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/regulator/of_regulator.h>
  22 #include <linux/of_device.h>
  23 #include <linux/i2c.h>
  24 #include <linux/slab.h>
  25 #include <linux/regmap.h>
  26 #include <linux/regulator/fan53555.h>
  27
  28 /* Voltage setting */
  29 #define FAN53555_VSEL0          0x00
  30 #define FAN53555_VSEL1          0x01
  31 /* Control register */
  32 #define FAN53555_CONTROL        0x02
  33 /* IC Type */
  34 #define FAN53555_ID1            0x03
  35 /* IC mask version */
  36 #define FAN53555_ID2            0x04
  37 /* Monitor register */
  38 #define FAN53555_MONITOR        0x05
  39
  40 /* VSEL bit definitions */
  41 #define VSEL_BUCK_EN    (1 << 7)
  42 #define VSEL_MODE               (1 << 6)
  43 #define VSEL_NSEL_MASK  0x3F
  44 /* Chip ID and Verison */
  45 #define DIE_ID          0x0F    /* ID1 */
  46 #define DIE_REV         0x0F    /* ID2 */
  47 /* Control bit definitions */
  48 #define CTL_OUTPUT_DISCHG       (1 << 7)
  49 #define CTL_SLEW_MASK           (0x7 << 4)
  50 #define CTL_SLEW_SHIFT          4
  51 #define CTL_RESET                       (1 << 2)
  52
  53 #define FAN53555_NVOLTAGES      64      /* Numbers of voltages */
  54
  55 /* IC Type */
  56 enum {
  57         FAN53555_CHIP_ID_00 = 0,
  58         FAN53555_CHIP_ID_01,
  59         FAN53555_CHIP_ID_02,
  60         FAN53555_CHIP_ID_03,
  61         FAN53555_CHIP_ID_04,
  62         FAN53555_CHIP_ID_05,
  63 };
  64
  65 struct fan53555_device_info {
  66         struct regmap *regmap;
  67         struct device *dev;
  68         struct regulator_desc desc;
  69         struct regulator_dev *rdev;
  70         struct regulator_init_data *regulator;
  71         /* IC Type and Rev */
  72         int chip_id;
  73         int chip_rev;
  74         /* Voltage setting register */
  75         unsigned int vol_reg;
  76         unsigned int sleep_reg;
  77         /* Voltage range and step(linear) */
  78         unsigned int vsel_min;
  79         unsigned int vsel_step;
  80         /* Voltage slew rate limiting */
  81         unsigned int slew_rate;
  82         /* Sleep voltage cache */
  83         unsigned int sleep_vol_cache;
  84 };
  85
  86 static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)
  87 {
  88         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
  89         int ret;
  90
  91         if (di->sleep_vol_cache == uV)
  92                 return 0;
  93         ret = regulator_map_voltage_linear(rdev, uV, uV);
  94         if (ret < 0)
  95                 return ret;
  96         ret = regmap_update_bits(di->regmap, di->sleep_reg,
  97                                         VSEL_NSEL_MASK, ret);
  98         if (ret < 0)
  99                 return ret;
 100         /* Cache the sleep voltage setting.
 101          * Might not be the real voltage which is rounded */
 102         di->sleep_vol_cache = uV;
 103
 104         return 0;
 105 }
 106
 107 static int fan53555_set_mode(struct regulator_dev *rdev, unsigned int mode)
 108 {
 109         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 110
 111         switch (mode) {
 112         case REGULATOR_MODE_FAST:
 113                 regmap_update_bits(di->regmap, di->vol_reg,
 114                                 VSEL_MODE, VSEL_MODE);
 115                 break;
 116         case REGULATOR_MODE_NORMAL:
 117                 regmap_update_bits(di->regmap, di->vol_reg, VSEL_MODE, 0);
 118                 break;
 119         default:
 120                 return -EINVAL;
 121         }
 122         return 0;
 123 }
 124
 125 static unsigned int fan53555_get_mode(struct regulator_dev *rdev)
 126 {
 127         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 128         unsigned int val;
 129         int ret = 0;
 130
 131         ret = regmap_read(di->regmap, di->vol_reg, &val);
 132         if (ret < 0)
 133                 return ret;
 134         if (val & VSEL_MODE)
 135                 return REGULATOR_MODE_FAST;
 136         else
 137                 return REGULATOR_MODE_NORMAL;
 138 }
 139
 140 static int slew_rates[] = {
 141         64000,
 142         32000,
 143         16000,
 144          8000,
 145          4000,
 146          2000,
 147          1000,
 148           500,
 149 };
 150
 151 static int fan53555_set_ramp(struct regulator_dev *rdev, int ramp)
 152 {
 153         struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 154         int regval = -1, i;
 155
 156         for (i = 0; i < ARRAY_SIZE(slew_rates); i++) {
 157                 if (ramp <= slew_rates[i])
 158                         regval = i;
 159                 else
 160                         break;
 161         }
 162
 163         if (regval < 0) {
 164                 dev_err(di->dev, "unsupported ramp value %d\n", ramp);
 165                 return -EINVAL;
 166         }
 167
 168         return regmap_update_bits(di->regmap, FAN53555_CONTROL,
 169                                   CTL_SLEW_MASK, regval << CTL_SLEW_SHIFT);
 170 }
 171
 172 static struct regulator_ops fan53555_regulator_ops = {
 173         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 174         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 175         .map_voltage = regulator_map_voltage_linear,
 176         .list_voltage = regulator_list_voltage_linear,
 177         .set_suspend_voltage = fan53555_set_suspend_voltage,
 178         .enable = regulator_enable_regmap,
 179         .disable = regulator_disable_regmap,
 180         .is_enabled = regulator_is_enabled_regmap,
 181         .set_mode = fan53555_set_mode,
 182         .get_mode = fan53555_get_mode,
 183         .set_ramp_delay = fan53555_set_ramp,
 184 };
 185
 186 /* For 00,01,03,05 options:
 187  * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
 188  * For 04 option:
 189  * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
 190  * */
 191 static int fan53555_device_setup(struct fan53555_device_info *di,
 192                                 struct fan53555_platform_data *pdata)
 193 {
 194         /* Setup voltage control register */
 195         switch (pdata->sleep_vsel_id) {
 196         case FAN53555_VSEL_ID_0:
 197                 di->sleep_reg = FAN53555_VSEL0;
 198                 di->vol_reg = FAN53555_VSEL1;
 199                 break;
 200         case FAN53555_VSEL_ID_1:
 201                 di->sleep_reg = FAN53555_VSEL1;
 202                 di->vol_reg = FAN53555_VSEL0;
 203                 break;
 204         default:
 205                 dev_err(di->dev, "Invalid VSEL ID!\n");
 206                 return -EINVAL;
 207         }
 208         /* Init voltage range and step */
 209         switch (di->chip_id) {
 210         case FAN53555_CHIP_ID_00:
 211         case FAN53555_CHIP_ID_01:
 212         case FAN53555_CHIP_ID_03:
 213         case FAN53555_CHIP_ID_05:
 214                 di->vsel_min = 600000;
 215                 di->vsel_step = 10000;
 216                 break;
 217         case FAN53555_CHIP_ID_04:
 218                 di->vsel_min = 603000;
 219                 di->vsel_step = 12826;
 220                 break;
 221         default:
 222                 dev_err(di->dev,
 223                         "Chip ID[%d]\n not supported!\n", di->chip_id);
 224                 return -EINVAL;
 225         }
 226
 227         return 0;
 228 }
 229
 230 static int fan53555_regulator_register(struct fan53555_device_info *di,
 231                         struct regulator_config *config)
 232 {
 233         struct regulator_desc *rdesc = &di->desc;
 234
 235         rdesc->name = "fan53555-reg";
 236         rdesc->supply_name = "vin";
 237         rdesc->ops = &fan53555_regulator_ops;
 238         rdesc->type = REGULATOR_VOLTAGE;
 239         rdesc->n_voltages = FAN53555_NVOLTAGES;
 240         rdesc->enable_reg = di->vol_reg;
 241         rdesc->enable_mask = VSEL_BUCK_EN;
 242         rdesc->min_uV = di->vsel_min;
 243         rdesc->uV_step = di->vsel_step;
 244         rdesc->vsel_reg = di->vol_reg;
 245         rdesc->vsel_mask = VSEL_NSEL_MASK;
 246         rdesc->owner = THIS_MODULE;
 247
 248         di->rdev = devm_regulator_register(di->dev, &di->desc, config);
 249         return PTR_ERR_OR_ZERO(di->rdev);
 250 }
 251
 252 static struct regmap_config fan53555_regmap_config = {
 253         .reg_bits = 8,
 254         .val_bits = 8,
 255 };
 256
 257 static struct fan53555_platform_data *fan53555_parse_dt(struct device *dev,
 258                                                         struct device_node *np)
 259 {
 260         struct fan53555_platform_data *pdata;
 261         int ret;
 262         u32 tmp;
 263
 264         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 265         if (!pdata)
 266                 return NULL;
 267
 268         pdata->regulator = of_get_regulator_init_data(dev, np);
 269
 270         ret = of_property_read_u32(np, "fcs,suspend-voltage-selector",
 271                                    &tmp);
 272         if (!ret)
 273                 pdata->sleep_vsel_id = tmp;
 274
 275         return pdata;
 276 }
 277
 278 static const struct of_device_id fan53555_dt_ids[] = {
 279         {
 280                 .compatible = "fcs,fan53555",
 281         },
 282         { }
 283 };
 284 MODULE_DEVICE_TABLE(of, fan53555_dt_ids);
 285
 286 static int fan53555_regulator_probe(struct i2c_client *client,
 287                                 const struct i2c_device_id *id)
 288 {
 289         struct device_node *np = client->dev.of_node;
 290         struct fan53555_device_info *di;
 291         struct fan53555_platform_data *pdata;
 292         struct regulator_config config = { };
 293         unsigned int val;
 294         int ret;
 295
 296         pdata = dev_get_platdata(&client->dev);
 297         if (!pdata)
 298                 pdata = fan53555_parse_dt(&client->dev, np);
 299
 300         if (!pdata || !pdata->regulator) {
 301                 dev_err(&client->dev, "Platform data not found!\n");
 302                 return -ENODEV;
 303         }
 304
 305         di = devm_kzalloc(&client->dev, sizeof(struct fan53555_device_info),
 306                                         GFP_KERNEL);
 307         if (!di)
 308                 return -ENOMEM;
 309
 310         if (!client->dev.of_node) {
 311                 /* if no ramp constraint set, get the pdata ramp_delay */
 312                 if (!di->regulator->constraints.ramp_delay) {
 313                         int slew_idx = (pdata->slew_rate & 0x7)
 314                                                 ? pdata->slew_rate : 0;
 315
 316                         di->regulator->constraints.ramp_delay
 317                                                 = slew_rates[slew_idx];
 318                 }
 319         }
 320
 321         di->regmap = devm_regmap_init_i2c(client, &fan53555_regmap_config);
 322         if (IS_ERR(di->regmap)) {
 323                 dev_err(&client->dev, "Failed to allocate regmap!\n");
 324                 return PTR_ERR(di->regmap);
 325         }
 326         di->dev = &client->dev;
 327         di->regulator = pdata->regulator;
 328         i2c_set_clientdata(client, di);
 329         /* Get chip ID */
 330         ret = regmap_read(di->regmap, FAN53555_ID1, &val);
 331         if (ret < 0) {
 332                 dev_err(&client->dev, "Failed to get chip ID!\n");
 333                 return ret;
 334         }
 335         di->chip_id = val & DIE_ID;
 336         /* Get chip revision */
 337         ret = regmap_read(di->regmap, FAN53555_ID2, &val);
 338         if (ret < 0) {
 339                 dev_err(&client->dev, "Failed to get chip Rev!\n");
 340                 return ret;
 341         }
 342         di->chip_rev = val & DIE_REV;
 343         dev_info(&client->dev, "FAN53555 Option[%d] Rev[%d] Detected!\n",
 344                                 di->chip_id, di->chip_rev);
 345         /* Device init */
 346         ret = fan53555_device_setup(di, pdata);
 347         if (ret < 0) {
 348                 dev_err(&client->dev, "Failed to setup device!\n");
 349                 return ret;
 350         }
 351         /* Register regulator */
 352         config.dev = di->dev;
 353         config.init_data = di->regulator;
 354         config.regmap = di->regmap;
 355         config.driver_data = di;
 356         config.of_node = np;
 357
 358         ret = fan53555_regulator_register(di, &config);
 359         if (ret < 0)
 360                 dev_err(&client->dev, "Failed to register regulator!\n");
 361         return ret;
 362
 363 }
 364
 365 static const struct i2c_device_id fan53555_id[] = {
 366         {"fan53555", -1},
 367         { },
 368 };
 369
 370 static struct i2c_driver fan53555_regulator_driver = {
 371         .driver = {
 372                 .name = "fan53555-regulator",
 373                 .of_match_table = of_match_ptr(fan53555_dt_ids),
 374         },
 375         .probe = fan53555_regulator_probe,
 376         .id_table = fan53555_id,
 377 };
 378
 379 module_i2c_driver(fan53555_regulator_driver);
 380
 381 MODULE_AUTHOR("Yunfan Zhang <yfzhang@marvell.com>");
 382 MODULE_DESCRIPTION("FAN53555 regulator driver");
 383 MODULE_LICENSE("GPL v2");