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