drivers/regulator/max8660.c

   1 /*
   2  * max8660.c  --  Voltage regulation for the Maxim 8660/8661
   3  *
   4  * based on max1586.c and wm8400-regulator.c
   5  *
   6  * Copyright (C) 2009 Wolfram Sang, Pengutronix e.K.
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; version 2 of the License.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  *
  17  * You should have received a copy of the GNU General Public License along with
  18  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  19  * Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  * Some info:
  22  *
  23  * Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8660-MAX8661.pdf
  24  *
  25  * This chip is a bit nasty because it is a write-only device. Thus, the driver
  26  * uses shadow registers to keep track of its values. The main problem appears
  27  * to be the initialization: When Linux boots up, we cannot know if the chip is
  28  * in the default state or not, so we would have to pass such information in
  29  * platform_data. As this adds a bit of complexity to the driver, this is left
  30  * out for now until it is really needed.
  31  *
  32  * [A|S|M]DTV1 registers are currently not used, but [A|S|M]DTV2.
  33  *
  34  * If the driver is feature complete, it might be worth to check if one set of
  35  * functions for V3-V7 is sufficient. For maximum flexibility during
  36  * development, they are separated for now.
  37  *
  38  */
  39
  40 #include <linux/module.h>
  41 #include <linux/err.h>
  42 #include <linux/i2c.h>
  43 #include <linux/platform_device.h>
  44 #include <linux/regulator/driver.h>
  45 #include <linux/regulator/max8660.h>
  46
  47 #define MAX8660_DCDC_MIN_UV      725000
  48 #define MAX8660_DCDC_MAX_UV     1800000
  49 #define MAX8660_DCDC_STEP         25000
  50 #define MAX8660_DCDC_MAX_SEL    0x2b
  51
  52 #define MAX8660_LDO5_MIN_UV     1700000
  53 #define MAX8660_LDO5_MAX_UV     2000000
  54 #define MAX8660_LDO5_STEP         25000
  55 #define MAX8660_LDO5_MAX_SEL    0x0c
  56
  57 #define MAX8660_LDO67_MIN_UV    1800000
  58 #define MAX8660_LDO67_MAX_UV    3300000
  59 #define MAX8660_LDO67_STEP       100000
  60 #define MAX8660_LDO67_MAX_SEL   0x0f
  61
  62 enum {
  63         MAX8660_OVER1,
  64         MAX8660_OVER2,
  65         MAX8660_VCC1,
  66         MAX8660_ADTV1,
  67         MAX8660_ADTV2,
  68         MAX8660_SDTV1,
  69         MAX8660_SDTV2,
  70         MAX8660_MDTV1,
  71         MAX8660_MDTV2,
  72         MAX8660_L12VCR,
  73         MAX8660_FPWM,
  74         MAX8660_N_REGS, /* not a real register */
  75 };
  76
  77 struct max8660 {
  78         struct i2c_client *client;
  79         u8 shadow_regs[MAX8660_N_REGS];         /* as chip is write only */
  80         struct regulator_dev *rdev[];
  81 };
  82
  83 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
  84 {
  85         static const u8 max8660_addresses[MAX8660_N_REGS] =
  86           { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 };
  87
  88         int ret;
  89         u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
  90         dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
  91                         max8660_addresses[reg], reg_val);
  92
  93         ret = i2c_smbus_write_byte_data(max8660->client,
  94                         max8660_addresses[reg], reg_val);
  95         if (ret == 0)
  96                 max8660->shadow_regs[reg] = reg_val;
  97
  98         return ret;
  99 }
 100
 101
 102 /*
 103  * DCDC functions
 104  */
 105
 106 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
 107 {
 108         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 109         u8 val = max8660->shadow_regs[MAX8660_OVER1];
 110         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 111         return !!(val & mask);
 112 }
 113
 114 static int max8660_dcdc_enable(struct regulator_dev *rdev)
 115 {
 116         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 117         u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 118         return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
 119 }
 120
 121 static int max8660_dcdc_disable(struct regulator_dev *rdev)
 122 {
 123         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 124         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
 125         return max8660_write(max8660, MAX8660_OVER1, mask, 0);
 126 }
 127
 128 static int max8660_dcdc_list(struct regulator_dev *rdev, unsigned selector)
 129 {
 130         if (selector > MAX8660_DCDC_MAX_SEL)
 131                 return -EINVAL;
 132         return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
 133 }
 134
 135 static int max8660_dcdc_get(struct regulator_dev *rdev)
 136 {
 137         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 138         u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 139         u8 selector = max8660->shadow_regs[reg];
 140         return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
 141 }
 142
 143 static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 144 {
 145         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 146         u8 reg, selector, bits;
 147         int ret;
 148
 149         if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV)
 150                 return -EINVAL;
 151         if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV)
 152                 return -EINVAL;
 153
 154         selector = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1))
 155                         / MAX8660_DCDC_STEP;
 156
 157         ret = max8660_dcdc_list(rdev, selector);
 158         if (ret < 0 || ret > max_uV)
 159                 return -EINVAL;
 160
 161         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 162         ret = max8660_write(max8660, reg, 0, selector);
 163         if (ret)
 164                 return ret;
 165
 166         /* Select target voltage register and activate regulation */
 167         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 168         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 169 }
 170
 171 static struct regulator_ops max8660_dcdc_ops = {
 172         .is_enabled = max8660_dcdc_is_enabled,
 173         .list_voltage = max8660_dcdc_list,
 174         .set_voltage = max8660_dcdc_set,
 175         .get_voltage = max8660_dcdc_get,
 176 };
 177
 178
 179 /*
 180  * LDO5 functions
 181  */
 182
 183 static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector)
 184 {
 185         if (selector > MAX8660_LDO5_MAX_SEL)
 186                 return -EINVAL;
 187         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 188 }
 189
 190 static int max8660_ldo5_get(struct regulator_dev *rdev)
 191 {
 192         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 193         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 194
 195         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 196 }
 197
 198 static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 199 {
 200         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 201         u8 selector;
 202         int ret;
 203
 204         if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV)
 205                 return -EINVAL;
 206         if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV)
 207                 return -EINVAL;
 208
 209         selector = (min_uV - (MAX8660_LDO5_MIN_UV - MAX8660_LDO5_STEP + 1))
 210                         / MAX8660_LDO5_STEP;
 211         ret = max8660_ldo5_list(rdev, selector);
 212         if (ret < 0 || ret > max_uV)
 213                 return -EINVAL;
 214
 215         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 216         if (ret)
 217                 return ret;
 218
 219         /* Select target voltage register and activate regulation */
 220         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 221 }
 222
 223 static struct regulator_ops max8660_ldo5_ops = {
 224         .list_voltage = max8660_ldo5_list,
 225         .set_voltage = max8660_ldo5_set,
 226         .get_voltage = max8660_ldo5_get,
 227 };
 228
 229
 230 /*
 231  * LDO67 functions
 232  */
 233
 234 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 235 {
 236         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 237         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 238         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 239         return !!(val & mask);
 240 }
 241
 242 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 243 {
 244         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 245         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 246         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 247 }
 248
 249 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 250 {
 251         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 252         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 253         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 254 }
 255
 256 static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector)
 257 {
 258         if (selector > MAX8660_LDO67_MAX_SEL)
 259                 return -EINVAL;
 260         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 261 }
 262
 263 static int max8660_ldo67_get(struct regulator_dev *rdev)
 264 {
 265         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 266         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 267         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 268
 269         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 270 }
 271
 272 static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 273 {
 274         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 275         u8 selector;
 276         int ret;
 277
 278         if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV)
 279                 return -EINVAL;
 280         if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV)
 281                 return -EINVAL;
 282
 283         selector = (min_uV - (MAX8660_LDO67_MIN_UV - MAX8660_LDO67_STEP + 1))
 284                         / MAX8660_LDO67_STEP;
 285
 286         ret = max8660_ldo67_list(rdev, selector);
 287         if (ret < 0 || ret > max_uV)
 288                 return -EINVAL;
 289
 290         if (rdev_get_id(rdev) == MAX8660_V6)
 291                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 292         else
 293                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4);
 294 }
 295
 296 static struct regulator_ops max8660_ldo67_ops = {
 297         .is_enabled = max8660_ldo67_is_enabled,
 298         .enable = max8660_ldo67_enable,
 299         .disable = max8660_ldo67_disable,
 300         .list_voltage = max8660_ldo67_list,
 301         .get_voltage = max8660_ldo67_get,
 302         .set_voltage = max8660_ldo67_set,
 303 };
 304
 305 static struct regulator_desc max8660_reg[] = {
 306         {
 307                 .name = "V3(DCDC)",
 308                 .id = MAX8660_V3,
 309                 .ops = &max8660_dcdc_ops,
 310                 .type = REGULATOR_VOLTAGE,
 311                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 312                 .owner = THIS_MODULE,
 313         },
 314         {
 315                 .name = "V4(DCDC)",
 316                 .id = MAX8660_V4,
 317                 .ops = &max8660_dcdc_ops,
 318                 .type = REGULATOR_VOLTAGE,
 319                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 320                 .owner = THIS_MODULE,
 321         },
 322         {
 323                 .name = "V5(LDO)",
 324                 .id = MAX8660_V5,
 325                 .ops = &max8660_ldo5_ops,
 326                 .type = REGULATOR_VOLTAGE,
 327                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 328                 .owner = THIS_MODULE,
 329         },
 330         {
 331                 .name = "V6(LDO)",
 332                 .id = MAX8660_V6,
 333                 .ops = &max8660_ldo67_ops,
 334                 .type = REGULATOR_VOLTAGE,
 335                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 336                 .owner = THIS_MODULE,
 337         },
 338         {
 339                 .name = "V7(LDO)",
 340                 .id = MAX8660_V7,
 341                 .ops = &max8660_ldo67_ops,
 342                 .type = REGULATOR_VOLTAGE,
 343                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 344                 .owner = THIS_MODULE,
 345         },
 346 };
 347
 348 static int max8660_probe(struct i2c_client *client,
 349                               const struct i2c_device_id *i2c_id)
 350 {
 351         struct regulator_dev **rdev;
 352         struct max8660_platform_data *pdata = client->dev.platform_data;
 353         struct max8660 *max8660;
 354         int boot_on, i, id, ret = -EINVAL;
 355
 356         if (pdata->num_subdevs > MAX8660_V_END) {
 357                 dev_err(&client->dev, "Too much regulators found!\n");
 358                 goto out;
 359         }
 360
 361         max8660 = kzalloc(sizeof(struct max8660) +
 362                         sizeof(struct regulator_dev *) * MAX8660_V_END,
 363                         GFP_KERNEL);
 364         if (!max8660) {
 365                 ret = -ENOMEM;
 366                 goto out;
 367         }
 368
 369         max8660->client = client;
 370         rdev = max8660->rdev;
 371
 372         if (pdata->en34_is_high) {
 373                 /* Simulate always on */
 374                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 375         } else {
 376                 /* Otherwise devices can be toggled via software */
 377                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 378                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 379         }
 380
 381         /*
 382          * First, set up shadow registers to prevent glitches. As some
 383          * registers are shared between regulators, everything must be properly
 384          * set up for all regulators in advance.
 385          */
 386         max8660->shadow_regs[MAX8660_ADTV1] =
 387                 max8660->shadow_regs[MAX8660_ADTV2] =
 388                 max8660->shadow_regs[MAX8660_SDTV1] =
 389                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 390         max8660->shadow_regs[MAX8660_MDTV1] =
 391                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 392
 393         for (i = 0; i < pdata->num_subdevs; i++) {
 394
 395                 if (!pdata->subdevs[i].platform_data)
 396                         goto err_free;
 397
 398                 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 399
 400                 switch (pdata->subdevs[i].id) {
 401                 case MAX8660_V3:
 402                         if (boot_on)
 403                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 404                         break;
 405
 406                 case MAX8660_V4:
 407                         if (boot_on)
 408                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 409                         break;
 410
 411                 case MAX8660_V5:
 412                         break;
 413
 414                 case MAX8660_V6:
 415                         if (boot_on)
 416                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 417                         break;
 418
 419                 case MAX8660_V7:
 420                         if (!strcmp(i2c_id->name, "max8661")) {
 421                                 dev_err(&client->dev, "Regulator not on this chip!\n");
 422                                 goto err_free;
 423                         }
 424
 425                         if (boot_on)
 426                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 427                         break;
 428
 429                 default:
 430                         dev_err(&client->dev, "invalid regulator %s\n",
 431                                  pdata->subdevs[i].name);
 432                         goto err_free;
 433                 }
 434         }
 435
 436         /* Finally register devices */
 437         for (i = 0; i < pdata->num_subdevs; i++) {
 438
 439                 id = pdata->subdevs[i].id;
 440
 441                 rdev[i] = regulator_register(&max8660_reg[id], &client->dev,
 442                                              pdata->subdevs[i].platform_data,
 443                                              max8660);
 444                 if (IS_ERR(rdev[i])) {
 445                         ret = PTR_ERR(rdev[i]);
 446                         dev_err(&client->dev, "failed to register %s\n",
 447                                 max8660_reg[id].name);
 448                         goto err_unregister;
 449                 }
 450         }
 451
 452         i2c_set_clientdata(client, rdev);
 453         dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n");
 454         return 0;
 455
 456 err_unregister:
 457         while (--i >= 0)
 458                 regulator_unregister(rdev[i]);
 459 err_free:
 460         kfree(max8660);
 461 out:
 462         return ret;
 463 }
 464
 465 static int max8660_remove(struct i2c_client *client)
 466 {
 467         struct regulator_dev **rdev = i2c_get_clientdata(client);
 468         int i;
 469
 470         for (i = 0; i < MAX8660_V_END; i++)
 471                 if (rdev[i])
 472                         regulator_unregister(rdev[i]);
 473         kfree(rdev);
 474         i2c_set_clientdata(client, NULL);
 475
 476         return 0;
 477 }
 478
 479 static const struct i2c_device_id max8660_id[] = {
 480         { "max8660", 0 },
 481         { "max8661", 0 },
 482         { }
 483 };
 484 MODULE_DEVICE_TABLE(i2c, max8660_id);
 485
 486 static struct i2c_driver max8660_driver = {
 487         .probe = max8660_probe,
 488         .remove = max8660_remove,
 489         .driver         = {
 490                 .name   = "max8660",
 491         },
 492         .id_table       = max8660_id,
 493 };
 494
 495 static int __init max8660_init(void)
 496 {
 497         return i2c_add_driver(&max8660_driver);
 498 }
 499 subsys_initcall(max8660_init);
 500
 501 static void __exit max8660_exit(void)
 502 {
 503         i2c_del_driver(&max8660_driver);
 504 }
 505 module_exit(max8660_exit);
 506
 507 /* Module information */
 508 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 509 MODULE_AUTHOR("Wolfram Sang");
 510 MODULE_LICENSE("GPL v2");