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 device           *dev;
  53         struct regmap           *regmap;
  54
  55         unsigned        mode:2; /* bit[1:0] = VID1, VID0 */
  56         unsigned        extclk_freq:2;
  57         unsigned        extclk:1;
  58         unsigned        ramp_timing:3;
  59         unsigned        ramp_down:1;
  60 };
  61
  62 static int max8649_enable_time(struct regulator_dev *rdev)
  63 {
  64         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  65         int voltage, rate, ret;
  66         unsigned int val;
  67
  68         /* get voltage */
  69         ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
  70         if (ret != 0)
  71                 return ret;
  72         val &= MAX8649_VOL_MASK;
  73         voltage = regulator_list_voltage_linear(rdev, (unsigned char)val);
  74
  75         /* get rate */
  76         ret = regmap_read(info->regmap, MAX8649_RAMP, &val);
  77         if (ret != 0)
  78                 return ret;
  79         ret = (val & MAX8649_RAMP_MASK) >> 5;
  80         rate = (32 * 1000) >> ret;      /* uV/uS */
  81
  82         return DIV_ROUND_UP(voltage, rate);
  83 }
  84
  85 static int max8649_set_mode(struct regulator_dev *rdev, unsigned int mode)
  86 {
  87         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
  88
  89         switch (mode) {
  90         case REGULATOR_MODE_FAST:
  91                 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
  92                                    MAX8649_FORCE_PWM, MAX8649_FORCE_PWM);
  93                 break;
  94         case REGULATOR_MODE_NORMAL:
  95                 regmap_update_bits(info->regmap, rdev->desc->vsel_reg,
  96                                    MAX8649_FORCE_PWM, 0);
  97                 break;
  98         default:
  99                 return -EINVAL;
 100         }
 101         return 0;
 102 }
 103
 104 static unsigned int max8649_get_mode(struct regulator_dev *rdev)
 105 {
 106         struct max8649_regulator_info *info = rdev_get_drvdata(rdev);
 107         unsigned int val;
 108         int ret;
 109
 110         ret = regmap_read(info->regmap, rdev->desc->vsel_reg, &val);
 111         if (ret != 0)
 112                 return ret;
 113         if (val & MAX8649_FORCE_PWM)
 114                 return REGULATOR_MODE_FAST;
 115         return REGULATOR_MODE_NORMAL;
 116 }
 117
 118 static const struct regulator_ops max8649_dcdc_ops = {
 119         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 120         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 121         .list_voltage   = regulator_list_voltage_linear,
 122         .map_voltage    = regulator_map_voltage_linear,
 123         .enable         = regulator_enable_regmap,
 124         .disable        = regulator_disable_regmap,
 125         .is_enabled     = regulator_is_enabled_regmap,
 126         .enable_time    = max8649_enable_time,
 127         .set_mode       = max8649_set_mode,
 128         .get_mode       = max8649_get_mode,
 129
 130 };
 131
 132 static struct regulator_desc dcdc_desc = {
 133         .name           = "max8649",
 134         .ops            = &max8649_dcdc_ops,
 135         .type           = REGULATOR_VOLTAGE,
 136         .n_voltages     = 1 << 6,
 137         .owner          = THIS_MODULE,
 138         .vsel_mask      = MAX8649_VOL_MASK,
 139         .min_uV         = MAX8649_DCDC_VMIN,
 140         .uV_step        = MAX8649_DCDC_STEP,
 141         .enable_reg     = MAX8649_CONTROL,
 142         .enable_mask    = MAX8649_EN_PD,
 143         .enable_is_inverted = true,
 144 };
 145
 146 static const struct regmap_config max8649_regmap_config = {
 147         .reg_bits = 8,
 148         .val_bits = 8,
 149 };
 150
 151 static int max8649_regulator_probe(struct i2c_client *client,
 152                                              const struct i2c_device_id *id)
 153 {
 154         struct max8649_platform_data *pdata = dev_get_platdata(&client->dev);
 155         struct max8649_regulator_info *info = NULL;
 156         struct regulator_dev *regulator;
 157         struct regulator_config config = { };
 158         unsigned int val;
 159         unsigned char data;
 160         int ret;
 161
 162         info = devm_kzalloc(&client->dev, sizeof(struct max8649_regulator_info),
 163                             GFP_KERNEL);
 164         if (!info)
 165                 return -ENOMEM;
 166
 167         info->regmap = devm_regmap_init_i2c(client, &max8649_regmap_config);
 168         if (IS_ERR(info->regmap)) {
 169                 ret = PTR_ERR(info->regmap);
 170                 dev_err(&client->dev, "Failed to allocate register map: %d\n", ret);
 171                 return ret;
 172         }
 173
 174         info->dev = &client->dev;
 175         i2c_set_clientdata(client, info);
 176
 177         info->mode = pdata->mode;
 178         switch (info->mode) {
 179         case 0:
 180                 dcdc_desc.vsel_reg = MAX8649_MODE0;
 181                 break;
 182         case 1:
 183                 dcdc_desc.vsel_reg = MAX8649_MODE1;
 184                 break;
 185         case 2:
 186                 dcdc_desc.vsel_reg = MAX8649_MODE2;
 187                 break;
 188         case 3:
 189                 dcdc_desc.vsel_reg = MAX8649_MODE3;
 190                 break;
 191         default:
 192                 break;
 193         }
 194
 195         ret = regmap_read(info->regmap, MAX8649_CHIP_ID1, &val);
 196         if (ret != 0) {
 197                 dev_err(info->dev, "Failed to detect ID of MAX8649:%d\n",
 198                         ret);
 199                 return ret;
 200         }
 201         dev_info(info->dev, "Detected MAX8649 (ID:%x)\n", val);
 202
 203         /* enable VID0 & VID1 */
 204         regmap_update_bits(info->regmap, MAX8649_CONTROL, MAX8649_VID_MASK, 0);
 205
 206         /* enable/disable external clock synchronization */
 207         info->extclk = pdata->extclk;
 208         data = (info->extclk) ? MAX8649_SYNC_EXTCLK : 0;
 209         regmap_update_bits(info->regmap, dcdc_desc.vsel_reg,
 210                            MAX8649_SYNC_EXTCLK, data);
 211         if (info->extclk) {
 212                 /* set external clock frequency */
 213                 info->extclk_freq = pdata->extclk_freq;
 214                 regmap_update_bits(info->regmap, MAX8649_SYNC, MAX8649_EXT_MASK,
 215                                    info->extclk_freq << 6);
 216         }
 217
 218         if (pdata->ramp_timing) {
 219                 info->ramp_timing = pdata->ramp_timing;
 220                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_MASK,
 221                                    info->ramp_timing << 5);
 222         }
 223
 224         info->ramp_down = pdata->ramp_down;
 225         if (info->ramp_down) {
 226                 regmap_update_bits(info->regmap, MAX8649_RAMP, MAX8649_RAMP_DOWN,
 227                                    MAX8649_RAMP_DOWN);
 228         }
 229
 230         config.dev = &client->dev;
 231         config.init_data = pdata->regulator;
 232         config.driver_data = info;
 233         config.regmap = info->regmap;
 234
 235         regulator = devm_regulator_register(&client->dev, &dcdc_desc,
 236                                                   &config);
 237         if (IS_ERR(regulator)) {
 238                 dev_err(info->dev, "failed to register regulator %s\n",
 239                         dcdc_desc.name);
 240                 return PTR_ERR(regulator);
 241         }
 242
 243         return 0;
 244 }
 245
 246 static const struct i2c_device_id max8649_id[] = {
 247         { "max8649", 0 },
 248         { }
 249 };
 250 MODULE_DEVICE_TABLE(i2c, max8649_id);
 251
 252 static struct i2c_driver max8649_driver = {
 253         .probe          = max8649_regulator_probe,
 254         .driver         = {
 255                 .name   = "max8649",
 256         },
 257         .id_table       = max8649_id,
 258 };
 259
 260 static int __init max8649_init(void)
 261 {
 262         return i2c_add_driver(&max8649_driver);
 263 }
 264 subsys_initcall(max8649_init);
 265
 266 static void __exit max8649_exit(void)
 267 {
 268         i2c_del_driver(&max8649_driver);
 269 }
 270 module_exit(max8649_exit);
 271
 272 /* Module information */
 273 MODULE_DESCRIPTION("MAXIM 8649 voltage regulator driver");
 274 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
 275 MODULE_LICENSE("GPL");