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 = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1))
 157                         / MAX8660_DCDC_STEP;
 158         *s = selector;
 159
 160         ret = max8660_dcdc_list(rdev, selector);
 161         if (ret < 0 || ret > max_uV)
 162                 return -EINVAL;
 163
 164         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 165         ret = max8660_write(max8660, reg, 0, selector);
 166         if (ret)
 167                 return ret;
 168
 169         /* Select target voltage register and activate regulation */
 170         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 171         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 172 }
 173
 174 static struct regulator_ops max8660_dcdc_ops = {
 175         .is_enabled = max8660_dcdc_is_enabled,
 176         .list_voltage = max8660_dcdc_list,
 177         .set_voltage = max8660_dcdc_set,
 178         .get_voltage = max8660_dcdc_get,
 179 };
 180
 181
 182 /*
 183  * LDO5 functions
 184  */
 185
 186 static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector)
 187 {
 188         if (selector > MAX8660_LDO5_MAX_SEL)
 189                 return -EINVAL;
 190         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 191 }
 192
 193 static int max8660_ldo5_get(struct regulator_dev *rdev)
 194 {
 195         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 196         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 197
 198         return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 199 }
 200
 201 static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV,
 202                             unsigned int *s)
 203 {
 204         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 205         u8 selector;
 206         int ret;
 207
 208         if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV)
 209                 return -EINVAL;
 210         if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV)
 211                 return -EINVAL;
 212
 213         selector = (min_uV - (MAX8660_LDO5_MIN_UV - MAX8660_LDO5_STEP + 1))
 214                         / MAX8660_LDO5_STEP;
 215         ret = max8660_ldo5_list(rdev, selector);
 216         if (ret < 0 || ret > max_uV)
 217                 return -EINVAL;
 218
 219         *s = selector;
 220
 221         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 222         if (ret)
 223                 return ret;
 224
 225         /* Select target voltage register and activate regulation */
 226         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 227 }
 228
 229 static struct regulator_ops max8660_ldo5_ops = {
 230         .list_voltage = max8660_ldo5_list,
 231         .set_voltage = max8660_ldo5_set,
 232         .get_voltage = max8660_ldo5_get,
 233 };
 234
 235
 236 /*
 237  * LDO67 functions
 238  */
 239
 240 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 241 {
 242         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 243         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 244         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 245         return !!(val & mask);
 246 }
 247
 248 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 249 {
 250         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 251         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 252         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 253 }
 254
 255 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 256 {
 257         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 258         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 259         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 260 }
 261
 262 static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector)
 263 {
 264         if (selector > MAX8660_LDO67_MAX_SEL)
 265                 return -EINVAL;
 266         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 267 }
 268
 269 static int max8660_ldo67_get(struct regulator_dev *rdev)
 270 {
 271         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 272         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 273         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 274
 275         return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 276 }
 277
 278 static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV,
 279                              int max_uV, unsigned int *s)
 280 {
 281         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 282         u8 selector;
 283         int ret;
 284
 285         if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV)
 286                 return -EINVAL;
 287         if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV)
 288                 return -EINVAL;
 289
 290         selector = (min_uV - (MAX8660_LDO67_MIN_UV - MAX8660_LDO67_STEP + 1))
 291                         / MAX8660_LDO67_STEP;
 292
 293         ret = max8660_ldo67_list(rdev, selector);
 294         if (ret < 0 || ret > max_uV)
 295                 return -EINVAL;
 296
 297         *s = selector;
 298
 299         if (rdev_get_id(rdev) == MAX8660_V6)
 300                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 301         else
 302                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4);
 303 }
 304
 305 static struct regulator_ops max8660_ldo67_ops = {
 306         .is_enabled = max8660_ldo67_is_enabled,
 307         .enable = max8660_ldo67_enable,
 308         .disable = max8660_ldo67_disable,
 309         .list_voltage = max8660_ldo67_list,
 310         .get_voltage = max8660_ldo67_get,
 311         .set_voltage = max8660_ldo67_set,
 312 };
 313
 314 static struct regulator_desc max8660_reg[] = {
 315         {
 316                 .name = "V3(DCDC)",
 317                 .id = MAX8660_V3,
 318                 .ops = &max8660_dcdc_ops,
 319                 .type = REGULATOR_VOLTAGE,
 320                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 321                 .owner = THIS_MODULE,
 322         },
 323         {
 324                 .name = "V4(DCDC)",
 325                 .id = MAX8660_V4,
 326                 .ops = &max8660_dcdc_ops,
 327                 .type = REGULATOR_VOLTAGE,
 328                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 329                 .owner = THIS_MODULE,
 330         },
 331         {
 332                 .name = "V5(LDO)",
 333                 .id = MAX8660_V5,
 334                 .ops = &max8660_ldo5_ops,
 335                 .type = REGULATOR_VOLTAGE,
 336                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 337                 .owner = THIS_MODULE,
 338         },
 339         {
 340                 .name = "V6(LDO)",
 341                 .id = MAX8660_V6,
 342                 .ops = &max8660_ldo67_ops,
 343                 .type = REGULATOR_VOLTAGE,
 344                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 345                 .owner = THIS_MODULE,
 346         },
 347         {
 348                 .name = "V7(LDO)",
 349                 .id = MAX8660_V7,
 350                 .ops = &max8660_ldo67_ops,
 351                 .type = REGULATOR_VOLTAGE,
 352                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 353                 .owner = THIS_MODULE,
 354         },
 355 };
 356
 357 static int __devinit max8660_probe(struct i2c_client *client,
 358                                    const struct i2c_device_id *i2c_id)
 359 {
 360         struct regulator_dev **rdev;
 361         struct max8660_platform_data *pdata = client->dev.platform_data;
 362         struct max8660 *max8660;
 363         int boot_on, i, id, ret = -EINVAL;
 364
 365         if (pdata->num_subdevs > MAX8660_V_END) {
 366                 dev_err(&client->dev, "Too many regulators found!\n");
 367                 goto out;
 368         }
 369
 370         max8660 = kzalloc(sizeof(struct max8660) +
 371                         sizeof(struct regulator_dev *) * MAX8660_V_END,
 372                         GFP_KERNEL);
 373         if (!max8660) {
 374                 ret = -ENOMEM;
 375                 goto out;
 376         }
 377
 378         max8660->client = client;
 379         rdev = max8660->rdev;
 380
 381         if (pdata->en34_is_high) {
 382                 /* Simulate always on */
 383                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 384         } else {
 385                 /* Otherwise devices can be toggled via software */
 386                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 387                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 388         }
 389
 390         /*
 391          * First, set up shadow registers to prevent glitches. As some
 392          * registers are shared between regulators, everything must be properly
 393          * set up for all regulators in advance.
 394          */
 395         max8660->shadow_regs[MAX8660_ADTV1] =
 396                 max8660->shadow_regs[MAX8660_ADTV2] =
 397                 max8660->shadow_regs[MAX8660_SDTV1] =
 398                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 399         max8660->shadow_regs[MAX8660_MDTV1] =
 400                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 401
 402         for (i = 0; i < pdata->num_subdevs; i++) {
 403
 404                 if (!pdata->subdevs[i].platform_data)
 405                         goto err_free;
 406
 407                 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 408
 409                 switch (pdata->subdevs[i].id) {
 410                 case MAX8660_V3:
 411                         if (boot_on)
 412                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 413                         break;
 414
 415                 case MAX8660_V4:
 416                         if (boot_on)
 417                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 418                         break;
 419
 420                 case MAX8660_V5:
 421                         break;
 422
 423                 case MAX8660_V6:
 424                         if (boot_on)
 425                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 426                         break;
 427
 428                 case MAX8660_V7:
 429                         if (!strcmp(i2c_id->name, "max8661")) {
 430                                 dev_err(&client->dev, "Regulator not on this chip!\n");
 431                                 goto err_free;
 432                         }
 433
 434                         if (boot_on)
 435                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 436                         break;
 437
 438                 default:
 439                         dev_err(&client->dev, "invalid regulator %s\n",
 440                                  pdata->subdevs[i].name);
 441                         goto err_free;
 442                 }
 443         }
 444
 445         /* Finally register devices */
 446         for (i = 0; i < pdata->num_subdevs; i++) {
 447
 448                 id = pdata->subdevs[i].id;
 449
 450                 rdev[i] = regulator_register(&max8660_reg[id], &client->dev,
 451                                              pdata->subdevs[i].platform_data,
 452                                              max8660);
 453                 if (IS_ERR(rdev[i])) {
 454                         ret = PTR_ERR(rdev[i]);
 455                         dev_err(&client->dev, "failed to register %s\n",
 456                                 max8660_reg[id].name);
 457                         goto err_unregister;
 458                 }
 459         }
 460
 461         i2c_set_clientdata(client, max8660);
 462         dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n");
 463         return 0;
 464
 465 err_unregister:
 466         while (--i >= 0)
 467                 regulator_unregister(rdev[i]);
 468 err_free:
 469         kfree(max8660);
 470 out:
 471         return ret;
 472 }
 473
 474 static int __devexit max8660_remove(struct i2c_client *client)
 475 {
 476         struct max8660 *max8660 = i2c_get_clientdata(client);
 477         int i;
 478
 479         for (i = 0; i < MAX8660_V_END; i++)
 480                 if (max8660->rdev[i])
 481                         regulator_unregister(max8660->rdev[i]);
 482         kfree(max8660);
 483
 484         return 0;
 485 }
 486
 487 static const struct i2c_device_id max8660_id[] = {
 488         { "max8660", 0 },
 489         { "max8661", 0 },
 490         { }
 491 };
 492 MODULE_DEVICE_TABLE(i2c, max8660_id);
 493
 494 static struct i2c_driver max8660_driver = {
 495         .probe = max8660_probe,
 496         .remove = __devexit_p(max8660_remove),
 497         .driver         = {
 498                 .name   = "max8660",
 499                 .owner  = THIS_MODULE,
 500         },
 501         .id_table       = max8660_id,
 502 };
 503
 504 static int __init max8660_init(void)
 505 {
 506         return i2c_add_driver(&max8660_driver);
 507 }
 508 subsys_initcall(max8660_init);
 509
 510 static void __exit max8660_exit(void)
 511 {
 512         i2c_del_driver(&max8660_driver);
 513 }
 514 module_exit(max8660_exit);
 515
 516 /* Module information */
 517 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 518 MODULE_AUTHOR("Wolfram Sang");
 519 MODULE_LICENSE("GPL v2");