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 i2c_client *client;
 132        struct device *hwmon_dev;
 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 i2c_client *client = to_i2c_client(dev);
 210        struct g762_data *data = i2c_get_clientdata(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 i2c_client *client = to_i2c_client(dev);
 270        struct g762_data *data = i2c_get_clientdata(client);
 271
 272        if (val > 0xffffff)
 273                return -EINVAL;
 274        if (!val)
 275                val = 32768;
 276
 277        data->clk_freq = val;
 278
 279        return 0;
 280}
 281
 282/* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */
 283static int do_set_pwm_mode(struct device *dev, unsigned long val)
 284{
 285        struct i2c_client *client = to_i2c_client(dev);
 286        struct g762_data *data = g762_update_client(dev);
 287        int ret;
 288
 289        if (IS_ERR(data))
 290                return PTR_ERR(data);
 291
 292        mutex_lock(&data->update_lock);
 293        switch (val) {
 294        case G762_OUT_MODE_PWM:
 295                data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;
 296                break;
 297        case G762_OUT_MODE_DC:
 298                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
 299                break;
 300        default:
 301                ret = -EINVAL;
 302                goto out;
 303        }
 304        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
 305                                        data->fan_cmd1);
 306        data->valid = false;
 307 out:
 308        mutex_unlock(&data->update_lock);
 309
 310        return ret;
 311}
 312
 313/* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
 314static int do_set_fan_div(struct device *dev, unsigned long val)
 315{
 316        struct i2c_client *client = to_i2c_client(dev);
 317        struct g762_data *data = g762_update_client(dev);
 318        int ret;
 319
 320        if (IS_ERR(data))
 321                return PTR_ERR(data);
 322
 323        mutex_lock(&data->update_lock);
 324        switch (val) {
 325        case 1:
 326                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 327                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 328                break;
 329        case 2:
 330                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 331                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 332                break;
 333        case 4:
 334                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 335                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 336                break;
 337        case 8:
 338                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 339                data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 340                break;
 341        default:
 342                ret = -EINVAL;
 343                goto out;
 344        }
 345        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
 346                                        data->fan_cmd1);
 347        data->valid = false;
 348 out:
 349        mutex_unlock(&data->update_lock);
 350
 351        return ret;
 352}
 353
 354/* Set fan gear mode. Accepts either 0, 1 or 2. */
 355static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
 356{
 357        struct i2c_client *client = to_i2c_client(dev);
 358        struct g762_data *data = g762_update_client(dev);
 359        int ret;
 360
 361        if (IS_ERR(data))
 362                return PTR_ERR(data);
 363
 364        mutex_lock(&data->update_lock);
 365        switch (val) {
 366        case 0:
 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 1:
 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        case 2:
 375                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 376                data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
 377                break;
 378        default:
 379                ret = -EINVAL;
 380                goto out;
 381        }
 382        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD2,
 383                                        data->fan_cmd2);
 384        data->valid = false;
 385 out:
 386        mutex_unlock(&data->update_lock);
 387
 388        return ret;
 389}
 390
 391/* Set number of fan pulses per revolution. Accepts either 2 or 4. */
 392static int do_set_fan_pulses(struct device *dev, unsigned long val)
 393{
 394        struct i2c_client *client = to_i2c_client(dev);
 395        struct g762_data *data = g762_update_client(dev);
 396        int ret;
 397
 398        if (IS_ERR(data))
 399                return PTR_ERR(data);
 400
 401        mutex_lock(&data->update_lock);
 402        switch (val) {
 403        case 2:
 404                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
 405                break;
 406        case 4:
 407                data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
 408                break;
 409        default:
 410                ret = -EINVAL;
 411                goto out;
 412        }
 413        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
 414                                        data->fan_cmd1);
 415        data->valid = false;
 416 out:
 417        mutex_unlock(&data->update_lock);
 418
 419        return ret;
 420}
 421
 422/* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
 423static int do_set_pwm_enable(struct device *dev, unsigned long val)
 424{
 425        struct i2c_client *client = to_i2c_client(dev);
 426        struct g762_data *data = g762_update_client(dev);
 427        int ret;
 428
 429        if (IS_ERR(data))
 430                return PTR_ERR(data);
 431
 432        mutex_lock(&data->update_lock);
 433        switch (val) {
 434        case G762_FAN_MODE_CLOSED_LOOP:
 435                data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
 436                break;
 437        case G762_FAN_MODE_OPEN_LOOP:
 438                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
 439                /*
 440                 * BUG FIX: if SET_CNT register value is 255 then, for some
 441                 * unknown reason, fan will not rotate as expected, no matter
 442                 * the value of SET_OUT (to be specific, this seems to happen
 443                 * only in PWM mode). To workaround this bug, we give SET_CNT
 444                 * value of 254 if it is 255 when switching to open-loop.
 445                 */
 446                if (data->set_cnt == 0xff)
 447                        i2c_smbus_write_byte_data(client, G762_REG_SET_CNT,
 448                                                  254);
 449                break;
 450        default:
 451                ret = -EINVAL;
 452                goto out;
 453        }
 454
 455        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
 456                                        data->fan_cmd1);
 457        data->valid = false;
 458 out:
 459        mutex_unlock(&data->update_lock);
 460
 461        return ret;
 462}
 463
 464/* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */
 465static int do_set_pwm_polarity(struct device *dev, unsigned long val)
 466{
 467        struct i2c_client *client = to_i2c_client(dev);
 468        struct g762_data *data = g762_update_client(dev);
 469        int ret;
 470
 471        if (IS_ERR(data))
 472                return PTR_ERR(data);
 473
 474        mutex_lock(&data->update_lock);
 475        switch (val) {
 476        case G762_PWM_POLARITY_POSITIVE:
 477                data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
 478                break;
 479        case G762_PWM_POLARITY_NEGATIVE:
 480                data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
 481                break;
 482        default:
 483                ret = -EINVAL;
 484                goto out;
 485        }
 486        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
 487                                        data->fan_cmd1);
 488        data->valid = false;
 489 out:
 490        mutex_unlock(&data->update_lock);
 491
 492        return ret;
 493}
 494
 495/*
 496 * Set pwm value. Accepts values between 0 (stops the fan) and
 497 * 255 (full speed). This only makes sense in open-loop mode.
 498 */
 499static int do_set_pwm(struct device *dev, unsigned long val)
 500{
 501        struct i2c_client *client = to_i2c_client(dev);
 502        struct g762_data *data = i2c_get_clientdata(client);
 503        int ret;
 504
 505        if (val > 255)
 506                return -EINVAL;
 507
 508        mutex_lock(&data->update_lock);
 509        ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val);
 510        data->valid = false;
 511        mutex_unlock(&data->update_lock);
 512
 513        return ret;
 514}
 515
 516/*
 517 * Set fan RPM value. Can be called both in closed and open-loop mode
 518 * but effect will only be seen after closed-loop mode is configured.
 519 */
 520static int do_set_fan_target(struct device *dev, unsigned long val)
 521{
 522        struct i2c_client *client = to_i2c_client(dev);
 523        struct g762_data *data = g762_update_client(dev);
 524        int ret;
 525
 526        if (IS_ERR(data))
 527                return PTR_ERR(data);
 528
 529        mutex_lock(&data->update_lock);
 530        data->set_cnt = cnt_from_rpm(val, data->clk_freq,
 531                                     G762_PULSE_FROM_REG(data->fan_cmd1),
 532                                     G762_CLKDIV_FROM_REG(data->fan_cmd1),
 533                                     G762_GEARMULT_FROM_REG(data->fan_cmd2));
 534        ret = i2c_smbus_write_byte_data(client, G762_REG_SET_CNT,
 535                                        data->set_cnt);
 536        data->valid = false;
 537        mutex_unlock(&data->update_lock);
 538
 539        return ret;
 540}
 541
 542/* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
 543static int do_set_fan_startv(struct device *dev, unsigned long val)
 544{
 545        struct i2c_client *client = to_i2c_client(dev);
 546        struct g762_data *data = g762_update_client(dev);
 547        int ret;
 548
 549        if (IS_ERR(data))
 550                return PTR_ERR(data);
 551
 552        mutex_lock(&data->update_lock);
 553        switch (val) {
 554        case 0:
 555                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 556                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 557                break;
 558        case 1:
 559                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 560                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 561                break;
 562        case 2:
 563                data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 564                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 565                break;
 566        case 3:
 567                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 568                data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 569                break;
 570        default:
 571                ret = -EINVAL;
 572                goto out;
 573        }
 574        ret = i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD2,
 575                                        data->fan_cmd2);
 576        data->valid = false;
 577 out:
 578        mutex_unlock(&data->update_lock);
 579
 580        return ret;
 581}
 582
 583/*
 584 * Helper to import hardware characteristics from .dts file and push
 585 * those to the chip.
 586 */
 587
 588#ifdef CONFIG_OF
 589static struct of_device_id g762_dt_match[] = {
 590        { .compatible = "gmt,g762" },
 591        { .compatible = "gmt,g763" },
 592        { },
 593};
 594
 595/*
 596 * Grab clock (a required property), enable it, get (fixed) clock frequency
 597 * and store it. Note: upon success, clock has been prepared and enabled; it
 598 * must later be unprepared and disabled (e.g. during module unloading) by a
 599 * call to g762_of_clock_disable(). Note that a reference to clock is kept
 600 * in our private data structure to be used in this function.
 601 */
 602static int g762_of_clock_enable(struct i2c_client *client)
 603{
 604        struct g762_data *data;
 605        unsigned long clk_freq;
 606        struct clk *clk;
 607        int ret;
 608
 609        if (!client->dev.of_node)
 610                return 0;
 611
 612        clk = of_clk_get(client->dev.of_node, 0);
 613        if (IS_ERR(clk)) {
 614                dev_err(&client->dev, "failed to get clock\n");
 615                return PTR_ERR(clk);
 616        }
 617
 618        ret = clk_prepare_enable(clk);
 619        if (ret) {
 620                dev_err(&client->dev, "failed to enable clock\n");
 621                goto clk_put;
 622        }
 623
 624        clk_freq = clk_get_rate(clk);
 625        ret = do_set_clk_freq(&client->dev, clk_freq);
 626        if (ret) {
 627                dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);
 628                goto clk_unprep;
 629        }
 630
 631        data = i2c_get_clientdata(client);
 632        data->clk = clk;
 633
 634        return 0;
 635
 636 clk_unprep:
 637        clk_disable_unprepare(clk);
 638
 639 clk_put:
 640        clk_put(clk);
 641
 642        return ret;
 643}
 644
 645static void g762_of_clock_disable(struct i2c_client *client)
 646{
 647        struct g762_data *data = i2c_get_clientdata(client);
 648
 649        if (!data->clk)
 650                return;
 651
 652        clk_disable_unprepare(data->clk);
 653        clk_put(data->clk);
 654}
 655
 656static int g762_of_prop_import_one(struct i2c_client *client,
 657                                   const char *pname,
 658                                   int (*psetter)(struct device *dev,
 659                                                  unsigned long val))
 660{
 661        const __be32 *prop;
 662        int len, ret;
 663        u32 pval;
 664
 665        prop = of_get_property(client->dev.of_node, pname, &len);
 666        if (!prop || len != sizeof(u32))
 667                return 0;
 668
 669        pval = be32_to_cpu(prop[0]);
 670        dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);
 671        ret = (*psetter)(&client->dev, pval);
 672        if (ret)
 673                dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);
 674
 675        return ret;
 676}
 677
 678static int g762_of_prop_import(struct i2c_client *client)
 679{
 680        int ret;
 681
 682        if (!client->dev.of_node)
 683                return 0;
 684
 685        ret = g762_of_prop_import_one(client, "fan_gear_mode",
 686                                      do_set_fan_gear_mode);
 687        if (ret)
 688                return ret;
 689
 690        ret = g762_of_prop_import_one(client, "pwm_polarity",
 691                                      do_set_pwm_polarity);
 692        if (ret)
 693                return ret;
 694
 695        return g762_of_prop_import_one(client, "fan_startv",
 696                                       do_set_fan_startv);
 697}
 698
 699#else
 700static int g762_of_prop_import(struct i2c_client *client)
 701{
 702        return 0;
 703}
 704
 705static int g762_of_clock_enable(struct i2c_client *client)
 706{
 707        return 0;
 708}
 709
 710static void g762_of_clock_disable(struct i2c_client *client) { }
 711#endif
 712
 713/*
 714 * Helper to import hardware characteristics from .dts file and push
 715 * those to the chip.
 716 */
 717
 718static int g762_pdata_prop_import(struct i2c_client *client)
 719{
 720        struct g762_platform_data *pdata = dev_get_platdata(&client->dev);
 721        int ret;
 722
 723        if (!pdata)
 724                return 0;
 725
 726        ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);
 727        if (ret)
 728                return ret;
 729
 730        ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);
 731        if (ret)
 732                return ret;
 733
 734        ret = do_set_fan_startv(&client->dev, pdata->fan_startv);
 735        if (ret)
 736                return ret;
 737
 738        return do_set_clk_freq(&client->dev, pdata->clk_freq);
 739}
 740
 741/*
 742 * sysfs attributes
 743 */
 744
 745/*
 746 * Read function for fan1_input sysfs file. Return current fan RPM value, or
 747 * 0 if fan is out of control.
 748 */
 749static ssize_t get_fan_rpm(struct device *dev, struct device_attribute *da,
 750                           char *buf)
 751{
 752        struct g762_data *data = g762_update_client(dev);
 753        unsigned int rpm = 0;
 754
 755        if (IS_ERR(data))
 756                return PTR_ERR(data);
 757
 758        mutex_lock(&data->update_lock);
 759        /* reverse logic: fan out of control reporting is enabled low */
 760        if (data->fan_sta & G762_REG_FAN_STA_OOC) {
 761                rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,
 762                                   G762_PULSE_FROM_REG(data->fan_cmd1),
 763                                   G762_CLKDIV_FROM_REG(data->fan_cmd1),
 764                                   G762_GEARMULT_FROM_REG(data->fan_cmd2));
 765        }
 766        mutex_unlock(&data->update_lock);
 767
 768        return sprintf(buf, "%u\n", rpm);
 769}
 770
 771/*
 772 * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
 773 * control mode i.e. PWM (1) or DC (0).
 774 */
 775static ssize_t get_pwm_mode(struct device *dev, struct device_attribute *da,
 776                            char *buf)
 777{
 778        struct g762_data *data = g762_update_client(dev);
 779
 780        if (IS_ERR(data))
 781                return PTR_ERR(data);
 782
 783        return sprintf(buf, "%d\n",
 784                       !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));
 785}
 786
 787static ssize_t set_pwm_mode(struct device *dev, struct device_attribute *da,
 788                            const char *buf, size_t count)
 789{
 790        unsigned long val;
 791        int ret;
 792
 793        if (kstrtoul(buf, 10, &val))
 794                return -EINVAL;
 795
 796        ret = do_set_pwm_mode(dev, val);
 797        if (ret < 0)
 798                return ret;
 799
 800        return count;
 801}
 802
 803/*
 804 * Read and write functions for fan1_div sysfs file. Get and set fan
 805 * controller prescaler value
 806 */
 807static ssize_t get_fan_div(struct device *dev,
 808                           struct device_attribute *da, char *buf)
 809{
 810        struct g762_data *data = g762_update_client(dev);
 811
 812        if (IS_ERR(data))
 813                return PTR_ERR(data);
 814
 815        return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));
 816}
 817
 818static ssize_t set_fan_div(struct device *dev,
 819                           struct device_attribute *da,
 820                           const char *buf, size_t count)
 821{
 822        unsigned long val;
 823        int ret;
 824
 825        if (kstrtoul(buf, 10, &val))
 826                return -EINVAL;
 827
 828        ret = do_set_fan_div(dev, val);
 829        if (ret < 0)
 830                return ret;
 831
 832        return count;
 833}
 834
 835/*
 836 * Read and write functions for fan1_pulses sysfs file. Get and set number
 837 * of tachometer pulses per fan revolution.
 838 */
 839static ssize_t get_fan_pulses(struct device *dev,
 840                              struct device_attribute *da, char *buf)
 841{
 842        struct g762_data *data = g762_update_client(dev);
 843
 844        if (IS_ERR(data))
 845                return PTR_ERR(data);
 846
 847        return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));
 848}
 849
 850static ssize_t set_fan_pulses(struct device *dev,
 851                              struct device_attribute *da,
 852                              const char *buf, size_t count)
 853{
 854        unsigned long val;
 855        int ret;
 856
 857        if (kstrtoul(buf, 10, &val))
 858                return -EINVAL;
 859
 860        ret = do_set_fan_pulses(dev, val);
 861        if (ret < 0)
 862                return ret;
 863
 864        return count;
 865}
 866
 867/*
 868 * Read and write functions for pwm1_enable. Get and set fan speed control mode
 869 * (i.e. closed or open-loop).
 870 *
 871 * Following documentation about hwmon's sysfs interface, a pwm1_enable node
 872 * should accept followings:
 873 *
 874 *  0 : no fan speed control (i.e. fan at full speed)
 875 *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
 876 *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
 877 *
 878 * but we do not accept 0 as this mode is not natively supported by the chip
 879 * and it is not emulated by g762 driver. -EINVAL is returned in this case.
 880 */
 881static ssize_t get_pwm_enable(struct device *dev,
 882                              struct device_attribute *da, char *buf)
 883{
 884        struct g762_data *data = g762_update_client(dev);
 885
 886        if (IS_ERR(data))
 887                return PTR_ERR(data);
 888
 889        return sprintf(buf, "%d\n",
 890                       (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);
 891}
 892
 893static ssize_t set_pwm_enable(struct device *dev,
 894                              struct device_attribute *da,
 895                              const char *buf, size_t count)
 896{
 897        unsigned long val;
 898        int ret;
 899
 900        if (kstrtoul(buf, 10, &val))
 901                return -EINVAL;
 902
 903        ret = do_set_pwm_enable(dev, val);
 904        if (ret < 0)
 905                return ret;
 906
 907        return count;
 908}
 909
 910/*
 911 * Read and write functions for pwm1 sysfs file. Get and set pwm value
 912 * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
 913 * makes it run at full speed.
 914 */
 915static ssize_t get_pwm(struct device *dev, struct device_attribute *da,
 916                       char *buf)
 917{
 918        struct g762_data *data = g762_update_client(dev);
 919
 920        if (IS_ERR(data))
 921                return PTR_ERR(data);
 922
 923        return sprintf(buf, "%d\n", data->set_out);
 924}
 925
 926static ssize_t set_pwm(struct device *dev, struct device_attribute *da,
 927                       const char *buf, size_t count)
 928{
 929        unsigned long val;
 930        int ret;
 931
 932        if (kstrtoul(buf, 10, &val))
 933                return -EINVAL;
 934
 935        ret = do_set_pwm(dev, val);
 936        if (ret < 0)
 937                return ret;
 938
 939        return count;
 940}
 941
 942/*
 943 * Read and write function for fan1_target sysfs file. Get/set the fan speed in
 944 * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
 945 * the fan speed using pulses from fan tachometer.
 946 *
 947 * Refer to rpm_from_cnt() implementation above to get info about count number
 948 * calculation.
 949 *
 950 * Also note that due to rounding errors it is possible that you don't read
 951 * back exactly the value you have set.
 952 */
 953static ssize_t get_fan_target(struct device *dev, struct device_attribute *da,
 954                              char *buf)
 955{
 956        struct g762_data *data = g762_update_client(dev);
 957        unsigned int rpm;
 958
 959        if (IS_ERR(data))
 960                return PTR_ERR(data);
 961
 962        mutex_lock(&data->update_lock);
 963        rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,
 964                           G762_PULSE_FROM_REG(data->fan_cmd1),
 965                           G762_CLKDIV_FROM_REG(data->fan_cmd1),
 966                           G762_GEARMULT_FROM_REG(data->fan_cmd2));
 967        mutex_unlock(&data->update_lock);
 968
 969        return sprintf(buf, "%u\n", rpm);
 970}
 971
 972static ssize_t set_fan_target(struct device *dev, struct device_attribute *da,
 973                              const char *buf, size_t count)
 974{
 975        unsigned long val;
 976        int ret;
 977
 978        if (kstrtoul(buf, 10, &val))
 979                return -EINVAL;
 980
 981        ret = do_set_fan_target(dev, val);
 982        if (ret < 0)
 983                return ret;
 984
 985        return count;
 986}
 987
 988/* read function for fan1_fault sysfs file. */
 989static ssize_t get_fan_failure(struct device *dev, struct device_attribute *da,
 990                               char *buf)
 991{
 992        struct g762_data *data = g762_update_client(dev);
 993
 994        if (IS_ERR(data))
 995                return PTR_ERR(data);
 996
 997        return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));
 998}
 999
1000/*
1001 * read function for fan1_alarm sysfs file. Note that OOC condition is
1002 * enabled low
1003 */
1004static ssize_t get_fan_ooc(struct device *dev, struct device_attribute *da,
1005                           char *buf)
1006{
1007        struct g762_data *data = g762_update_client(dev);
1008
1009        if (IS_ERR(data))
1010                return PTR_ERR(data);
1011
1012        return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));
1013}
1014
1015static DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, get_pwm, set_pwm);
1016static DEVICE_ATTR(pwm1_mode, S_IWUSR | S_IRUGO, get_pwm_mode, set_pwm_mode);
1017static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
1018                   get_pwm_enable, set_pwm_enable);
1019static DEVICE_ATTR(fan1_input, S_IRUGO, get_fan_rpm, NULL);
1020static DEVICE_ATTR(fan1_alarm, S_IRUGO, get_fan_ooc, NULL);
1021static DEVICE_ATTR(fan1_fault, S_IRUGO, get_fan_failure, NULL);
1022static DEVICE_ATTR(fan1_target, S_IWUSR | S_IRUGO,
1023                   get_fan_target, set_fan_target);
1024static DEVICE_ATTR(fan1_div, S_IWUSR | S_IRUGO, get_fan_div, set_fan_div);
1025static DEVICE_ATTR(fan1_pulses, S_IWUSR | S_IRUGO,
1026                   get_fan_pulses, set_fan_pulses);
1027
1028/* Driver data */
1029static struct attribute *g762_attributes[] = {
1030        &dev_attr_fan1_input.attr,
1031        &dev_attr_fan1_alarm.attr,
1032        &dev_attr_fan1_fault.attr,
1033        &dev_attr_fan1_target.attr,
1034        &dev_attr_fan1_div.attr,
1035        &dev_attr_fan1_pulses.attr,
1036        &dev_attr_pwm1.attr,
1037        &dev_attr_pwm1_mode.attr,
1038        &dev_attr_pwm1_enable.attr,
1039        NULL
1040};
1041
1042static const struct attribute_group g762_group = {
1043        .attrs = g762_attributes,
1044};
1045
1046/*
1047 * Enable both fan failure detection and fan out of control protection. The
1048 * function does not protect change/access to data structure; it must thus
1049 * only be called during initialization.
1050 */
1051static inline int g762_fan_init(struct device *dev)
1052{
1053        struct i2c_client *client = to_i2c_client(dev);
1054        struct g762_data *data = g762_update_client(dev);
1055
1056        if (IS_ERR(data))
1057                return PTR_ERR(data);
1058
1059        data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
1060        data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
1061        data->valid = false;
1062
1063        return i2c_smbus_write_byte_data(client, G762_REG_FAN_CMD1,
1064                                         data->fan_cmd1);
1065}
1066
1067static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)
1068{
1069        struct g762_data *data;
1070        int ret;
1071
1072        if (!i2c_check_functionality(client->adapter,
1073                                     I2C_FUNC_SMBUS_BYTE_DATA))
1074                return -ENODEV;
1075
1076        data = devm_kzalloc(&client->dev, sizeof(struct g762_data), GFP_KERNEL);
1077        if (!data)
1078                return -ENOMEM;
1079
1080        i2c_set_clientdata(client, data);
1081        data->client = client;
1082        mutex_init(&data->update_lock);
1083
1084        /* Enable fan failure detection and fan out of control protection */
1085        ret = g762_fan_init(&client->dev);
1086        if (ret)
1087                return ret;
1088
1089        /* Get configuration via DT ... */
1090        ret = g762_of_clock_enable(client);
1091        if (ret)
1092                return ret;
1093        ret = g762_of_prop_import(client);
1094        if (ret)
1095                goto clock_dis;
1096        /* ... or platform_data */
1097        ret = g762_pdata_prop_import(client);
1098        if (ret)
1099                goto clock_dis;
1100
1101        /* Register sysfs hooks */
1102        ret = sysfs_create_group(&client->dev.kobj, &g762_group);
1103        if (ret)
1104                goto clock_dis;
1105
1106        data->hwmon_dev = hwmon_device_register(&client->dev);
1107        if (IS_ERR(data->hwmon_dev)) {
1108                ret = PTR_ERR(data->hwmon_dev);
1109                goto sysfs_rem;
1110        }
1111
1112        return 0;
1113
1114 sysfs_rem:
1115        sysfs_remove_group(&client->dev.kobj, &g762_group);
1116
1117 clock_dis:
1118        g762_of_clock_disable(client);
1119
1120        return ret;
1121}
1122
1123static int g762_remove(struct i2c_client *client)
1124{
1125        struct g762_data *data = i2c_get_clientdata(client);
1126
1127        hwmon_device_unregister(data->hwmon_dev);
1128        sysfs_remove_group(&client->dev.kobj, &g762_group);
1129        g762_of_clock_disable(client);
1130
1131        return 0;
1132}
1133
1134static struct i2c_driver g762_driver = {
1135        .driver = {
1136                .name = DRVNAME,
1137                .owner = THIS_MODULE,
1138                .of_match_table = of_match_ptr(g762_dt_match),
1139        },
1140        .probe    = g762_probe,
1141        .remove   = g762_remove,
1142        .id_table = g762_id,
1143};
1144
1145module_i2c_driver(g762_driver);
1146
1147MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1148MODULE_DESCRIPTION("GMT G762/G763 driver");
1149MODULE_LICENSE("GPL");
1150
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