linux/drivers/regulator/max8660.c
<<
>>
Prefs
   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_get_voltage_sel(struct regulator_dev *rdev)
 130{
 131        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 132
 133        u8 reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 134        u8 selector = max8660->shadow_regs[reg];
 135        return selector;
 136}
 137
 138static int max8660_dcdc_set_voltage_sel(struct regulator_dev *rdev,
 139                                        unsigned int selector)
 140{
 141        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 142        u8 reg, bits;
 143        int ret;
 144
 145        reg = (rdev_get_id(rdev) == MAX8660_V3) ? MAX8660_ADTV2 : MAX8660_SDTV2;
 146        ret = max8660_write(max8660, reg, 0, selector);
 147        if (ret)
 148                return ret;
 149
 150        /* Select target voltage register and activate regulation */
 151        bits = (rdev_get_id(rdev) == MAX8660_V3) ? 0x03 : 0x30;
 152        return max8660_write(max8660, MAX8660_VCC1, 0xff, bits);
 153}
 154
 155static struct regulator_ops max8660_dcdc_ops = {
 156        .is_enabled = max8660_dcdc_is_enabled,
 157        .list_voltage = regulator_list_voltage_linear,
 158        .map_voltage = regulator_map_voltage_linear,
 159        .set_voltage_sel = max8660_dcdc_set_voltage_sel,
 160        .get_voltage_sel = max8660_dcdc_get_voltage_sel,
 161};
 162
 163
 164/*
 165 * LDO5 functions
 166 */
 167
 168static int max8660_ldo5_get_voltage_sel(struct regulator_dev *rdev)
 169{
 170        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 171
 172        u8 selector = max8660->shadow_regs[MAX8660_MDTV2];
 173        return selector;
 174}
 175
 176static int max8660_ldo5_set_voltage_sel(struct regulator_dev *rdev,
 177                                        unsigned int selector)
 178{
 179        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 180        int ret;
 181
 182        ret = max8660_write(max8660, MAX8660_MDTV2, 0, selector);
 183        if (ret)
 184                return ret;
 185
 186        /* Select target voltage register and activate regulation */
 187        return max8660_write(max8660, MAX8660_VCC1, 0xff, 0xc0);
 188}
 189
 190static struct regulator_ops max8660_ldo5_ops = {
 191        .list_voltage = regulator_list_voltage_linear,
 192        .map_voltage = regulator_map_voltage_linear,
 193        .set_voltage_sel = max8660_ldo5_set_voltage_sel,
 194        .get_voltage_sel = max8660_ldo5_get_voltage_sel,
 195};
 196
 197
 198/*
 199 * LDO67 functions
 200 */
 201
 202static int max8660_ldo67_is_enabled(struct regulator_dev *rdev)
 203{
 204        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 205        u8 val = max8660->shadow_regs[MAX8660_OVER2];
 206        u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 207        return !!(val & mask);
 208}
 209
 210static int max8660_ldo67_enable(struct regulator_dev *rdev)
 211{
 212        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 213        u8 bit = (rdev_get_id(rdev) == MAX8660_V6) ? 2 : 4;
 214        return max8660_write(max8660, MAX8660_OVER2, 0xff, bit);
 215}
 216
 217static int max8660_ldo67_disable(struct regulator_dev *rdev)
 218{
 219        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 220        u8 mask = (rdev_get_id(rdev) == MAX8660_V6) ? ~2 : ~4;
 221        return max8660_write(max8660, MAX8660_OVER2, mask, 0);
 222}
 223
 224static int max8660_ldo67_get_voltage_sel(struct regulator_dev *rdev)
 225{
 226        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 227
 228        u8 shift = (rdev_get_id(rdev) == MAX8660_V6) ? 0 : 4;
 229        u8 selector = (max8660->shadow_regs[MAX8660_L12VCR] >> shift) & 0xf;
 230        return selector;
 231}
 232
 233static int max8660_ldo67_set_voltage_sel(struct regulator_dev *rdev,
 234                                         unsigned int selector)
 235{
 236        struct max8660 *max8660 = rdev_get_drvdata(rdev);
 237
 238        if (rdev_get_id(rdev) == MAX8660_V6)
 239                return max8660_write(max8660, MAX8660_L12VCR, 0xf0, selector);
 240        else
 241                return max8660_write(max8660, MAX8660_L12VCR, 0x0f,
 242                                     selector << 4);
 243}
 244
 245static struct regulator_ops max8660_ldo67_ops = {
 246        .is_enabled = max8660_ldo67_is_enabled,
 247        .enable = max8660_ldo67_enable,
 248        .disable = max8660_ldo67_disable,
 249        .list_voltage = regulator_list_voltage_linear,
 250        .map_voltage = regulator_map_voltage_linear,
 251        .get_voltage_sel = max8660_ldo67_get_voltage_sel,
 252        .set_voltage_sel = max8660_ldo67_set_voltage_sel,
 253};
 254
 255static const struct regulator_desc max8660_reg[] = {
 256        {
 257                .name = "V3(DCDC)",
 258                .id = MAX8660_V3,
 259                .ops = &max8660_dcdc_ops,
 260                .type = REGULATOR_VOLTAGE,
 261                .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 262                .owner = THIS_MODULE,
 263                .min_uV = MAX8660_DCDC_MIN_UV,
 264                .uV_step = MAX8660_DCDC_STEP,
 265        },
 266        {
 267                .name = "V4(DCDC)",
 268                .id = MAX8660_V4,
 269                .ops = &max8660_dcdc_ops,
 270                .type = REGULATOR_VOLTAGE,
 271                .n_voltages = MAX8660_DCDC_MAX_SEL + 1,
 272                .owner = THIS_MODULE,
 273                .min_uV = MAX8660_DCDC_MIN_UV,
 274                .uV_step = MAX8660_DCDC_STEP,
 275        },
 276        {
 277                .name = "V5(LDO)",
 278                .id = MAX8660_V5,
 279                .ops = &max8660_ldo5_ops,
 280                .type = REGULATOR_VOLTAGE,
 281                .n_voltages = MAX8660_LDO5_MAX_SEL + 1,
 282                .owner = THIS_MODULE,
 283                .min_uV = MAX8660_LDO5_MIN_UV,
 284                .uV_step = MAX8660_LDO5_STEP,
 285        },
 286        {
 287                .name = "V6(LDO)",
 288                .id = MAX8660_V6,
 289                .ops = &max8660_ldo67_ops,
 290                .type = REGULATOR_VOLTAGE,
 291                .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 292                .owner = THIS_MODULE,
 293                .min_uV = MAX8660_LDO67_MIN_UV,
 294                .uV_step = MAX8660_LDO67_STEP,
 295        },
 296        {
 297                .name = "V7(LDO)",
 298                .id = MAX8660_V7,
 299                .ops = &max8660_ldo67_ops,
 300                .type = REGULATOR_VOLTAGE,
 301                .n_voltages = MAX8660_LDO67_MAX_SEL + 1,
 302                .owner = THIS_MODULE,
 303                .min_uV = MAX8660_LDO67_MIN_UV,
 304                .uV_step = MAX8660_LDO67_STEP,
 305        },
 306};
 307
 308static int max8660_probe(struct i2c_client *client,
 309                                   const struct i2c_device_id *i2c_id)
 310{
 311        struct regulator_dev **rdev;
 312        struct max8660_platform_data *pdata = client->dev.platform_data;
 313        struct regulator_config config = { };
 314        struct max8660 *max8660;
 315        int boot_on, i, id, ret = -EINVAL;
 316
 317        if (pdata->num_subdevs > MAX8660_V_END) {
 318                dev_err(&client->dev, "Too many regulators found!\n");
 319                return -EINVAL;
 320        }
 321
 322        max8660 = devm_kzalloc(&client->dev, sizeof(struct max8660) +
 323                        sizeof(struct regulator_dev *) * MAX8660_V_END,
 324                        GFP_KERNEL);
 325        if (!max8660)
 326                return -ENOMEM;
 327
 328        max8660->client = client;
 329        rdev = max8660->rdev;
 330
 331        if (pdata->en34_is_high) {
 332                /* Simulate always on */
 333                max8660->shadow_regs[MAX8660_OVER1] = 5;
 334        } else {
 335                /* Otherwise devices can be toggled via software */
 336                max8660_dcdc_ops.enable = max8660_dcdc_enable;
 337                max8660_dcdc_ops.disable = max8660_dcdc_disable;
 338        }
 339
 340        /*
 341         * First, set up shadow registers to prevent glitches. As some
 342         * registers are shared between regulators, everything must be properly
 343         * set up for all regulators in advance.
 344         */
 345        max8660->shadow_regs[MAX8660_ADTV1] =
 346                max8660->shadow_regs[MAX8660_ADTV2] =
 347                max8660->shadow_regs[MAX8660_SDTV1] =
 348                max8660->shadow_regs[MAX8660_SDTV2] = 0x1b;
 349        max8660->shadow_regs[MAX8660_MDTV1] =
 350                max8660->shadow_regs[MAX8660_MDTV2] = 0x04;
 351
 352        for (i = 0; i < pdata->num_subdevs; i++) {
 353
 354                if (!pdata->subdevs[i].platform_data)
 355                        goto err_out;
 356
 357                boot_on = pdata->subdevs[i].platform_data->constraints.boot_on;
 358
 359                switch (pdata->subdevs[i].id) {
 360                case MAX8660_V3:
 361                        if (boot_on)
 362                                max8660->shadow_regs[MAX8660_OVER1] |= 1;
 363                        break;
 364
 365                case MAX8660_V4:
 366                        if (boot_on)
 367                                max8660->shadow_regs[MAX8660_OVER1] |= 4;
 368                        break;
 369
 370                case MAX8660_V5:
 371                        break;
 372
 373                case MAX8660_V6:
 374                        if (boot_on)
 375                                max8660->shadow_regs[MAX8660_OVER2] |= 2;
 376                        break;
 377
 378                case MAX8660_V7:
 379                        if (!strcmp(i2c_id->name, "max8661")) {
 380                                dev_err(&client->dev, "Regulator not on this chip!\n");
 381                                goto err_out;
 382                        }
 383
 384                        if (boot_on)
 385                                max8660->shadow_regs[MAX8660_OVER2] |= 4;
 386                        break;
 387
 388                default:
 389                        dev_err(&client->dev, "invalid regulator %s\n",
 390                                 pdata->subdevs[i].name);
 391                        goto err_out;
 392                }
 393        }
 394
 395        /* Finally register devices */
 396        for (i = 0; i < pdata->num_subdevs; i++) {
 397
 398                id = pdata->subdevs[i].id;
 399
 400                config.dev = &client->dev;
 401                config.init_data = pdata->subdevs[i].platform_data;
 402                config.driver_data = max8660;
 403
 404                rdev[i] = regulator_register(&max8660_reg[id], &config);
 405                if (IS_ERR(rdev[i])) {
 406                        ret = PTR_ERR(rdev[i]);
 407                        dev_err(&client->dev, "failed to register %s\n",
 408                                max8660_reg[id].name);
 409                        goto err_unregister;
 410                }
 411        }
 412
 413        i2c_set_clientdata(client, max8660);
 414        return 0;
 415
 416err_unregister:
 417        while (--i >= 0)
 418                regulator_unregister(rdev[i]);
 419err_out:
 420        return ret;
 421}
 422
 423static int max8660_remove(struct i2c_client *client)
 424{
 425        struct max8660 *max8660 = i2c_get_clientdata(client);
 426        int i;
 427
 428        for (i = 0; i < MAX8660_V_END; i++)
 429                regulator_unregister(max8660->rdev[i]);
 430        return 0;
 431}
 432
 433static const struct i2c_device_id max8660_id[] = {
 434        { "max8660", 0 },
 435        { "max8661", 0 },
 436        { }
 437};
 438MODULE_DEVICE_TABLE(i2c, max8660_id);
 439
 440static struct i2c_driver max8660_driver = {
 441        .probe = max8660_probe,
 442        .remove = max8660_remove,
 443        .driver         = {
 444                .name   = "max8660",
 445                .owner  = THIS_MODULE,
 446        },
 447        .id_table       = max8660_id,
 448};
 449
 450static int __init max8660_init(void)
 451{
 452        return i2c_add_driver(&max8660_driver);
 453}
 454subsys_initcall(max8660_init);
 455
 456static void __exit max8660_exit(void)
 457{
 458        i2c_del_driver(&max8660_driver);
 459}
 460module_exit(max8660_exit);
 461
 462/* Module information */
 463MODULE_DESCRIPTION("MAXIM 8660/8661 voltage regulator driver");
 464MODULE_AUTHOR("Wolfram Sang");
 465MODULE_LICENSE("GPL v2");
 466
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.