LXR linux/drivers/hwmon/tc654.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * tc654.c - Linux kernel modules for fan speed controller
   4 *
   5 * Copyright (C) 2016 Allied Telesis Labs NZ
   6 */
   7
   8#include <linux/bitops.h>
   9#include <linux/err.h>
  10#include <linux/hwmon.h>
  11#include <linux/hwmon-sysfs.h>
  12#include <linux/i2c.h>
  13#include <linux/init.h>
  14#include <linux/jiffies.h>
  15#include <linux/module.h>
  16#include <linux/mutex.h>
  17#include <linux/slab.h>
  18#include <linux/util_macros.h>
  19
  20enum tc654_regs {
  21        TC654_REG_RPM1 = 0x00,  /* RPM Output 1 */
  22        TC654_REG_RPM2 = 0x01,  /* RPM Output 2 */
  23        TC654_REG_FAN_FAULT1 = 0x02,    /* Fan Fault 1 Threshold */
  24        TC654_REG_FAN_FAULT2 = 0x03,    /* Fan Fault 2 Threshold */
  25        TC654_REG_CONFIG = 0x04,        /* Configuration */
  26        TC654_REG_STATUS = 0x05,        /* Status */
  27        TC654_REG_DUTY_CYCLE = 0x06,    /* Fan Speed Duty Cycle */
  28        TC654_REG_MFR_ID = 0x07,        /* Manufacturer Identification */
  29        TC654_REG_VER_ID = 0x08,        /* Version Identification */
  30};
  31
  32/* Macros to easily index the registers */
  33#define TC654_REG_RPM(idx)              (TC654_REG_RPM1 + (idx))
  34#define TC654_REG_FAN_FAULT(idx)        (TC654_REG_FAN_FAULT1 + (idx))
  35
  36/* Config register bits */
  37#define TC654_REG_CONFIG_RES            BIT(6)  /* Resolution Selection */
  38#define TC654_REG_CONFIG_DUTYC          BIT(5)  /* Duty Cycle Control */
  39#define TC654_REG_CONFIG_SDM            BIT(0)  /* Shutdown Mode */
  40
  41/* Status register bits */
  42#define TC654_REG_STATUS_F2F            BIT(1)  /* Fan 2 Fault */
  43#define TC654_REG_STATUS_F1F            BIT(0)  /* Fan 1 Fault */
  44
  45/* RPM resolution for RPM Output registers */
  46#define TC654_HIGH_RPM_RESOLUTION       25      /* 25 RPM resolution */
  47#define TC654_LOW_RPM_RESOLUTION        50      /* 50 RPM resolution */
  48
  49/* Convert to the fan fault RPM threshold from register value */
  50#define TC654_FAN_FAULT_FROM_REG(val)   ((val) * 50)    /* 50 RPM resolution */
  51
  52/* Convert to register value from the fan fault RPM threshold */
  53#define TC654_FAN_FAULT_TO_REG(val)     (((val) / 50) & 0xff)
  54
  55/* Register data is read (and cached) at most once per second. */
  56#define TC654_UPDATE_INTERVAL           HZ
  57
  58struct tc654_data {
  59        struct i2c_client *client;
  60
  61        /* update mutex */
  62        struct mutex update_lock;
  63
  64        /* tc654 register cache */
  65        bool valid;
  66        unsigned long last_updated;     /* in jiffies */
  67
  68        u8 rpm_output[2];       /* The fan RPM data for fans 1 and 2 is then
  69                                 * written to registers RPM1 and RPM2
  70                                 */
  71        u8 fan_fault[2];        /* The Fan Fault Threshold Registers are used to
  72                                 * set the fan fault threshold levels for fan 1
  73                                 * and fan 2
  74                                 */
  75        u8 config;      /* The Configuration Register is an 8-bit read/
  76                         * writable multi-function control register
  77                         *   7: Fan Fault Clear
  78                         *      1 = Clear Fan Fault
  79                         *      0 = Normal Operation (default)
  80                         *   6: Resolution Selection for RPM Output Registers
  81                         *      RPM Output Registers (RPM1 and RPM2) will be
  82                         *      set for
  83                         *      1 = 25 RPM (9-bit) resolution
  84                         *      0 = 50 RPM (8-bit) resolution (default)
  85                         *   5: Duty Cycle Control Method
  86                         *      The V OUT duty cycle will be controlled via
  87                         *      1 = the SMBus interface.
  88                         *      0 = via the V IN analog input pin. (default)
  89                         * 4,3: Fan 2 Pulses Per Rotation
  90                         *      00 = 1
  91                         *      01 = 2 (default)
  92                         *      10 = 4
  93                         *      11 = 8
  94                         * 2,1: Fan 1 Pulses Per Rotation
  95                         *      00 = 1
  96                         *      01 = 2 (default)
  97                         *      10 = 4
  98                         *      11 = 8
  99                         *   0: Shutdown Mode
 100                         *      1 = Shutdown mode.
 101                         *      0 = Normal operation. (default)
 102                         */
 103        u8 status;      /* The Status register provides all the information
 104                         * about what is going on within the TC654/TC655
 105                         * devices.
 106                         * 7,6: Unimplemented, Read as '0'
 107                         *   5: Over-Temperature Fault Condition
 108                         *      1 = Over-Temperature condition has occurred
 109                         *      0 = Normal operation. V IN is less than 2.6V
 110                         *   4: RPM2 Counter Overflow
 111                         *      1 = Fault condition
 112                         *      0 = Normal operation
 113                         *   3: RPM1 Counter Overflow
 114                         *      1 = Fault condition
 115                         *      0 = Normal operation
 116                         *   2: V IN Input Status
 117                         *      1 = V IN is open
 118                         *      0 = Normal operation. voltage present at V IN
 119                         *   1: Fan 2 Fault
 120                         *      1 = Fault condition
 121                         *      0 = Normal operation
 122                         *   0: Fan 1 Fault
 123                         *      1 = Fault condition
 124                         *      0 = Normal operation
 125                         */
 126        u8 duty_cycle;  /* The DUTY_CYCLE register is a 4-bit read/
 127                         * writable register used to control the duty
 128                         * cycle of the V OUT output.
 129                         */
 130};
 131
 132/* helper to grab and cache data, at most one time per second */
 133static struct tc654_data *tc654_update_client(struct device *dev)
 134{
 135        struct tc654_data *data = dev_get_drvdata(dev);
 136        struct i2c_client *client = data->client;
 137        int ret = 0;
 138
 139        mutex_lock(&data->update_lock);
 140        if (time_before(jiffies, data->last_updated + TC654_UPDATE_INTERVAL) &&
 141            likely(data->valid))
 142                goto out;
 143
 144        ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(0));
 145        if (ret < 0)
 146                goto out;
 147        data->rpm_output[0] = ret;
 148
 149        ret = i2c_smbus_read_byte_data(client, TC654_REG_RPM(1));
 150        if (ret < 0)
 151                goto out;
 152        data->rpm_output[1] = ret;
 153
 154        ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(0));
 155        if (ret < 0)
 156                goto out;
 157        data->fan_fault[0] = ret;
 158
 159        ret = i2c_smbus_read_byte_data(client, TC654_REG_FAN_FAULT(1));
 160        if (ret < 0)
 161                goto out;
 162        data->fan_fault[1] = ret;
 163
 164        ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG);
 165        if (ret < 0)
 166                goto out;
 167        data->config = ret;
 168
 169        ret = i2c_smbus_read_byte_data(client, TC654_REG_STATUS);
 170        if (ret < 0)
 171                goto out;
 172        data->status = ret;
 173
 174        ret = i2c_smbus_read_byte_data(client, TC654_REG_DUTY_CYCLE);
 175        if (ret < 0)
 176                goto out;
 177        data->duty_cycle = ret & 0x0f;
 178
 179        data->last_updated = jiffies;
 180        data->valid = true;
 181out:
 182        mutex_unlock(&data->update_lock);
 183
 184        if (ret < 0)            /* upon error, encode it in return value */
 185                data = ERR_PTR(ret);
 186
 187        return data;
 188}
 189
 190/*
 191 * sysfs attributes
 192 */
 193
 194static ssize_t fan_show(struct device *dev, struct device_attribute *da,
 195                        char *buf)
 196{
 197        int nr = to_sensor_dev_attr(da)->index;
 198        struct tc654_data *data = tc654_update_client(dev);
 199        int val;
 200
 201        if (IS_ERR(data))
 202                return PTR_ERR(data);
 203
 204        if (data->config & TC654_REG_CONFIG_RES)
 205                val = data->rpm_output[nr] * TC654_HIGH_RPM_RESOLUTION;
 206        else
 207                val = data->rpm_output[nr] * TC654_LOW_RPM_RESOLUTION;
 208
 209        return sprintf(buf, "%d\n", val);
 210}
 211
 212static ssize_t fan_min_show(struct device *dev, struct device_attribute *da,
 213                            char *buf)
 214{
 215        int nr = to_sensor_dev_attr(da)->index;
 216        struct tc654_data *data = tc654_update_client(dev);
 217
 218        if (IS_ERR(data))
 219                return PTR_ERR(data);
 220
 221        return sprintf(buf, "%d\n",
 222                       TC654_FAN_FAULT_FROM_REG(data->fan_fault[nr]));
 223}
 224
 225static ssize_t fan_min_store(struct device *dev, struct device_attribute *da,
 226                             const char *buf, size_t count)
 227{
 228        int nr = to_sensor_dev_attr(da)->index;
 229        struct tc654_data *data = dev_get_drvdata(dev);
 230        struct i2c_client *client = data->client;
 231        unsigned long val;
 232        int ret;
 233
 234        if (kstrtoul(buf, 10, &val))
 235                return -EINVAL;
 236
 237        val = clamp_val(val, 0, 12750);
 238
 239        mutex_lock(&data->update_lock);
 240
 241        data->fan_fault[nr] = TC654_FAN_FAULT_TO_REG(val);
 242        ret = i2c_smbus_write_byte_data(client, TC654_REG_FAN_FAULT(nr),
 243                                        data->fan_fault[nr]);
 244
 245        mutex_unlock(&data->update_lock);
 246        return ret < 0 ? ret : count;
 247}
 248
 249static ssize_t fan_alarm_show(struct device *dev, struct device_attribute *da,
 250                              char *buf)
 251{
 252        int nr = to_sensor_dev_attr(da)->index;
 253        struct tc654_data *data = tc654_update_client(dev);
 254        int val;
 255
 256        if (IS_ERR(data))
 257                return PTR_ERR(data);
 258
 259        if (nr == 0)
 260                val = !!(data->status & TC654_REG_STATUS_F1F);
 261        else
 262                val = !!(data->status & TC654_REG_STATUS_F2F);
 263
 264        return sprintf(buf, "%d\n", val);
 265}
 266
 267static const u8 TC654_FAN_PULSE_SHIFT[] = { 1, 3 };
 268
 269static ssize_t fan_pulses_show(struct device *dev,
 270                               struct device_attribute *da, char *buf)
 271{
 272        int nr = to_sensor_dev_attr(da)->index;
 273        struct tc654_data *data = tc654_update_client(dev);
 274        u8 val;
 275
 276        if (IS_ERR(data))
 277                return PTR_ERR(data);
 278
 279        val = BIT((data->config >> TC654_FAN_PULSE_SHIFT[nr]) & 0x03);
 280        return sprintf(buf, "%d\n", val);
 281}
 282
 283static ssize_t fan_pulses_store(struct device *dev,
 284                                struct device_attribute *da, const char *buf,
 285                                size_t count)
 286{
 287        int nr = to_sensor_dev_attr(da)->index;
 288        struct tc654_data *data = dev_get_drvdata(dev);
 289        struct i2c_client *client = data->client;
 290        u8 config;
 291        unsigned long val;
 292        int ret;
 293
 294        if (kstrtoul(buf, 10, &val))
 295                return -EINVAL;
 296
 297        switch (val) {
 298        case 1:
 299                config = 0;
 300                break;
 301        case 2:
 302                config = 1;
 303                break;
 304        case 4:
 305                config = 2;
 306                break;
 307        case 8:
 308                config = 3;
 309                break;
 310        default:
 311                return -EINVAL;
 312        }
 313
 314        mutex_lock(&data->update_lock);
 315
 316        data->config &= ~(0x03 << TC654_FAN_PULSE_SHIFT[nr]);
 317        data->config |= (config << TC654_FAN_PULSE_SHIFT[nr]);
 318        ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
 319
 320        mutex_unlock(&data->update_lock);
 321        return ret < 0 ? ret : count;
 322}
 323
 324static ssize_t pwm_mode_show(struct device *dev, struct device_attribute *da,
 325                             char *buf)
 326{
 327        struct tc654_data *data = tc654_update_client(dev);
 328
 329        if (IS_ERR(data))
 330                return PTR_ERR(data);
 331
 332        return sprintf(buf, "%d\n", !!(data->config & TC654_REG_CONFIG_DUTYC));
 333}
 334
 335static ssize_t pwm_mode_store(struct device *dev, struct device_attribute *da,
 336                              const char *buf, size_t count)
 337{
 338        struct tc654_data *data = dev_get_drvdata(dev);
 339        struct i2c_client *client = data->client;
 340        unsigned long val;
 341        int ret;
 342
 343        if (kstrtoul(buf, 10, &val))
 344                return -EINVAL;
 345
 346        if (val != 0 && val != 1)
 347                return -EINVAL;
 348
 349        mutex_lock(&data->update_lock);
 350
 351        if (val)
 352                data->config |= TC654_REG_CONFIG_DUTYC;
 353        else
 354                data->config &= ~TC654_REG_CONFIG_DUTYC;
 355
 356        ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
 357
 358        mutex_unlock(&data->update_lock);
 359        return ret < 0 ? ret : count;
 360}
 361
 362static const int tc654_pwm_map[16] = { 77,  88, 102, 112, 124, 136, 148, 160,
 363                                      172, 184, 196, 207, 219, 231, 243, 255};
 364
 365static ssize_t pwm_show(struct device *dev, struct device_attribute *da,
 366                        char *buf)
 367{
 368        struct tc654_data *data = tc654_update_client(dev);
 369        int pwm;
 370
 371        if (IS_ERR(data))
 372                return PTR_ERR(data);
 373
 374        if (data->config & TC654_REG_CONFIG_SDM)
 375                pwm = 0;
 376        else
 377                pwm = tc654_pwm_map[data->duty_cycle];
 378
 379        return sprintf(buf, "%d\n", pwm);
 380}
 381
 382static ssize_t pwm_store(struct device *dev, struct device_attribute *da,
 383                         const char *buf, size_t count)
 384{
 385        struct tc654_data *data = dev_get_drvdata(dev);
 386        struct i2c_client *client = data->client;
 387        unsigned long val;
 388        int ret;
 389
 390        if (kstrtoul(buf, 10, &val))
 391                return -EINVAL;
 392        if (val > 255)
 393                return -EINVAL;
 394
 395        mutex_lock(&data->update_lock);
 396
 397        if (val == 0)
 398                data->config |= TC654_REG_CONFIG_SDM;
 399        else
 400                data->config &= ~TC654_REG_CONFIG_SDM;
 401
 402        data->duty_cycle = find_closest(val, tc654_pwm_map,
 403                                        ARRAY_SIZE(tc654_pwm_map));
 404
 405        ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);
 406        if (ret < 0)
 407                goto out;
 408
 409        ret = i2c_smbus_write_byte_data(client, TC654_REG_DUTY_CYCLE,
 410                                        data->duty_cycle);
 411
 412out:
 413        mutex_unlock(&data->update_lock);
 414        return ret < 0 ? ret : count;
 415}
 416
 417static SENSOR_DEVICE_ATTR_RO(fan1_input, fan, 0);
 418static SENSOR_DEVICE_ATTR_RO(fan2_input, fan, 1);
 419static SENSOR_DEVICE_ATTR_RW(fan1_min, fan_min, 0);
 420static SENSOR_DEVICE_ATTR_RW(fan2_min, fan_min, 1);
 421static SENSOR_DEVICE_ATTR_RO(fan1_alarm, fan_alarm, 0);
 422static SENSOR_DEVICE_ATTR_RO(fan2_alarm, fan_alarm, 1);
 423static SENSOR_DEVICE_ATTR_RW(fan1_pulses, fan_pulses, 0);
 424static SENSOR_DEVICE_ATTR_RW(fan2_pulses, fan_pulses, 1);
 425static SENSOR_DEVICE_ATTR_RW(pwm1_mode, pwm_mode, 0);
 426static SENSOR_DEVICE_ATTR_RW(pwm1, pwm, 0);
 427
 428/* Driver data */
 429static struct attribute *tc654_attrs[] = {
 430        &sensor_dev_attr_fan1_input.dev_attr.attr,
 431        &sensor_dev_attr_fan2_input.dev_attr.attr,
 432        &sensor_dev_attr_fan1_min.dev_attr.attr,
 433        &sensor_dev_attr_fan2_min.dev_attr.attr,
 434        &sensor_dev_attr_fan1_alarm.dev_attr.attr,
 435        &sensor_dev_attr_fan2_alarm.dev_attr.attr,
 436        &sensor_dev_attr_fan1_pulses.dev_attr.attr,
 437        &sensor_dev_attr_fan2_pulses.dev_attr.attr,
 438        &sensor_dev_attr_pwm1_mode.dev_attr.attr,
 439        &sensor_dev_attr_pwm1.dev_attr.attr,
 440        NULL
 441};
 442
 443ATTRIBUTE_GROUPS(tc654);
 444
 445/*
 446 * device probe and removal
 447 */
 448
 449static int tc654_probe(struct i2c_client *client)
 450{
 451        struct device *dev = &client->dev;
 452        struct tc654_data *data;
 453        struct device *hwmon_dev;
 454        int ret;
 455
 456        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 457                return -ENODEV;
 458
 459        data = devm_kzalloc(dev, sizeof(struct tc654_data), GFP_KERNEL);
 460        if (!data)
 461                return -ENOMEM;
 462
 463        data->client = client;
 464        mutex_init(&data->update_lock);
 465
 466        ret = i2c_smbus_read_byte_data(client, TC654_REG_CONFIG);
 467        if (ret < 0)
 468                return ret;
 469
 470        data->config = ret;
 471
 472        hwmon_dev =
 473            devm_hwmon_device_register_with_groups(dev, client->name, data,
 474                                                   tc654_groups);
 475        return PTR_ERR_OR_ZERO(hwmon_dev);
 476}
 477
 478static const struct i2c_device_id tc654_id[] = {
 479        {"tc654", 0},
 480        {"tc655", 0},
 481        {}
 482};
 483
 484MODULE_DEVICE_TABLE(i2c, tc654_id);
 485
 486static struct i2c_driver tc654_driver = {
 487        .driver = {
 488                   .name = "tc654",
 489                   },
 490        .probe_new = tc654_probe,
 491        .id_table = tc654_id,
 492};
 493
 494module_i2c_driver(tc654_driver);
 495
 496MODULE_AUTHOR("Allied Telesis Labs");
 497MODULE_DESCRIPTION("Microchip TC654/TC655 driver");
 498MODULE_LICENSE("GPL");
 499