LXR linux/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
  63enum {
  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
  78struct 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
  84static 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
 107static 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
 115static 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
 122static 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
 129static 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
 136static 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
 144static 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
 174static 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
 186static 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
 193static 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
 201static 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
 229static 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
 240static 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
 248static 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
 255static 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
 262static 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
 269static 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
 278static 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
 305static 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
 314static 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
 357static 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
 465err_unregister:
 466        while (--i >= 0)
 467                regulator_unregister(rdev[i]);
 468err_free:
 469        kfree(max8660);
 470out:
 471        return ret;
 472}
 473
 474static 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
 487static const struct i2c_device_id max8660_id[] = {
 488        { "max8660", 0 },
 489        { "max8661", 0 },
 490        { }
 491};
 492MODULE_DEVICE_TABLE(i2c, max8660_id);
 493
 494static 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
 504static int __init max8660_init(void)
 505{
 506        return i2c_add_driver(&max8660_driver);
 507}
 508subsys_initcall(max8660_init);
 509
 510static void __exit max8660_exit(void)
 511{
 512        i2c_del_driver(&max8660_driver);
 513}
 514module_exit(max8660_exit);
 515
 516/* Module information */
 517MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 518MODULE_AUTHOR("Wolfram Sang");
 519MODULE_LICENSE("GPL v2");
 520