| 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"); |