drivers/hwmon/lm83.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
   4  *          monitoring
   5  * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
   6  *
   7  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
   8  * a sensor chip made by National Semiconductor. It reports up to four
   9  * temperatures (its own plus up to three external ones) with a 1 deg
  10  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
  11  * from National's website at:
  12  *   http://www.national.com/pf/LM/LM83.html
  13  * Since the datasheet omits to give the chip stepping code, I give it
  14  * here: 0x03 (at register 0xff).
  15  *
  16  * Also supports the LM82 temp sensor, which is basically a stripped down
  17  * model of the LM83.  Datasheet is here:
  18  * http://www.national.com/pf/LM/LM82.html
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/i2c.h>
  26 #include <linux/hwmon-sysfs.h>
  27 #include <linux/hwmon.h>
  28 #include <linux/err.h>
  29 #include <linux/mutex.h>
  30 #include <linux/sysfs.h>
  31
  32 /*
  33  * Addresses to scan
  34  * Address is selected using 2 three-level pins, resulting in 9 possible
  35  * addresses.
  36  */
  37
  38 static const unsigned short normal_i2c[] = {
  39         0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  40
  41 enum chips { lm83, lm82 };
  42
  43 /*
  44  * The LM83 registers
  45  * Manufacturer ID is 0x01 for National Semiconductor.
  46  */
  47
  48 #define LM83_REG_R_MAN_ID               0xFE
  49 #define LM83_REG_R_CHIP_ID              0xFF
  50 #define LM83_REG_R_CONFIG               0x03
  51 #define LM83_REG_W_CONFIG               0x09
  52 #define LM83_REG_R_STATUS1              0x02
  53 #define LM83_REG_R_STATUS2              0x35
  54 #define LM83_REG_R_LOCAL_TEMP           0x00
  55 #define LM83_REG_R_LOCAL_HIGH           0x05
  56 #define LM83_REG_W_LOCAL_HIGH           0x0B
  57 #define LM83_REG_R_REMOTE1_TEMP         0x30
  58 #define LM83_REG_R_REMOTE1_HIGH         0x38
  59 #define LM83_REG_W_REMOTE1_HIGH         0x50
  60 #define LM83_REG_R_REMOTE2_TEMP         0x01
  61 #define LM83_REG_R_REMOTE2_HIGH         0x07
  62 #define LM83_REG_W_REMOTE2_HIGH         0x0D
  63 #define LM83_REG_R_REMOTE3_TEMP         0x31
  64 #define LM83_REG_R_REMOTE3_HIGH         0x3A
  65 #define LM83_REG_W_REMOTE3_HIGH         0x52
  66 #define LM83_REG_R_TCRIT                0x42
  67 #define LM83_REG_W_TCRIT                0x5A
  68
  69 /*
  70  * Conversions and various macros
  71  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
  72  */
  73
  74 #define TEMP_FROM_REG(val)      ((val) * 1000)
  75 #define TEMP_TO_REG(val)        ((val) <= -128000 ? -128 : \
  76                                  (val) >= 127000 ? 127 : \
  77                                  (val) < 0 ? ((val) - 500) / 1000 : \
  78                                  ((val) + 500) / 1000)
  79
  80 static const u8 LM83_REG_R_TEMP[] = {
  81         LM83_REG_R_LOCAL_TEMP,
  82         LM83_REG_R_REMOTE1_TEMP,
  83         LM83_REG_R_REMOTE2_TEMP,
  84         LM83_REG_R_REMOTE3_TEMP,
  85         LM83_REG_R_LOCAL_HIGH,
  86         LM83_REG_R_REMOTE1_HIGH,
  87         LM83_REG_R_REMOTE2_HIGH,
  88         LM83_REG_R_REMOTE3_HIGH,
  89         LM83_REG_R_TCRIT,
  90 };
  91
  92 static const u8 LM83_REG_W_HIGH[] = {
  93         LM83_REG_W_LOCAL_HIGH,
  94         LM83_REG_W_REMOTE1_HIGH,
  95         LM83_REG_W_REMOTE2_HIGH,
  96         LM83_REG_W_REMOTE3_HIGH,
  97         LM83_REG_W_TCRIT,
  98 };
  99
 100 /*
 101  * Client data (each client gets its own)
 102  */
 103
 104 struct lm83_data {
 105         struct i2c_client *client;
 106         const struct attribute_group *groups[3];
 107         struct mutex update_lock;
 108         char valid; /* zero until following fields are valid */
 109         unsigned long last_updated; /* in jiffies */
 110
 111         /* registers values */
 112         s8 temp[9];     /* 0..3: input 1-4,
 113                            4..7: high limit 1-4,
 114                            8   : critical limit */
 115         u16 alarms; /* bitvector, combined */
 116 };
 117
 118 static struct lm83_data *lm83_update_device(struct device *dev)
 119 {
 120         struct lm83_data *data = dev_get_drvdata(dev);
 121         struct i2c_client *client = data->client;
 122
 123         mutex_lock(&data->update_lock);
 124
 125         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 126                 int nr;
 127
 128                 dev_dbg(&client->dev, "Updating lm83 data.\n");
 129                 for (nr = 0; nr < 9; nr++) {
 130                         data->temp[nr] =
 131                             i2c_smbus_read_byte_data(client,
 132                             LM83_REG_R_TEMP[nr]);
 133                 }
 134                 data->alarms =
 135                     i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
 136                     + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
 137                     << 8);
 138
 139                 data->last_updated = jiffies;
 140                 data->valid = 1;
 141         }
 142
 143         mutex_unlock(&data->update_lock);
 144
 145         return data;
 146 }
 147
 148 /*
 149  * Sysfs stuff
 150  */
 151
 152 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
 153                          char *buf)
 154 {
 155         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 156         struct lm83_data *data = lm83_update_device(dev);
 157         return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
 158 }
 159
 160 static ssize_t temp_store(struct device *dev,
 161                           struct device_attribute *devattr, const char *buf,
 162                           size_t count)
 163 {
 164         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 165         struct lm83_data *data = dev_get_drvdata(dev);
 166         struct i2c_client *client = data->client;
 167         long val;
 168         int nr = attr->index;
 169         int err;
 170
 171         err = kstrtol(buf, 10, &val);
 172         if (err < 0)
 173                 return err;
 174
 175         mutex_lock(&data->update_lock);
 176         data->temp[nr] = TEMP_TO_REG(val);
 177         i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
 178                                   data->temp[nr]);
 179         mutex_unlock(&data->update_lock);
 180         return count;
 181 }
 182
 183 static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
 184                            char *buf)
 185 {
 186         struct lm83_data *data = lm83_update_device(dev);
 187         return sprintf(buf, "%d\n", data->alarms);
 188 }
 189
 190 static ssize_t alarm_show(struct device *dev,
 191                           struct device_attribute *devattr, char *buf)
 192 {
 193         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 194         struct lm83_data *data = lm83_update_device(dev);
 195         int bitnr = attr->index;
 196
 197         return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 198 }
 199
 200 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
 201 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
 202 static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
 203 static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 3);
 204 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 4);
 205 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 5);
 206 static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 6);
 207 static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 7);
 208 static SENSOR_DEVICE_ATTR_RO(temp1_crit, temp, 8);
 209 static SENSOR_DEVICE_ATTR_RO(temp2_crit, temp, 8);
 210 static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 8);
 211 static SENSOR_DEVICE_ATTR_RO(temp4_crit, temp, 8);
 212
 213 /* Individual alarm files */
 214 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 0);
 215 static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 1);
 216 static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 2);
 217 static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 4);
 218 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
 219 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 8);
 220 static SENSOR_DEVICE_ATTR_RO(temp4_crit_alarm, alarm, 9);
 221 static SENSOR_DEVICE_ATTR_RO(temp4_fault, alarm, 10);
 222 static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, alarm, 12);
 223 static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 13);
 224 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 15);
 225 /* Raw alarm file for compatibility */
 226 static DEVICE_ATTR_RO(alarms);
 227
 228 static struct attribute *lm83_attributes[] = {
 229         &sensor_dev_attr_temp1_input.dev_attr.attr,
 230         &sensor_dev_attr_temp3_input.dev_attr.attr,
 231         &sensor_dev_attr_temp1_max.dev_attr.attr,
 232         &sensor_dev_attr_temp3_max.dev_attr.attr,
 233         &sensor_dev_attr_temp1_crit.dev_attr.attr,
 234         &sensor_dev_attr_temp3_crit.dev_attr.attr,
 235
 236         &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
 237         &sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
 238         &sensor_dev_attr_temp3_fault.dev_attr.attr,
 239         &sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
 240         &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
 241         &dev_attr_alarms.attr,
 242         NULL
 243 };
 244
 245 static const struct attribute_group lm83_group = {
 246         .attrs = lm83_attributes,
 247 };
 248
 249 static struct attribute *lm83_attributes_opt[] = {
 250         &sensor_dev_attr_temp2_input.dev_attr.attr,
 251         &sensor_dev_attr_temp4_input.dev_attr.attr,
 252         &sensor_dev_attr_temp2_max.dev_attr.attr,
 253         &sensor_dev_attr_temp4_max.dev_attr.attr,
 254         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 255         &sensor_dev_attr_temp4_crit.dev_attr.attr,
 256
 257         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 258         &sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
 259         &sensor_dev_attr_temp4_fault.dev_attr.attr,
 260         &sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
 261         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 262         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 263         NULL
 264 };
 265
 266 static const struct attribute_group lm83_group_opt = {
 267         .attrs = lm83_attributes_opt,
 268 };
 269
 270 /*
 271  * Real code
 272  */
 273
 274 /* Return 0 if detection is successful, -ENODEV otherwise */
 275 static int lm83_detect(struct i2c_client *new_client,
 276                        struct i2c_board_info *info)
 277 {
 278         struct i2c_adapter *adapter = new_client->adapter;
 279         const char *name;
 280         u8 man_id, chip_id;
 281
 282         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 283                 return -ENODEV;
 284
 285         /* Detection */
 286         if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
 287             (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
 288             (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
 289                 dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
 290                         new_client->addr);
 291                 return -ENODEV;
 292         }
 293
 294         /* Identification */
 295         man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
 296         if (man_id != 0x01)     /* National Semiconductor */
 297                 return -ENODEV;
 298
 299         chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
 300         switch (chip_id) {
 301         case 0x03:
 302                 name = "lm83";
 303                 break;
 304         case 0x01:
 305                 name = "lm82";
 306                 break;
 307         default:
 308                 /* identification failed */
 309                 dev_info(&adapter->dev,
 310                          "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
 311                          man_id, chip_id);
 312                 return -ENODEV;
 313         }
 314
 315         strlcpy(info->type, name, I2C_NAME_SIZE);
 316
 317         return 0;
 318 }
 319
 320 static int lm83_probe(struct i2c_client *new_client,
 321                       const struct i2c_device_id *id)
 322 {
 323         struct device *hwmon_dev;
 324         struct lm83_data *data;
 325
 326         data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
 327                             GFP_KERNEL);
 328         if (!data)
 329                 return -ENOMEM;
 330
 331         data->client = new_client;
 332         mutex_init(&data->update_lock);
 333
 334         /*
 335          * Register sysfs hooks
 336          * The LM82 can only monitor one external diode which is
 337          * at the same register as the LM83 temp3 entry - so we
 338          * declare 1 and 3 common, and then 2 and 4 only for the LM83.
 339          */
 340         data->groups[0] = &lm83_group;
 341         if (id->driver_data == lm83)
 342                 data->groups[1] = &lm83_group_opt;
 343
 344         hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
 345                                                            new_client->name,
 346                                                            data, data->groups);
 347         return PTR_ERR_OR_ZERO(hwmon_dev);
 348 }
 349
 350 /*
 351  * Driver data (common to all clients)
 352  */
 353
 354 static const struct i2c_device_id lm83_id[] = {
 355         { "lm83", lm83 },
 356         { "lm82", lm82 },
 357         { }
 358 };
 359 MODULE_DEVICE_TABLE(i2c, lm83_id);
 360
 361 static struct i2c_driver lm83_driver = {
 362         .class          = I2C_CLASS_HWMON,
 363         .driver = {
 364                 .name   = "lm83",
 365         },
 366         .probe          = lm83_probe,
 367         .id_table       = lm83_id,
 368         .detect         = lm83_detect,
 369         .address_list   = normal_i2c,
 370 };
 371
 372 module_i2c_driver(lm83_driver);
 373
 374 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
 375 MODULE_DESCRIPTION("LM83 driver");
 376 MODULE_LICENSE("GPL");