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{
 146        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 147        u8 reg, selector, bits;
 148        int ret;
 149
 150        if (min_uV < MAX8660_DCDC_MIN_UV || min_uV > MAX8660_DCDC_MAX_UV)
 151                return -EINVAL;
 152        if (max_uV < MAX8660_DCDC_MIN_UV || max_uV > MAX8660_DCDC_MAX_UV)
 153                return -EINVAL;
 154
 155        selector = (min_uV - (MAX8660_DCDC_MIN_UV - MAX8660_DCDC_STEP + 1))
 156                        / MAX8660_DCDC_STEP;
 157
 158        ret = max8660_dcdc_list(rdev, selector);
 159        if (ret < 0 || ret > max_uV)
 160                return -EINVAL;
 161
 162        reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 163        ret = max8660_write(max8660, reg, 0, selector);
 164        if (ret)
 165                return ret;
 166
 167        /* Select target voltage register and activate regulation */
 168        bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 169        return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 170}
 171
 172static struct regulator_ops max8660_dcdc_ops = {
 173        .is_enabled = max8660_dcdc_is_enabled,
 174        .list_voltage = max8660_dcdc_list,
 175        .set_voltage = max8660_dcdc_set,
 176        .get_voltage = max8660_dcdc_get,
 177};
 178
 179
 180/*
 181 * LDO5 functions
 182 */
 183
 184static int max8660_ldo5_list(struct regulator_dev *rdev, unsigned selector)
 185{
 186        if (selector > MAX8660_LDO5_MAX_SEL)
 187                return -EINVAL;
 188        return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 189}
 190
 191static int max8660_ldo5_get(struct regulator_dev *rdev)
 192{
 193        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 194        u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 195
 196        return MAX8660_LDO5_MIN_UV + selector * MAX8660_LDO5_STEP;
 197}
 198
 199static int max8660_ldo5_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 200{
 201        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 202        u8 selector;
 203        int ret;
 204
 205        if (min_uV < MAX8660_LDO5_MIN_UV || min_uV > MAX8660_LDO5_MAX_UV)
 206                return -EINVAL;
 207        if (max_uV < MAX8660_LDO5_MIN_UV || max_uV > MAX8660_LDO5_MAX_UV)
 208                return -EINVAL;
 209
 210        selector = (min_uV - (MAX8660_LDO5_MIN_UV - MAX8660_LDO5_STEP + 1))
 211                        / MAX8660_LDO5_STEP;
 212        ret = max8660_ldo5_list(rdev, selector);
 213        if (ret < 0 || ret > max_uV)
 214                return -EINVAL;
 215
 216        ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 217        if (ret)
 218                return ret;
 219
 220        /* Select target voltage register and activate regulation */
 221        return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 222}
 223
 224static struct regulator_ops max8660_ldo5_ops = {
 225        .list_voltage = max8660_ldo5_list,
 226        .set_voltage = max8660_ldo5_set,
 227        .get_voltage = max8660_ldo5_get,
 228};
 229
 230
 231/*
 232 * LDO67 functions
 233 */
 234
 235static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 236{
 237        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 238        u8 val = max8660->shadow_regs[MAX8660_OVER2];
 239        u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 240        return !!(val & mask);
 241}
 242
 243static int max8660_ldo67_enable(struct regulator_dev *rdev)
 244{
 245        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 246        u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 247        return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 248}
 249
 250static int max8660_ldo67_disable(struct regulator_dev *rdev)
 251{
 252        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 253        u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 254        return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 255}
 256
 257static int max8660_ldo67_list(struct regulator_dev *rdev, unsigned selector)
 258{
 259        if (selector > MAX8660_LDO67_MAX_SEL)
 260                return -EINVAL;
 261        return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 262}
 263
 264static int max8660_ldo67_get(struct regulator_dev *rdev)
 265{
 266        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 267        u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 268        u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 269
 270        return MAX8660_LDO67_MIN_UV + selector * MAX8660_LDO67_STEP;
 271}
 272
 273static int max8660_ldo67_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 274{
 275        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 276        u8 selector;
 277        int ret;
 278
 279        if (min_uV < MAX8660_LDO67_MIN_UV || min_uV > MAX8660_LDO67_MAX_UV)
 280                return -EINVAL;
 281        if (max_uV < MAX8660_LDO67_MIN_UV || max_uV > MAX8660_LDO67_MAX_UV)
 282                return -EINVAL;
 283
 284        selector = (min_uV - (MAX8660_LDO67_MIN_UV - MAX8660_LDO67_STEP + 1))
 285                        / MAX8660_LDO67_STEP;
 286
 287        ret = max8660_ldo67_list(rdev, selector);
 288        if (ret < 0 || ret > max_uV)
 289                return -EINVAL;
 290
 291        if (rdev_get_id(rdev) == MAX8660_V6)
 292                return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 293        else
 294                return max8660_write(max8660, MAX8660_L12VCR, 0x0f, selector << 4);
 295}
 296
 297static struct regulator_ops max8660_ldo67_ops = {
 298        .is_enabled = max8660_ldo67_is_enabled,
 299        .enable = max8660_ldo67_enable,
 300        .disable = max8660_ldo67_disable,
 301        .list_voltage = max8660_ldo67_list,
 302        .get_voltage = max8660_ldo67_get,
 303        .set_voltage = max8660_ldo67_set,
 304};
 305
 306static struct regulator_desc max8660_reg[] = {
 307        {
 308                .name = "V3(DCDC)",
 309                .id = MAX8660_V3,
 310                .ops = &max8660_dcdc_ops,
 311                .type = REGULATOR_VOLTAGE,
 312                .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 313                .owner = THIS_MODULE,
 314        },
 315        {
 316                .name = "V4(DCDC)",
 317                .id = MAX8660_V4,
 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 = "V5(LDO)",
 325                .id = MAX8660_V5,
 326                .ops = &max8660_ldo5_ops,
 327                .type = REGULATOR_VOLTAGE,
 328                .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 329                .owner = THIS_MODULE,
 330        },
 331        {
 332                .name = "V6(LDO)",
 333                .id = MAX8660_V6,
 334                .ops = &max8660_ldo67_ops,
 335                .type = REGULATOR_VOLTAGE,
 336                .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 337                .owner = THIS_MODULE,
 338        },
 339        {
 340                .name = "V7(LDO)",
 341                .id = MAX8660_V7,
 342                .ops = &max8660_ldo67_ops,
 343                .type = REGULATOR_VOLTAGE,
 344                .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 345                .owner = THIS_MODULE,
 346        },
 347};
 348
 349static int __devinit max8660_probe(struct i2c_client *client,
 350                                   const struct i2c_device_id *i2c_id)
 351{
 352        struct regulator_dev **rdev;
 353        struct max8660_platform_data *pdata = client->dev.platform_data;
 354        struct max8660 *max8660;
 355        int boot_on, i, id, ret = -EINVAL;
 356
 357        if (pdata->num_subdevs > MAX8660_V_END) {
 358                dev_err(&client->dev, "Too many regulators found!\n");
 359                goto out;
 360        }
 361
 362        max8660 = kzalloc(sizeof(struct max8660) +
 363                        sizeof(struct regulator_dev *) * MAX8660_V_END,
 364                        GFP_KERNEL);
 365        if (!max8660) {
 366                ret = -ENOMEM;
 367                goto out;
 368        }
 369
 370        max8660->client = client;
 371        rdev = max8660->rdev;
 372
 373        if (pdata->en34_is_high) {
 374                /* Simulate always on */
 375                max8660->shadow_regs[MAX8660_OVER1] = 5;
 376        } else {
 377                /* Otherwise devices can be toggled via software */
 378                max8660_dcdc_ops.enable = max8660_dcdc_enable;
 379                max8660_dcdc_ops.disable = max8660_dcdc_disable;
 380        }
 381
 382        /*
 383         * First, set up shadow registers to prevent glitches. As some
 384         * registers are shared between regulators, everything must be properly
 385         * set up for all regulators in advance.
 386         */
 387        max8660->shadow_regs[MAX8660_ADTV1] =
 388                max8660->shadow_regs[MAX8660_ADTV2] =
 389                max8660->shadow_regs[MAX8660_SDTV1] =
 390                max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 391        max8660->shadow_regs[MAX8660_MDTV1] =
 392                max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 393
 394        for (i = 0; i < pdata->num_subdevs; i++) {
 395
 396                if (!pdata->subdevs[i].platform_data)
 397                        goto err_free;
 398
 399                boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 400
 401                switch (pdata->subdevs[i].id) {
 402                case MAX8660_V3:
 403                        if (boot_on)
 404                                max8660->shadow_regs[MAX8660_OVER1] |= 1;
 405                        break;
 406
 407                case MAX8660_V4:
 408                        if (boot_on)
 409                                max8660->shadow_regs[MAX8660_OVER1] |= 4;
 410                        break;
 411
 412                case MAX8660_V5:
 413                        break;
 414
 415                case MAX8660_V6:
 416                        if (boot_on)
 417                                max8660->shadow_regs[MAX8660_OVER2] |= 2;
 418                        break;
 419
 420                case MAX8660_V7:
 421                        if (!strcmp(i2c_id->name, "max8661")) {
 422                                dev_err(&client->dev, "Regulator not on this chip!\n");
 423                                goto err_free;
 424                        }
 425
 426                        if (boot_on)
 427                                max8660->shadow_regs[MAX8660_OVER2] |= 4;
 428                        break;
 429
 430                default:
 431                        dev_err(&client->dev, "invalid regulator %s\n",
 432                                 pdata->subdevs[i].name);
 433                        goto err_free;
 434                }
 435        }
 436
 437        /* Finally register devices */
 438        for (i = 0; i < pdata->num_subdevs; i++) {
 439
 440                id = pdata->subdevs[i].id;
 441
 442                rdev[i] = regulator_register(&max8660_reg[id], &client->dev,
 443                                             pdata->subdevs[i].platform_data,
 444                                             max8660);
 445                if (IS_ERR(rdev[i])) {
 446                        ret = PTR_ERR(rdev[i]);
 447                        dev_err(&client->dev, "failed to register %s\n",
 448                                max8660_reg[id].name);
 449                        goto err_unregister;
 450                }
 451        }
 452
 453        i2c_set_clientdata(client, max8660);
 454        dev_info(&client->dev, "Maxim 8660/8661 regulator driver loaded\n");
 455        return 0;
 456
 457err_unregister:
 458        while (--i >= 0)
 459                regulator_unregister(rdev[i]);
 460err_free:
 461        kfree(max8660);
 462out:
 463        return ret;
 464}
 465
 466static int __devexit max8660_remove(struct i2c_client *client)
 467{
 468        struct max8660 *max8660 = i2c_get_clientdata(client);
 469        int i;
 470
 471        for (i = 0; i < MAX8660_V_END; i++)
 472                if (max8660->rdev[i])
 473                        regulator_unregister(max8660->rdev[i]);
 474        kfree(max8660);
 475
 476        return 0;
 477}
 478
 479static const struct i2c_device_id max8660_id[] = {
 480        { "max8660", 0 },
 481        { "max8661", 0 },
 482        { }
 483};
 484MODULE_DEVICE_TABLE(i2c, max8660_id);
 485
 486static struct i2c_driver max8660_driver = {
 487        .probe = max8660_probe,
 488        .remove = __devexit_p(max8660_remove),
 489        .driver         = {
 490                .name   = "max8660",
 491                .owner  = THIS_MODULE,
 492        },
 493        .id_table       = max8660_id,
 494};
 495
 496static int __init max8660_init(void)
 497{
 498        return i2c_add_driver(&max8660_driver);
 499}
 500subsys_initcall(max8660_init);
 501
 502static void __exit max8660_exit(void)
 503{
 504        i2c_del_driver(&max8660_driver);
 505}
 506module_exit(max8660_exit);
 507
 508/* Module information */
 509MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 510MODULE_AUTHOR("Wolfram Sang");
 511MODULE_LICENSE("GPL v2");
 512