target/linux/bcm27xx/patches-5.15/950-0890-hwmon-emc2305-add-support-for-EMC2301-2-3-5-RPM-base.patch

   1 From 23395c6df3c8ef7b6e43b4968de402169ec7c755 Mon Sep 17 00:00:00 2001
   2 From: Michael Shych <michaelsh@nvidia.com>
   3 Date: Sat, 30 Apr 2022 14:49:03 +0300
   4 Subject: [PATCH] hwmon: (emc2305) add support for EMC2301/2/3/5
   5  RPM-based PWM Fan Speed Controller.
   6
   7 Submitted to linux-hwmon mailing list at
   8 https://patchwork.kernel.org/project/linux-hwmon/patch/20220430114905.53448-2-michaelsh@nvidia.com/
   9
  10 Add driver for Microchip EMC2301/2/3/5 RPM-based PWM Fan Speed Controller.
  11 Modify Makefile and Kconfig to support Microchip EMC2305 RPM-based
  12 PWM Fan Speed Controller.
  13
  14 Signed-off-by: Michael Shych <michaelsh@nvidia.com>
  15 Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
  16 ---
  17  drivers/hwmon/Kconfig   |  13 +
  18  drivers/hwmon/Makefile  |   1 +
  19  drivers/hwmon/emc2305.c | 629 ++++++++++++++++++++++++++++++++++++++++
  20  3 files changed, 643 insertions(+)
  21  create mode 100644 drivers/hwmon/emc2305.c
  22
  23 --- a/drivers/hwmon/Kconfig
  24 +++ b/drivers/hwmon/Kconfig
  25 @@ -1684,6 +1684,19 @@ config SENSORS_EMC2103
  26           This driver can also be built as a module. If so, the module
  27           will be called emc2103.
  28
  29 +config SENSORS_EMC2305
  30 +       tristate "Microchip EMC2305 and compatible EMC2301/2/3"
  31 +       depends on I2C
  32 +       imply THERMAL
  33 +       help
  34 +         If you say yes here you get support for the Microchip EMC2305
  35 +         fan controller chips.
  36 +         The Microchip EMC2305 is a fan controller for up to 5 fans.
  37 +         Fan rotation speeds are reported in RPM.
  38 +
  39 +         This driver can also be built as a module.  If so, the module
  40 +         will be called emc2305.
  41 +
  42  config SENSORS_EMC6W201
  43         tristate "SMSC EMC6W201"
  44         depends on I2C
  45 --- a/drivers/hwmon/Makefile
  46 +++ b/drivers/hwmon/Makefile
  47 @@ -67,6 +67,7 @@ obj-$(CONFIG_SENSORS_DS620)   += ds620.o
  48  obj-$(CONFIG_SENSORS_DS1621)   += ds1621.o
  49  obj-$(CONFIG_SENSORS_EMC1403)  += emc1403.o
  50  obj-$(CONFIG_SENSORS_EMC2103)  += emc2103.o
  51 +obj-$(CONFIG_SENSORS_EMC2305)  += emc2305.o
  52  obj-$(CONFIG_SENSORS_EMC6W201) += emc6w201.o
  53  obj-$(CONFIG_SENSORS_F71805F)  += f71805f.o
  54  obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o
  55 --- /dev/null
  56 +++ b/drivers/hwmon/emc2305.c
  57 @@ -0,0 +1,629 @@
  58 +// SPDX-License-Identifier: GPL-2.0+
  59 +/*
  60 + * Hardware monitoring driver for EMC2305 fan controller
  61 + *
  62 + * Copyright (C) 2022 Nvidia Technologies Ltd and Delta Networks, Inc.
  63 + */
  64 +
  65 +#include <linux/err.h>
  66 +#include <linux/hwmon.h>
  67 +#include <linux/hwmon-sysfs.h>
  68 +#include <linux/i2c.h>
  69 +#include <linux/module.h>
  70 +#include <linux/of.h>
  71 +#include <linux/thermal.h>
  72 +#include <linux/version.h>
  73 +
  74 +static const unsigned short
  75 +emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END };
  76 +
  77 +#define EMC2305_REG_DRIVE_FAIL_STATUS  0x27
  78 +#define EMC2305_REG_DEVICE             0xfd
  79 +#define EMC2305_REG_VENDOR             0xfe
  80 +#define EMC2305_FAN_MAX                        0xff
  81 +#define EMC2305_FAN_MIN                        0x00
  82 +#define EMC2305_FAN_MAX_STATE          10
  83 +#define EMC2305_DEVICE                 0x34
  84 +#define EMC2305_VENDOR                 0x5d
  85 +#define EMC2305_REG_PRODUCT_ID         0xfd
  86 +#define EMC2305_TACH_REGS_UNUSE_BITS   3
  87 +#define EMC2305_TACH_CNT_MULTIPLIER    0x02
  88 +#define EMC2305_PWM_MAX                        5
  89 +#define EMC2305_PWM_CHNL_CMN           0
  90 +
  91 +#define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \
  92 +       (DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max)))
  93 +#define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \
  94 +       (DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state)))
  95 +
  96 +/* Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges
  97 + * equal (poles * 2 + 1).
  98 + */
  99 +#define EMC2305_RPM_FACTOR             3932160
 100 +
 101 +#define EMC2305_REG_FAN_DRIVE(n) (0x30 + 0x10 * (n))
 102 +#define EMC2305_REG_FAN_MIN_DRIVE(n) (0x38 + 0x10 * (n))
 103 +#define EMC2305_REG_FAN_TACH(n) (0x3e + 0x10 * (n))
 104 +
 105 +enum emc230x_product_id {
 106 +       EMC2305 = 0x34,
 107 +       EMC2303 = 0x35,
 108 +       EMC2302 = 0x36,
 109 +       EMC2301 = 0x37,
 110 +};
 111 +
 112 +static const struct i2c_device_id emc2305_ids[] = {
 113 +       { "emc2305", 0 },
 114 +       { "emc2303", 0 },
 115 +       { "emc2302", 0 },
 116 +       { "emc2301", 0 },
 117 +       { }
 118 +};
 119 +MODULE_DEVICE_TABLE(i2c, emc2305_ids);
 120 +
 121 +static const struct of_device_id emc2305_dt_ids[] = {
 122 +       { .compatible = "smsc,emc2305" },
 123 +       { }
 124 +};
 125 +MODULE_DEVICE_TABLE(of, emc2305_dt_ids);
 126 +
 127 +/**
 128 + * @cdev: cooling device;
 129 + * @curr_state: cooling current state;
 130 + * @last_hwmon_state: last cooling state updated by hwmon subsystem;
 131 + * @last_thermal_state: last cooling state updated by thermal subsystem;
 132 + *
 133 + * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit
 134 + * speed feature. The purpose of this feature is to provides ability to limit fan speed
 135 + * according to some system wise considerations, like absence of some replaceable units (PSU or
 136 + * line cards), high system ambient temperature, unreliable transceivers temperature sensing or
 137 + * some other factors which indirectly impacts system's airflow
 138 + * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is
 139 + * used for setting low limit for fan speed in case 'thermal' subsystem is configured in
 140 + * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal'
 141 + * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm'
 142 + * attribute.
 143 + * From other side, fan speed is to be updated in hardware through 'pwm' only in case the
 144 + * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan
 145 + * speed will be just stored with no PWM update.
 146 + */
 147 +struct emc2305_cdev_data {
 148 +       struct thermal_cooling_device *cdev;
 149 +       unsigned int cur_state;
 150 +       unsigned long last_hwmon_state;
 151 +       unsigned long last_thermal_state;
 152 +};
 153 +
 154 +/**
 155 + * @client: i2c client;
 156 + * @hwmon_dev: hwmon device;
 157 + * @max_state: maximum cooling state of the cooling device;
 158 + * @pwm_max: maximum PWM;
 159 + * @pwm_min: minimum PWM;
 160 + * @pwm_channel: maximum number of PWM channels;
 161 + * @cdev_data: array of cooling devices data;
 162 + */
 163 +struct emc2305_data {
 164 +       struct i2c_client *client;
 165 +       struct device *hwmon_dev;
 166 +       u8 max_state;
 167 +       u8 pwm_max;
 168 +       u8 pwm_min;
 169 +       u8 pwm_num;
 170 +       u8 pwm_channel;
 171 +       struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
 172 +};
 173 +
 174 +static char *emc2305_fan_name[] = {
 175 +       "emc2305_fan",
 176 +       "emc2305_fan1",
 177 +       "emc2305_fan2",
 178 +       "emc2305_fan3",
 179 +       "emc2305_fan4",
 180 +       "emc2305_fan5",
 181 +};
 182 +
 183 +static int emc2305_get_max_channel(struct emc2305_data *data)
 184 +{
 185 +       if (data->pwm_channel == EMC2305_PWM_CHNL_CMN)
 186 +               return data->pwm_num;
 187 +       else
 188 +               return data->pwm_channel;
 189 +}
 190 +
 191 +static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev)
 192 +{
 193 +       struct emc2305_data *data = cdev->devdata;
 194 +       size_t len = strlen(cdev->type);
 195 +       int ret;
 196 +
 197 +       if (len <= 0)
 198 +               return -EINVAL;
 199 +
 200 +       /* Retuns index of cooling device 0..4 in case of separate PWM setting.
 201 +        * Zero index is used in case of one common PWM setting.
 202 +        * If the mode is set as EMC2305_PWM_CHNL_CMN, all PWMs are to be bound
 203 +        * to the common thermal zone and should work at the same speed
 204 +        * to perform cooling for the same thermal junction.
 205 +        * Otherwise, return specific channel that will be used in bound
 206 +        * related PWM to the thermal zone.
 207 +        */
 208 +       if (data->pwm_channel == EMC2305_PWM_CHNL_CMN)
 209 +               return 0;
 210 +
 211 +       ret = cdev->type[len - 1];
 212 +       switch (ret) {
 213 +       case '1' ... '5':
 214 +               return ret - '1';
 215 +       default:
 216 +               break;
 217 +       }
 218 +       return -EINVAL;
 219 +}
 220 +
 221 +static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)
 222 +{
 223 +       int cdev_idx;
 224 +       struct emc2305_data *data = cdev->devdata;
 225 +
 226 +       cdev_idx = emc2305_get_cdev_idx(cdev);
 227 +       if (cdev_idx < 0)
 228 +               return cdev_idx;
 229 +
 230 +       *state = data->cdev_data[cdev_idx].cur_state;
 231 +       return 0;
 232 +}
 233 +
 234 +static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)
 235 +{
 236 +       struct emc2305_data *data = cdev->devdata;
 237 +       *state = data->max_state;
 238 +       return 0;
 239 +}
 240 +
 241 +static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
 242 +{
 243 +       int cdev_idx;
 244 +       struct emc2305_data *data = cdev->devdata;
 245 +       struct i2c_client *client = data->client;
 246 +       u8 val, i;
 247 +
 248 +       if (state > data->max_state)
 249 +               return -EINVAL;
 250 +
 251 +       cdev_idx =  emc2305_get_cdev_idx(cdev);
 252 +       if (cdev_idx < 0)
 253 +               return cdev_idx;
 254 +
 255 +       /* Save thermal state. */
 256 +       data->cdev_data[cdev_idx].last_thermal_state = state;
 257 +       state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state);
 258 +
 259 +       val = EMC2305_PWM_STATE2DUTY(state, data->max_state, data->pwm_max);
 260 +       if (val > EMC2305_FAN_MAX)
 261 +               return -EINVAL;
 262 +
 263 +       data->cdev_data[cdev_idx].cur_state = state;
 264 +       if (data->pwm_channel == EMC2305_PWM_CHNL_CMN)
 265 +       /* Set the same PWM value in all channels
 266 +        * if common PWM channel is used.
 267 +        */
 268 +               for (i = 0; i < data->pwm_num; i++)
 269 +                       i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val);
 270 +       else
 271 +               i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val);
 272 +
 273 +       return 0;
 274 +}
 275 +
 276 +static const struct thermal_cooling_device_ops emc2305_cooling_ops = {
 277 +       .get_max_state = emc2305_get_max_state,
 278 +       .get_cur_state = emc2305_get_cur_state,
 279 +       .set_cur_state = emc2305_set_cur_state,
 280 +};
 281 +
 282 +static int emc2305_show_fault(struct device *dev, int channel)
 283 +{
 284 +       struct emc2305_data *data = dev_get_drvdata(dev);
 285 +       struct i2c_client *client = data->client;
 286 +       int status_reg;
 287 +
 288 +       status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS);
 289 +       return status_reg & (1 << channel) ? 1 : 0;
 290 +}
 291 +
 292 +static int emc2305_show_fan(struct device *dev, int channel)
 293 +{
 294 +       struct emc2305_data *data = dev_get_drvdata(dev);
 295 +       struct i2c_client *client = data->client;
 296 +       int ret;
 297 +
 298 +       ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel));
 299 +       if (ret < 0)
 300 +               return ret;
 301 +
 302 +       ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS;
 303 +       return EMC2305_RPM_FACTOR * EMC2305_TACH_CNT_MULTIPLIER / (ret > 0 ? ret : 1);
 304 +}
 305 +
 306 +static int emc2305_show_pwm(struct device *dev, int channel)
 307 +{
 308 +       struct emc2305_data *data = dev_get_drvdata(dev);
 309 +       struct i2c_client *client = data->client;
 310 +
 311 +       return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel));
 312 +}
 313 +
 314 +static int emc2305_set_pwm(struct device *dev, long val, int channel)
 315 +{
 316 +       struct emc2305_data *data = dev_get_drvdata(dev);
 317 +       struct i2c_client *client = data->client;
 318 +
 319 +       if (val < data->pwm_min || val > data->pwm_max)
 320 +               return -EINVAL;
 321 +
 322 +       i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val);
 323 +       data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state,
 324 +                                                                   data->pwm_max);
 325 +       return 0;
 326 +}
 327 +
 328 +static int emc2305_get_tz_of(struct device *dev)
 329 +{
 330 +       struct device_node *np = dev->of_node;
 331 +       struct emc2305_data *data = dev_get_drvdata(dev);
 332 +       int ret = 0;
 333 +
 334 +       /* OF parameters are optional - overwrite default setting
 335 +        * if some of them are provided.
 336 +        */
 337 +
 338 +       if (of_find_property(np, "emc2305,cooling-levels", NULL)) {
 339 +               ret = of_property_read_u8(np, "emc2305,cooling-levels", &data->max_state);
 340 +               if (ret)
 341 +                       return ret;
 342 +       }
 343 +
 344 +       if (of_find_property(np, "emc2305,pwm-max", NULL)) {
 345 +               ret = of_property_read_u8(np, "emc2305,pwm-max", &data->pwm_max);
 346 +               if (ret)
 347 +                       return ret;
 348 +       }
 349 +
 350 +       if (of_find_property(np, "emc2305,pwm-min", NULL)) {
 351 +               ret = of_property_read_u8(np, "emc2305,pwm-min", &data->pwm_min);
 352 +               if (ret)
 353 +                       return ret;
 354 +       }
 355 +
 356 +       /* Not defined or 0 means one thermal zone over all colling devices.
 357 +        * Otherwise - separted thermal zones for each PWM channel.
 358 +        */
 359 +       if (of_find_property(np, "emc2305,pwm-channel", NULL)) {
 360 +               ret = of_property_read_u8(np, "emc2305,pwm-channel", &data->pwm_channel);
 361 +               if (ret)
 362 +                       return ret;
 363 +       }
 364 +
 365 +       return ret;
 366 +}
 367 +
 368 +static int emc2305_set_single_tz(struct device *dev, int idx)
 369 +{
 370 +       struct emc2305_data *data = dev_get_drvdata(dev);
 371 +       long pwm = data->pwm_max;
 372 +       int cdev_idx;
 373 +
 374 +       cdev_idx = (idx) ? idx - 1 : 0;
 375 +
 376 +       if (dev->of_node)
 377 +               data->cdev_data[cdev_idx].cdev =
 378 +                       devm_thermal_of_cooling_device_register(dev, dev->of_node,
 379 +                                                               emc2305_fan_name[idx], data,
 380 +                                                               &emc2305_cooling_ops);
 381 +       else
 382 +               data->cdev_data[cdev_idx].cdev =
 383 +                       thermal_cooling_device_register(emc2305_fan_name[idx], data,
 384 +                                                       &emc2305_cooling_ops);
 385 +
 386 +       if (IS_ERR(data->cdev_data[cdev_idx].cdev)) {
 387 +               dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]);
 388 +               return PTR_ERR(data->cdev_data[cdev_idx].cdev);
 389 +       }
 390 +       emc2305_set_pwm(dev, pwm, cdev_idx);
 391 +       data->cdev_data[cdev_idx].cur_state = data->max_state;
 392 +       /* Set minimal PWM speed. */
 393 +       data->cdev_data[cdev_idx].last_hwmon_state = EMC2305_PWM_DUTY2STATE(data->pwm_min,
 394 +                                                                           data->max_state,
 395 +                                                                           data->pwm_max);
 396 +       return 0;
 397 +}
 398 +
 399 +static int emc2305_set_tz(struct device *dev)
 400 +{
 401 +       struct emc2305_data *data = dev_get_drvdata(dev);
 402 +       int i, ret;
 403 +
 404 +       if (data->pwm_channel == EMC2305_PWM_CHNL_CMN)
 405 +               return emc2305_set_single_tz(dev, 0);
 406 +
 407 +       for (i = 0; i < data->pwm_channel; i++) {
 408 +               ret = emc2305_set_single_tz(dev, i + 1);
 409 +               if (ret)
 410 +                       goto thermal_cooling_device_register_fail;
 411 +       }
 412 +       return 0;
 413 +
 414 +thermal_cooling_device_register_fail:
 415 +       emc2305_unset_tz(dev);
 416 +       return ret;
 417 +}
 418 +
 419 +static void emc2305_unset_tz(struct device *dev)
 420 +{
 421 +       struct emc2305_data *data = dev_get_drvdata(dev);
 422 +       int i;
 423 +
 424 +       /* Unregister cooling device in case they have been registered by
 425 +        * thermal_cooling_device_unregister(). No need for clean-up flow in case they
 426 +        * have been registered by devm_thermal_of_cooling_device_register()
 427 +        */
 428 +       if (!dev->of_node) {
 429 +               for (i = 0; i < EMC2305_PWM_MAX; i++)
 430 +                       if (data->cdev_data[i].cdev)
 431 +                               thermal_cooling_device_unregister(data->cdev_data[i].cdev);
 432 +       }
 433 +}
 434 +
 435 +static umode_t
 436 +emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel)
 437 +{
 438 +       int max_channel = emc2305_get_max_channel((struct emc2305_data *)data);
 439 +
 440 +       /* Don't show channels which are not physically connected. */
 441 +       if ((channel + 1) > max_channel)
 442 +               return 0;
 443 +       switch (type) {
 444 +       case hwmon_fan:
 445 +               switch (attr) {
 446 +               case hwmon_fan_input:
 447 +                       return 0444;
 448 +               case hwmon_fan_fault:
 449 +                       return 0444;
 450 +               default:
 451 +                       break;
 452 +               }
 453 +               break;
 454 +       case hwmon_pwm:
 455 +               switch (attr) {
 456 +               case hwmon_pwm_input:
 457 +                       return 0644;
 458 +               default:
 459 +                       break;
 460 +               }
 461 +               break;
 462 +       default:
 463 +               break;
 464 +       }
 465 +
 466 +       return 0;
 467 +};
 468 +
 469 +static int
 470 +emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val)
 471 +{
 472 +       struct emc2305_data *data = dev_get_drvdata(dev);
 473 +
 474 +       switch (type) {
 475 +       case hwmon_pwm:
 476 +               switch (attr) {
 477 +               case hwmon_pwm_input:
 478 +                       /* If thermal is configured - handle PWM limit setting. */
 479 +                       if (IS_REACHABLE(CONFIG_THERMAL)) {
 480 +                               data->cdev_data[channel].last_hwmon_state =
 481 +                                       EMC2305_PWM_DUTY2STATE(val, data->max_state, data->pwm_max);
 482 +                               /* Update PWM only in case requested state is not less than the
 483 +                                * last thermal state.
 484 +                                */
 485 +                               if (data->cdev_data[channel].last_hwmon_state >=
 486 +                                   data->cdev_data[channel].last_thermal_state)
 487 +                                       return emc2305_set_cur_state(data->cdev_data[channel].cdev,
 488 +                                                       data->cdev_data[channel].last_hwmon_state);
 489 +                               return 0;
 490 +                       }
 491 +                       return emc2305_set_pwm(dev, val, channel);
 492 +               default:
 493 +                       break;
 494 +               }
 495 +               break;
 496 +       default:
 497 +               break;
 498 +       }
 499 +
 500 +       return -EOPNOTSUPP;
 501 +};
 502 +
 503 +static int
 504 +emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val)
 505 +{
 506 +       int ret;
 507 +
 508 +       switch (type) {
 509 +       case hwmon_fan:
 510 +               switch (attr) {
 511 +               case hwmon_fan_input:
 512 +                       ret = emc2305_show_fan(dev, channel);
 513 +                       if (ret < 0)
 514 +                               return ret;
 515 +                       *val = ret;
 516 +                       return 0;
 517 +               case hwmon_fan_fault:
 518 +                       ret = emc2305_show_fault(dev, channel);
 519 +                       if (ret < 0)
 520 +                               return ret;
 521 +                       *val = ret;
 522 +                       return 0;
 523 +               default:
 524 +                       break;
 525 +               }
 526 +               break;
 527 +       case hwmon_pwm:
 528 +               switch (attr) {
 529 +               case hwmon_pwm_input:
 530 +                       ret = emc2305_show_pwm(dev, channel);
 531 +                       if (ret < 0)
 532 +                               return ret;
 533 +                       *val = ret;
 534 +                       return 0;
 535 +               default:
 536 +                       break;
 537 +               }
 538 +               break;
 539 +       default:
 540 +               break;
 541 +       }
 542 +
 543 +       return -EOPNOTSUPP;
 544 +};
 545 +
 546 +static const struct hwmon_ops emc2305_ops = {
 547 +       .is_visible = emc2305_is_visible,
 548 +       .read = emc2305_read,
 549 +       .write = emc2305_write,
 550 +};
 551 +
 552 +static const struct hwmon_channel_info *emc2305_info[] = {
 553 +       HWMON_CHANNEL_INFO(fan,
 554 +                          HWMON_F_INPUT | HWMON_F_FAULT,
 555 +                          HWMON_F_INPUT | HWMON_F_FAULT,
 556 +                          HWMON_F_INPUT | HWMON_F_FAULT,
 557 +                          HWMON_F_INPUT | HWMON_F_FAULT,
 558 +                          HWMON_F_INPUT | HWMON_F_FAULT),
 559 +       HWMON_CHANNEL_INFO(pwm,
 560 +                          HWMON_PWM_INPUT,
 561 +                          HWMON_PWM_INPUT,
 562 +                          HWMON_PWM_INPUT,
 563 +                          HWMON_PWM_INPUT,
 564 +                          HWMON_PWM_INPUT),
 565 +       NULL
 566 +};
 567 +
 568 +static const struct hwmon_chip_info emc2305_chip_info = {
 569 +       .ops = &emc2305_ops,
 570 +       .info = emc2305_info,
 571 +};
 572 +
 573 +static int emc2305_identify(struct device *dev)
 574 +{
 575 +       struct i2c_client *client = to_i2c_client(dev);
 576 +       struct emc2305_data *data = i2c_get_clientdata(client);
 577 +       int ret;
 578 +
 579 +       ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID);
 580 +       if (ret < 0)
 581 +               return ret;
 582 +
 583 +       switch (ret) {
 584 +       case EMC2305:
 585 +               data->pwm_num = 5;
 586 +               break;
 587 +       case EMC2303:
 588 +               data->pwm_num = 3;
 589 +               break;
 590 +       case EMC2302:
 591 +               data->pwm_num = 2;
 592 +               break;
 593 +       case EMC2301:
 594 +               data->pwm_num = 1;
 595 +               break;
 596 +       default:
 597 +               return -EINVAL;
 598 +       }
 599 +
 600 +       return 0;
 601 +}
 602 +
 603 +static int emc2305_probe(struct i2c_client *client, const struct i2c_device_id *id)
 604 +{
 605 +       struct i2c_adapter *adapter = client->adapter;
 606 +       struct device *dev = &client->dev;
 607 +       struct emc2305_data *data;
 608 +       int vendor, device;
 609 +       int ret;
 610 +       int i;
 611 +
 612 +       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
 613 +               return -ENODEV;
 614 +
 615 +       vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR);
 616 +       if (vendor != EMC2305_VENDOR)
 617 +               return -ENODEV;
 618 +
 619 +       device = i2c_smbus_read_byte_data(client, EMC2305_REG_DEVICE);
 620 +       if (device != EMC2305_DEVICE)
 621 +               return -ENODEV;
 622 +
 623 +       data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 624 +       if (!data)
 625 +               return -ENOMEM;
 626 +
 627 +       i2c_set_clientdata(client, data);
 628 +       data->client = client;
 629 +
 630 +       ret = emc2305_identify(dev);
 631 +       if (ret)
 632 +               return ret;
 633 +
 634 +       data->max_state = EMC2305_FAN_MAX_STATE;
 635 +       data->pwm_max = EMC2305_FAN_MAX;
 636 +       data->pwm_min = EMC2305_FAN_MIN;
 637 +       data->pwm_channel = EMC2305_PWM_CHNL_CMN;
 638 +       if (dev->of_node) {
 639 +               ret = emc2305_get_tz_of(dev);
 640 +               if (ret < 0)
 641 +                       return ret;
 642 +       }
 643 +
 644 +       data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data,
 645 +                                                              &emc2305_chip_info, NULL);
 646 +       if (IS_ERR(data->hwmon_dev))
 647 +               return PTR_ERR(data->hwmon_dev);
 648 +
 649 +       if (IS_REACHABLE(CONFIG_THERMAL)) {
 650 +               ret = emc2305_set_tz(dev);
 651 +               if (ret != 0)
 652 +                       return ret;
 653 +       }
 654 +
 655 +       for (i = 0; i < data->pwm_num; i++)
 656 +               i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i), data->pwm_min);
 657 +
 658 +       return 0;
 659 +}
 660 +
 661 +static int emc2305_remove(struct i2c_client *client)
 662 +{
 663 +       struct device *dev = &client->dev;
 664 +
 665 +       if (IS_REACHABLE(CONFIG_THERMAL))
 666 +               emc2305_unset_tz(dev);
 667 +       return 0;
 668 +}
 669 +
 670 +static struct i2c_driver emc2305_driver = {
 671 +       .class  = I2C_CLASS_HWMON,
 672 +       .driver = {
 673 +               .name = "emc2305",
 674 +               .of_match_table = emc2305_dt_ids,
 675 +       },
 676 +       .probe    = emc2305_probe,
 677 +       .remove   = emc2305_remove,
 678 +       .id_table = emc2305_ids,
 679 +       .address_list = emc2305_normal_i2c,
 680 +};
 681 +
 682 +module_i2c_driver(emc2305_driver);
 683 +
 684 +MODULE_AUTHOR("Nvidia");
 685 +MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver");
 686 +MODULE_LICENSE("GPL");