drivers/hwmon/max1619.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
   4  *             monitoring
   5  * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
   6  *                         Jean Delvare <jdelvare@suse.de>
   7  *
   8  * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
   9  * It reports up to two temperatures (its own plus up to
  10  * one external one). Complete datasheet can be
  11  * obtained from Maxim's website at:
  12  *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
  13  */
  14
  15 #include <linux/err.h>
  16 #include <linux/hwmon.h>
  17 #include <linux/i2c.h>
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/regmap.h>
  21 #include <linux/util_macros.h>
  22
  23 static const unsigned short normal_i2c[] = {
  24         0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  25
  26 #define MAX1619_REG_LOCAL_TEMP          0x00
  27 #define MAX1619_REG_REMOTE_TEMP         0x01
  28 #define MAX1619_REG_STATUS              0x02
  29 #define MAX1619_REG_CONFIG              0x03
  30 #define MAX1619_REG_CONVRATE            0x04
  31 #define MAX1619_REG_REMOTE_HIGH         0x07
  32 #define MAX1619_REG_REMOTE_LOW          0x08
  33 #define MAX1619_REG_REMOTE_CRIT         0x10
  34 #define MAX1619_REG_REMOTE_CRIT_HYST    0x11
  35 #define MAX1619_REG_MAN_ID              0xFE
  36 #define MAX1619_REG_CHIP_ID             0xFF
  37
  38 static int get_alarms(struct regmap *regmap)
  39 {
  40         static u32 regs[2] = { MAX1619_REG_STATUS, MAX1619_REG_CONFIG };
  41         u8 regdata[2];
  42         int ret;
  43
  44         ret = regmap_multi_reg_read(regmap, regs, regdata, 2);
  45         if (ret)
  46                 return ret;
  47
  48         /* OVERT status bit may be reversed */
  49         if (!(regdata[1] & 0x20))
  50                 regdata[0] ^= 0x02;
  51
  52         return regdata[0] & 0x1e;
  53 }
  54
  55 static int max1619_temp_read(struct regmap *regmap, u32 attr, int channel, long *val)
  56 {
  57         int reg = -1, alarm_bit = 0;
  58         u32 temp;
  59         int ret;
  60
  61         switch (attr) {
  62         case hwmon_temp_input:
  63                 reg = channel ? MAX1619_REG_REMOTE_TEMP : MAX1619_REG_LOCAL_TEMP;
  64                 break;
  65         case hwmon_temp_min:
  66                 reg = MAX1619_REG_REMOTE_LOW;
  67                 break;
  68         case hwmon_temp_max:
  69                 reg = MAX1619_REG_REMOTE_HIGH;
  70                 break;
  71         case hwmon_temp_crit:
  72                 reg = MAX1619_REG_REMOTE_CRIT;
  73                 break;
  74         case hwmon_temp_crit_hyst:
  75                 reg = MAX1619_REG_REMOTE_CRIT_HYST;
  76                 break;
  77         case hwmon_temp_min_alarm:
  78                 alarm_bit = 3;
  79                 break;
  80         case hwmon_temp_max_alarm:
  81                 alarm_bit = 4;
  82                 break;
  83         case hwmon_temp_crit_alarm:
  84                 alarm_bit = 1;
  85                 break;
  86         case hwmon_temp_fault:
  87                 alarm_bit = 2;
  88                 break;
  89         default:
  90                 return -EOPNOTSUPP;
  91         }
  92         if (reg >= 0) {
  93                 ret = regmap_read(regmap, reg, &temp);
  94                 if (ret < 0)
  95                         return ret;
  96                 *val = sign_extend32(temp, 7) * 1000;
  97         } else {
  98                 ret = get_alarms(regmap);
  99                 if (ret < 0)
 100                         return ret;
 101                 *val = !!(ret & BIT(alarm_bit));
 102         }
 103         return 0;
 104 }
 105
 106 static u16 update_intervals[] = { 16000, 8000, 4000, 2000, 1000, 500, 250, 125 };
 107
 108 static int max1619_chip_read(struct regmap *regmap, u32 attr, long *val)
 109 {
 110         int alarms, ret;
 111         u32 regval;
 112
 113         switch (attr) {
 114         case hwmon_chip_update_interval:
 115                 ret = regmap_read(regmap, MAX1619_REG_CONVRATE, &regval);
 116                 if (ret < 0)
 117                         return ret;
 118                 *val = update_intervals[regval & 7];
 119                 break;
 120         case hwmon_chip_alarms:
 121                 alarms = get_alarms(regmap);
 122                 if (alarms < 0)
 123                         return alarms;
 124                 *val = alarms;
 125                 break;
 126         default:
 127                 return -EOPNOTSUPP;
 128         }
 129         return 0;
 130 }
 131
 132 static int max1619_read(struct device *dev, enum hwmon_sensor_types type,
 133                         u32 attr, int channel, long *val)
 134 {
 135         struct regmap *regmap = dev_get_drvdata(dev);
 136
 137         switch (type) {
 138         case hwmon_chip:
 139                 return max1619_chip_read(regmap, attr, val);
 140         case hwmon_temp:
 141                 return max1619_temp_read(regmap, attr, channel, val);
 142         default:
 143                 return -EOPNOTSUPP;
 144         }
 145 }
 146
 147 static int max1619_chip_write(struct regmap *regmap, u32 attr, long val)
 148 {
 149         switch (attr) {
 150         case hwmon_chip_update_interval:
 151                 val = find_closest_descending(val, update_intervals, ARRAY_SIZE(update_intervals));
 152                 return regmap_write(regmap, MAX1619_REG_CONVRATE, val);
 153         default:
 154                 return -EOPNOTSUPP;
 155         }
 156 }
 157
 158 static int max1619_temp_write(struct regmap *regmap,
 159                               u32 attr, int channel, long val)
 160 {
 161         int reg;
 162
 163         switch (attr) {
 164         case hwmon_temp_min:
 165                 reg = MAX1619_REG_REMOTE_LOW;
 166                 break;
 167         case hwmon_temp_max:
 168                 reg = MAX1619_REG_REMOTE_HIGH;
 169                 break;
 170         case hwmon_temp_crit:
 171                 reg = MAX1619_REG_REMOTE_CRIT;
 172                 break;
 173         case hwmon_temp_crit_hyst:
 174                 reg = MAX1619_REG_REMOTE_CRIT_HYST;
 175                 break;
 176         default:
 177                 return -EOPNOTSUPP;
 178         }
 179         val = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
 180         return regmap_write(regmap, reg, val);
 181 }
 182
 183 static int max1619_write(struct device *dev, enum hwmon_sensor_types type,
 184                          u32 attr, int channel, long val)
 185 {
 186         struct regmap *regmap = dev_get_drvdata(dev);
 187
 188         switch (type) {
 189         case hwmon_chip:
 190                 return max1619_chip_write(regmap, attr, val);
 191         case hwmon_temp:
 192                 return max1619_temp_write(regmap, attr, channel, val);
 193         default:
 194                 return -EOPNOTSUPP;
 195         }
 196 }
 197
 198 static umode_t max1619_is_visible(const void *_data, enum hwmon_sensor_types type,
 199                                   u32 attr, int channel)
 200 {
 201         switch (type) {
 202         case hwmon_chip:
 203                 switch (attr) {
 204                 case hwmon_chip_update_interval:
 205                         return 0644;
 206                 case hwmon_chip_alarms:
 207                         return 0444;
 208                 default:
 209                         break;
 210                 }
 211                 break;
 212         case hwmon_temp:
 213                 switch (attr) {
 214                 case hwmon_temp_input:
 215                         return 0444;
 216                 case hwmon_temp_min:
 217                 case hwmon_temp_max:
 218                 case hwmon_temp_crit:
 219                 case hwmon_temp_crit_hyst:
 220                         return 0644;
 221                 case hwmon_temp_min_alarm:
 222                 case hwmon_temp_max_alarm:
 223                 case hwmon_temp_crit_alarm:
 224                 case hwmon_temp_fault:
 225                         return 0444;
 226                 default:
 227                         break;
 228                 }
 229                 break;
 230         default:
 231                 break;
 232         }
 233         return 0;
 234 }
 235
 236 static const struct hwmon_channel_info * const max1619_info[] = {
 237         HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS | HWMON_C_UPDATE_INTERVAL),
 238         HWMON_CHANNEL_INFO(temp,
 239                            HWMON_T_INPUT,
 240                            HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
 241                            HWMON_T_CRIT | HWMON_T_CRIT_HYST |
 242                            HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
 243                            HWMON_T_CRIT_ALARM | HWMON_T_FAULT),
 244         NULL
 245 };
 246
 247 static const struct hwmon_ops max1619_hwmon_ops = {
 248         .is_visible = max1619_is_visible,
 249         .read = max1619_read,
 250         .write = max1619_write,
 251 };
 252
 253 static const struct hwmon_chip_info max1619_chip_info = {
 254         .ops = &max1619_hwmon_ops,
 255         .info = max1619_info,
 256 };
 257
 258 /* Return 0 if detection is successful, -ENODEV otherwise */
 259 static int max1619_detect(struct i2c_client *client,
 260                           struct i2c_board_info *info)
 261 {
 262         struct i2c_adapter *adapter = client->adapter;
 263         int regval;
 264
 265         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 266                 return -ENODEV;
 267
 268         regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONFIG);
 269         if (regval < 0 || (regval & 0x03))
 270                 return -ENODEV;
 271         regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CONVRATE);
 272         if (regval < 0 || regval > 0x07)
 273                 return -ENODEV;
 274         regval = i2c_smbus_read_byte_data(client, MAX1619_REG_STATUS);
 275         if (regval < 0 || (regval & 0x61))
 276                 return -ENODEV;
 277
 278         regval = i2c_smbus_read_byte_data(client, MAX1619_REG_MAN_ID);
 279         if (regval != 0x4d)
 280                 return -ENODEV;
 281         regval = i2c_smbus_read_byte_data(client, MAX1619_REG_CHIP_ID);
 282         if (regval != 0x04)
 283                 return -ENODEV;
 284
 285         strscpy(info->type, "max1619", I2C_NAME_SIZE);
 286
 287         return 0;
 288 }
 289
 290 static int max1619_init_chip(struct regmap *regmap)
 291 {
 292         int ret;
 293
 294         ret = regmap_write(regmap, MAX1619_REG_CONVRATE, 5);    /* 2 Hz */
 295         if (ret)
 296                 return ret;
 297
 298         /* Start conversions */
 299         return regmap_clear_bits(regmap, MAX1619_REG_CONFIG, 0x40);
 300 }
 301
 302 /* regmap */
 303
 304 static int max1619_reg_read(void *context, unsigned int reg, unsigned int *val)
 305 {
 306         int ret;
 307
 308         ret = i2c_smbus_read_byte_data(context, reg);
 309         if (ret < 0)
 310                 return ret;
 311
 312         *val = ret;
 313         return 0;
 314 }
 315
 316 static int max1619_reg_write(void *context, unsigned int reg, unsigned int val)
 317 {
 318         int offset = reg < MAX1619_REG_REMOTE_CRIT ? 6 : 2;
 319
 320         return i2c_smbus_write_byte_data(context, reg + offset, val);
 321 }
 322
 323 static bool max1619_regmap_is_volatile(struct device *dev, unsigned int reg)
 324 {
 325         return reg <= MAX1619_REG_STATUS;
 326 }
 327
 328 static bool max1619_regmap_is_writeable(struct device *dev, unsigned int reg)
 329 {
 330         return reg > MAX1619_REG_STATUS && reg <= MAX1619_REG_REMOTE_CRIT_HYST;
 331 }
 332
 333 static const struct regmap_config max1619_regmap_config = {
 334         .reg_bits = 8,
 335         .val_bits = 8,
 336         .max_register = MAX1619_REG_REMOTE_CRIT_HYST,
 337         .cache_type = REGCACHE_MAPLE,
 338         .volatile_reg = max1619_regmap_is_volatile,
 339         .writeable_reg = max1619_regmap_is_writeable,
 340 };
 341
 342 static const struct regmap_bus max1619_regmap_bus = {
 343         .reg_write = max1619_reg_write,
 344         .reg_read = max1619_reg_read,
 345 };
 346
 347 static int max1619_probe(struct i2c_client *client)
 348 {
 349         struct device *dev = &client->dev;
 350         struct device *hwmon_dev;
 351         struct regmap *regmap;
 352         int ret;
 353
 354         regmap = devm_regmap_init(dev, &max1619_regmap_bus, client,
 355                                   &max1619_regmap_config);
 356         if (IS_ERR(regmap))
 357                 return PTR_ERR(regmap);
 358
 359         ret = max1619_init_chip(regmap);
 360         if (ret)
 361                 return ret;
 362
 363         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 364                                                          regmap, &max1619_chip_info, NULL);
 365         return PTR_ERR_OR_ZERO(hwmon_dev);
 366 }
 367
 368 static const struct i2c_device_id max1619_id[] = {
 369         { "max1619" },
 370         { }
 371 };
 372 MODULE_DEVICE_TABLE(i2c, max1619_id);
 373
 374 #ifdef CONFIG_OF
 375 static const struct of_device_id max1619_of_match[] = {
 376         { .compatible = "maxim,max1619", },
 377         {},
 378 };
 379
 380 MODULE_DEVICE_TABLE(of, max1619_of_match);
 381 #endif
 382
 383 static struct i2c_driver max1619_driver = {
 384         .class          = I2C_CLASS_HWMON,
 385         .driver = {
 386                 .name   = "max1619",
 387                 .of_match_table = of_match_ptr(max1619_of_match),
 388         },
 389         .probe          = max1619_probe,
 390         .id_table       = max1619_id,
 391         .detect         = max1619_detect,
 392         .address_list   = normal_i2c,
 393 };
 394
 395 module_i2c_driver(max1619_driver);
 396
 397 MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
 398 MODULE_DESCRIPTION("MAX1619 sensor driver");
 399 MODULE_LICENSE("GPL");