1 /* 2 * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware 3 * monitoring 4 * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23 5 * based on lm75.c by Frodo Looijaard <frodol@dds.nl> 6 * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 7 * the help of Jean Delvare <khali@linux-fr.org> 8 * 9 * This program is free software; you can redistribute it and/or modify 10 * it under the terms of the GNU General Public License as published by 11 * the Free Software Foundation; either version 2 of the License, or 12 * (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 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 #include "lm75.h" 35 36 /* Addresses to scan */ 37 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 38 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 39 40 /* Insmod parameters */ 41 static int polarity = -1; 42 module_param(polarity, int, 0); 43 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 44 45 /* Many DS1621 constants specified below */ 46 /* Config register used for detection */ 47 /* 7 6 5 4 3 2 1 0 */ 48 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 49 #define DS1621_REG_CONFIG_NVB 0x10 50 #define DS1621_REG_CONFIG_POLARITY 0x02 51 #define DS1621_REG_CONFIG_1SHOT 0x01 52 #define DS1621_REG_CONFIG_DONE 0x80 53 54 /* The DS1621 registers */ 55 static const u8 DS1621_REG_TEMP[3] = { 56 0xAA, /* input, word, RO */ 57 0xA2, /* min, word, RW */ 58 0xA1, /* max, word, RW */ 59 }; 60 #define DS1621_REG_CONF 0xAC /* byte, RW */ 61 #define DS1621_COM_START 0xEE /* no data */ 62 #define DS1621_COM_STOP 0x22 /* no data */ 63 64 /* The DS1621 configuration register */ 65 #define DS1621_ALARM_TEMP_HIGH 0x40 66 #define DS1621_ALARM_TEMP_LOW 0x20 67 68 /* Conversions */ 69 #define ALARMS_FROM_REG(val) ((val) & \ 70 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 71 72 /* Each client has this additional data */ 73 struct ds1621_data { 74 struct device *hwmon_dev; 75 struct mutex update_lock; 76 char valid; /* !=0 if following fields are valid */ 77 unsigned long last_updated; /* In jiffies */ 78 79 u16 temp[3]; /* Register values, word */ 80 u8 conf; /* Register encoding, combined */ 81 }; 82 83 static void ds1621_init_client(struct i2c_client *client) 84 { 85 u8 conf, new_conf; 86 87 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 88 /* switch to continuous conversion mode */ 89 new_conf &= ~DS1621_REG_CONFIG_1SHOT; 90 91 /* setup output polarity */ 92 if (polarity == 0) 93 new_conf &= ~DS1621_REG_CONFIG_POLARITY; 94 else if (polarity == 1) 95 new_conf |= DS1621_REG_CONFIG_POLARITY; 96 97 if (conf != new_conf) 98 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); 99 100 /* start conversion */ 101 i2c_smbus_write_byte(client, DS1621_COM_START); 102 } 103 104 static struct ds1621_data *ds1621_update_client(struct device *dev) 105 { 106 struct i2c_client *client = to_i2c_client(dev); 107 struct ds1621_data *data = i2c_get_clientdata(client); 108 u8 new_conf; 109 110 mutex_lock(&data->update_lock); 111 112 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 113 || !data->valid) { 114 int i; 115 116 dev_dbg(&client->dev, "Starting ds1621 update\n"); 117 118 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 119 120 for (i = 0; i < ARRAY_SIZE(data->temp); i++) 121 data->temp[i] = i2c_smbus_read_word_swapped(client, 122 DS1621_REG_TEMP[i]); 123 124 /* reset alarms if necessary */ 125 new_conf = data->conf; 126 if (data->temp[0] > data->temp[1]) /* input > min */ 127 new_conf &= ~DS1621_ALARM_TEMP_LOW; 128 if (data->temp[0] < data->temp[2]) /* input < max */ 129 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 130 if (data->conf != new_conf) 131 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, 132 new_conf); 133 134 data->last_updated = jiffies; 135 data->valid = 1; 136 } 137 138 mutex_unlock(&data->update_lock); 139 140 return data; 141 } 142 143 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 144 char *buf) 145 { 146 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 147 struct ds1621_data *data = ds1621_update_client(dev); 148 return sprintf(buf, "%d\n", 149 LM75_TEMP_FROM_REG(data->temp[attr->index])); 150 } 151 152 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 153 const char *buf, size_t count) 154 { 155 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 156 struct i2c_client *client = to_i2c_client(dev); 157 struct ds1621_data *data = i2c_get_clientdata(client); 158 long val; 159 int err; 160 161 err = kstrtol(buf, 10, &val); 162 if (err) 163 return err; 164 165 mutex_lock(&data->update_lock); 166 data->temp[attr->index] = LM75_TEMP_TO_REG(val); 167 i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index], 168 data->temp[attr->index]); 169 mutex_unlock(&data->update_lock); 170 return count; 171 } 172 173 static ssize_t show_alarms(struct device *dev, struct device_attribute *da, 174 char *buf) 175 { 176 struct ds1621_data *data = ds1621_update_client(dev); 177 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 178 } 179 180 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 181 char *buf) 182 { 183 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 184 struct ds1621_data *data = ds1621_update_client(dev); 185 return sprintf(buf, "%d\n", !!(data->conf & attr->index)); 186 } 187 188 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 189 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 190 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 191 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 192 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 193 DS1621_ALARM_TEMP_LOW); 194 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 195 DS1621_ALARM_TEMP_HIGH); 196 197 static struct attribute *ds1621_attributes[] = { 198 &sensor_dev_attr_temp1_input.dev_attr.attr, 199 &sensor_dev_attr_temp1_min.dev_attr.attr, 200 &sensor_dev_attr_temp1_max.dev_attr.attr, 201 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 202 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 203 &dev_attr_alarms.attr, 204 NULL 205 }; 206 207 static const struct attribute_group ds1621_group = { 208 .attrs = ds1621_attributes, 209 }; 210 211 212 /* Return 0 if detection is successful, -ENODEV otherwise */ 213 static int ds1621_detect(struct i2c_client *client, 214 struct i2c_board_info *info) 215 { 216 struct i2c_adapter *adapter = client->adapter; 217 int conf, temp; 218 int i; 219 220 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 221 | I2C_FUNC_SMBUS_WORD_DATA 222 | I2C_FUNC_SMBUS_WRITE_BYTE)) 223 return -ENODEV; 224 225 /* 226 * Now, we do the remaining detection. It is lousy. 227 * 228 * The NVB bit should be low if no EEPROM write has been requested 229 * during the latest 10ms, which is highly improbable in our case. 230 */ 231 conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); 232 if (conf < 0 || conf & DS1621_REG_CONFIG_NVB) 233 return -ENODEV; 234 /* The 7 lowest bits of a temperature should always be 0. */ 235 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) { 236 temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]); 237 if (temp < 0 || (temp & 0x7f00)) 238 return -ENODEV; 239 } 240 241 strlcpy(info->type, "ds1621", I2C_NAME_SIZE); 242 243 return 0; 244 } 245 246 static int ds1621_probe(struct i2c_client *client, 247 const struct i2c_device_id *id) 248 { 249 struct ds1621_data *data; 250 int err; 251 252 data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data), 253 GFP_KERNEL); 254 if (!data) 255 return -ENOMEM; 256 257 i2c_set_clientdata(client, data); 258 mutex_init(&data->update_lock); 259 260 /* Initialize the DS1621 chip */ 261 ds1621_init_client(client); 262 263 /* Register sysfs hooks */ 264 err = sysfs_create_group(&client->dev.kobj, &ds1621_group); 265 if (err) 266 return err; 267 268 data->hwmon_dev = hwmon_device_register(&client->dev); 269 if (IS_ERR(data->hwmon_dev)) { 270 err = PTR_ERR(data->hwmon_dev); 271 goto exit_remove_files; 272 } 273 274 return 0; 275 276 exit_remove_files: 277 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 278 return err; 279 } 280 281 static int ds1621_remove(struct i2c_client *client) 282 { 283 struct ds1621_data *data = i2c_get_clientdata(client); 284 285 hwmon_device_unregister(data->hwmon_dev); 286 sysfs_remove_group(&client->dev.kobj, &ds1621_group); 287 288 return 0; 289 } 290 291 static const struct i2c_device_id ds1621_id[] = { 292 { "ds1621", 0 }, 293 { "ds1625", 0 }, 294 { } 295 }; 296 MODULE_DEVICE_TABLE(i2c, ds1621_id); 297 298 /* This is the driver that will be inserted */ 299 static struct i2c_driver ds1621_driver = { 300 .class = I2C_CLASS_HWMON, 301 .driver = { 302 .name = "ds1621", 303 }, 304 .probe = ds1621_probe, 305 .remove = ds1621_remove, 306 .id_table = ds1621_id, 307 .detect = ds1621_detect, 308 .address_list = normal_i2c, 309 }; 310 311 module_i2c_driver(ds1621_driver); 312 313 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 314 MODULE_DESCRIPTION("DS1621 driver"); 315 MODULE_LICENSE("GPL"); 316