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/i2c-sensor.h> 30 #include "lm75.h" 31 32 /* Addresses to scan */ 33 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, 34 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; 35 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; 36 37 /* Insmod parameters */ 38 SENSORS_INSMOD_1(ds1621); 39 static int polarity = -1; 40 module_param(polarity, int, 0); 41 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); 42 43 /* Many DS1621 constants specified below */ 44 /* Config register used for detection */ 45 /* 7 6 5 4 3 2 1 0 */ 46 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */ 47 #define DS1621_REG_CONFIG_NVB 0x10 48 #define DS1621_REG_CONFIG_POLARITY 0x02 49 #define DS1621_REG_CONFIG_1SHOT 0x01 50 #define DS1621_REG_CONFIG_DONE 0x80 51 52 /* The DS1621 registers */ 53 #define DS1621_REG_TEMP 0xAA /* word, RO */ 54 #define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */ 55 #define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */ 56 #define DS1621_REG_CONF 0xAC /* byte, RW */ 57 #define DS1621_COM_START 0xEE /* no data */ 58 #define DS1621_COM_STOP 0x22 /* no data */ 59 60 /* The DS1621 configuration register */ 61 #define DS1621_ALARM_TEMP_HIGH 0x40 62 #define DS1621_ALARM_TEMP_LOW 0x20 63 64 /* Conversions. Rounding and limit checking is only done on the TO_REG 65 variants. Note that you should be a bit careful with which arguments 66 these macros are called: arguments may be evaluated more than once. 67 Fixing this is just not worth it. */ 68 #define ALARMS_FROM_REG(val) ((val) & \ 69 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) 70 71 /* Each client has this additional data */ 72 struct ds1621_data { 73 struct i2c_client client; 74 struct semaphore update_lock; 75 char valid; /* !=0 if following fields are valid */ 76 unsigned long last_updated; /* In jiffies */ 77 78 u16 temp, temp_min, temp_max; /* Register values, word */ 79 u8 conf; /* Register encoding, combined */ 80 }; 81 82 static int ds1621_attach_adapter(struct i2c_adapter *adapter); 83 static int ds1621_detect(struct i2c_adapter *adapter, int address, 84 int kind); 85 static void ds1621_init_client(struct i2c_client *client); 86 static int ds1621_detach_client(struct i2c_client *client); 87 static struct ds1621_data *ds1621_update_client(struct device *dev); 88 89 /* This is the driver that will be inserted */ 90 static struct i2c_driver ds1621_driver = { 91 .owner = THIS_MODULE, 92 .name = "ds1621", 93 .id = I2C_DRIVERID_DS1621, 94 .flags = I2C_DF_NOTIFY, 95 .attach_adapter = ds1621_attach_adapter, 96 .detach_client = ds1621_detach_client, 97 }; 98 99 /* All registers are word-sized, except for the configuration register. 100 DS1621 uses a high-byte first convention, which is exactly opposite to 101 the usual practice. */ 102 static int ds1621_read_value(struct i2c_client *client, u8 reg) 103 { 104 if (reg == DS1621_REG_CONF) 105 return i2c_smbus_read_byte_data(client, reg); 106 else 107 return swab16(i2c_smbus_read_word_data(client, reg)); 108 } 109 110 /* All registers are word-sized, except for the configuration register. 111 DS1621 uses a high-byte first convention, which is exactly opposite to 112 the usual practice. */ 113 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value) 114 { 115 if (reg == DS1621_REG_CONF) 116 return i2c_smbus_write_byte_data(client, reg, value); 117 else 118 return i2c_smbus_write_word_data(client, reg, swab16(value)); 119 } 120 121 static void ds1621_init_client(struct i2c_client *client) 122 { 123 int reg = ds1621_read_value(client, DS1621_REG_CONF); 124 /* switch to continuous conversion mode */ 125 reg &= ~ DS1621_REG_CONFIG_1SHOT; 126 127 /* setup output polarity */ 128 if (polarity == 0) 129 reg &= ~DS1621_REG_CONFIG_POLARITY; 130 else if (polarity == 1) 131 reg |= DS1621_REG_CONFIG_POLARITY; 132 133 ds1621_write_value(client, DS1621_REG_CONF, reg); 134 135 /* start conversion */ 136 i2c_smbus_write_byte(client, DS1621_COM_START); 137 } 138 139 #define show(value) \ 140 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ 141 { \ 142 struct ds1621_data *data = ds1621_update_client(dev); \ 143 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ 144 } 145 146 show(temp); 147 show(temp_min); 148 show(temp_max); 149 150 #define set_temp(suffix, value, reg) \ 151 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \ 152 size_t count) \ 153 { \ 154 struct i2c_client *client = to_i2c_client(dev); \ 155 struct ds1621_data *data = ds1621_update_client(dev); \ 156 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \ 157 \ 158 down(&data->update_lock); \ 159 data->value = val; \ 160 ds1621_write_value(client, reg, data->value); \ 161 up(&data->update_lock); \ 162 return count; \ 163 } 164 165 set_temp(min, temp_min, DS1621_REG_TEMP_MIN); 166 set_temp(max, temp_max, DS1621_REG_TEMP_MAX); 167 168 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) 169 { 170 struct ds1621_data *data = ds1621_update_client(dev); 171 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); 172 } 173 174 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); 175 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL); 176 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min); 177 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); 178 179 180 static int ds1621_attach_adapter(struct i2c_adapter *adapter) 181 { 182 return i2c_detect(adapter, &addr_data, ds1621_detect); 183 } 184 185 /* This function is called by i2c_detect */ 186 int ds1621_detect(struct i2c_adapter *adapter, int address, 187 int kind) 188 { 189 int conf, temp; 190 struct i2c_client *new_client; 191 struct ds1621_data *data; 192 int err = 0; 193 194 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA 195 | I2C_FUNC_SMBUS_WORD_DATA 196 | I2C_FUNC_SMBUS_WRITE_BYTE)) 197 goto exit; 198 199 /* OK. For now, we presume we have a valid client. We now create the 200 client structure, even though we cannot fill it completely yet. 201 But it allows us to access ds1621_{read,write}_value. */ 202 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) { 203 err = -ENOMEM; 204 goto exit; 205 } 206 memset(data, 0, sizeof(struct ds1621_data)); 207 208 new_client = &data->client; 209 i2c_set_clientdata(new_client, data); 210 new_client->addr = address; 211 new_client->adapter = adapter; 212 new_client->driver = &ds1621_driver; 213 new_client->flags = 0; 214 215 216 /* Now, we do the remaining detection. It is lousy. */ 217 if (kind < 0) { 218 /* The NVB bit should be low if no EEPROM write has been 219 requested during the latest 10ms, which is highly 220 improbable in our case. */ 221 conf = ds1621_read_value(new_client, DS1621_REG_CONF); 222 if (conf & DS1621_REG_CONFIG_NVB) 223 goto exit_free; 224 /* The 7 lowest bits of a temperature should always be 0. */ 225 temp = ds1621_read_value(new_client, DS1621_REG_TEMP); 226 if (temp & 0x007f) 227 goto exit_free; 228 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN); 229 if (temp & 0x007f) 230 goto exit_free; 231 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX); 232 if (temp & 0x007f) 233 goto exit_free; 234 } 235 236 /* Determine the chip type - only one kind supported! */ 237 if (kind <= 0) 238 kind = ds1621; 239 240 /* Fill in remaining client fields and put it into the global list */ 241 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE); 242 data->valid = 0; 243 init_MUTEX(&data->update_lock); 244 245 /* Tell the I2C layer a new client has arrived */ 246 if ((err = i2c_attach_client(new_client))) 247 goto exit_free; 248 249 /* Initialize the DS1621 chip */ 250 ds1621_init_client(new_client); 251 252 /* Register sysfs hooks */ 253 device_create_file(&new_client->dev, &dev_attr_alarms); 254 device_create_file(&new_client->dev, &dev_attr_temp1_input); 255 device_create_file(&new_client->dev, &dev_attr_temp1_min); 256 device_create_file(&new_client->dev, &dev_attr_temp1_max); 257 258 return 0; 259 260 /* OK, this is not exactly good programming practice, usually. But it is 261 very code-efficient in this case. */ 262 exit_free: 263 kfree(data); 264 exit: 265 return err; 266 } 267 268 static int ds1621_detach_client(struct i2c_client *client) 269 { 270 int err; 271 272 if ((err = i2c_detach_client(client))) { 273 dev_err(&client->dev, "Client deregistration failed, " 274 "client not detached.\n"); 275 return err; 276 } 277 278 kfree(i2c_get_clientdata(client)); 279 280 return 0; 281 } 282 283 284 static struct ds1621_data *ds1621_update_client(struct device *dev) 285 { 286 struct i2c_client *client = to_i2c_client(dev); 287 struct ds1621_data *data = i2c_get_clientdata(client); 288 u8 new_conf; 289 290 down(&data->update_lock); 291 292 if (time_after(jiffies, data->last_updated + HZ + HZ / 2) 293 || !data->valid) { 294 295 dev_dbg(&client->dev, "Starting ds1621 update\n"); 296 297 data->conf = ds1621_read_value(client, DS1621_REG_CONF); 298 299 data->temp = ds1621_read_value(client, DS1621_REG_TEMP); 300 301 data->temp_min = ds1621_read_value(client, 302 DS1621_REG_TEMP_MIN); 303 data->temp_max = ds1621_read_value(client, 304 DS1621_REG_TEMP_MAX); 305 306 /* reset alarms if necessary */ 307 new_conf = data->conf; 308 if (data->temp < data->temp_min) 309 new_conf &= ~DS1621_ALARM_TEMP_LOW; 310 if (data->temp > data->temp_max) 311 new_conf &= ~DS1621_ALARM_TEMP_HIGH; 312 if (data->conf != new_conf) 313 ds1621_write_value(client, DS1621_REG_CONF, 314 new_conf); 315 316 data->last_updated = jiffies; 317 data->valid = 1; 318 } 319 320 up(&data->update_lock); 321 322 return data; 323 } 324 325 static int __init ds1621_init(void) 326 { 327 return i2c_add_driver(&ds1621_driver); 328 } 329 330 static void __exit ds1621_exit(void) 331 { 332 i2c_del_driver(&ds1621_driver); 333 } 334 335 336 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); 337 MODULE_DESCRIPTION("DS1621 driver"); 338 MODULE_LICENSE("GPL"); 339 340 module_init(ds1621_init); 341 module_exit(ds1621_exit); 342