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