drivers/hwmon/max1619.c

   1 /*
   2  * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
   3  *             monitoring
   4  * Copyright (C) 2003-2004 Oleksij Rempel <bug-track@fisher-privat.net>
   5  *                         Jean Delvare <jdelvare@suse.de>
   6  *
   7  * Based on the lm90 driver. The MAX1619 is a sensor chip made by Maxim.
   8  * It reports up to two temperatures (its own plus up to
   9  * one external one). Complete datasheet can be
  10  * obtained from Maxim's website at:
  11  *   http://pdfserv.maxim-ic.com/en/ds/MAX1619.pdf
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * This program is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/slab.h>
  27 #include <linux/jiffies.h>
  28 #include <linux/i2c.h>
  29 #include <linux/hwmon.h>
  30 #include <linux/hwmon-sysfs.h>
  31 #include <linux/err.h>
  32 #include <linux/mutex.h>
  33 #include <linux/sysfs.h>
  34
  35 static const unsigned short normal_i2c[] = {
  36         0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  37
  38 /*
  39  * The MAX1619 registers
  40  */
  41
  42 #define MAX1619_REG_R_MAN_ID            0xFE
  43 #define MAX1619_REG_R_CHIP_ID           0xFF
  44 #define MAX1619_REG_R_CONFIG            0x03
  45 #define MAX1619_REG_W_CONFIG            0x09
  46 #define MAX1619_REG_R_CONVRATE          0x04
  47 #define MAX1619_REG_W_CONVRATE          0x0A
  48 #define MAX1619_REG_R_STATUS            0x02
  49 #define MAX1619_REG_R_LOCAL_TEMP        0x00
  50 #define MAX1619_REG_R_REMOTE_TEMP       0x01
  51 #define MAX1619_REG_R_REMOTE_HIGH       0x07
  52 #define MAX1619_REG_W_REMOTE_HIGH       0x0D
  53 #define MAX1619_REG_R_REMOTE_LOW        0x08
  54 #define MAX1619_REG_W_REMOTE_LOW        0x0E
  55 #define MAX1619_REG_R_REMOTE_CRIT       0x10
  56 #define MAX1619_REG_W_REMOTE_CRIT       0x12
  57 #define MAX1619_REG_R_TCRIT_HYST        0x11
  58 #define MAX1619_REG_W_TCRIT_HYST        0x13
  59
  60 /*
  61  * Conversions
  62  */
  63
  64 static int temp_from_reg(int val)
  65 {
  66         return (val & 0x80 ? val-0x100 : val) * 1000;
  67 }
  68
  69 static int temp_to_reg(int val)
  70 {
  71         return (val < 0 ? val+0x100*1000 : val) / 1000;
  72 }
  73
  74 enum temp_index {
  75         t_input1 = 0,
  76         t_input2,
  77         t_low2,
  78         t_high2,
  79         t_crit2,
  80         t_hyst2,
  81         t_num_regs
  82 };
  83
  84 /*
  85  * Client data (each client gets its own)
  86  */
  87
  88 struct max1619_data {
  89         struct i2c_client *client;
  90         struct mutex update_lock;
  91         char valid; /* zero until following fields are valid */
  92         unsigned long last_updated; /* in jiffies */
  93
  94         /* registers values */
  95         u8 temp[t_num_regs];    /* index with enum temp_index */
  96         u8 alarms;
  97 };
  98
  99 static const u8 regs_read[t_num_regs] = {
 100         [t_input1] = MAX1619_REG_R_LOCAL_TEMP,
 101         [t_input2] = MAX1619_REG_R_REMOTE_TEMP,
 102         [t_low2] = MAX1619_REG_R_REMOTE_LOW,
 103         [t_high2] = MAX1619_REG_R_REMOTE_HIGH,
 104         [t_crit2] = MAX1619_REG_R_REMOTE_CRIT,
 105         [t_hyst2] = MAX1619_REG_R_TCRIT_HYST,
 106 };
 107
 108 static const u8 regs_write[t_num_regs] = {
 109         [t_low2] = MAX1619_REG_W_REMOTE_LOW,
 110         [t_high2] = MAX1619_REG_W_REMOTE_HIGH,
 111         [t_crit2] = MAX1619_REG_W_REMOTE_CRIT,
 112         [t_hyst2] = MAX1619_REG_W_TCRIT_HYST,
 113 };
 114
 115 static struct max1619_data *max1619_update_device(struct device *dev)
 116 {
 117         struct max1619_data *data = dev_get_drvdata(dev);
 118         struct i2c_client *client = data->client;
 119         int config, i;
 120
 121         mutex_lock(&data->update_lock);
 122
 123         if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 124                 dev_dbg(&client->dev, "Updating max1619 data.\n");
 125                 for (i = 0; i < t_num_regs; i++)
 126                         data->temp[i] = i2c_smbus_read_byte_data(client,
 127                                         regs_read[i]);
 128                 data->alarms = i2c_smbus_read_byte_data(client,
 129                                         MAX1619_REG_R_STATUS);
 130                 /* If OVERT polarity is low, reverse alarm bit */
 131                 config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
 132                 if (!(config & 0x20))
 133                         data->alarms ^= 0x02;
 134
 135                 data->last_updated = jiffies;
 136                 data->valid = 1;
 137         }
 138
 139         mutex_unlock(&data->update_lock);
 140
 141         return data;
 142 }
 143
 144 /*
 145  * Sysfs stuff
 146  */
 147
 148 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
 149                          char *buf)
 150 {
 151         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 152         struct max1619_data *data = max1619_update_device(dev);
 153
 154         return sprintf(buf, "%d\n", temp_from_reg(data->temp[attr->index]));
 155 }
 156
 157 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
 158                            const char *buf, size_t count)
 159 {
 160         struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
 161         struct max1619_data *data = dev_get_drvdata(dev);
 162         struct i2c_client *client = data->client;
 163         long val;
 164         int err = kstrtol(buf, 10, &val);
 165         if (err)
 166                 return err;
 167
 168         mutex_lock(&data->update_lock);
 169         data->temp[attr->index] = temp_to_reg(val);
 170         i2c_smbus_write_byte_data(client, regs_write[attr->index],
 171                                   data->temp[attr->index]);
 172         mutex_unlock(&data->update_lock);
 173         return count;
 174 }
 175
 176 static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
 177                            char *buf)
 178 {
 179         struct max1619_data *data = max1619_update_device(dev);
 180         return sprintf(buf, "%d\n", data->alarms);
 181 }
 182
 183 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
 184                           char *buf)
 185 {
 186         int bitnr = to_sensor_dev_attr(attr)->index;
 187         struct max1619_data *data = max1619_update_device(dev);
 188         return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 189 }
 190
 191 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input1);
 192 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, t_input2);
 193 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
 194                           t_low2);
 195 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
 196                           t_high2);
 197 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
 198                           t_crit2);
 199 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp,
 200                           set_temp, t_hyst2);
 201
 202 static DEVICE_ATTR_RO(alarms);
 203 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 204 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
 205 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
 206 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 207
 208 static struct attribute *max1619_attrs[] = {
 209         &sensor_dev_attr_temp1_input.dev_attr.attr,
 210         &sensor_dev_attr_temp2_input.dev_attr.attr,
 211         &sensor_dev_attr_temp2_min.dev_attr.attr,
 212         &sensor_dev_attr_temp2_max.dev_attr.attr,
 213         &sensor_dev_attr_temp2_crit.dev_attr.attr,
 214         &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
 215
 216         &dev_attr_alarms.attr,
 217         &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 218         &sensor_dev_attr_temp2_fault.dev_attr.attr,
 219         &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 220         &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 221         NULL
 222 };
 223 ATTRIBUTE_GROUPS(max1619);
 224
 225 /* Return 0 if detection is successful, -ENODEV otherwise */
 226 static int max1619_detect(struct i2c_client *client,
 227                           struct i2c_board_info *info)
 228 {
 229         struct i2c_adapter *adapter = client->adapter;
 230         u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
 231
 232         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 233                 return -ENODEV;
 234
 235         /* detection */
 236         reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
 237         reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
 238         reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
 239         if ((reg_config & 0x03) != 0x00
 240          || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
 241                 dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
 242                         client->addr);
 243                 return -ENODEV;
 244         }
 245
 246         /* identification */
 247         man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
 248         chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
 249         if (man_id != 0x4D || chip_id != 0x04) {
 250                 dev_info(&adapter->dev,
 251                          "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
 252                          man_id, chip_id);
 253                 return -ENODEV;
 254         }
 255
 256         strlcpy(info->type, "max1619", I2C_NAME_SIZE);
 257
 258         return 0;
 259 }
 260
 261 static void max1619_init_client(struct i2c_client *client)
 262 {
 263         u8 config;
 264
 265         /*
 266          * Start the conversions.
 267          */
 268         i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
 269                                   5); /* 2 Hz */
 270         config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
 271         if (config & 0x40)
 272                 i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
 273                                           config & 0xBF); /* run */
 274 }
 275
 276 static int max1619_probe(struct i2c_client *new_client,
 277                          const struct i2c_device_id *id)
 278 {
 279         struct max1619_data *data;
 280         struct device *hwmon_dev;
 281
 282         data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
 283                             GFP_KERNEL);
 284         if (!data)
 285                 return -ENOMEM;
 286
 287         data->client = new_client;
 288         mutex_init(&data->update_lock);
 289
 290         /* Initialize the MAX1619 chip */
 291         max1619_init_client(new_client);
 292
 293         hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
 294                                                            new_client->name,
 295                                                            data,
 296                                                            max1619_groups);
 297         return PTR_ERR_OR_ZERO(hwmon_dev);
 298 }
 299
 300 static const struct i2c_device_id max1619_id[] = {
 301         { "max1619", 0 },
 302         { }
 303 };
 304 MODULE_DEVICE_TABLE(i2c, max1619_id);
 305
 306 static struct i2c_driver max1619_driver = {
 307         .class          = I2C_CLASS_HWMON,
 308         .driver = {
 309                 .name   = "max1619",
 310         },
 311         .probe          = max1619_probe,
 312         .id_table       = max1619_id,
 313         .detect         = max1619_detect,
 314         .address_list   = normal_i2c,
 315 };
 316
 317 module_i2c_driver(max1619_driver);
 318
 319 MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
 320 MODULE_DESCRIPTION("MAX1619 sensor driver");
 321 MODULE_LICENSE("GPL");