linux/drivers/hwmon/g762.c
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   1/*
   2 * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed
   3 *        PWM controller chips from G762 family, i.e. G762 and G763
   4 *
   5 * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
   6 *
   7 * This work is based on a basic version for 2.6.31 kernel developed
   8 * by Olivier Mouchet for LaCie. Updates and correction have been
   9 * performed to run on recent kernels. Additional features, like the
  10 * ability to configure various characteristics via .dts file or
  11 * board init file have been added. Detailed datasheet on which this
  12 * development is based is available here:
  13 *
  14 *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
  15 *
  16 * Headers from previous developments have been kept below:
  17 *
  18 * Copyright (c) 2009 LaCie
  19 *
  20 * Author: Olivier Mouchet <olivier.mouchet@gmail.com>
  21 *
  22 * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org>
  23 * Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>
  24 *
  25 * g762: minimal datasheet available at:
  26 *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
  27 *
  28 * This program is free software; you can redistribute it and/or modify
  29 * it under the terms of the GNU General Public License as published by
  30 * the Free Software Foundation; either version 2 of the License, or
  31 * (at your option) any later version.
  32 *
  33 * This program is distributed in the hope that it will be useful,
  34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  36 * GNU General Public License for more details.
  37 *
  38 * You should have received a copy of the GNU General Public License
  39 * along with this program; if not, write to the Free Software
  40 * Foundation.
  41 */
  42
  43#include <linux/device.h>
  44#include <linux/module.h>
  45#include <linux/init.h>
  46#include <linux/jiffies.h>
  47#include <linux/i2c.h>
  48#include <linux/hwmon.h>
  49#include <linux/hwmon-sysfs.h>
  50#include <linux/err.h>
  51#include <linux/mutex.h>
  52#include <linux/kernel.h>
  53#include <linux/clk.h>
  54#include <linux/of.h>
  55#include <linux/of_device.h>
  56#include <linux/platform_data/g762.h>
  57
  58#define DRVNAME "g762"
  59
  60static const struct i2c_device_id g762_id[] = {
  61        { "g762", 0 },
  62        { "g763", 0 },
  63        { }
  64};
  65MODULE_DEVICE_TABLE(i2c, g762_id);
  66
  67enum g762_regs {
  68        G762_REG_SET_CNT  = 0x00,
  69        G762_REG_ACT_CNT  = 0x01,
  70        G762_REG_FAN_STA  = 0x02,
  71        G762_REG_SET_OUT  = 0x03,
  72        G762_REG_FAN_CMD1 = 0x04,
  73        G762_REG_FAN_CMD2 = 0x05,
  74};
  75
  76/* Config register bits */
  77#define G762_REG_FAN_CMD1_DET_FAN_FAIL  0x80 /* enable fan_fail signal */
  78#define G762_REG_FAN_CMD1_DET_FAN_OOC   0x40 /* enable fan_out_of_control */
  79#define G762_REG_FAN_CMD1_OUT_MODE      0x20 /* out mode: PWM or DC */
  80#define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: closed/open-loop */
  81#define G762_REG_FAN_CMD1_CLK_DIV_ID1   0x08 /* clock divisor value */
  82#define G762_REG_FAN_CMD1_CLK_DIV_ID0   0x04
  83#define G762_REG_FAN_CMD1_PWM_POLARITY  0x02 /* PWM polarity */
  84#define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
  85
  86#define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
  87#define G762_REG_FAN_CMD2_GEAR_MODE_0   0x04
  88#define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
  89#define G762_REG_FAN_CMD2_FAN_STARTV_0  0x01
  90
  91#define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
  92#define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
  93
  94/* Config register values */
  95#define G762_OUT_MODE_PWM            1
  96#define G762_OUT_MODE_DC             0
  97
  98#define G762_FAN_MODE_CLOSED_LOOP    2
  99#define G762_FAN_MODE_OPEN_LOOP      1
 100
 101#define G762_PWM_POLARITY_NEGATIVE   1
 102#define G762_PWM_POLARITY_POSITIVE   0
 103
 104/* Register data is read (and cached) at most once per second. */
 105#define G762_UPDATE_INTERVAL    HZ
 106
 107/*
 108 * Extract pulse count per fan revolution value (2 or 4) from given
 109 * FAN_CMD1 register value.
 110 */
 111#define G762_PULSE_FROM_REG(reg) \
 112        ((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1)
 113
 114/*
 115 * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
 116 * register value.
 117 */
 118#define G762_CLKDIV_FROM_REG(reg) \
 119        (1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 |        \
 120                         G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2))
 121
 122/*
 123 * Extract fan gear mode multiplier value (0, 2 or 4) from given
 124 * FAN_CMD2 register value.
 125 */
 126#define G762_GEARMULT_FROM_REG(reg) \
 127        (1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 |        \
 128                         G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))
 129
 130struct g762_data {
 131        struct device *hwmon_dev;
 132        struct i2c_client *client;
 133        struct clk *clk;
 134
 135        /* update mutex */
 136        struct mutex update_lock;
 137
 138        /* board specific parameters. */
 139        u32 clk_freq;
 140
 141        /* g762 register cache */
 142        bool valid;
 143        unsigned long last_updated; /* in jiffies */
 144
 145        u8 set_cnt;  /* controls fan rotation speed in closed-loop mode */
 146        u8 act_cnt;  /* provides access to current fan RPM value */
 147        u8 fan_sta;  /* bit 0: set when actual fan speed is more than
 148                      *        25% outside requested fan speed
 149                      * bit 1: set when no transition occurs on fan
 150                      *        pin for 0.7s
 151                      */
 152        u8 set_out;  /* controls fan rotation speed in open-loop mode */
 153        u8 fan_cmd1; /*   0: FG_PLS_ID0 FG pulses count per revolution
 154                      *      0: 2 counts per revolution
 155                      *      1: 4 counts per revolution
 156                      *   1: PWM_POLARITY 1: negative_duty
 157                      *                   0: positive_duty
 158                      * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1]
 159                      *         00: Divide fan clock by 1
 160                      *         01: Divide fan clock by 2
 161                      *         10: Divide fan clock by 4
 162                      *         11: Divide fan clock by 8
 163                      *   4: FAN_MODE 1:closed-loop, 0:open-loop
 164                      *   5: OUT_MODE 1:PWM, 0:DC
 165                      *   6: DET_FAN_OOC enable "fan ooc" status
 166                      *   7: DET_FAN_FAIL enable "fan fail" status
 167                      */
 168        u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
 169                      * 2,3: FG_GEAR_MODE
 170                      *         00: multiplier = 1
 171                      *         01: multiplier = 2
 172                      *         10: multiplier = 4
 173                      *   4: Mask ALERT# (g763 only)
 174                      */
 175};
 176
 177/*
 178 * Convert count value from fan controller register (FAN_SET_CNT) into fan
 179 * speed RPM value. Note that the datasheet documents a basic formula;
 180 * influence of additional parameters (fan clock divisor, fan gear mode)
 181 * have been infered from examples in the datasheet and tests.
 182 */
 183static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p,
 184                                        u8 clk_div, u8 gear_mult)
 185{
 186        if (cnt == 0xff)  /* setting cnt to 255 stops the fan */
 187                return 0;
 188
 189        return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div);
 190}
 191
 192/*
 193 * Convert fan RPM value from sysfs into count value for fan controller
 194 * register (FAN_SET_CNT).
 195 */
 196static inline unsigned char cnt_from_rpm(u32 rpm, u32 clk_freq, u16 p,
 197                                         u8 clk_div, u8 gear_mult)
 198{
 199        if (!rpm)         /* to stop the fan, set cnt to 255 */
 200                return 0xff;
 201
 202        return clamp_val(((clk_freq * 30 * gear_mult) / (rpm * p * clk_div)),
 203                         0, 255);
 204}
 205
 206/* helper to grab and cache data, at most one time per second */
 207static struct g762_data *g762_update_client(struct device *dev)
 208{
 209        struct g762_data *data = dev_get_drvdata(dev);
 210        struct i2c_client *client = data->client;
 211        int ret = 0;
 212
 213        mutex_lock(&data->update_lock);
 214        if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) &&
 215            likely(data->valid))
 216                goto out;
 217
 218        ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT);
 219        if (ret < 0)
 220                goto out;
 221        data->set_cnt = ret;
 222
 223        ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT);
 224        if (ret < 0)
 225                goto out;
 226        data->act_cnt = ret;
 227
 228        ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA);
 229        if (ret < 0)
 230                goto out;
 231        data->fan_sta = ret;
 232
 233        ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT);
 234        if (ret < 0)
 235                goto out;
 236        data->set_out = ret;
 237
 238        ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1);
 239        if (ret < 0)
 240                goto out;
 241        data->fan_cmd1 = ret;
 242
 243        ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2);
 244        if (ret < 0)
 245                goto out;
 246        data->fan_cmd2 = ret;
 247
 248        data->last_updated = jiffies;
 249        data->valid = true;
 250 out:
 251        mutex_unlock(&data->update_lock);
 252
 253        if (ret < 0) /* upon error, encode it in return value */
 254                data = ERR_PTR(ret);
 255
 256        return data;
 257}
 258
 259/* helpers for writing hardware parameters */
 260
 261/*
 262 * Set input clock frequency received on CLK pin of the chip. Accepted values
 263 * are between 0 and 0xffffff. If zero is given, then default frequency
 264 * (32,768Hz) is used. Note that clock frequency is a characteristic of the
 265 * system but an internal parameter, i.e. value is not passed to the device.
 266 */
 267static int do_set_clk_freq(struct device *dev, unsigned long val)
 268{
 269        struct g762_data *data = dev_get_drvdata(dev);
 270
 271        if (val > 0xffffff)
 272                return -EINVAL;
 273        if (!val)
 274                val = 32768;
 275
 276        data->clk_freq = val;
 277
 278        return 0;
 279}
 280
 281/* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */
 282static int do_set_pwm_mode(struct device *dev, unsigned long val)
 283{
 284        struct g762_data *data = g762_update_client(dev);
 285        int ret;
 286
 287        if (IS_ERR(data))
 288                return PTR_ERR(data);
 289
 290        mutex_lock(&data->update_lock);
 291        switch (val) {
 292        case G762_OUT_MODE_PWM:
 293                data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;
 294                break;
 295        case G762_OUT_MODE_DC:
 296                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
 297                break;
 298        default:
 299                ret = -EINVAL;
 300                goto out;
 301        }
 302        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 303                                        data->fan_cmd1);
 304        data->valid = false;
 305 out:
 306        mutex_unlock(&data->update_lock);
 307
 308        return ret;
 309}
 310
 311/* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
 312static int do_set_fan_div(struct device *dev, unsigned long val)
 313{
 314        struct g762_data *data = g762_update_client(dev);
 315        int ret;
 316
 317        if (IS_ERR(data))
 318                return PTR_ERR(data);
 319
 320        mutex_lock(&data->update_lock);
 321        switch (val) {
 322        case 1:
 323                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 324                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 325                break;
 326        case 2:
 327                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 328                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 329                break;
 330        case 4:
 331                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 332                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 333                break;
 334        case 8:
 335                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 336                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 337                break;
 338        default:
 339                ret = -EINVAL;
 340                goto out;
 341        }
 342        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 343                                        data->fan_cmd1);
 344        data->valid = false;
 345 out:
 346        mutex_unlock(&data->update_lock);
 347
 348        return ret;
 349}
 350
 351/* Set fan gear mode. Accepts either 0, 1 or 2. */
 352static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
 353{
 354        struct g762_data *data = g762_update_client(dev);
 355        int ret;
 356
 357        if (IS_ERR(data))
 358                return PTR_ERR(data);
 359
 360        mutex_lock(&data->update_lock);
 361        switch (val) {
 362        case 0:
 363                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 364                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 365                break;
 366        case 1:
 367                data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;
 368                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 369                break;
 370        case 2:
 371                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 372                data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
 373                break;
 374        default:
 375                ret = -EINVAL;
 376                goto out;
 377        }
 378        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 379                                        data->fan_cmd2);
 380        data->valid = false;
 381 out:
 382        mutex_unlock(&data->update_lock);
 383
 384        return ret;
 385}
 386
 387/* Set number of fan pulses per revolution. Accepts either 2 or 4. */
 388static int do_set_fan_pulses(struct device *dev, unsigned long val)
 389{
 390        struct g762_data *data = g762_update_client(dev);
 391        int ret;
 392
 393        if (IS_ERR(data))
 394                return PTR_ERR(data);
 395
 396        mutex_lock(&data->update_lock);
 397        switch (val) {
 398        case 2:
 399                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
 400                break;
 401        case 4:
 402                data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
 403                break;
 404        default:
 405                ret = -EINVAL;
 406                goto out;
 407        }
 408        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 409                                        data->fan_cmd1);
 410        data->valid = false;
 411 out:
 412        mutex_unlock(&data->update_lock);
 413
 414        return ret;
 415}
 416
 417/* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
 418static int do_set_pwm_enable(struct device *dev, unsigned long val)
 419{
 420        struct g762_data *data = g762_update_client(dev);
 421        int ret;
 422
 423        if (IS_ERR(data))
 424                return PTR_ERR(data);
 425
 426        mutex_lock(&data->update_lock);
 427        switch (val) {
 428        case G762_FAN_MODE_CLOSED_LOOP:
 429                data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
 430                break;
 431        case G762_FAN_MODE_OPEN_LOOP:
 432                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
 433                /*
 434                 * BUG FIX: if SET_CNT register value is 255 then, for some
 435                 * unknown reason, fan will not rotate as expected, no matter
 436                 * the value of SET_OUT (to be specific, this seems to happen
 437                 * only in PWM mode). To workaround this bug, we give SET_CNT
 438                 * value of 254 if it is 255 when switching to open-loop.
 439                 */
 440                if (data->set_cnt == 0xff)
 441                        i2c_smbus_write_byte_data(data->client,
 442                                                  G762_REG_SET_CNT, 254);
 443                break;
 444        default:
 445                ret = -EINVAL;
 446                goto out;
 447        }
 448
 449        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 450                                        data->fan_cmd1);
 451        data->valid = false;
 452 out:
 453        mutex_unlock(&data->update_lock);
 454
 455        return ret;
 456}
 457
 458/* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */
 459static int do_set_pwm_polarity(struct device *dev, unsigned long val)
 460{
 461        struct g762_data *data = g762_update_client(dev);
 462        int ret;
 463
 464        if (IS_ERR(data))
 465                return PTR_ERR(data);
 466
 467        mutex_lock(&data->update_lock);
 468        switch (val) {
 469        case G762_PWM_POLARITY_POSITIVE:
 470                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
 471                break;
 472        case G762_PWM_POLARITY_NEGATIVE:
 473                data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
 474                break;
 475        default:
 476                ret = -EINVAL;
 477                goto out;
 478        }
 479        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 480                                        data->fan_cmd1);
 481        data->valid = false;
 482 out:
 483        mutex_unlock(&data->update_lock);
 484
 485        return ret;
 486}
 487
 488/*
 489 * Set pwm value. Accepts values between 0 (stops the fan) and
 490 * 255 (full speed). This only makes sense in open-loop mode.
 491 */
 492static int do_set_pwm(struct device *dev, unsigned long val)
 493{
 494        struct g762_data *data = dev_get_drvdata(dev);
 495        struct i2c_client *client = data->client;
 496        int ret;
 497
 498        if (val > 255)
 499                return -EINVAL;
 500
 501        mutex_lock(&data->update_lock);
 502        ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val);
 503        data->valid = false;
 504        mutex_unlock(&data->update_lock);
 505
 506        return ret;
 507}
 508
 509/*
 510 * Set fan RPM value. Can be called both in closed and open-loop mode
 511 * but effect will only be seen after closed-loop mode is configured.
 512 */
 513static int do_set_fan_target(struct device *dev, unsigned long val)
 514{
 515        struct g762_data *data = g762_update_client(dev);
 516        int ret;
 517
 518        if (IS_ERR(data))
 519                return PTR_ERR(data);
 520
 521        mutex_lock(&data->update_lock);
 522        data->set_cnt = cnt_from_rpm(val, data->clk_freq,
 523                                     G762_PULSE_FROM_REG(data->fan_cmd1),
 524                                     G762_CLKDIV_FROM_REG(data->fan_cmd1),
 525                                     G762_GEARMULT_FROM_REG(data->fan_cmd2));
 526        ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT,
 527                                        data->set_cnt);
 528        data->valid = false;
 529        mutex_unlock(&data->update_lock);
 530
 531        return ret;
 532}
 533
 534/* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
 535static int do_set_fan_startv(struct device *dev, unsigned long val)
 536{
 537        struct g762_data *data = g762_update_client(dev);
 538        int ret;
 539
 540        if (IS_ERR(data))
 541                return PTR_ERR(data);
 542
 543        mutex_lock(&data->update_lock);
 544        switch (val) {
 545        case 0:
 546                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 547                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 548                break;
 549        case 1:
 550                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 551                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 552                break;
 553        case 2:
 554                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 555                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 556                break;
 557        case 3:
 558                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 559                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 560                break;
 561        default:
 562                ret = -EINVAL;
 563                goto out;
 564        }
 565        ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 566                                        data->fan_cmd2);
 567        data->valid = false;
 568 out:
 569        mutex_unlock(&data->update_lock);
 570
 571        return ret;
 572}
 573
 574/*
 575 * Helper to import hardware characteristics from .dts file and push
 576 * those to the chip.
 577 */
 578
 579#ifdef CONFIG_OF
 580static const struct of_device_id g762_dt_match[] = {
 581        { .compatible = "gmt,g762" },
 582        { .compatible = "gmt,g763" },
 583        { },
 584};
 585
 586/*
 587 * Grab clock (a required property), enable it, get (fixed) clock frequency
 588 * and store it. Note: upon success, clock has been prepared and enabled; it
 589 * must later be unprepared and disabled (e.g. during module unloading) by a
 590 * call to g762_of_clock_disable(). Note that a reference to clock is kept
 591 * in our private data structure to be used in this function.
 592 */
 593static int g762_of_clock_enable(struct i2c_client *client)
 594{
 595        struct g762_data *data;
 596        unsigned long clk_freq;
 597        struct clk *clk;
 598        int ret;
 599
 600        if (!client->dev.of_node)
 601                return 0;
 602
 603        clk = of_clk_get(client->dev.of_node, 0);
 604        if (IS_ERR(clk)) {
 605                dev_err(&client->dev, "failed to get clock\n");
 606                return PTR_ERR(clk);
 607        }
 608
 609        ret = clk_prepare_enable(clk);
 610        if (ret) {
 611                dev_err(&client->dev, "failed to enable clock\n");
 612                goto clk_put;
 613        }
 614
 615        clk_freq = clk_get_rate(clk);
 616        ret = do_set_clk_freq(&client->dev, clk_freq);
 617        if (ret) {
 618                dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);
 619                goto clk_unprep;
 620        }
 621
 622        data = i2c_get_clientdata(client);
 623        data->clk = clk;
 624
 625        return 0;
 626
 627 clk_unprep:
 628        clk_disable_unprepare(clk);
 629
 630 clk_put:
 631        clk_put(clk);
 632
 633        return ret;
 634}
 635
 636static void g762_of_clock_disable(struct i2c_client *client)
 637{
 638        struct g762_data *data = i2c_get_clientdata(client);
 639
 640        if (!data->clk)
 641                return;
 642
 643        clk_disable_unprepare(data->clk);
 644        clk_put(data->clk);
 645}
 646
 647static int g762_of_prop_import_one(struct i2c_client *client,
 648                                   const char *pname,
 649                                   int (*psetter)(struct device *dev,
 650                                                  unsigned long val))
 651{
 652        int ret;
 653        u32 pval;
 654
 655        if (of_property_read_u32(client->dev.of_node, pname, &pval))
 656                return 0;
 657
 658        dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);
 659        ret = (*psetter)(&client->dev, pval);
 660        if (ret)
 661                dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);
 662
 663        return ret;
 664}
 665
 666static int g762_of_prop_import(struct i2c_client *client)
 667{
 668        int ret;
 669
 670        if (!client->dev.of_node)
 671                return 0;
 672
 673        ret = g762_of_prop_import_one(client, "fan_gear_mode",
 674                                      do_set_fan_gear_mode);
 675        if (ret)
 676                return ret;
 677
 678        ret = g762_of_prop_import_one(client, "pwm_polarity",
 679                                      do_set_pwm_polarity);
 680        if (ret)
 681                return ret;
 682
 683        return g762_of_prop_import_one(client, "fan_startv",
 684                                       do_set_fan_startv);
 685}
 686
 687#else
 688static int g762_of_prop_import(struct i2c_client *client)
 689{
 690        return 0;
 691}
 692
 693static int g762_of_clock_enable(struct i2c_client *client)
 694{
 695        return 0;
 696}
 697
 698static void g762_of_clock_disable(struct i2c_client *client) { }
 699#endif
 700
 701/*
 702 * Helper to import hardware characteristics from .dts file and push
 703 * those to the chip.
 704 */
 705
 706static int g762_pdata_prop_import(struct i2c_client *client)
 707{
 708        struct g762_platform_data *pdata = dev_get_platdata(&client->dev);
 709        int ret;
 710
 711        if (!pdata)
 712                return 0;
 713
 714        ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);
 715        if (ret)
 716                return ret;
 717
 718        ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);
 719        if (ret)
 720                return ret;
 721
 722        ret = do_set_fan_startv(&client->dev, pdata->fan_startv);
 723        if (ret)
 724                return ret;
 725
 726        return do_set_clk_freq(&client->dev, pdata->clk_freq);
 727}
 728
 729/*
 730 * sysfs attributes
 731 */
 732
 733/*
 734 * Read function for fan1_input sysfs file. Return current fan RPM value, or
 735 * 0 if fan is out of control.
 736 */
 737static ssize_t get_fan_rpm(struct device *dev, struct device_attribute *da,
 738                           char *buf)
 739{
 740        struct g762_data *data = g762_update_client(dev);
 741        unsigned int rpm = 0;
 742
 743        if (IS_ERR(data))
 744                return PTR_ERR(data);
 745
 746        mutex_lock(&data->update_lock);
 747        /* reverse logic: fan out of control reporting is enabled low */
 748        if (data->fan_sta & G762_REG_FAN_STA_OOC) {
 749                rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,
 750                                   G762_PULSE_FROM_REG(data->fan_cmd1),
 751                                   G762_CLKDIV_FROM_REG(data->fan_cmd1),
 752                                   G762_GEARMULT_FROM_REG(data->fan_cmd2));
 753        }
 754        mutex_unlock(&data->update_lock);
 755
 756        return sprintf(buf, "%u\n", rpm);
 757}
 758
 759/*
 760 * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
 761 * control mode i.e. PWM (1) or DC (0).
 762 */
 763static ssize_t get_pwm_mode(struct device *dev, struct device_attribute *da,
 764                            char *buf)
 765{
 766        struct g762_data *data = g762_update_client(dev);
 767
 768        if (IS_ERR(data))
 769                return PTR_ERR(data);
 770
 771        return sprintf(buf, "%d\n",
 772                       !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));
 773}
 774
 775static ssize_t set_pwm_mode(struct device *dev, struct device_attribute *da,
 776                            const char *buf, size_t count)
 777{
 778        unsigned long val;
 779        int ret;
 780
 781        if (kstrtoul(buf, 10, &val))
 782                return -EINVAL;
 783
 784        ret = do_set_pwm_mode(dev, val);
 785        if (ret < 0)
 786                return ret;
 787
 788        return count;
 789}
 790
 791/*
 792 * Read and write functions for fan1_div sysfs file. Get and set fan
 793 * controller prescaler value
 794 */
 795static ssize_t get_fan_div(struct device *dev,
 796                           struct device_attribute *da, char *buf)
 797{
 798        struct g762_data *data = g762_update_client(dev);
 799
 800        if (IS_ERR(data))
 801                return PTR_ERR(data);
 802
 803        return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));
 804}
 805
 806static ssize_t set_fan_div(struct device *dev,
 807                           struct device_attribute *da,
 808                           const char *buf, size_t count)
 809{
 810        unsigned long val;
 811        int ret;
 812
 813        if (kstrtoul(buf, 10, &val))
 814                return -EINVAL;
 815
 816        ret = do_set_fan_div(dev, val);
 817        if (ret < 0)
 818                return ret;
 819
 820        return count;
 821}
 822
 823/*
 824 * Read and write functions for fan1_pulses sysfs file. Get and set number
 825 * of tachometer pulses per fan revolution.
 826 */
 827static ssize_t get_fan_pulses(struct device *dev,
 828                              struct device_attribute *da, char *buf)
 829{
 830        struct g762_data *data = g762_update_client(dev);
 831
 832        if (IS_ERR(data))
 833                return PTR_ERR(data);
 834
 835        return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));
 836}
 837
 838static ssize_t set_fan_pulses(struct device *dev,
 839                              struct device_attribute *da,
 840                              const char *buf, size_t count)
 841{
 842        unsigned long val;
 843        int ret;
 844
 845        if (kstrtoul(buf, 10, &val))
 846                return -EINVAL;
 847
 848        ret = do_set_fan_pulses(dev, val);
 849        if (ret < 0)
 850                return ret;
 851
 852        return count;
 853}
 854
 855/*
 856 * Read and write functions for pwm1_enable. Get and set fan speed control mode
 857 * (i.e. closed or open-loop).
 858 *
 859 * Following documentation about hwmon's sysfs interface, a pwm1_enable node
 860 * should accept followings:
 861 *
 862 *  0 : no fan speed control (i.e. fan at full speed)
 863 *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
 864 *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
 865 *
 866 * but we do not accept 0 as this mode is not natively supported by the chip
 867 * and it is not emulated by g762 driver. -EINVAL is returned in this case.
 868 */
 869static ssize_t get_pwm_enable(struct device *dev,
 870                              struct device_attribute *da, char *buf)
 871{
 872        struct g762_data *data = g762_update_client(dev);
 873
 874        if (IS_ERR(data))
 875                return PTR_ERR(data);
 876
 877        return sprintf(buf, "%d\n",
 878                       (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);
 879}
 880
 881static ssize_t set_pwm_enable(struct device *dev,
 882                              struct device_attribute *da,
 883                              const char *buf, size_t count)
 884{
 885        unsigned long val;
 886        int ret;
 887
 888        if (kstrtoul(buf, 10, &val))
 889                return -EINVAL;
 890
 891        ret = do_set_pwm_enable(dev, val);
 892        if (ret < 0)
 893                return ret;
 894
 895        return count;
 896}
 897
 898/*
 899 * Read and write functions for pwm1 sysfs file. Get and set pwm value
 900 * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
 901 * makes it run at full speed.
 902 */
 903static ssize_t get_pwm(struct device *dev, struct device_attribute *da,
 904                       char *buf)
 905{
 906        struct g762_data *data = g762_update_client(dev);
 907
 908        if (IS_ERR(data))
 909                return PTR_ERR(data);
 910
 911        return sprintf(buf, "%d\n", data->set_out);
 912}
 913
 914static ssize_t set_pwm(struct device *dev, struct device_attribute *da,
 915                       const char *buf, size_t count)
 916{
 917        unsigned long val;
 918        int ret;
 919
 920        if (kstrtoul(buf, 10, &val))
 921                return -EINVAL;
 922
 923        ret = do_set_pwm(dev, val);
 924        if (ret < 0)
 925                return ret;
 926
 927        return count;
 928}
 929
 930/*
 931 * Read and write function for fan1_target sysfs file. Get/set the fan speed in
 932 * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
 933 * the fan speed using pulses from fan tachometer.
 934 *
 935 * Refer to rpm_from_cnt() implementation above to get info about count number
 936 * calculation.
 937 *
 938 * Also note that due to rounding errors it is possible that you don't read
 939 * back exactly the value you have set.
 940 */
 941static ssize_t get_fan_target(struct device *dev, struct device_attribute *da,
 942                              char *buf)
 943{
 944        struct g762_data *data = g762_update_client(dev);
 945        unsigned int rpm;
 946
 947        if (IS_ERR(data))
 948                return PTR_ERR(data);
 949
 950        mutex_lock(&data->update_lock);
 951        rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,
 952                           G762_PULSE_FROM_REG(data->fan_cmd1),
 953                           G762_CLKDIV_FROM_REG(data->fan_cmd1),
 954                           G762_GEARMULT_FROM_REG(data->fan_cmd2));
 955        mutex_unlock(&data->update_lock);
 956
 957        return sprintf(buf, "%u\n", rpm);
 958}
 959
 960static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
 961                              const char *buf, size_t count)
 962{
 963        unsigned long val;
 964        int ret;
 965
 966        if (kstrtoul(buf, 10, &val))
 967                return -EINVAL;
 968
 969        ret = do_set_fan_target(dev, val);
 970        if (ret < 0)
 971                return ret;
 972
 973        return count;
 974}
 975
 976/* read function for fan1_fault sysfs file. */
 977static ssize_t get_fan_failure(struct device *dev, struct device_attribute *da,
 978                               char *buf)
 979{
 980        struct g762_data *data = g762_update_client(dev);
 981
 982        if (IS_ERR(data))
 983                return PTR_ERR(data);
 984
 985        return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));
 986}
 987
 988/*
 989 * read function for fan1_alarm sysfs file. Note that OOC condition is
 990 * enabled low
 991 */
 992static ssize_t get_fan_ooc(struct device *dev, struct device_attribute *da,
 993                           char *buf)
 994{
 995        struct g762_data *data = g762_update_client(dev);
 996
 997        if (IS_ERR(data))
 998                return PTR_ERR(data);
 999
1000        return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));
1001}
1002
1003static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
1004static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, get_pwm_mode, set_pwm_mode);
1005static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
1006                   get_pwm_enable, set_pwm_enable);
1007static DEVICE_ATTR(fan1_input, S_IRUGO, get_fan_rpm, NULL);
1008static DEVICE_ATTR(fan1_alarm, S_IRUGO, get_fan_ooc, NULL);
1009static DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_failure, NULL);
1010static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
1011                   get_fan_target, set_fan_target);
1012static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_fan_div, set_fan_div);
1013static DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO,
1014                   get_fan_pulses, set_fan_pulses);
1015
1016/* Driver data */
1017static struct attribute *g762_attrs[] = {
1018        &dev_attr_fan1_input.attr,
1019        &dev_attr_fan1_alarm.attr,
1020        &dev_attr_fan1_fault.attr,
1021        &dev_attr_fan1_target.attr,
1022        &dev_attr_fan1_div.attr,
1023        &dev_attr_fan1_pulses.attr,
1024        &dev_attr_pwm1.attr,
1025        &dev_attr_pwm1_mode.attr,
1026        &dev_attr_pwm1_enable.attr,
1027        NULL
1028};
1029
1030ATTRIBUTE_GROUPS(g762);
1031
1032/*
1033 * Enable both fan failure detection and fan out of control protection. The
1034 * function does not protect change/access to data structure; it must thus
1035 * only be called during initialization.
1036 */
1037static inline int g762_fan_init(struct device *dev)
1038{
1039        struct g762_data *data = g762_update_client(dev);
1040
1041        if (IS_ERR(data))
1042                return PTR_ERR(data);
1043
1044        data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
1045        data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
1046        data->valid = false;
1047
1048        return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
1049                                         data->fan_cmd1);
1050}
1051
1052static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)
1053{
1054        struct device *dev = &client->dev;
1055        struct g762_data *data;
1056        int ret;
1057
1058        if (!i2c_check_functionality(client->adapter,
1059                                     I2C_FUNC_SMBUS_BYTE_DATA))
1060                return -ENODEV;
1061
1062        data = devm_kzalloc(dev, sizeof(struct g762_data), GFP_KERNEL);
1063        if (!data)
1064                return -ENOMEM;
1065
1066        i2c_set_clientdata(client, data);
1067        data->client = client;
1068        mutex_init(&data->update_lock);
1069
1070        /* Enable fan failure detection and fan out of control protection */
1071        ret = g762_fan_init(dev);
1072        if (ret)
1073                return ret;
1074
1075        /* Get configuration via DT ... */
1076        ret = g762_of_clock_enable(client);
1077        if (ret)
1078                return ret;
1079        ret = g762_of_prop_import(client);
1080        if (ret)
1081                goto clock_dis;
1082        /* ... or platform_data */
1083        ret = g762_pdata_prop_import(client);
1084        if (ret)
1085                goto clock_dis;
1086
1087        data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
1088                                                            data, g762_groups);
1089        if (IS_ERR(data->hwmon_dev)) {
1090                ret = PTR_ERR(data->hwmon_dev);
1091                goto clock_dis;
1092        }
1093
1094        return 0;
1095
1096 clock_dis:
1097        g762_of_clock_disable(client);
1098
1099        return ret;
1100}
1101
1102static int g762_remove(struct i2c_client *client)
1103{
1104        struct g762_data *data = i2c_get_clientdata(client);
1105
1106        hwmon_device_unregister(data->hwmon_dev);
1107        g762_of_clock_disable(client);
1108
1109        return 0;
1110}
1111
1112static struct i2c_driver g762_driver = {
1113        .driver = {
1114                .name = DRVNAME,
1115                .owner = THIS_MODULE,
1116                .of_match_table = of_match_ptr(g762_dt_match),
1117        },
1118        .probe    = g762_probe,
1119        .remove   = g762_remove,
1120        .id_table = g762_id,
1121};
1122
1123module_i2c_driver(g762_driver);
1124
1125MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1126MODULE_DESCRIPTION("GMT G762/G763 driver");
1127MODULE_LICENSE("GPL");
1128
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