1 /* 2 * ds620.c - Support for temperature sensor and thermostat DS620 3 * 4 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> 5 * 6 * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 21 */ 22 23 #include <linux/module.h> 24 #include <linux/init.h> 25 #include <linux/slab.h> 26 #include <linux/jiffies.h> 27 #include <linux/i2c.h> 28 #include <linux/hwmon.h> 29 #include <linux/hwmon-sysfs.h> 30 #include <linux/err.h> 31 #include <linux/mutex.h> 32 #include <linux/sysfs.h> 33 #include <linux/i2c/ds620.h> 34 35 /* 36 * Many DS620 constants specified below 37 * 15 14 13 12 11 10 09 08 38 * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT| 39 * 40 * 07 06 05 04 03 02 01 00 41 * |PO2 |PO1 |A2 |A1 |A0 | | | | 42 */ 43 #define DS620_REG_CONFIG_DONE 0x8000 44 #define DS620_REG_CONFIG_NVB 0x4000 45 #define DS620_REG_CONFIG_THF 0x2000 46 #define DS620_REG_CONFIG_TLF 0x1000 47 #define DS620_REG_CONFIG_R1 0x0800 48 #define DS620_REG_CONFIG_R0 0x0400 49 #define DS620_REG_CONFIG_AUTOC 0x0200 50 #define DS620_REG_CONFIG_1SHOT 0x0100 51 #define DS620_REG_CONFIG_PO2 0x0080 52 #define DS620_REG_CONFIG_PO1 0x0040 53 #define DS620_REG_CONFIG_A2 0x0020 54 #define DS620_REG_CONFIG_A1 0x0010 55 #define DS620_REG_CONFIG_A0 0x0008 56 57 /* The DS620 registers */ 58 static const u8 DS620_REG_TEMP[3] = { 59 0xAA, /* input, word, RO */ 60 0xA2, /* min, word, RW */ 61 0xA0, /* max, word, RW */ 62 }; 63 64 #define DS620_REG_CONF 0xAC /* word, RW */ 65 #define DS620_COM_START 0x51 /* no data */ 66 #define DS620_COM_STOP 0x22 /* no data */ 67 68 /* Each client has this additional data */ 69 struct ds620_data { 70 struct device *hwmon_dev; 71 struct mutex update_lock; 72 char valid; /* !=0 if following fields are valid */ 73 unsigned long last_updated; /* In jiffies */ 74 75 u16 temp[3]; /* Register values, word */ 76 }; 77 78 /* 79 * Temperature registers are word-sized. 80 * DS620 uses a high-byte first convention, which is exactly opposite to 81 * the SMBus standard. 82 */ 83 static int ds620_read_temp(struct i2c_client *client, u8 reg) 84 { 85 int ret; 86 87 ret = i2c_smbus_read_word_data(client, reg); 88 if (ret < 0) 89 return ret; 90 return swab16(ret); 91 } 92 93 static int ds620_write_temp(struct i2c_client *client, u8 reg, u16 value) 94 { 95 return i2c_smbus_write_word_data(client, reg, swab16(value)); 96 } 97 98 static void ds620_init_client(struct i2c_client *client) 99 { 100 struct ds620_platform_data *ds620_info = client->dev.platform_data; 101 u16 conf, new_conf; 102 103 new_conf = conf = 104 swab16(i2c_smbus_read_word_data(client, DS620_REG_CONF)); 105 106 /* switch to continuous conversion mode */ 107 new_conf &= ~DS620_REG_CONFIG_1SHOT; 108 /* already high at power-on, but don't trust the BIOS! */ 109 new_conf |= DS620_REG_CONFIG_PO2; 110 /* thermostat mode according to platform data */ 111 if (ds620_info && ds620_info->pomode == 1) 112 new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */ 113 else if (ds620_info && ds620_info->pomode == 2) 114 new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */ 115 else 116 new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */ 117 /* with highest precision */ 118 new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0; 119 120 if (conf != new_conf) 121 i2c_smbus_write_word_data(client, DS620_REG_CONF, 122 swab16(new_conf)); 123 124 /* start conversion */ 125 i2c_smbus_write_byte(client, DS620_COM_START); 126 } 127 128 static struct ds620_data *ds620_update_client(struct device *dev) 129 { 130 struct i2c_client *client = to_i2c_client(dev); 131 struct ds620_data *data = i2c_get_clientdata(client); 132 struct ds620_data *ret = data; 133 134 mutex_lock(&data->update_lock); 135 136 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 137 || !data->valid) { 138 int i; 139 int res; 140 141 dev_dbg(&client->dev, "Starting ds620 update\n"); 142 143 for (i = 0; i < ARRAY_SIZE(data->temp); i++) { 144 res = ds620_read_temp(client, 145 DS620_REG_TEMP[i]); 146 if (res < 0) { 147 ret = ERR_PTR(res); 148 goto abort; 149 } 150 151 data->temp[i] = res; 152 } 153 154 data->last_updated = jiffies; 155 data->valid = 1; 156 } 157 abort: 158 mutex_unlock(&data->update_lock); 159 160 return ret; 161 } 162 163 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 164 char *buf) 165 { 166 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 167 struct ds620_data *data = ds620_update_client(dev); 168 169 if (IS_ERR(data)) 170 return PTR_ERR(data); 171 172 return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10); 173 } 174 175 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 176 const char *buf, size_t count) 177 { 178 int res; 179 long val; 180 181 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 182 struct i2c_client *client = to_i2c_client(dev); 183 struct ds620_data *data = i2c_get_clientdata(client); 184 185 res = strict_strtol(buf, 10, &val); 186 187 if (res) 188 return res; 189 190 val = (val * 10 / 625) * 8; 191 192 mutex_lock(&data->update_lock); 193 data->temp[attr->index] = val; 194 ds620_write_temp(client, DS620_REG_TEMP[attr->index], 195 data->temp[attr->index]); 196 mutex_unlock(&data->update_lock); 197 return count; 198 } 199 200 static ssize_t show_alarm(struct device *dev, struct device_attribute *da, 201 char *buf) 202 { 203 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 204 struct ds620_data *data = ds620_update_client(dev); 205 struct i2c_client *client = to_i2c_client(dev); 206 u16 conf, new_conf; 207 int res; 208 209 if (IS_ERR(data)) 210 return PTR_ERR(data); 211 212 /* reset alarms if necessary */ 213 res = i2c_smbus_read_word_data(client, DS620_REG_CONF); 214 if (res < 0) 215 return res; 216 217 conf = swab16(res); 218 new_conf = conf; 219 new_conf &= ~attr->index; 220 if (conf != new_conf) { 221 res = i2c_smbus_write_word_data(client, DS620_REG_CONF, 222 swab16(new_conf)); 223 if (res < 0) 224 return res; 225 } 226 227 return sprintf(buf, "%d\n", !!(conf & attr->index)); 228 } 229 230 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 231 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); 232 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); 233 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 234 DS620_REG_CONFIG_TLF); 235 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 236 DS620_REG_CONFIG_THF); 237 238 static struct attribute *ds620_attributes[] = { 239 &sensor_dev_attr_temp1_input.dev_attr.attr, 240 &sensor_dev_attr_temp1_min.dev_attr.attr, 241 &sensor_dev_attr_temp1_max.dev_attr.attr, 242 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 243 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 244 NULL 245 }; 246 247 static const struct attribute_group ds620_group = { 248 .attrs = ds620_attributes, 249 }; 250 251 static int ds620_probe(struct i2c_client *client, 252 const struct i2c_device_id *id) 253 { 254 struct ds620_data *data; 255 int err; 256 257 data = kzalloc(sizeof(struct ds620_data), GFP_KERNEL); 258 if (!data) { 259 err = -ENOMEM; 260 goto exit; 261 } 262 263 i2c_set_clientdata(client, data); 264 mutex_init(&data->update_lock); 265 266 /* Initialize the DS620 chip */ 267 ds620_init_client(client); 268 269 /* Register sysfs hooks */ 270 err = sysfs_create_group(&client->dev.kobj, &ds620_group); 271 if (err) 272 goto exit_free; 273 274 data->hwmon_dev = hwmon_device_register(&client->dev); 275 if (IS_ERR(data->hwmon_dev)) { 276 err = PTR_ERR(data->hwmon_dev); 277 goto exit_remove_files; 278 } 279 280 dev_info(&client->dev, "temperature sensor found\n"); 281 282 return 0; 283 284 exit_remove_files: 285 sysfs_remove_group(&client->dev.kobj, &ds620_group); 286 exit_free: 287 kfree(data); 288 exit: 289 return err; 290 } 291 292 static int ds620_remove(struct i2c_client *client) 293 { 294 struct ds620_data *data = i2c_get_clientdata(client); 295 296 hwmon_device_unregister(data->hwmon_dev); 297 sysfs_remove_group(&client->dev.kobj, &ds620_group); 298 299 kfree(data); 300 301 return 0; 302 } 303 304 static const struct i2c_device_id ds620_id[] = { 305 {"ds620", 0}, 306 {} 307 }; 308 309 MODULE_DEVICE_TABLE(i2c, ds620_id); 310 311 /* This is the driver that will be inserted */ 312 static struct i2c_driver ds620_driver = { 313 .class = I2C_CLASS_HWMON, 314 .driver = { 315 .name = "ds620", 316 }, 317 .probe = ds620_probe, 318 .remove = ds620_remove, 319 .id_table = ds620_id, 320 }; 321 322 static int __init ds620_init(void) 323 { 324 return i2c_add_driver(&ds620_driver); 325 } 326 327 static void __exit ds620_exit(void) 328 { 329 i2c_del_driver(&ds620_driver); 330 } 331 332 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); 333 MODULE_DESCRIPTION("DS620 driver"); 334 MODULE_LICENSE("GPL"); 335 336 module_init(ds620_init); 337 module_exit(ds620_exit); 338