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         unsigned        mode:2; /* bit[1:0] = VID1, VID0 */
  57         unsigned        extclk_freq:2;
  58         unsigned        extclk:1;
  59         unsigned        ramp_timing:3;
  60         unsigned        ramp_down:1;
  61 };
  62
  63 /* EN_PD means pulldown on EN input */
  64 static int max8649_enable(struct regulator_dev *rdev)
  65 {
  66         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  67         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD, 0);
  68 }
  69
  70 /*
  71  * Applied internal pulldown resistor on EN input pin.
  72  * If pulldown EN pin outside, it would be better.
  73  */
  74 static int max8649_disable(struct regulator_dev *rdev)
  75 {
  76         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  77         return regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_EN_PD,
  78                                 MAX8649_EN_PD);
  79 }
  80
  81 static int max8649_is_enabled(struct regulator_dev *rdev)
  82 {
  83         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  84         unsigned int val;
  85         int ret;
  86
  87         ret = regmap_read(info->regmap, MAX8649_CONTROL, &val);
  88         if (ret != 0)
  89                 return ret;
  90         return !((unsigned char)val & MAX8649_EN_PD);
  91 }
  92
  93 static int max8649_enable_time(struct regulator_dev *rdev)
  94 {
  95         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  96         int voltage, rate, ret;
  97         unsigned int val;
  98
  99         /* get voltage */
 100         ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
 101         if (ret != 0)
 102                 return ret;
 103         val &= MAX8649_VOL_MASK;
 104         voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
 105
 106         /* get rate */
 107         ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
 108         if (ret != 0)
 109                 return ret;
 110         ret = (val & MAX8649_RAMP_MASK) >> 5;
 111         rate = (32 * 1000) >> ret;      /* uV/uS */
 112
 113         return DIV_ROUND_UP(voltage, rate);
 114 }
 115
 116 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
 117 {
 118         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 119
 120         switch (mode) {
 121         case REGULATOR_MODE_FAST:
 122                 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
 123                                    MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
 124                 break;
 125         case REGULATOR_MODE_NORMAL:
 126                 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
 127                                    MAX8649_FORCE_PWM, 0);
 128                 break;
 129         default:
 130                 return -EINVAL;
 131         }
 132         return 0;
 133 }
 134
 135 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
 136 {
 137         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 138         unsigned int val;
 139         int ret;
 140
 141         ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
 142         if (ret != 0)
 143                 return ret;
 144         if (val & MAX8649_FORCE_PWM)
 145                 return REGULATOR_MODE_FAST;
 146         return REGULATOR_MODE_NORMAL;
 147 }
 148
 149 static struct regulator_ops max8649_dcdc_ops = {
 150         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 151         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 152         .list_voltage   = regulator_list_voltage_linear,
 153         .map_voltage    = regulator_map_voltage_linear,
 154         .enable         = max8649_enable,
 155         .disable        = max8649_disable,
 156         .is_enabled     = max8649_is_enabled,
 157         .enable_time    = max8649_enable_time,
 158         .set_mode       = max8649_set_mode,
 159         .get_mode       = max8649_get_mode,
 160
 161 };
 162
 163 static struct regulator_desc dcdc_desc = {
 164         .name           = "max8649",
 165         .ops            = &max8649_dcdc_ops,
 166         .type           = REGULATOR_VOLTAGE,
 167         .n_voltages     = 1 << 6,
 168         .owner          = THIS_MODULE,
 169         .vsel_mask      = MAX8649_VOL_MASK,
 170         .min_uV         = MAX8649_DCDC_VMIN,
 171         .uV_step        = MAX8649_DCDC_STEP,
 172 };
 173
 174 static struct regmap_config max8649_regmap_config = {
 175         .reg_bits = 8,
 176         .val_bits = 8,
 177 };
 178
 179 static int max8649_regulator_probe(struct i2c_client *client,
 180                                              const struct i2c_device_id *id)
 181 {
 182         struct max8649_platform_data *pdata = client->dev.platform_data;
 183         struct max8649_regulator_info *info = NULL;
 184         struct regulator_config config = { };
 185         unsigned int val;
 186         unsigned char data;
 187         int ret;
 188
 189         info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
 190                             GFP_KERNEL);
 191         if (!info) {
 192                 dev_err(&client->dev, "No enough memory\n");
 193                 return -ENOMEM;
 194         }
 195
 196         info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
 197         if (IS_ERR(info->regmap)) {
 198                 ret = PTR_ERR(info->regmap);
 199                 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
 200                 return ret;
 201         }
 202
 203         info->dev = &client->dev;
 204         i2c_set_clientdata(client, info);
 205
 206         info->mode = pdata->mode;
 207         switch (info->mode) {
 208         case 0:
 209                 dcdc_desc.vsel_reg = MAX8649_MODE0;
 210                 break;
 211         case 1:
 212                 dcdc_desc.vsel_reg = MAX8649_MODE1;
 213                 break;
 214         case 2:
 215                 dcdc_desc.vsel_reg = MAX8649_MODE2;
 216                 break;
 217         case 3:
 218                 dcdc_desc.vsel_reg = MAX8649_MODE3;
 219                 break;
 220         default:
 221                 break;
 222         }
 223
 224         ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
 225         if (ret != 0) {
 226                 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
 227                         ret);
 228                 return ret;
 229         }
 230         dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
 231
 232         /* enable VID0 & VID1 */
 233         regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
 234
 235         /* enable/disable external clock synchronization */
 236         info->extclk = pdata->extclk;
 237         data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
 238         regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
 239                            MAX8649_SYNC_EXTCLK, data);
 240         if (info->extclk) {
 241                 /* set external clock frequency */
 242                 info->extclk_freq = pdata->extclk_freq;
 243                 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
 244                                    info->extclk_freq << 6);
 245         }
 246
 247         if (pdata->ramp_timing) {
 248                 info->ramp_timing = pdata->ramp_timing;
 249                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
 250                                    info->ramp_timing << 5);
 251         }
 252
 253         info->ramp_down = pdata->ramp_down;
 254         if (info->ramp_down) {
 255                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
 256                                    MAX8649_RAMP_DOWN);
 257         }
 258
 259         config.dev = &client->dev;
 260         config.init_data = pdata->regulator;
 261         config.driver_data = info;
 262         config.regmap = info->regmap;
 263
 264         info->regulator = regulator_register(&dcdc_desc, &config);
 265         if (IS_ERR(info->regulator)) {
 266                 dev_err(info->dev, "failed to register regulator %s\n",
 267                         dcdc_desc.name);
 268                 return PTR_ERR(info->regulator);
 269         }
 270
 271         return 0;
 272 }
 273
 274 static int max8649_regulator_remove(struct i2c_client *client)
 275 {
 276         struct max8649_regulator_info *info = i2c_get_clientdata(client);
 277
 278         if (info) {
 279                 if (info->regulator)
 280                         regulator_unregister(info->regulator);
 281         }
 282
 283         return 0;
 284 }
 285
 286 static const struct i2c_device_id max8649_id[] = {
 287         { "max8649", 0 },
 288         { }
 289 };
 290 MODULE_DEVICE_TABLE(i2c, max8649_id);
 291
 292 static struct i2c_driver max8649_driver = {
 293         .probe          = max8649_regulator_probe,
 294         .remove         = max8649_regulator_remove,
 295         .driver         = {
 296                 .name   = "max8649",
 297         },
 298         .id_table       = max8649_id,
 299 };
 300
 301 static int __init max8649_init(void)
 302 {
 303         return i2c_add_driver(&max8649_driver);
 304 }
 305 subsys_initcall(max8649_init);
 306
 307 static void __exit max8649_exit(void)
 308 {
 309         i2c_del_driver(&max8649_driver);
 310 }
 311 module_exit(max8649_exit);
 312
 313 /* Module information */
 314 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
 315 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 316 MODULE_LICENSE("GPL");