drivers/hwmon/g762.c

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This source file includes following definitions.
rpm_from_cnt
cnt_from_rpm
g762_update_client
do_set_clk_freq
do_set_pwm_mode
do_set_fan_div
do_set_fan_gear_mode
do_set_fan_pulses
do_set_pwm_enable
do_set_pwm_polarity
do_set_pwm
do_set_fan_target
do_set_fan_startv
g762_of_clock_disable
g762_of_clock_enable
g762_of_prop_import_one
g762_of_prop_import
g762_of_prop_import
g762_of_clock_enable
g762_pdata_prop_import
fan1_input_show
pwm1_mode_show
pwm1_mode_store
fan1_div_show
fan1_div_store
fan1_pulses_show
fan1_pulses_store
pwm1_enable_show
pwm1_enable_store
pwm1_show
pwm1_store
fan1_target_show
fan1_target_store
fan1_fault_show
fan1_alarm_show
g762_fan_init
g762_probe
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * g762 - Driver for the Global Mixed-mode Technology Inc. fan speed
   4  *        PWM controller chips from G762 family, i.e. G762 and G763
   5  *
   6  * Copyright (C) 2013, Arnaud EBALARD <arno@natisbad.org>
   7  *
   8  * This work is based on a basic version for 2.6.31 kernel developed
   9  * by Olivier Mouchet for LaCie. Updates and correction have been
  10  * performed to run on recent kernels. Additional features, like the
  11  * ability to configure various characteristics via .dts file or
  12  * board init file have been added. Detailed datasheet on which this
  13  * development is based is available here:
  14  *
  15  *  http://natisbad.org/NAS/refs/GMT_EDS-762_763-080710-0.2.pdf
  16  *
  17  * Headers from previous developments have been kept below:
  18  *
  19  * Copyright (c) 2009 LaCie
  20  *
  21  * Author: Olivier Mouchet <olivier.mouchet@gmail.com>
  22  *
  23  * based on g760a code written by Herbert Valerio Riedel <hvr@gnu.org>
  24  * Copyright (C) 2007  Herbert Valerio Riedel <hvr@gnu.org>
  25  *
  26  * g762: minimal datasheet available at:
  27  *       http://www.gmt.com.tw/product/datasheet/EDS-762_3.pdf
  28  */
  29 
  30 #include <linux/device.h>
  31 #include <linux/module.h>
  32 #include <linux/init.h>
  33 #include <linux/jiffies.h>
  34 #include <linux/i2c.h>
  35 #include <linux/hwmon.h>
  36 #include <linux/hwmon-sysfs.h>
  37 #include <linux/err.h>
  38 #include <linux/mutex.h>
  39 #include <linux/kernel.h>
  40 #include <linux/clk.h>
  41 #include <linux/of.h>
  42 #include <linux/of_device.h>
  43 #include <linux/platform_data/g762.h>
  44 
  45 #define DRVNAME "g762"
  46 
  47 static const struct i2c_device_id g762_id[] = {
  48         { "g762", 0 },
  49         { "g763", 0 },
  50         { }
  51 };
  52 MODULE_DEVICE_TABLE(i2c, g762_id);
  53 
  54 enum g762_regs {
  55         G762_REG_SET_CNT  = 0x00,
  56         G762_REG_ACT_CNT  = 0x01,
  57         G762_REG_FAN_STA  = 0x02,
  58         G762_REG_SET_OUT  = 0x03,
  59         G762_REG_FAN_CMD1 = 0x04,
  60         G762_REG_FAN_CMD2 = 0x05,
  61 };
  62 
  63 /* Config register bits */
  64 #define G762_REG_FAN_CMD1_DET_FAN_FAIL  0x80 /* enable fan_fail signal */
  65 #define G762_REG_FAN_CMD1_DET_FAN_OOC   0x40 /* enable fan_out_of_control */
  66 #define G762_REG_FAN_CMD1_OUT_MODE      0x20 /* out mode: PWM or DC */
  67 #define G762_REG_FAN_CMD1_FAN_MODE      0x10 /* fan mode: closed/open-loop */
  68 #define G762_REG_FAN_CMD1_CLK_DIV_ID1   0x08 /* clock divisor value */
  69 #define G762_REG_FAN_CMD1_CLK_DIV_ID0   0x04
  70 #define G762_REG_FAN_CMD1_PWM_POLARITY  0x02 /* PWM polarity */
  71 #define G762_REG_FAN_CMD1_PULSE_PER_REV 0x01 /* pulse per fan revolution */
  72 
  73 #define G762_REG_FAN_CMD2_GEAR_MODE_1   0x08 /* fan gear mode */
  74 #define G762_REG_FAN_CMD2_GEAR_MODE_0   0x04
  75 #define G762_REG_FAN_CMD2_FAN_STARTV_1  0x02 /* fan startup voltage */
  76 #define G762_REG_FAN_CMD2_FAN_STARTV_0  0x01
  77 
  78 #define G762_REG_FAN_STA_FAIL           0x02 /* fan fail */
  79 #define G762_REG_FAN_STA_OOC            0x01 /* fan out of control */
  80 
  81 /* Config register values */
  82 #define G762_OUT_MODE_PWM            1
  83 #define G762_OUT_MODE_DC             0
  84 
  85 #define G762_FAN_MODE_CLOSED_LOOP    2
  86 #define G762_FAN_MODE_OPEN_LOOP      1
  87 
  88 #define G762_PWM_POLARITY_NEGATIVE   1
  89 #define G762_PWM_POLARITY_POSITIVE   0
  90 
  91 /* Register data is read (and cached) at most once per second. */
  92 #define G762_UPDATE_INTERVAL    HZ
  93 
  94 /*
  95  * Extract pulse count per fan revolution value (2 or 4) from given
  96  * FAN_CMD1 register value.
  97  */
  98 #define G762_PULSE_FROM_REG(reg) \
  99         ((((reg) & G762_REG_FAN_CMD1_PULSE_PER_REV) + 1) << 1)
 100 
 101 /*
 102  * Extract fan clock divisor (1, 2, 4 or 8) from given FAN_CMD1
 103  * register value.
 104  */
 105 #define G762_CLKDIV_FROM_REG(reg) \
 106         (1 << (((reg) & (G762_REG_FAN_CMD1_CLK_DIV_ID0 |        \
 107                          G762_REG_FAN_CMD1_CLK_DIV_ID1)) >> 2))
 108 
 109 /*
 110  * Extract fan gear mode multiplier value (0, 2 or 4) from given
 111  * FAN_CMD2 register value.
 112  */
 113 #define G762_GEARMULT_FROM_REG(reg) \
 114         (1 << (((reg) & (G762_REG_FAN_CMD2_GEAR_MODE_0 |        \
 115                          G762_REG_FAN_CMD2_GEAR_MODE_1)) >> 2))
 116 
 117 struct g762_data {
 118         struct i2c_client *client;
 119         struct clk *clk;
 120 
 121         /* update mutex */
 122         struct mutex update_lock;
 123 
 124         /* board specific parameters. */
 125         u32 clk_freq;
 126 
 127         /* g762 register cache */
 128         bool valid;
 129         unsigned long last_updated; /* in jiffies */
 130 
 131         u8 set_cnt;  /* controls fan rotation speed in closed-loop mode */
 132         u8 act_cnt;  /* provides access to current fan RPM value */
 133         u8 fan_sta;  /* bit 0: set when actual fan speed is more than
 134                       *        25% outside requested fan speed
 135                       * bit 1: set when no transition occurs on fan
 136                       *        pin for 0.7s
 137                       */
 138         u8 set_out;  /* controls fan rotation speed in open-loop mode */
 139         u8 fan_cmd1; /*   0: FG_PLS_ID0 FG pulses count per revolution
 140                       *      0: 2 counts per revolution
 141                       *      1: 4 counts per revolution
 142                       *   1: PWM_POLARITY 1: negative_duty
 143                       *                   0: positive_duty
 144                       * 2,3: [FG_CLOCK_ID0, FG_CLK_ID1]
 145                       *         00: Divide fan clock by 1
 146                       *         01: Divide fan clock by 2
 147                       *         10: Divide fan clock by 4
 148                       *         11: Divide fan clock by 8
 149                       *   4: FAN_MODE 1:closed-loop, 0:open-loop
 150                       *   5: OUT_MODE 1:PWM, 0:DC
 151                       *   6: DET_FAN_OOC enable "fan ooc" status
 152                       *   7: DET_FAN_FAIL enable "fan fail" status
 153                       */
 154         u8 fan_cmd2; /* 0,1: FAN_STARTV 0,1,2,3 -> 0,32,64,96 dac_code
 155                       * 2,3: FG_GEAR_MODE
 156                       *         00: multiplier = 1
 157                       *         01: multiplier = 2
 158                       *         10: multiplier = 4
 159                       *   4: Mask ALERT# (g763 only)
 160                       */
 161 };
 162 
 163 /*
 164  * Convert count value from fan controller register (FAN_SET_CNT) into fan
 165  * speed RPM value. Note that the datasheet documents a basic formula;
 166  * influence of additional parameters (fan clock divisor, fan gear mode)
 167  * have been infered from examples in the datasheet and tests.
 168  */
 169 static inline unsigned int rpm_from_cnt(u8 cnt, u32 clk_freq, u16 p,
 170                                         u8 clk_div, u8 gear_mult)
 171 {
 172         if (cnt == 0xff)  /* setting cnt to 255 stops the fan */
 173                 return 0;
 174 
 175         return (clk_freq * 30 * gear_mult) / ((cnt ? cnt : 1) * p * clk_div);
 176 }
 177 
 178 /*
 179  * Convert fan RPM value from sysfs into count value for fan controller
 180  * register (FAN_SET_CNT).
 181  */
 182 static inline unsigned char cnt_from_rpm(unsigned long rpm, u32 clk_freq, u16 p,
 183                                          u8 clk_div, u8 gear_mult)
 184 {
 185         unsigned long f1 = clk_freq * 30 * gear_mult;
 186         unsigned long f2 = p * clk_div;
 187 
 188         if (!rpm)       /* to stop the fan, set cnt to 255 */
 189                 return 0xff;
 190 
 191         rpm = clamp_val(rpm, f1 / (255 * f2), ULONG_MAX / f2);
 192         return DIV_ROUND_CLOSEST(f1, rpm * f2);
 193 }
 194 
 195 /* helper to grab and cache data, at most one time per second */
 196 static struct g762_data *g762_update_client(struct device *dev)
 197 {
 198         struct g762_data *data = dev_get_drvdata(dev);
 199         struct i2c_client *client = data->client;
 200         int ret = 0;
 201 
 202         mutex_lock(&data->update_lock);
 203         if (time_before(jiffies, data->last_updated + G762_UPDATE_INTERVAL) &&
 204             likely(data->valid))
 205                 goto out;
 206 
 207         ret = i2c_smbus_read_byte_data(client, G762_REG_SET_CNT);
 208         if (ret < 0)
 209                 goto out;
 210         data->set_cnt = ret;
 211 
 212         ret = i2c_smbus_read_byte_data(client, G762_REG_ACT_CNT);
 213         if (ret < 0)
 214                 goto out;
 215         data->act_cnt = ret;
 216 
 217         ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_STA);
 218         if (ret < 0)
 219                 goto out;
 220         data->fan_sta = ret;
 221 
 222         ret = i2c_smbus_read_byte_data(client, G762_REG_SET_OUT);
 223         if (ret < 0)
 224                 goto out;
 225         data->set_out = ret;
 226 
 227         ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD1);
 228         if (ret < 0)
 229                 goto out;
 230         data->fan_cmd1 = ret;
 231 
 232         ret = i2c_smbus_read_byte_data(client, G762_REG_FAN_CMD2);
 233         if (ret < 0)
 234                 goto out;
 235         data->fan_cmd2 = ret;
 236 
 237         data->last_updated = jiffies;
 238         data->valid = true;
 239  out:
 240         mutex_unlock(&data->update_lock);
 241 
 242         if (ret < 0) /* upon error, encode it in return value */
 243                 data = ERR_PTR(ret);
 244 
 245         return data;
 246 }
 247 
 248 /* helpers for writing hardware parameters */
 249 
 250 /*
 251  * Set input clock frequency received on CLK pin of the chip. Accepted values
 252  * are between 0 and 0xffffff. If zero is given, then default frequency
 253  * (32,768Hz) is used. Note that clock frequency is a characteristic of the
 254  * system but an internal parameter, i.e. value is not passed to the device.
 255  */
 256 static int do_set_clk_freq(struct device *dev, unsigned long val)
 257 {
 258         struct g762_data *data = dev_get_drvdata(dev);
 259 
 260         if (val > 0xffffff)
 261                 return -EINVAL;
 262         if (!val)
 263                 val = 32768;
 264 
 265         data->clk_freq = val;
 266 
 267         return 0;
 268 }
 269 
 270 /* Set pwm mode. Accepts either 0 (PWM mode) or 1 (DC mode) */
 271 static int do_set_pwm_mode(struct device *dev, unsigned long val)
 272 {
 273         struct g762_data *data = g762_update_client(dev);
 274         int ret;
 275 
 276         if (IS_ERR(data))
 277                 return PTR_ERR(data);
 278 
 279         mutex_lock(&data->update_lock);
 280         switch (val) {
 281         case G762_OUT_MODE_PWM:
 282                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_OUT_MODE;
 283                 break;
 284         case G762_OUT_MODE_DC:
 285                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_OUT_MODE;
 286                 break;
 287         default:
 288                 ret = -EINVAL;
 289                 goto out;
 290         }
 291         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 292                                         data->fan_cmd1);
 293         data->valid = false;
 294  out:
 295         mutex_unlock(&data->update_lock);
 296 
 297         return ret;
 298 }
 299 
 300 /* Set fan clock divisor. Accepts either 1, 2, 4 or 8. */
 301 static int do_set_fan_div(struct device *dev, unsigned long val)
 302 {
 303         struct g762_data *data = g762_update_client(dev);
 304         int ret;
 305 
 306         if (IS_ERR(data))
 307                 return PTR_ERR(data);
 308 
 309         mutex_lock(&data->update_lock);
 310         switch (val) {
 311         case 1:
 312                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 313                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 314                 break;
 315         case 2:
 316                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 317                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID1;
 318                 break;
 319         case 4:
 320                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_CLK_DIV_ID0;
 321                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 322                 break;
 323         case 8:
 324                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID0;
 325                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_CLK_DIV_ID1;
 326                 break;
 327         default:
 328                 ret = -EINVAL;
 329                 goto out;
 330         }
 331         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 332                                         data->fan_cmd1);
 333         data->valid = false;
 334  out:
 335         mutex_unlock(&data->update_lock);
 336 
 337         return ret;
 338 }
 339 
 340 /* Set fan gear mode. Accepts either 0, 1 or 2. */
 341 static int do_set_fan_gear_mode(struct device *dev, unsigned long val)
 342 {
 343         struct g762_data *data = g762_update_client(dev);
 344         int ret;
 345 
 346         if (IS_ERR(data))
 347                 return PTR_ERR(data);
 348 
 349         mutex_lock(&data->update_lock);
 350         switch (val) {
 351         case 0:
 352                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 353                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 354                 break;
 355         case 1:
 356                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_0;
 357                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_1;
 358                 break;
 359         case 2:
 360                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_GEAR_MODE_0;
 361                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_GEAR_MODE_1;
 362                 break;
 363         default:
 364                 ret = -EINVAL;
 365                 goto out;
 366         }
 367         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 368                                         data->fan_cmd2);
 369         data->valid = false;
 370  out:
 371         mutex_unlock(&data->update_lock);
 372 
 373         return ret;
 374 }
 375 
 376 /* Set number of fan pulses per revolution. Accepts either 2 or 4. */
 377 static int do_set_fan_pulses(struct device *dev, unsigned long val)
 378 {
 379         struct g762_data *data = g762_update_client(dev);
 380         int ret;
 381 
 382         if (IS_ERR(data))
 383                 return PTR_ERR(data);
 384 
 385         mutex_lock(&data->update_lock);
 386         switch (val) {
 387         case 2:
 388                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PULSE_PER_REV;
 389                 break;
 390         case 4:
 391                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_PULSE_PER_REV;
 392                 break;
 393         default:
 394                 ret = -EINVAL;
 395                 goto out;
 396         }
 397         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 398                                         data->fan_cmd1);
 399         data->valid = false;
 400  out:
 401         mutex_unlock(&data->update_lock);
 402 
 403         return ret;
 404 }
 405 
 406 /* Set fan mode. Accepts either 1 (open-loop) or 2 (closed-loop). */
 407 static int do_set_pwm_enable(struct device *dev, unsigned long val)
 408 {
 409         struct g762_data *data = g762_update_client(dev);
 410         int ret;
 411 
 412         if (IS_ERR(data))
 413                 return PTR_ERR(data);
 414 
 415         mutex_lock(&data->update_lock);
 416         switch (val) {
 417         case G762_FAN_MODE_CLOSED_LOOP:
 418                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_FAN_MODE;
 419                 break;
 420         case G762_FAN_MODE_OPEN_LOOP:
 421                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_FAN_MODE;
 422                 /*
 423                  * BUG FIX: if SET_CNT register value is 255 then, for some
 424                  * unknown reason, fan will not rotate as expected, no matter
 425                  * the value of SET_OUT (to be specific, this seems to happen
 426                  * only in PWM mode). To workaround this bug, we give SET_CNT
 427                  * value of 254 if it is 255 when switching to open-loop.
 428                  */
 429                 if (data->set_cnt == 0xff)
 430                         i2c_smbus_write_byte_data(data->client,
 431                                                   G762_REG_SET_CNT, 254);
 432                 break;
 433         default:
 434                 ret = -EINVAL;
 435                 goto out;
 436         }
 437 
 438         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 439                                         data->fan_cmd1);
 440         data->valid = false;
 441  out:
 442         mutex_unlock(&data->update_lock);
 443 
 444         return ret;
 445 }
 446 
 447 /* Set PWM polarity. Accepts either 0 (positive duty) or 1 (negative duty) */
 448 static int do_set_pwm_polarity(struct device *dev, unsigned long val)
 449 {
 450         struct g762_data *data = g762_update_client(dev);
 451         int ret;
 452 
 453         if (IS_ERR(data))
 454                 return PTR_ERR(data);
 455 
 456         mutex_lock(&data->update_lock);
 457         switch (val) {
 458         case G762_PWM_POLARITY_POSITIVE:
 459                 data->fan_cmd1 &= ~G762_REG_FAN_CMD1_PWM_POLARITY;
 460                 break;
 461         case G762_PWM_POLARITY_NEGATIVE:
 462                 data->fan_cmd1 |=  G762_REG_FAN_CMD1_PWM_POLARITY;
 463                 break;
 464         default:
 465                 ret = -EINVAL;
 466                 goto out;
 467         }
 468         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
 469                                         data->fan_cmd1);
 470         data->valid = false;
 471  out:
 472         mutex_unlock(&data->update_lock);
 473 
 474         return ret;
 475 }
 476 
 477 /*
 478  * Set pwm value. Accepts values between 0 (stops the fan) and
 479  * 255 (full speed). This only makes sense in open-loop mode.
 480  */
 481 static int do_set_pwm(struct device *dev, unsigned long val)
 482 {
 483         struct g762_data *data = dev_get_drvdata(dev);
 484         struct i2c_client *client = data->client;
 485         int ret;
 486 
 487         if (val > 255)
 488                 return -EINVAL;
 489 
 490         mutex_lock(&data->update_lock);
 491         ret = i2c_smbus_write_byte_data(client, G762_REG_SET_OUT, val);
 492         data->valid = false;
 493         mutex_unlock(&data->update_lock);
 494 
 495         return ret;
 496 }
 497 
 498 /*
 499  * Set fan RPM value. Can be called both in closed and open-loop mode
 500  * but effect will only be seen after closed-loop mode is configured.
 501  */
 502 static int do_set_fan_target(struct device *dev, unsigned long val)
 503 {
 504         struct g762_data *data = g762_update_client(dev);
 505         int ret;
 506 
 507         if (IS_ERR(data))
 508                 return PTR_ERR(data);
 509 
 510         mutex_lock(&data->update_lock);
 511         data->set_cnt = cnt_from_rpm(val, data->clk_freq,
 512                                      G762_PULSE_FROM_REG(data->fan_cmd1),
 513                                      G762_CLKDIV_FROM_REG(data->fan_cmd1),
 514                                      G762_GEARMULT_FROM_REG(data->fan_cmd2));
 515         ret = i2c_smbus_write_byte_data(data->client, G762_REG_SET_CNT,
 516                                         data->set_cnt);
 517         data->valid = false;
 518         mutex_unlock(&data->update_lock);
 519 
 520         return ret;
 521 }
 522 
 523 /* Set fan startup voltage. Accepted values are either 0, 1, 2 or 3. */
 524 static int do_set_fan_startv(struct device *dev, unsigned long val)
 525 {
 526         struct g762_data *data = g762_update_client(dev);
 527         int ret;
 528 
 529         if (IS_ERR(data))
 530                 return PTR_ERR(data);
 531 
 532         mutex_lock(&data->update_lock);
 533         switch (val) {
 534         case 0:
 535                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 536                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 537                 break;
 538         case 1:
 539                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 540                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_1;
 541                 break;
 542         case 2:
 543                 data->fan_cmd2 &= ~G762_REG_FAN_CMD2_FAN_STARTV_0;
 544                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 545                 break;
 546         case 3:
 547                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_0;
 548                 data->fan_cmd2 |=  G762_REG_FAN_CMD2_FAN_STARTV_1;
 549                 break;
 550         default:
 551                 ret = -EINVAL;
 552                 goto out;
 553         }
 554         ret = i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD2,
 555                                         data->fan_cmd2);
 556         data->valid = false;
 557  out:
 558         mutex_unlock(&data->update_lock);
 559 
 560         return ret;
 561 }
 562 
 563 /*
 564  * Helper to import hardware characteristics from .dts file and push
 565  * those to the chip.
 566  */
 567 
 568 #ifdef CONFIG_OF
 569 static const struct of_device_id g762_dt_match[] = {
 570         { .compatible = "gmt,g762" },
 571         { .compatible = "gmt,g763" },
 572         { },
 573 };
 574 MODULE_DEVICE_TABLE(of, g762_dt_match);
 575 
 576 /*
 577  * Grab clock (a required property), enable it, get (fixed) clock frequency
 578  * and store it. Note: upon success, clock has been prepared and enabled; it
 579  * must later be unprepared and disabled (e.g. during module unloading) by a
 580  * call to g762_of_clock_disable(). Note that a reference to clock is kept
 581  * in our private data structure to be used in this function.
 582  */
 583 static void g762_of_clock_disable(void *data)
 584 {
 585         struct g762_data *g762 = data;
 586 
 587         clk_disable_unprepare(g762->clk);
 588         clk_put(g762->clk);
 589 }
 590 
 591 static int g762_of_clock_enable(struct i2c_client *client)
 592 {
 593         struct g762_data *data;
 594         unsigned long clk_freq;
 595         struct clk *clk;
 596         int ret;
 597 
 598         if (!client->dev.of_node)
 599                 return 0;
 600 
 601         clk = of_clk_get(client->dev.of_node, 0);
 602         if (IS_ERR(clk)) {
 603                 dev_err(&client->dev, "failed to get clock\n");
 604                 return PTR_ERR(clk);
 605         }
 606 
 607         ret = clk_prepare_enable(clk);
 608         if (ret) {
 609                 dev_err(&client->dev, "failed to enable clock\n");
 610                 goto clk_put;
 611         }
 612 
 613         clk_freq = clk_get_rate(clk);
 614         ret = do_set_clk_freq(&client->dev, clk_freq);
 615         if (ret) {
 616                 dev_err(&client->dev, "invalid clock freq %lu\n", clk_freq);
 617                 goto clk_unprep;
 618         }
 619 
 620         data = i2c_get_clientdata(client);
 621         data->clk = clk;
 622 
 623         devm_add_action(&client->dev, g762_of_clock_disable, data);
 624         return 0;
 625 
 626  clk_unprep:
 627         clk_disable_unprepare(clk);
 628 
 629  clk_put:
 630         clk_put(clk);
 631 
 632         return ret;
 633 }
 634 
 635 static int g762_of_prop_import_one(struct i2c_client *client,
 636                                    const char *pname,
 637                                    int (*psetter)(struct device *dev,
 638                                                   unsigned long val))
 639 {
 640         int ret;
 641         u32 pval;
 642 
 643         if (of_property_read_u32(client->dev.of_node, pname, &pval))
 644                 return 0;
 645 
 646         dev_dbg(&client->dev, "found %s (%d)\n", pname, pval);
 647         ret = (*psetter)(&client->dev, pval);
 648         if (ret)
 649                 dev_err(&client->dev, "unable to set %s (%d)\n", pname, pval);
 650 
 651         return ret;
 652 }
 653 
 654 static int g762_of_prop_import(struct i2c_client *client)
 655 {
 656         int ret;
 657 
 658         if (!client->dev.of_node)
 659                 return 0;
 660 
 661         ret = g762_of_prop_import_one(client, "fan_gear_mode",
 662                                       do_set_fan_gear_mode);
 663         if (ret)
 664                 return ret;
 665 
 666         ret = g762_of_prop_import_one(client, "pwm_polarity",
 667                                       do_set_pwm_polarity);
 668         if (ret)
 669                 return ret;
 670 
 671         return g762_of_prop_import_one(client, "fan_startv",
 672                                        do_set_fan_startv);
 673 }
 674 
 675 #else
 676 static int g762_of_prop_import(struct i2c_client *client)
 677 {
 678         return 0;
 679 }
 680 
 681 static int g762_of_clock_enable(struct i2c_client *client)
 682 {
 683         return 0;
 684 }
 685 #endif
 686 
 687 /*
 688  * Helper to import hardware characteristics from .dts file and push
 689  * those to the chip.
 690  */
 691 
 692 static int g762_pdata_prop_import(struct i2c_client *client)
 693 {
 694         struct g762_platform_data *pdata = dev_get_platdata(&client->dev);
 695         int ret;
 696 
 697         if (!pdata)
 698                 return 0;
 699 
 700         ret = do_set_fan_gear_mode(&client->dev, pdata->fan_gear_mode);
 701         if (ret)
 702                 return ret;
 703 
 704         ret = do_set_pwm_polarity(&client->dev, pdata->pwm_polarity);
 705         if (ret)
 706                 return ret;
 707 
 708         ret = do_set_fan_startv(&client->dev, pdata->fan_startv);
 709         if (ret)
 710                 return ret;
 711 
 712         return do_set_clk_freq(&client->dev, pdata->clk_freq);
 713 }
 714 
 715 /*
 716  * sysfs attributes
 717  */
 718 
 719 /*
 720  * Read function for fan1_input sysfs file. Return current fan RPM value, or
 721  * 0 if fan is out of control.
 722  */
 723 static ssize_t fan1_input_show(struct device *dev,
 724                                struct device_attribute *da, char *buf)
 725 {
 726         struct g762_data *data = g762_update_client(dev);
 727         unsigned int rpm = 0;
 728 
 729         if (IS_ERR(data))
 730                 return PTR_ERR(data);
 731 
 732         mutex_lock(&data->update_lock);
 733         /* reverse logic: fan out of control reporting is enabled low */
 734         if (data->fan_sta & G762_REG_FAN_STA_OOC) {
 735                 rpm = rpm_from_cnt(data->act_cnt, data->clk_freq,
 736                                    G762_PULSE_FROM_REG(data->fan_cmd1),
 737                                    G762_CLKDIV_FROM_REG(data->fan_cmd1),
 738                                    G762_GEARMULT_FROM_REG(data->fan_cmd2));
 739         }
 740         mutex_unlock(&data->update_lock);
 741 
 742         return sprintf(buf, "%u\n", rpm);
 743 }
 744 
 745 /*
 746  * Read and write functions for pwm1_mode sysfs file. Get and set fan speed
 747  * control mode i.e. PWM (1) or DC (0).
 748  */
 749 static ssize_t pwm1_mode_show(struct device *dev, struct device_attribute *da,
 750                               char *buf)
 751 {
 752         struct g762_data *data = g762_update_client(dev);
 753 
 754         if (IS_ERR(data))
 755                 return PTR_ERR(data);
 756 
 757         return sprintf(buf, "%d\n",
 758                        !!(data->fan_cmd1 & G762_REG_FAN_CMD1_OUT_MODE));
 759 }
 760 
 761 static ssize_t pwm1_mode_store(struct device *dev,
 762                                struct device_attribute *da, const char *buf,
 763                                size_t count)
 764 {
 765         unsigned long val;
 766         int ret;
 767 
 768         if (kstrtoul(buf, 10, &val))
 769                 return -EINVAL;
 770 
 771         ret = do_set_pwm_mode(dev, val);
 772         if (ret < 0)
 773                 return ret;
 774 
 775         return count;
 776 }
 777 
 778 /*
 779  * Read and write functions for fan1_div sysfs file. Get and set fan
 780  * controller prescaler value
 781  */
 782 static ssize_t fan1_div_show(struct device *dev, struct device_attribute *da,
 783                              char *buf)
 784 {
 785         struct g762_data *data = g762_update_client(dev);
 786 
 787         if (IS_ERR(data))
 788                 return PTR_ERR(data);
 789 
 790         return sprintf(buf, "%d\n", G762_CLKDIV_FROM_REG(data->fan_cmd1));
 791 }
 792 
 793 static ssize_t fan1_div_store(struct device *dev, struct device_attribute *da,
 794                               const char *buf, size_t count)
 795 {
 796         unsigned long val;
 797         int ret;
 798 
 799         if (kstrtoul(buf, 10, &val))
 800                 return -EINVAL;
 801 
 802         ret = do_set_fan_div(dev, val);
 803         if (ret < 0)
 804                 return ret;
 805 
 806         return count;
 807 }
 808 
 809 /*
 810  * Read and write functions for fan1_pulses sysfs file. Get and set number
 811  * of tachometer pulses per fan revolution.
 812  */
 813 static ssize_t fan1_pulses_show(struct device *dev,
 814                                 struct device_attribute *da, char *buf)
 815 {
 816         struct g762_data *data = g762_update_client(dev);
 817 
 818         if (IS_ERR(data))
 819                 return PTR_ERR(data);
 820 
 821         return sprintf(buf, "%d\n", G762_PULSE_FROM_REG(data->fan_cmd1));
 822 }
 823 
 824 static ssize_t fan1_pulses_store(struct device *dev,
 825                                  struct device_attribute *da, const char *buf,
 826                                  size_t count)
 827 {
 828         unsigned long val;
 829         int ret;
 830 
 831         if (kstrtoul(buf, 10, &val))
 832                 return -EINVAL;
 833 
 834         ret = do_set_fan_pulses(dev, val);
 835         if (ret < 0)
 836                 return ret;
 837 
 838         return count;
 839 }
 840 
 841 /*
 842  * Read and write functions for pwm1_enable. Get and set fan speed control mode
 843  * (i.e. closed or open-loop).
 844  *
 845  * Following documentation about hwmon's sysfs interface, a pwm1_enable node
 846  * should accept the following:
 847  *
 848  *  0 : no fan speed control (i.e. fan at full speed)
 849  *  1 : manual fan speed control enabled (use pwm[1-*]) (open-loop)
 850  *  2+: automatic fan speed control enabled (use fan[1-*]_target) (closed-loop)
 851  *
 852  * but we do not accept 0 as this mode is not natively supported by the chip
 853  * and it is not emulated by g762 driver. -EINVAL is returned in this case.
 854  */
 855 static ssize_t pwm1_enable_show(struct device *dev,
 856                                 struct device_attribute *da, char *buf)
 857 {
 858         struct g762_data *data = g762_update_client(dev);
 859 
 860         if (IS_ERR(data))
 861                 return PTR_ERR(data);
 862 
 863         return sprintf(buf, "%d\n",
 864                        (!!(data->fan_cmd1 & G762_REG_FAN_CMD1_FAN_MODE)) + 1);
 865 }
 866 
 867 static ssize_t pwm1_enable_store(struct device *dev,
 868                                  struct device_attribute *da, const char *buf,
 869                                  size_t count)
 870 {
 871         unsigned long val;
 872         int ret;
 873 
 874         if (kstrtoul(buf, 10, &val))
 875                 return -EINVAL;
 876 
 877         ret = do_set_pwm_enable(dev, val);
 878         if (ret < 0)
 879                 return ret;
 880 
 881         return count;
 882 }
 883 
 884 /*
 885  * Read and write functions for pwm1 sysfs file. Get and set pwm value
 886  * (which affects fan speed) in open-loop mode. 0 stops the fan and 255
 887  * makes it run at full speed.
 888  */
 889 static ssize_t pwm1_show(struct device *dev, struct device_attribute *da,
 890                          char *buf)
 891 {
 892         struct g762_data *data = g762_update_client(dev);
 893 
 894         if (IS_ERR(data))
 895                 return PTR_ERR(data);
 896 
 897         return sprintf(buf, "%d\n", data->set_out);
 898 }
 899 
 900 static ssize_t pwm1_store(struct device *dev, struct device_attribute *da,
 901                           const char *buf, size_t count)
 902 {
 903         unsigned long val;
 904         int ret;
 905 
 906         if (kstrtoul(buf, 10, &val))
 907                 return -EINVAL;
 908 
 909         ret = do_set_pwm(dev, val);
 910         if (ret < 0)
 911                 return ret;
 912 
 913         return count;
 914 }
 915 
 916 /*
 917  * Read and write function for fan1_target sysfs file. Get/set the fan speed in
 918  * closed-loop mode. Speed is given as a RPM value; then the chip will regulate
 919  * the fan speed using pulses from fan tachometer.
 920  *
 921  * Refer to rpm_from_cnt() implementation above to get info about count number
 922  * calculation.
 923  *
 924  * Also note that due to rounding errors it is possible that you don't read
 925  * back exactly the value you have set.
 926  */
 927 static ssize_t fan1_target_show(struct device *dev,
 928                                 struct device_attribute *da, char *buf)
 929 {
 930         struct g762_data *data = g762_update_client(dev);
 931         unsigned int rpm;
 932 
 933         if (IS_ERR(data))
 934                 return PTR_ERR(data);
 935 
 936         mutex_lock(&data->update_lock);
 937         rpm = rpm_from_cnt(data->set_cnt, data->clk_freq,
 938                            G762_PULSE_FROM_REG(data->fan_cmd1),
 939                            G762_CLKDIV_FROM_REG(data->fan_cmd1),
 940                            G762_GEARMULT_FROM_REG(data->fan_cmd2));
 941         mutex_unlock(&data->update_lock);
 942 
 943         return sprintf(buf, "%u\n", rpm);
 944 }
 945 
 946 static ssize_t fan1_target_store(struct device *dev,
 947                                  struct device_attribute *da, const char *buf,
 948                                  size_t count)
 949 {
 950         unsigned long val;
 951         int ret;
 952 
 953         if (kstrtoul(buf, 10, &val))
 954                 return -EINVAL;
 955 
 956         ret = do_set_fan_target(dev, val);
 957         if (ret < 0)
 958                 return ret;
 959 
 960         return count;
 961 }
 962 
 963 /* read function for fan1_fault sysfs file. */
 964 static ssize_t fan1_fault_show(struct device *dev, struct device_attribute *da,
 965                                char *buf)
 966 {
 967         struct g762_data *data = g762_update_client(dev);
 968 
 969         if (IS_ERR(data))
 970                 return PTR_ERR(data);
 971 
 972         return sprintf(buf, "%u\n", !!(data->fan_sta & G762_REG_FAN_STA_FAIL));
 973 }
 974 
 975 /*
 976  * read function for fan1_alarm sysfs file. Note that OOC condition is
 977  * enabled low
 978  */
 979 static ssize_t fan1_alarm_show(struct device *dev,
 980                                struct device_attribute *da, char *buf)
 981 {
 982         struct g762_data *data = g762_update_client(dev);
 983 
 984         if (IS_ERR(data))
 985                 return PTR_ERR(data);
 986 
 987         return sprintf(buf, "%u\n", !(data->fan_sta & G762_REG_FAN_STA_OOC));
 988 }
 989 
 990 static DEVICE_ATTR_RW(pwm1);
 991 static DEVICE_ATTR_RW(pwm1_mode);
 992 static DEVICE_ATTR_RW(pwm1_enable);
 993 static DEVICE_ATTR_RO(fan1_input);
 994 static DEVICE_ATTR_RO(fan1_alarm);
 995 static DEVICE_ATTR_RO(fan1_fault);
 996 static DEVICE_ATTR_RW(fan1_target);
 997 static DEVICE_ATTR_RW(fan1_div);
 998 static DEVICE_ATTR_RW(fan1_pulses);
 999 
1000 /* Driver data */
1001 static struct attribute *g762_attrs[] = {
1002         &dev_attr_fan1_input.attr,
1003         &dev_attr_fan1_alarm.attr,
1004         &dev_attr_fan1_fault.attr,
1005         &dev_attr_fan1_target.attr,
1006         &dev_attr_fan1_div.attr,
1007         &dev_attr_fan1_pulses.attr,
1008         &dev_attr_pwm1.attr,
1009         &dev_attr_pwm1_mode.attr,
1010         &dev_attr_pwm1_enable.attr,
1011         NULL
1012 };
1013 
1014 ATTRIBUTE_GROUPS(g762);
1015 
1016 /*
1017  * Enable both fan failure detection and fan out of control protection. The
1018  * function does not protect change/access to data structure; it must thus
1019  * only be called during initialization.
1020  */
1021 static inline int g762_fan_init(struct device *dev)
1022 {
1023         struct g762_data *data = g762_update_client(dev);
1024 
1025         if (IS_ERR(data))
1026                 return PTR_ERR(data);
1027 
1028         data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_FAIL;
1029         data->fan_cmd1 |= G762_REG_FAN_CMD1_DET_FAN_OOC;
1030         data->valid = false;
1031 
1032         return i2c_smbus_write_byte_data(data->client, G762_REG_FAN_CMD1,
1033                                          data->fan_cmd1);
1034 }
1035 
1036 static int g762_probe(struct i2c_client *client, const struct i2c_device_id *id)
1037 {
1038         struct device *dev = &client->dev;
1039         struct device *hwmon_dev;
1040         struct g762_data *data;
1041         int ret;
1042 
1043         if (!i2c_check_functionality(client->adapter,
1044                                      I2C_FUNC_SMBUS_BYTE_DATA))
1045                 return -ENODEV;
1046 
1047         data = devm_kzalloc(dev, sizeof(struct g762_data), GFP_KERNEL);
1048         if (!data)
1049                 return -ENOMEM;
1050 
1051         i2c_set_clientdata(client, data);
1052         data->client = client;
1053         mutex_init(&data->update_lock);
1054 
1055         /* Enable fan failure detection and fan out of control protection */
1056         ret = g762_fan_init(dev);
1057         if (ret)
1058                 return ret;
1059 
1060         /* Get configuration via DT ... */
1061         ret = g762_of_clock_enable(client);
1062         if (ret)
1063                 return ret;
1064         ret = g762_of_prop_import(client);
1065         if (ret)
1066                 return ret;
1067         /* ... or platform_data */
1068         ret = g762_pdata_prop_import(client);
1069         if (ret)
1070                 return ret;
1071 
1072         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
1073                                                             data, g762_groups);
1074         return PTR_ERR_OR_ZERO(hwmon_dev);
1075 }
1076 
1077 static struct i2c_driver g762_driver = {
1078         .driver = {
1079                 .name = DRVNAME,
1080                 .of_match_table = of_match_ptr(g762_dt_match),
1081         },
1082         .probe    = g762_probe,
1083         .id_table = g762_id,
1084 };
1085 
1086 module_i2c_driver(g762_driver);
1087 
1088 MODULE_AUTHOR("Arnaud EBALARD <arno@natisbad.org>");
1089 MODULE_DESCRIPTION("GMT G762/G763 driver");
1090 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/hwmon/g762.c

DEFINITIONS
