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/slab.h>
  46 #include <linux/regulator/max8660.h>
  47
  48 #define MAX8660_DCDC_MIN_UV      725000
  49 #define MAX8660_DCDC_MAX_UV     1800000
  50 #define MAX8660_DCDC_STEP         25000
  51 #define MAX8660_DCDC_MAX_SEL    0x2b
  52
  53 #define MAX8660_LDO5_MIN_UV     1700000
  54 #define MAX8660_LDO5_MAX_UV     2000000
  55 #define MAX8660_LDO5_STEP         25000
  56 #define MAX8660_LDO5_MAX_SEL    0x0c
  57
  58 #define MAX8660_LDO67_MIN_UV    1800000
  59 #define MAX8660_LDO67_MAX_UV    3300000
  60 #define MAX8660_LDO67_STEP       100000
  61 #define MAX8660_LDO67_MAX_SEL   0x0f
  62
  63 enum {
  64         MAX8660_OVER1,
  65         MAX8660_OVER2,
  66         MAX8660_VCC1,
  67         MAX8660_ADTV1,
  68         MAX8660_ADTV2,
  69         MAX8660_SDTV1,
  70         MAX8660_SDTV2,
  71         MAX8660_MDTV1,
  72         MAX8660_MDTV2,
  73         MAX8660_L12VCR,
  74         MAX8660_FPWM,
  75         MAX8660_N_REGS, /* not a real register */
  76 };
  77
  78 struct max8660 {
  79         struct i2c_client *client;
  80         u8 shadow_regs[MAX8660_N_REGS];         /* as chip is write only */
  81         struct regulator_dev *rdev[];
  82 };
  83
  84 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
  85 {
  86         static const u8 max8660_addresses[MAX8660_N_REGS] =
  87           { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 };
  88
  89         int ret;
  90         u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
  91         dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
  92                         max8660_addresses[reg], reg_val);
  93
  94         ret = i2c_smbus_write_byte_data(max8660->client,
  95                         max8660_addresses[reg], reg_val);
  96         if (ret == 0)
  97                 max8660->shadow_regs[reg] = reg_val;
  98
  99         return ret;
 100 }
 101
 102
 103 /*
 104  * DCDC functions
 105  */
 106
 107 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
 108 {
 109         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 110         u8 val = max8660->shadow_regs[MAX8660_OVER1];
 111         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 112         return !!(val & mask);
 113 }
 114
 115 static int max8660_dcdc_enable(struct regulator_dev *rdev)
 116 {
 117         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 118         u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 119         return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
 120 }
 121
 122 static int max8660_dcdc_disable(struct regulator_dev *rdev)
 123 {
 124         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 125         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
 126         return max8660_write(max8660, MAX8660_OVER1, mask, 0);
 127 }
 128
 129 static int max8660_dcdc_list(struct regulator_dev *rdev, unsigned selector)
 130 {
 131         if (selector > MAX8660_DCDC_MAX_SEL)
 132                 return -EINVAL;
 133         return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
 134 }
 135
 136 static int max8660_dcdc_get(struct regulator_dev *rdev)
 137 {
 138         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 139         u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 140         u8 selector = max8660->shadow_regs[reg];
 141         return MAX8660_DCDC_MIN_UV + selector * MAX8660_DCDC_STEP;
 142 }
 143
 144 static int max8660_dcdc_set(struct regulator_dev *rdev, int min_uV, int max_uV,
 145                             unsigned int *s)
 146 {
 147         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 148         u8 reg, selector, bits;
 149         int ret;
 150
 151         if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV)
 152                 return -EINVAL;
 153         if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV)
 154                 return -EINVAL;
 155
 156         selector = DIV_ROUND_UP(min_uV - MAX8660_DCDC_MIN_UV,
 157                                 MAX8660_DCDC_STEP);
 158
 159         ret = max8660_dcdc_list(rdev, selector);
 160         if (ret < 0 || ret > max_uV)
 161                 return -EINVAL;
 162
 163         *s = selector;
 164
 165         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 166         ret = max8660_write(max8660, reg, 0, selector);
 167         if (ret)
 168                 return ret;
 169
 170         /* Select target voltage register and activate regulation */
 171         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 172         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 173 }
 174
 175 static struct regulator_ops max8660_dcdc_ops = {
 176         .is_enabled = max8660_dcdc_is_enabled,
 177         .list_voltage = max8660_dcdc_list,
 178         .set_voltage = max8660_dcdc_set,
 179         .get_voltage = max8660_dcdc_get,
 180 };
 181
 182
 183 /*
 184  * LDO5 functions
 185  */
 186
 187 static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector)
 188 {
 189         if (selector > MAX8660_LDO5_MAX_SEL)
 190                 return -EINVAL;
 191         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 192 }
 193
 194 static int max8660_ldo5_get(struct regulator_dev *rdev)
 195 {
 196         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 197         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 198
 199         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 200 }
 201
 202 static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV,
 203                             unsigned int *s)
 204 {
 205         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 206         u8 selector;
 207         int ret;
 208
 209         if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV)
 210                 return -EINVAL;
 211         if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV)
 212                 return -EINVAL;
 213
 214         selector = DIV_ROUND_UP(min_uV - MAX8660_LDO5_MIN_UV,
 215                                 MAX8660_LDO5_STEP);
 216
 217         ret = max8660_ldo5_list(rdev, selector);
 218         if (ret < 0 || ret > max_uV)
 219                 return -EINVAL;
 220
 221         *s = selector;
 222
 223         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 224         if (ret)
 225                 return ret;
 226
 227         /* Select target voltage register and activate regulation */
 228         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 229 }
 230
 231 static struct regulator_ops max8660_ldo5_ops = {
 232         .list_voltage = max8660_ldo5_list,
 233         .set_voltage = max8660_ldo5_set,
 234         .get_voltage = max8660_ldo5_get,
 235 };
 236
 237
 238 /*
 239  * LDO67 functions
 240  */
 241
 242 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 243 {
 244         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 245         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 246         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 247         return !!(val & mask);
 248 }
 249
 250 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 251 {
 252         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 253         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 254         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 255 }
 256
 257 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 258 {
 259         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 260         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 261         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 262 }
 263
 264 static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector)
 265 {
 266         if (selector > MAX8660_LDO67_MAX_SEL)
 267                 return -EINVAL;
 268         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 269 }
 270
 271 static int max8660_ldo67_get(struct regulator_dev *rdev)
 272 {
 273         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 274         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 275         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 276
 277         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 278 }
 279
 280 static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV,
 281                              int max_uV, unsigned int *s)
 282 {
 283         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 284         u8 selector;
 285         int ret;
 286
 287         if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV)
 288                 return -EINVAL;
 289         if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV)
 290                 return -EINVAL;
 291
 292         selector = DIV_ROUND_UP(min_uV - MAX8660_LDO67_MIN_UV,
 293                                 MAX8660_LDO67_STEP);
 294
 295         ret = max8660_ldo67_list(rdev, selector);
 296         if (ret < 0 || ret > max_uV)
 297                 return -EINVAL;
 298
 299         *s = selector;
 300
 301         if (rdev_get_id(rdev) == MAX8660_V6)
 302                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 303         else
 304                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4);
 305 }
 306
 307 static struct regulator_ops max8660_ldo67_ops = {
 308         .is_enabled = max8660_ldo67_is_enabled,
 309         .enable = max8660_ldo67_enable,
 310         .disable = max8660_ldo67_disable,
 311         .list_voltage = max8660_ldo67_list,
 312         .get_voltage = max8660_ldo67_get,
 313         .set_voltage = max8660_ldo67_set,
 314 };
 315
 316 static struct regulator_desc max8660_reg[] = {
 317         {
 318                 .name = "V3(DCDC)",
 319                 .id = MAX8660_V3,
 320                 .ops = &max8660_dcdc_ops,
 321                 .type = REGULATOR_VOLTAGE,
 322                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 323                 .owner = THIS_MODULE,
 324         },
 325         {
 326                 .name = "V4(DCDC)",
 327                 .id = MAX8660_V4,
 328                 .ops = &max8660_dcdc_ops,
 329                 .type = REGULATOR_VOLTAGE,
 330                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 331                 .owner = THIS_MODULE,
 332         },
 333         {
 334                 .name = "V5(LDO)",
 335                 .id = MAX8660_V5,
 336                 .ops = &max8660_ldo5_ops,
 337                 .type = REGULATOR_VOLTAGE,
 338                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 339                 .owner = THIS_MODULE,
 340         },
 341         {
 342                 .name = "V6(LDO)",
 343                 .id = MAX8660_V6,
 344                 .ops = &max8660_ldo67_ops,
 345                 .type = REGULATOR_VOLTAGE,
 346                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 347                 .owner = THIS_MODULE,
 348         },
 349         {
 350                 .name = "V7(LDO)",
 351                 .id = MAX8660_V7,
 352                 .ops = &max8660_ldo67_ops,
 353                 .type = REGULATOR_VOLTAGE,
 354                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 355                 .owner = THIS_MODULE,
 356         },
 357 };
 358
 359 static int __devinit max8660_probe(struct i2c_client *client,
 360                                    const struct i2c_device_id *i2c_id)
 361 {
 362         struct regulator_dev **rdev;
 363         struct max8660_platform_data *pdata = client->dev.platform_data;
 364         struct max8660 *max8660;
 365         int boot_on, i, id, ret = -EINVAL;
 366
 367         if (pdata->num_subdevs > MAX8660_V_END) {
 368                 dev_err(&client->dev, "Too many regulators found!\n");
 369                 goto out;
 370         }
 371
 372         max8660 = kzalloc(sizeof(struct max8660) +
 373                         sizeof(struct regulator_dev *) * MAX8660_V_END,
 374                         GFP_KERNEL);
 375         if (!max8660) {
 376                 ret = -ENOMEM;
 377                 goto out;
 378         }
 379
 380         max8660->client = client;
 381         rdev = max8660->rdev;
 382
 383         if (pdata->en34_is_high) {
 384                 /* Simulate always on */
 385                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 386         } else {
 387                 /* Otherwise devices can be toggled via software */
 388                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 389                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 390         }
 391
 392         /*
 393          * First, set up shadow registers to prevent glitches. As some
 394          * registers are shared between regulators, everything must be properly
 395          * set up for all regulators in advance.
 396          */
 397         max8660->shadow_regs[MAX8660_ADTV1] =
 398                 max8660->shadow_regs[MAX8660_ADTV2] =
 399                 max8660->shadow_regs[MAX8660_SDTV1] =
 400                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 401         max8660->shadow_regs[MAX8660_MDTV1] =
 402                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 403
 404         for (i = 0; i < pdata->num_subdevs; i++) {
 405
 406                 if (!pdata->subdevs[i].platform_data)
 407                         goto err_free;
 408
 409                 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 410
 411                 switch (pdata->subdevs[i].id) {
 412                 case MAX8660_V3:
 413                         if (boot_on)
 414                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 415                         break;
 416
 417                 case MAX8660_V4:
 418                         if (boot_on)
 419                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 420                         break;
 421
 422                 case MAX8660_V5:
 423                         break;
 424
 425                 case MAX8660_V6:
 426                         if (boot_on)
 427                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 428                         break;
 429
 430                 case MAX8660_V7:
 431                         if (!strcmp(i2c_id->name, "max8661")) {
 432                                 dev_err(&client->dev, "Regulator not on this chip!\n");
 433                                 goto err_free;
 434                         }
 435
 436                         if (boot_on)
 437                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 438                         break;
 439
 440                 default:
 441                         dev_err(&client->dev, "invalid regulator %s\n",
 442                                  pdata->subdevs[i].name);
 443                         goto err_free;
 444                 }
 445         }
 446
 447         /* Finally register devices */
 448         for (i = 0; i < pdata->num_subdevs; i++) {
 449
 450                 id = pdata->subdevs[i].id;
 451
 452                 rdev[i] = regulator_register(&max8660_reg[id], &client->dev,
 453                                              pdata->subdevs[i].platform_data,
 454                                              max8660, NULL);
 455                 if (IS_ERR(rdev[i])) {
 456                         ret = PTR_ERR(rdev[i]);
 457                         dev_err(&client->dev, "failed to register %s\n",
 458                                 max8660_reg[id].name);
 459                         goto err_unregister;
 460                 }
 461         }
 462
 463         i2c_set_clientdata(client, max8660);
 464         dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n");
 465         return 0;
 466
 467 err_unregister:
 468         while (--i >= 0)
 469                 regulator_unregister(rdev[i]);
 470 err_free:
 471         kfree(max8660);
 472 out:
 473         return ret;
 474 }
 475
 476 static int __devexit max8660_remove(struct i2c_client *client)
 477 {
 478         struct max8660 *max8660 = i2c_get_clientdata(client);
 479         int i;
 480
 481         for (i = 0; i < MAX8660_V_END; i++)
 482                 if (max8660->rdev[i])
 483                         regulator_unregister(max8660->rdev[i]);
 484         kfree(max8660);
 485
 486         return 0;
 487 }
 488
 489 static const struct i2c_device_id max8660_id[] = {
 490         { "max8660", 0 },
 491         { "max8661", 0 },
 492         { }
 493 };
 494 MODULE_DEVICE_TABLE(i2c, max8660_id);
 495
 496 static struct i2c_driver max8660_driver = {
 497         .probe = max8660_probe,
 498         .remove = __devexit_p(max8660_remove),
 499         .driver         = {
 500                 .name   = "max8660",
 501                 .owner  = THIS_MODULE,
 502         },
 503         .id_table       = max8660_id,
 504 };
 505
 506 static int __init max8660_init(void)
 507 {
 508         return i2c_add_driver(&max8660_driver);
 509 }
 510 subsys_initcall(max8660_init);
 511
 512 static void __exit max8660_exit(void)
 513 {
 514         i2c_del_driver(&max8660_driver);
 515 }
 516 module_exit(max8660_exit);
 517
 518 /* Module information */
 519 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 520 MODULE_AUTHOR("Wolfram Sang");
 521 MODULE_LICENSE("GPL v2");