata(client, info);
 247
 248         info->mode = pdata->mode;
 249         switch (info->mode) {
 250         case 0:
 251                 info->vol_reg = MAX8649_MODE0;
 252                 break;
 253         case 1:
 254                 info->vol_reg = MAX8649_MODE1;
 255                 break;
 256         case 2:
 257                 info->vol_reg = MAX8649_MODE2;
 258                 break;
 259         case 3:
 260                 info->vol_reg = MAX8649_MODE3;
 261                 break;
 262         default:
 263                 break;
 264         }
 265
 266         ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
 267         if (ret != 0) {
 268                 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
 269                         ret);
 270                 goto out;
 271         }
 272         dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
 273
 274         /* enable VID0 & VID1 */
 275         regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
 276
 277         /* enable/disable external clock synchronization */
 278         info->extclk = pdata->extclk;
 279         data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
 280         regmap_update_bits(info->regmap, info->vol_reg, MAX8649_SYNC_EXTCLK, data);
 281         if (info->extclk) {
 282                 /* set external clock frequency */
 283                 info->extclk_freq = pdata->extclk_freq;
 284                 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
 285                                    info->extclk_freq << 6);
 286         }
 287
 288         if (pdata->ramp_timing) {
 289                 info->ramp_timing = pdata->ramp_timing;
 290                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
 291                                    info->ramp_timing << 5);
 292         }
 293
 294         info->ramp_down = pdata->ramp_down;
 295         if (info->ramp_down) {
 296                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
 297                                    MAX8649_RAMP_DOWN);
 298         }
 299
 300         info->regulator = regulator_register(&dcdc_desc, &client->dev,
 301                                              pdata->regulator, info, NULL);
 302         if (IS_ERR(info->regulator)) {
 303                 dev_err(info->dev, "failed to register regulator %s\n",
 304                         dcdc_desc.name);
 305                 ret = PTR_ERR(info->regulator);
 306                 goto out;
 307         }
 308
 309         dev_info(info->dev, "Max8649 regulator device is detected.\n");
 310         return 0;
 311 out:
 312         regmap_exit(info->regmap);
 313 fail:
 314         kfree(info);
 315         return ret;
 316 }
 317
 318 static int __devexit max8649_regulator_remove(struct i2c_client *client)
 319 {
 320         struct max8649_regulator_info *info = i2c_get_clientdata(client);
 321
 322         if (info) {
 323                 if (info->regulator)
 324                         regulator_unregister(info->regulator);
 325                 regmap_exit(info->regmap);
 326                 kfree(info);
 327         }
 328
 329         return 0;
 330 }
 331
 332 static const struct i2c_device_id max8649_id[] = {
 333         { "max8649", 0 },
 334         { }
 335 };
 336 MODULE_DEVICE_TABLE(i2c, max8649_id);
 337
 338 static struct i2c_driver max8649_driver = {
 339         .probe          = max8649_regulator_probe,
 340         .remove         = __devexit_p(max8649_regulator_remove),
 341         .driver         = {
 342                 .name   = "max8649",
 343         },
 344         .id_table       = max8649_id,
 345 };
 346
 347 static int __init max8649_init(void)
 348 {
 349         return i2c_add_driver(&max8649_driver);
 350 }
 351 subsys_initcall(max8649_init);
 352
 353 static void __exit max8649_exit(void)
 354 {
 355         i2c_del_driver(&max8649_driver);
 356 }
 357 module_exit(max8649_exit);
 358
 359 /* Module information */
 360 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
 361 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 362 MODULE_LICENSE("GPL");
 363