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 #include <linux/of.h>
  48 #include <linux/of_device.h>
  49 #include <linux/regulator/of_regulator.h>
  50
  51 #define MAX8660_DCDC_MIN_UV      725000
  52 #define MAX8660_DCDC_MAX_UV     1800000
  53 #define MAX8660_DCDC_STEP         25000
  54 #define MAX8660_DCDC_MAX_SEL    0x2b
  55
  56 #define MAX8660_LDO5_MIN_UV     1700000
  57 #define MAX8660_LDO5_MAX_UV     2000000
  58 #define MAX8660_LDO5_STEP         25000
  59 #define MAX8660_LDO5_MAX_SEL    0x0c
  60
  61 #define MAX8660_LDO67_MIN_UV    1800000
  62 #define MAX8660_LDO67_MAX_UV    3300000
  63 #define MAX8660_LDO67_STEP       100000
  64 #define MAX8660_LDO67_MAX_SEL   0x0f
  65
  66 enum {
  67         MAX8660_OVER1,
  68         MAX8660_OVER2,
  69         MAX8660_VCC1,
  70         MAX8660_ADTV1,
  71         MAX8660_ADTV2,
  72         MAX8660_SDTV1,
  73         MAX8660_SDTV2,
  74         MAX8660_MDTV1,
  75         MAX8660_MDTV2,
  76         MAX8660_L12VCR,
  77         MAX8660_FPWM,
  78         MAX8660_N_REGS, /* not a real register */
  79 };
  80
  81 struct max8660 {
  82         struct i2c_client *client;
  83         u8 shadow_regs[MAX8660_N_REGS];         /* as chip is write only */
  84         struct regulator_dev *rdev[];
  85 };
  86
  87 static int max8660_write(struct max8660 *max8660, u8 reg, u8 mask, u8 val)
  88 {
  89         static const u8 max8660_addresses[MAX8660_N_REGS] =
  90           { 0x10, 0x12, 0x20, 0x23, 0x24, 0x29, 0x2a, 0x32, 0x33, 0x39, 0x80 };
  91
  92         int ret;
  93         u8 reg_val = (max8660->shadow_regs[reg] & mask) | val;
  94         dev_vdbg(&max8660->client->dev, "Writing reg %02x with %02x\n",
  95                         max8660_addresses[reg], reg_val);
  96
  97         ret = i2c_smbus_write_byte_data(max8660->client,
  98                         max8660_addresses[reg], reg_val);
  99         if (ret == 0)
 100                 max8660->shadow_regs[reg] = reg_val;
 101
 102         return ret;
 103 }
 104
 105
 106 /*
 107  * DCDC functions
 108  */
 109
 110 static int max8660_dcdc_is_enabled(struct regulator_dev *rdev)
 111 {
 112         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 113         u8 val = max8660->shadow_regs[MAX8660_OVER1];
 114         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 115         return !!(val & mask);
 116 }
 117
 118 static int max8660_dcdc_enable(struct regulator_dev *rdev)
 119 {
 120         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 121         u8 bit = (rdev_get_id(rdev) == MAX8660_V3) ? 1 : 4;
 122         return max8660_write(max8660, MAX8660_OVER1, 0xff, bit);
 123 }
 124
 125 static int max8660_dcdc_disable(struct regulator_dev *rdev)
 126 {
 127         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 128         u8 mask = (rdev_get_id(rdev) == MAX8660_V3) ? ~1 : ~4;
 129         return max8660_write(max8660, MAX8660_OVER1, mask, 0);
 130 }
 131
 132 static int max8660_dcdc_get_voltage_sel(struct regulator_dev *rdev)
 133 {
 134         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 135
 136         u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 137         u8 selector = max8660->shadow_regs[reg];
 138         return selector;
 139 }
 140
 141 static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
 142                                         unsigned int selector)
 143 {
 144         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 145         u8 reg, bits;
 146         int ret;
 147
 148         reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 149         ret = max8660_write(max8660, reg, 0, selector);
 150         if (ret)
 151                 return ret;
 152
 153         /* Select target voltage register and activate regulation */
 154         bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 155         return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 156 }
 157
 158 static struct regulator_ops max8660_dcdc_ops = {
 159         .is_enabled = max8660_dcdc_is_enabled,
 160         .list_voltage = regulator_list_voltage_linear,
 161         .map_voltage = regulator_map_voltage_linear,
 162         .set_voltage_sel = max8660_dcdc_set_voltage_sel,
 163         .get_voltage_sel = max8660_dcdc_get_voltage_sel,
 164 };
 165
 166
 167 /*
 168  * LDO5 functions
 169  */
 170
 171 static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
 172 {
 173         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 174
 175         u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 176         return selector;
 177 }
 178
 179 static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
 180                                         unsigned int selector)
 181 {
 182         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 183         int ret;
 184
 185         ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 186         if (ret)
 187                 return ret;
 188
 189         /* Select target voltage register and activate regulation */
 190         return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 191 }
 192
 193 static struct regulator_ops max8660_ldo5_ops = {
 194         .list_voltage = regulator_list_voltage_linear,
 195         .map_voltage = regulator_map_voltage_linear,
 196         .set_voltage_sel = max8660_ldo5_set_voltage_sel,
 197         .get_voltage_sel = max8660_ldo5_get_voltage_sel,
 198 };
 199
 200
 201 /*
 202  * LDO67 functions
 203  */
 204
 205 static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 206 {
 207         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 208         u8 val = max8660->shadow_regs[MAX8660_OVER2];
 209         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 210         return !!(val & mask);
 211 }
 212
 213 static int max8660_ldo67_enable(struct regulator_dev *rdev)
 214 {
 215         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 216         u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 217         return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 218 }
 219
 220 static int max8660_ldo67_disable(struct regulator_dev *rdev)
 221 {
 222         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 223         u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 224         return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 225 }
 226
 227 static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
 228 {
 229         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 230
 231         u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 232         u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 233         return selector;
 234 }
 235
 236 static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
 237                                          unsigned int selector)
 238 {
 239         struct max8660 *max8660 = rdev_get_drvdata(rdev);
 240
 241         if (rdev_get_id(rdev) == MAX8660_V6)
 242                 return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 243         else
 244                 return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
 245                                      selector << 4);
 246 }
 247
 248 static struct regulator_ops max8660_ldo67_ops = {
 249         .is_enabled = max8660_ldo67_is_enabled,
 250         .enable = max8660_ldo67_enable,
 251         .disable = max8660_ldo67_disable,
 252         .list_voltage = regulator_list_voltage_linear,
 253         .map_voltage = regulator_map_voltage_linear,
 254         .get_voltage_sel = max8660_ldo67_get_voltage_sel,
 255         .set_voltage_sel = max8660_ldo67_set_voltage_sel,
 256 };
 257
 258 static const struct regulator_desc max8660_reg[] = {
 259         {
 260                 .name = "V3(DCDC)",
 261                 .id = MAX8660_V3,
 262                 .ops = &max8660_dcdc_ops,
 263                 .type = REGULATOR_VOLTAGE,
 264                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 265                 .owner = THIS_MODULE,
 266                 .min_uV = MAX8660_DCDC_MIN_UV,
 267                 .uV_step = MAX8660_DCDC_STEP,
 268         },
 269         {
 270                 .name = "V4(DCDC)",
 271                 .id = MAX8660_V4,
 272                 .ops = &max8660_dcdc_ops,
 273                 .type = REGULATOR_VOLTAGE,
 274                 .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 275                 .owner = THIS_MODULE,
 276                 .min_uV = MAX8660_DCDC_MIN_UV,
 277                 .uV_step = MAX8660_DCDC_STEP,
 278         },
 279         {
 280                 .name = "V5(LDO)",
 281                 .id = MAX8660_V5,
 282                 .ops = &max8660_ldo5_ops,
 283                 .type = REGULATOR_VOLTAGE,
 284                 .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 285                 .owner = THIS_MODULE,
 286                 .min_uV = MAX8660_LDO5_MIN_UV,
 287                 .uV_step = MAX8660_LDO5_STEP,
 288         },
 289         {
 290                 .name = "V6(LDO)",
 291                 .id = MAX8660_V6,
 292                 .ops = &max8660_ldo67_ops,
 293                 .type = REGULATOR_VOLTAGE,
 294                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 295                 .owner = THIS_MODULE,
 296                 .min_uV = MAX8660_LDO67_MIN_UV,
 297                 .uV_step = MAX8660_LDO67_STEP,
 298         },
 299         {
 300                 .name = "V7(LDO)",
 301                 .id = MAX8660_V7,
 302                 .ops = &max8660_ldo67_ops,
 303                 .type = REGULATOR_VOLTAGE,
 304                 .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 305                 .owner = THIS_MODULE,
 306                 .min_uV = MAX8660_LDO67_MIN_UV,
 307                 .uV_step = MAX8660_LDO67_STEP,
 308         },
 309 };
 310
 311 enum {
 312         MAX8660 = 0,
 313         MAX8661 = 1,
 314 };
 315
 316 #ifdef CONFIG_OF
 317 static const struct of_device_id max8660_dt_ids[] = {
 318         { .compatible = "maxim,max8660", .data = (void *) MAX8660 },
 319         { .compatible = "maxim,max8661", .data = (void *) MAX8661 },
 320         { }
 321 };
 322 MODULE_DEVICE_TABLE(of, max8660_dt_ids);
 323
 324 static int max8660_pdata_from_dt(struct device *dev,
 325                                  struct device_node **of_node,
 326                                  struct max8660_platform_data *pdata)
 327 {
 328         int matched, i;
 329         struct device_node *np;
 330         struct max8660_subdev_data *sub;
 331         struct of_regulator_match rmatch[ARRAY_SIZE(max8660_reg)];
 332
 333         np = of_find_node_by_name(dev->of_node, "regulators");
 334         if (!np) {
 335                 dev_err(dev, "missing 'regulators' subnode in DT\n");
 336                 return -EINVAL;
 337         }
 338
 339         for (i = 0; i < ARRAY_SIZE(rmatch); i++)
 340                 rmatch[i].name = max8660_reg[i].name;
 341
 342         matched = of_regulator_match(dev, np, rmatch, ARRAY_SIZE(rmatch));
 343         if (matched <= 0)
 344                 return matched;
 345
 346         pdata->subdevs = devm_kzalloc(dev, sizeof(struct max8660_subdev_data) *
 347                                                 matched, GFP_KERNEL);
 348         if (!pdata->subdevs)
 349                 return -ENOMEM;
 350
 351         pdata->num_subdevs = matched;
 352         sub = pdata->subdevs;
 353
 354         for (i = 0; i < matched; i++) {
 355                 sub->id = i;
 356                 sub->name = rmatch[i].name;
 357                 sub->platform_data = rmatch[i].init_data;
 358                 of_node[i] = rmatch[i].of_node;
 359                 sub++;
 360         }
 361
 362         return 0;
 363 }
 364 #else
 365 static inline int max8660_pdata_from_dt(struct device *dev,
 366                                         struct device_node **of_node,
 367                                         struct max8660_platform_data *pdata)
 368 {
 369         return 0;
 370 }
 371 #endif
 372
 373 static int max8660_probe(struct i2c_client *client,
 374                                    const struct i2c_device_id *i2c_id)
 375 {
 376         struct regulator_dev **rdev;
 377         struct device *dev = &client->dev;
 378         struct max8660_platform_data *pdata = dev_get_platdata(dev);
 379         struct regulator_config config = { };
 380         struct max8660 *max8660;
 381         int boot_on, i, id, ret = -EINVAL;
 382         struct device_node *of_node[MAX8660_V_END];
 383         unsigned long type;
 384
 385         if (dev->of_node && !pdata) {
 386                 const struct of_device_id *id;
 387                 struct max8660_platform_data pdata_of;
 388
 389                 id = of_match_device(of_match_ptr(max8660_dt_ids), dev);
 390                 if (!id)
 391                         return -ENODEV;
 392
 393                 ret = max8660_pdata_from_dt(dev, of_node, &pdata_of);
 394                 if (ret < 0)
 395                         return ret;
 396
 397                 pdata = &pdata_of;
 398                 type = (unsigned long) id->data;
 399         } else {
 400                 type = i2c_id->driver_data;
 401                 memset(of_node, 0, sizeof(of_node));
 402         }
 403
 404         if (pdata->num_subdevs > MAX8660_V_END) {
 405                 dev_err(dev, "Too many regulators found!\n");
 406                 return -EINVAL;
 407         }
 408
 409         max8660 = devm_kzalloc(dev, sizeof(struct max8660) +
 410                         sizeof(struct regulator_dev *) * MAX8660_V_END,
 411                         GFP_KERNEL);
 412         if (!max8660)
 413                 return -ENOMEM;
 414
 415         max8660->client = client;
 416         rdev = max8660->rdev;
 417
 418         if (pdata->en34_is_high) {
 419                 /* Simulate always on */
 420                 max8660->shadow_regs[MAX8660_OVER1] = 5;
 421         } else {
 422                 /* Otherwise devices can be toggled via software */
 423                 max8660_dcdc_ops.enable = max8660_dcdc_enable;
 424                 max8660_dcdc_ops.disable = max8660_dcdc_disable;
 425         }
 426
 427         /*
 428          * First, set up shadow registers to prevent glitches. As some
 429          * registers are shared between regulators, everything must be properly
 430          * set up for all regulators in advance.
 431          */
 432         max8660->shadow_regs[MAX8660_ADTV1] =
 433                 max8660->shadow_regs[MAX8660_ADTV2] =
 434                 max8660->shadow_regs[MAX8660_SDTV1] =
 435                 max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 436         max8660->shadow_regs[MAX8660_MDTV1] =
 437                 max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 438
 439         for (i = 0; i < pdata->num_subdevs; i++) {
 440
 441                 if (!pdata->subdevs[i].platform_data)
 442                         goto err_out;
 443
 444                 boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 445
 446                 switch (pdata->subdevs[i].id) {
 447                 case MAX8660_V3:
 448                         if (boot_on)
 449                                 max8660->shadow_regs[MAX8660_OVER1] |= 1;
 450                         break;
 451
 452                 case MAX8660_V4:
 453                         if (boot_on)
 454                                 max8660->shadow_regs[MAX8660_OVER1] |= 4;
 455                         break;
 456
 457                 case MAX8660_V5:
 458                         break;
 459
 460                 case MAX8660_V6:
 461                         if (boot_on)
 462                                 max8660->shadow_regs[MAX8660_OVER2] |= 2;
 463                         break;
 464
 465                 case MAX8660_V7:
 466                         if (type == MAX8661) {
 467                                 dev_err(dev, "Regulator not on this chip!\n");
 468                                 goto err_out;
 469                         }
 470
 471                         if (boot_on)
 472                                 max8660->shadow_regs[MAX8660_OVER2] |= 4;
 473                         break;
 474
 475                 default:
 476                         dev_err(dev, "invalid regulator %s\n",
 477                                  pdata->subdevs[i].name);
 478                         goto err_out;
 479                 }
 480         }
 481
 482         /* Finally register devices */
 483         for (i = 0; i < pdata->num_subdevs; i++) {
 484
 485                 id = pdata->subdevs[i].id;
 486
 487                 config.dev = dev;
 488                 config.init_data = pdata->subdevs[i].platform_data;
 489                 config.of_node = of_node[i];
 490                 config.driver_data = max8660;
 491
 492                 rdev[i] = regulator_register(&max8660_reg[id], &config);
 493                 if (IS_ERR(rdev[i])) {
 494                         ret = PTR_ERR(rdev[i]);
 495                         dev_err(dev, "failed to register %s\n",
 496                                 max8660_reg[id].name);
 497                         goto err_unregister;
 498                 }
 499         }
 500
 501         i2c_set_clientdata(client, max8660);
 502         return 0;
 503
 504 err_unregister:
 505         while (--i >= 0)
 506                 regulator_unregister(rdev[i]);
 507 err_out:
 508         return ret;
 509 }
 510
 511 static int max8660_remove(struct i2c_client *client)
 512 {
 513         struct max8660 *max8660 = i2c_get_clientdata(client);
 514         int i;
 515
 516         for (i = 0; i < MAX8660_V_END; i++)
 517                 regulator_unregister(max8660->rdev[i]);
 518         return 0;
 519 }
 520
 521 static const struct i2c_device_id max8660_id[] = {
 522         { .name = "max8660", .driver_data = MAX8660 },
 523         { .name = "max8661", .driver_data = MAX8661 },
 524         { }
 525 };
 526 MODULE_DEVICE_TABLE(i2c, max8660_id);
 527
 528 static struct i2c_driver max8660_driver = {
 529         .probe = max8660_probe,
 530         .remove = max8660_remove,
 531         .driver         = {
 532                 .name   = "max8660",
 533                 .owner  = THIS_MODULE,
 534         },
 535         .id_table       = max8660_id,
 536 };
 537
 538 static int __init max8660_init(void)
 539 {
 540         return i2c_add_driver(&max8660_driver);
 541 }
 542 subsys_initcall(max8660_init);
 543
 544 static void __exit max8660_exit(void)
 545 {
 546         i2c_del_driver(&max8660_driver);
 547 }
 548 module_exit(max8660_exit);
 549
 550 /* Module information */
 551 MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 552 MODULE_AUTHOR("Wolfram Sang");
 553 MODULE_LICENSE("GPL v2");