drivers/regulator/fan53555.c

   1 /*
   2  * FAN53555 Fairchild Digitally Programmable TinyBuck Regulator Driver.
   3  *
   4  * Supported Part Numbers:
   5  * FAN53555UC00X/01X/03X/04X/05X
   6  *
   7  * Copyright (c) 2012 Marvell Technology Ltd.
   8  * Yunfan Zhang <yfzhang@marvell.com>
   9  *
  10  * This package is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  */
  15 #include <linux/module.h>
  16 #include <linux/param.h>
  17 #include <linux/err.h>
  18 #include <linux/platform_device.h>
  19 #include <linux/regulator/driver.h>
  20 #include <linux/regulator/machine.h>
  21 #include <linux/i2c.h>
  22 #include <linux/slab.h>
  23 #include <linux/regmap.h>
  24 #include <linux/regulator/fan53555.h>
  25
  26 /* Voltage setting */
  27 #define FAN53555_VSEL0          0x00
  28 #define FAN53555_VSEL1          0x01
  29 /* Control register */
  30 #define FAN53555_CONTROL        0x02
  31 /* IC Type */
  32 #define FAN53555_ID1            0x03
  33 /* IC mask version */
  34 #define FAN53555_ID2            0x04
  35 /* Monitor register */
  36 #define FAN53555_MONITOR        0x05
  37
  38 /* VSEL bit definitions */
  39 #define VSEL_BUCK_EN    (1 << 7)
  40 #define VSEL_MODE               (1 << 6)
  41 #define VSEL_NSEL_MASK  0x3F
  42 /* Chip ID and Verison */
  43 #define DIE_ID          0x0F    /* ID1 */
  44 #define DIE_REV         0x0F    /* ID2 */
  45 /* Control bit definitions */
  46 #define CTL_OUTPUT_DISCHG       (1 << 7)
  47 #define CTL_SLEW_MASK           (0x7 << 4)
  48 #define CTL_SLEW_SHIFT          4
  49 #define CTL_RESET                       (1 << 2)
  50
  51 #define FAN53555_NVOLTAGES      64      /* Numbers of voltages */
  52
  53 /* IC Type */
  54 enum {
  55         FAN53555_CHIP_ID_00 = 0,
  56         FAN53555_CHIP_ID_01,
  57         FAN53555_CHIP_ID_02,
  58         FAN53555_CHIP_ID_03,
  59         FAN53555_CHIP_ID_04,
  60         FAN53555_CHIP_ID_05,
  61 };
  62
  63 struct fan53555_device_info {
  64         struct regmap *regmap;
  65         struct device *dev;
  66         struct regulator_desc desc;
  67         struct regulator_dev *rdev;
  68         struct regulator_init_data *regulator;
  69         /* IC Type and Rev */
  70         int chip_id;
  71         int chip_rev;
  72         /* Voltage setting register */
  73         unsigned int vol_reg;
  74         unsigned int sleep_reg;
  75         /* Voltage range and step(linear) */
  76         unsigned int vsel_min;
  77         unsigned int vsel_step;
  78         /* Voltage slew rate limiting */
  79         unsigned int slew_rate;
  80         /* Sleep voltage cache */
  81         unsigned int sleep_vol_cache;
  82 };
  83
  84 static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)
  85 {
  86         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
  87         int ret;
  88
  89         if (di->sleep_vol_cache == uV)
  90                 return 0;
  91         ret = regulator_map_voltage_linear(rdev, uV, uV);
  92         if (ret < 0)
  93                 return ret;
  94         ret = regmap_update_bits(di->regmap, di->sleep_reg,
  95                                         VSEL_NSEL_MASK, ret);
  96         if (ret < 0)
  97                 return ret;
  98         /* Cache the sleep voltage setting.
  99          * Might not be the real voltage which is rounded */
 100         di->sleep_vol_cache = uV;
 101
 102         return 0;
 103 }
 104
 105 static int fan53555_set_mode(struct regulator_dev *rdev, unsigned int mode)
 106 {
 107         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 108
 109         switch (mode) {
 110         case REGULATOR_MODE_FAST:
 111                 regmap_update_bits(di->regmap, di->vol_reg,
 112                                 VSEL_MODE, VSEL_MODE);
 113                 break;
 114         case REGULATOR_MODE_NORMAL:
 115                 regmap_update_bits(di->regmap, di->vol_reg, VSEL_MODE, 0);
 116                 break;
 117         default:
 118                 return -EINVAL;
 119         }
 120         return 0;
 121 }
 122
 123 static unsigned int fan53555_get_mode(struct regulator_dev *rdev)
 124 {
 125         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 126         unsigned int val;
 127         int ret = 0;
 128
 129         ret = regmap_read(di->regmap, di->vol_reg, &val);
 130         if (ret < 0)
 131                 return ret;
 132         if (val & VSEL_MODE)
 133                 return REGULATOR_MODE_FAST;
 134         else
 135                 return REGULATOR_MODE_NORMAL;
 136 }
 137
 138 static struct regulator_ops fan53555_regulator_ops = {
 139         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 140         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 141         .map_voltage = regulator_map_voltage_linear,
 142         .list_voltage = regulator_list_voltage_linear,
 143         .set_suspend_voltage = fan53555_set_suspend_voltage,
 144         .enable = regulator_enable_regmap,
 145         .disable = regulator_disable_regmap,
 146         .is_enabled = regulator_is_enabled_regmap,
 147         .set_mode = fan53555_set_mode,
 148         .get_mode = fan53555_get_mode,
 149 };
 150
 151 /* For 00,01,03,05 options:
 152  * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
 153  * For 04 option:
 154  * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
 155  * */
 156 static int fan53555_device_setup(struct fan53555_device_info *di,
 157                                 struct fan53555_platform_data *pdata)
 158 {
 159         unsigned int reg, data, mask;
 160
 161         /* Setup voltage control register */
 162         switch (pdata->sleep_vsel_id) {
 163         case FAN53555_VSEL_ID_0:
 164                 di->sleep_reg = FAN53555_VSEL0;
 165                 di->vol_reg = FAN53555_VSEL1;
 166                 break;
 167         case FAN53555_VSEL_ID_1:
 168                 di->sleep_reg = FAN53555_VSEL1;
 169                 di->vol_reg = FAN53555_VSEL0;
 170                 break;
 171         default:
 172                 dev_err(di->dev, "Invalid VSEL ID!\n");
 173                 return -EINVAL;
 174         }
 175         /* Init voltage range and step */
 176         switch (di->chip_id) {
 177         case FAN53555_CHIP_ID_00:
 178         case FAN53555_CHIP_ID_01:
 179         case FAN53555_CHIP_ID_03:
 180         case FAN53555_CHIP_ID_05:
 181                 di->vsel_min = 600000;
 182                 di->vsel_step = 10000;
 183                 break;
 184         case FAN53555_CHIP_ID_04:
 185                 di->vsel_min = 603000;
 186                 di->vsel_step = 12826;
 187                 break;
 188         default:
 189                 dev_err(di->dev,
 190                         "Chip ID[%d]\n not supported!\n", di->chip_id);
 191                 return -EINVAL;
 192         }
 193         /* Init slew rate */
 194         if (pdata->slew_rate & 0x7)
 195                 di->slew_rate = pdata->slew_rate;
 196         else
 197                 di->slew_rate = FAN53555_SLEW_RATE_64MV;
 198         reg = FAN53555_CONTROL;
 199         data = di->slew_rate << CTL_SLEW_SHIFT;
 200         mask = CTL_SLEW_MASK;
 201         return regmap_update_bits(di->regmap, reg, mask, data);
 202 }
 203
 204 static int fan53555_regulator_register(struct fan53555_device_info *di,
 205                         struct regulator_config *config)
 206 {
 207         struct regulator_desc *rdesc = &di->desc;
 208
 209         rdesc->name = "fan53555-reg";
 210         rdesc->ops = &fan53555_regulator_ops;
 211         rdesc->type = REGULATOR_VOLTAGE;
 212         rdesc->n_voltages = FAN53555_NVOLTAGES;
 213         rdesc->enable_reg = di->vol_reg;
 214         rdesc->enable_mask = VSEL_BUCK_EN;
 215         rdesc->min_uV = di->vsel_min;
 216         rdesc->uV_step = di->vsel_step;
 217         rdesc->vsel_reg = di->vol_reg;
 218         rdesc->vsel_mask = VSEL_NSEL_MASK;
 219         rdesc->owner = THIS_MODULE;
 220
 221         di->rdev = devm_regulator_register(di->dev, &di->desc, config);
 222         return PTR_ERR_OR_ZERO(di->rdev);
 223 }
 224
 225 static struct regmap_config fan53555_regmap_config = {
 226         .reg_bits = 8,
 227         .val_bits = 8,
 228 };
 229
 230 static int fan53555_regulator_probe(struct i2c_client *client,
 231                                 const struct i2c_device_id *id)
 232 {
 233         struct fan53555_device_info *di;
 234         struct fan53555_platform_data *pdata;
 235         struct regulator_config config = { };
 236         unsigned int val;
 237         int ret;
 238
 239         pdata = dev_get_platdata(&client->dev);
 240         if (!pdata || !pdata->regulator) {
 241                 dev_err(&client->dev, "Platform data not found!\n");
 242                 return -ENODEV;
 243         }
 244
 245         di = devm_kzalloc(&client->dev, sizeof(struct fan53555_device_info),
 246                                         GFP_KERNEL);
 247         if (!di)
 248                 return -ENOMEM;
 249
 250         di->regmap = devm_regmap_init_i2c(client, &fan53555_regmap_config);
 251         if (IS_ERR(di->regmap)) {
 252                 dev_err(&client->dev, "Failed to allocate regmap!\n");
 253                 return PTR_ERR(di->regmap);
 254         }
 255         di->dev = &client->dev;
 256         di->regulator = pdata->regulator;
 257         i2c_set_clientdata(client, di);
 258         /* Get chip ID */
 259         ret = regmap_read(di->regmap, FAN53555_ID1, &val);
 260         if (ret < 0) {
 261                 dev_err(&client->dev, "Failed to get chip ID!\n");
 262                 return ret;
 263         }
 264         di->chip_id = val & DIE_ID;
 265         /* Get chip revision */
 266         ret = regmap_read(di->regmap, FAN53555_ID2, &val);
 267         if (ret < 0) {
 268                 dev_err(&client->dev, "Failed to get chip Rev!\n");
 269                 return ret;
 270         }
 271         di->chip_rev = val & DIE_REV;
 272         dev_info(&client->dev, "FAN53555 Option[%d] Rev[%d] Detected!\n",
 273                                 di->chip_id, di->chip_rev);
 274         /* Device init */
 275         ret = fan53555_device_setup(di, pdata);
 276         if (ret < 0) {
 277                 dev_err(&client->dev, "Failed to setup device!\n");
 278                 return ret;
 279         }
 280         /* Register regulator */
 281         config.dev = di->dev;
 282         config.init_data = di->regulator;
 283         config.regmap = di->regmap;
 284         config.driver_data = di;
 285         ret = fan53555_regulator_register(di, &config);
 286         if (ret < 0)
 287                 dev_err(&client->dev, "Failed to register regulator!\n");
 288         return ret;
 289
 290 }
 291
 292 static const struct i2c_device_id fan53555_id[] = {
 293         {"fan53555", -1},
 294         { },
 295 };
 296
 297 static struct i2c_driver fan53555_regulator_driver = {
 298         .driver = {
 299                 .name = "fan53555-regulator",
 300         },
 301         .probe = fan53555_regulator_probe,
 302         .id_table = fan53555_id,
 303 };
 304
 305 module_i2c_driver(fan53555_regulator_driver);
 306
 307 MODULE_AUTHOR("Yunfan Zhang <yfzhang@marvell.com>");
 308 MODULE_DESCRIPTION("FAN53555 regulator driver");
 309 MODULE_LICENSE("GPL v2");