LXR linux/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
  35static 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
  64static int temp_from_reg(int val)
  65{
  66        return (val & 0x80 ? val-0x100 : val) * 1000;
  67}
  68
  69static int temp_to_reg(int val)
  70{
  71        return (val < 0 ? val+0x100*1000 : val) / 1000;
  72}
  73
  74enum 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
  88struct 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
  99static 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
 108static 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
 115static 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
 148static 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
 157static 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
 176static ssize_t show_alarms(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
 183static 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
 191static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input1);
 192static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, t_input2);
 193static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
 194                          t_low2);
 195static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
 196                          t_high2);
 197static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
 198                          t_crit2);
 199static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp,
 200                          set_temp, t_hyst2);
 201
 202static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 203static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 204static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
 205static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
 206static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 207
 208static 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};
 223ATTRIBUTE_GROUPS(max1619);
 224
 225/* Return 0 if detection is successful, -ENODEV otherwise */
 226static 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
 261static 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
 276static 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
 300static const struct i2c_device_id max1619_id[] = {
 301        { "max1619", 0 },
 302        { }
 303};
 304MODULE_DEVICE_TABLE(i2c, max1619_id);
 305
 306static 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
 317module_i2c_driver(max1619_driver);
 318
 319MODULE_AUTHOR("Oleksij Rempel <bug-track@fisher-privat.net>, Jean Delvare <jdelvare@suse.de>");
 320MODULE_DESCRIPTION("MAX1619 sensor driver");
 321MODULE_LICENSE("GPL");
 322