linux/drivers/hwmon/max1619.c
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   1/*
   2 * max1619.c - Part of lm_sensors, Linux kernel modules for hardware
   3 *             monitoring
   4 * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru>
   5 *                         Jean Delvare <khali@linux-fr.org>
   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 * You should have received a copy of the GNU General Public License
  24 * along with this program; if not, write to the Free Software
  25 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  26 */
  27
  28
  29#include <linux/module.h>
  30#include <linux/init.h>
  31#include <linux/slab.h>
  32#include <linux/jiffies.h>
  33#include <linux/i2c.h>
  34#include <linux/hwmon.h>
  35#include <linux/hwmon-sysfs.h>
  36#include <linux/err.h>
  37#include <linux/mutex.h>
  38#include <linux/sysfs.h>
  39
  40static const unsigned short normal_i2c[] = {
  41        0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
  42
  43/*
  44 * The MAX1619 registers
  45 */
  46
  47#define MAX1619_REG_R_MAN_ID            0xFE
  48#define MAX1619_REG_R_CHIP_ID           0xFF
  49#define MAX1619_REG_R_CONFIG            0x03
  50#define MAX1619_REG_W_CONFIG            0x09
  51#define MAX1619_REG_R_CONVRATE          0x04
  52#define MAX1619_REG_W_CONVRATE          0x0A
  53#define MAX1619_REG_R_STATUS            0x02
  54#define MAX1619_REG_R_LOCAL_TEMP        0x00
  55#define MAX1619_REG_R_REMOTE_TEMP       0x01
  56#define MAX1619_REG_R_REMOTE_HIGH       0x07
  57#define MAX1619_REG_W_REMOTE_HIGH       0x0D
  58#define MAX1619_REG_R_REMOTE_LOW        0x08
  59#define MAX1619_REG_W_REMOTE_LOW        0x0E
  60#define MAX1619_REG_R_REMOTE_CRIT       0x10
  61#define MAX1619_REG_W_REMOTE_CRIT       0x12
  62#define MAX1619_REG_R_TCRIT_HYST        0x11
  63#define MAX1619_REG_W_TCRIT_HYST        0x13
  64
  65/*
  66 * Conversions
  67 */
  68
  69static int temp_from_reg(int val)
  70{
  71        return (val & 0x80 ? val-0x100 : val) * 1000;
  72}
  73
  74static int temp_to_reg(int val)
  75{
  76        return (val < 0 ? val+0x100*1000 : val) / 1000;
  77}
  78
  79/*
  80 * Functions declaration
  81 */
  82
  83static int max1619_probe(struct i2c_client *client,
  84                         const struct i2c_device_id *id);
  85static int max1619_detect(struct i2c_client *client,
  86                          struct i2c_board_info *info);
  87static void max1619_init_client(struct i2c_client *client);
  88static int max1619_remove(struct i2c_client *client);
  89static struct max1619_data *max1619_update_device(struct device *dev);
  90
  91/*
  92 * Driver data (common to all clients)
  93 */
  94
  95static const struct i2c_device_id max1619_id[] = {
  96        { "max1619", 0 },
  97        { }
  98};
  99MODULE_DEVICE_TABLE(i2c, max1619_id);
 100
 101static struct i2c_driver max1619_driver = {
 102        .class          = I2C_CLASS_HWMON,
 103        .driver = {
 104                .name   = "max1619",
 105        },
 106        .probe          = max1619_probe,
 107        .remove         = max1619_remove,
 108        .id_table       = max1619_id,
 109        .detect         = max1619_detect,
 110        .address_list   = normal_i2c,
 111};
 112
 113/*
 114 * Client data (each client gets its own)
 115 */
 116
 117struct max1619_data {
 118        struct device *hwmon_dev;
 119        struct mutex update_lock;
 120        char valid; /* zero until following fields are valid */
 121        unsigned long last_updated; /* in jiffies */
 122
 123        /* registers values */
 124        u8 temp_input1; /* local */
 125        u8 temp_input2, temp_low2, temp_high2; /* remote */
 126        u8 temp_crit2;
 127        u8 temp_hyst2;
 128        u8 alarms;
 129};
 130
 131/*
 132 * Sysfs stuff
 133 */
 134
 135#define show_temp(value) \
 136static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
 137                            char *buf) \
 138{ \
 139        struct max1619_data *data = max1619_update_device(dev); \
 140        return sprintf(buf, "%d\n", temp_from_reg(data->value)); \
 141}
 142show_temp(temp_input1);
 143show_temp(temp_input2);
 144show_temp(temp_low2);
 145show_temp(temp_high2);
 146show_temp(temp_crit2);
 147show_temp(temp_hyst2);
 148
 149#define set_temp2(value, reg) \
 150static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
 151                           const char *buf, \
 152        size_t count) \
 153{ \
 154        struct i2c_client *client = to_i2c_client(dev); \
 155        struct max1619_data *data = i2c_get_clientdata(client); \
 156        long val; \
 157        int err = kstrtol(buf, 10, &val); \
 158        if (err) \
 159                return err; \
 160\
 161        mutex_lock(&data->update_lock); \
 162        data->value = temp_to_reg(val); \
 163        i2c_smbus_write_byte_data(client, reg, data->value); \
 164        mutex_unlock(&data->update_lock); \
 165        return count; \
 166}
 167
 168set_temp2(temp_low2, MAX1619_REG_W_REMOTE_LOW);
 169set_temp2(temp_high2, MAX1619_REG_W_REMOTE_HIGH);
 170set_temp2(temp_crit2, MAX1619_REG_W_REMOTE_CRIT);
 171set_temp2(temp_hyst2, MAX1619_REG_W_TCRIT_HYST);
 172
 173static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
 174                           char *buf)
 175{
 176        struct max1619_data *data = max1619_update_device(dev);
 177        return sprintf(buf, "%d\n", data->alarms);
 178}
 179
 180static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
 181                          char *buf)
 182{
 183        int bitnr = to_sensor_dev_attr(attr)->index;
 184        struct max1619_data *data = max1619_update_device(dev);
 185        return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
 186}
 187
 188static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input1, NULL);
 189static DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_input2, NULL);
 190static DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp_low2,
 191        set_temp_low2);
 192static DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp_high2,
 193        set_temp_high2);
 194static DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_temp_crit2,
 195        set_temp_crit2);
 196static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst2,
 197        set_temp_hyst2);
 198static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
 199static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
 200static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
 201static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
 202static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
 203
 204static struct attribute *max1619_attributes[] = {
 205        &dev_attr_temp1_input.attr,
 206        &dev_attr_temp2_input.attr,
 207        &dev_attr_temp2_min.attr,
 208        &dev_attr_temp2_max.attr,
 209        &dev_attr_temp2_crit.attr,
 210        &dev_attr_temp2_crit_hyst.attr,
 211
 212        &dev_attr_alarms.attr,
 213        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
 214        &sensor_dev_attr_temp2_fault.dev_attr.attr,
 215        &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
 216        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
 217        NULL
 218};
 219
 220static const struct attribute_group max1619_group = {
 221        .attrs = max1619_attributes,
 222};
 223
 224/*
 225 * Real code
 226 */
 227
 228/* Return 0 if detection is successful, -ENODEV otherwise */
 229static int max1619_detect(struct i2c_client *client,
 230                          struct i2c_board_info *info)
 231{
 232        struct i2c_adapter *adapter = client->adapter;
 233        u8 reg_config, reg_convrate, reg_status, man_id, chip_id;
 234
 235        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 236                return -ENODEV;
 237
 238        /* detection */
 239        reg_config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
 240        reg_convrate = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONVRATE);
 241        reg_status = i2c_smbus_read_byte_data(client, MAX1619_REG_R_STATUS);
 242        if ((reg_config & 0x03) != 0x00
 243         || reg_convrate > 0x07 || (reg_status & 0x61) != 0x00) {
 244                dev_dbg(&adapter->dev, "MAX1619 detection failed at 0x%02x\n",
 245                        client->addr);
 246                return -ENODEV;
 247        }
 248
 249        /* identification */
 250        man_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_MAN_ID);
 251        chip_id = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CHIP_ID);
 252        if (man_id != 0x4D || chip_id != 0x04) {
 253                dev_info(&adapter->dev,
 254                         "Unsupported chip (man_id=0x%02X, chip_id=0x%02X).\n",
 255                         man_id, chip_id);
 256                return -ENODEV;
 257        }
 258
 259        strlcpy(info->type, "max1619", I2C_NAME_SIZE);
 260
 261        return 0;
 262}
 263
 264static int max1619_probe(struct i2c_client *new_client,
 265                         const struct i2c_device_id *id)
 266{
 267        struct max1619_data *data;
 268        int err;
 269
 270        data = devm_kzalloc(&new_client->dev, sizeof(struct max1619_data),
 271                            GFP_KERNEL);
 272        if (!data)
 273                return -ENOMEM;
 274
 275        i2c_set_clientdata(new_client, data);
 276        data->valid = 0;
 277        mutex_init(&data->update_lock);
 278
 279        /* Initialize the MAX1619 chip */
 280        max1619_init_client(new_client);
 281
 282        /* Register sysfs hooks */
 283        err = sysfs_create_group(&new_client->dev.kobj, &max1619_group);
 284        if (err)
 285                return err;
 286
 287        data->hwmon_dev = hwmon_device_register(&new_client->dev);
 288        if (IS_ERR(data->hwmon_dev)) {
 289                err = PTR_ERR(data->hwmon_dev);
 290                goto exit_remove_files;
 291        }
 292
 293        return 0;
 294
 295exit_remove_files:
 296        sysfs_remove_group(&new_client->dev.kobj, &max1619_group);
 297        return err;
 298}
 299
 300static void max1619_init_client(struct i2c_client *client)
 301{
 302        u8 config;
 303
 304        /*
 305         * Start the conversions.
 306         */
 307        i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONVRATE,
 308                                  5); /* 2 Hz */
 309        config = i2c_smbus_read_byte_data(client, MAX1619_REG_R_CONFIG);
 310        if (config & 0x40)
 311                i2c_smbus_write_byte_data(client, MAX1619_REG_W_CONFIG,
 312                                          config & 0xBF); /* run */
 313}
 314
 315static int max1619_remove(struct i2c_client *client)
 316{
 317        struct max1619_data *data = i2c_get_clientdata(client);
 318
 319        hwmon_device_unregister(data->hwmon_dev);
 320        sysfs_remove_group(&client->dev.kobj, &max1619_group);
 321
 322        return 0;
 323}
 324
 325static struct max1619_data *max1619_update_device(struct device *dev)
 326{
 327        struct i2c_client *client = to_i2c_client(dev);
 328        struct max1619_data *data = i2c_get_clientdata(client);
 329
 330        mutex_lock(&data->update_lock);
 331
 332        if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
 333                dev_dbg(&client->dev, "Updating max1619 data.\n");
 334                data->temp_input1 = i2c_smbus_read_byte_data(client,
 335                                        MAX1619_REG_R_LOCAL_TEMP);
 336                data->temp_input2 = i2c_smbus_read_byte_data(client,
 337                                        MAX1619_REG_R_REMOTE_TEMP);
 338                data->temp_high2 = i2c_smbus_read_byte_data(client,
 339                                        MAX1619_REG_R_REMOTE_HIGH);
 340                data->temp_low2 = i2c_smbus_read_byte_data(client,
 341                                        MAX1619_REG_R_REMOTE_LOW);
 342                data->temp_crit2 = i2c_smbus_read_byte_data(client,
 343                                        MAX1619_REG_R_REMOTE_CRIT);
 344                data->temp_hyst2 = i2c_smbus_read_byte_data(client,
 345                                        MAX1619_REG_R_TCRIT_HYST);
 346                data->alarms = i2c_smbus_read_byte_data(client,
 347                                        MAX1619_REG_R_STATUS);
 348
 349                data->last_updated = jiffies;
 350                data->valid = 1;
 351        }
 352
 353        mutex_unlock(&data->update_lock);
 354
 355        return data;
 356}
 357
 358module_i2c_driver(max1619_driver);
 359
 360MODULE_AUTHOR("Alexey Fisher <fishor@mail.ru> and "
 361        "Jean Delvare <khali@linux-fr.org>");
 362MODULE_DESCRIPTION("MAX1619 sensor driver");
 363MODULE_LICENSE("GPL");
 364
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