1 /* 2 * LM73 Sensor driver 3 * Based on LM75 4 * 5 * Copyright (C) 2007, CenoSYS (www.cenosys.com). 6 * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu). 7 * 8 * Guillaume Ligneul <guillaume.ligneul@gmail.com> 9 * Adrien Demarez <adrien.demarez@bolloretelecom.eu> 10 * Jeremy Laine <jeremy.laine@bolloretelecom.eu> 11 * Chris Verges <kg4ysn@gmail.com> 12 * 13 * This software program is licensed subject to the GNU General Public License 14 * (GPL).Version 2,June 1991, available at 15 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html 16 */ 17 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/i2c.h> 21 #include <linux/hwmon.h> 22 #include <linux/hwmon-sysfs.h> 23 #include <linux/err.h> 24 25 26 /* Addresses scanned */ 27 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, 28 0x4d, 0x4e, I2C_CLIENT_END }; 29 30 /* LM73 registers */ 31 #define LM73_REG_INPUT 0x00 32 #define LM73_REG_CONF 0x01 33 #define LM73_REG_MAX 0x02 34 #define LM73_REG_MIN 0x03 35 #define LM73_REG_CTRL 0x04 36 #define LM73_REG_ID 0x07 37 38 #define LM73_ID 0x9001 /* 0x0190, byte-swapped */ 39 #define DRVNAME "lm73" 40 #define LM73_TEMP_MIN (-256000 / 250) 41 #define LM73_TEMP_MAX (255750 / 250) 42 43 #define LM73_CTRL_RES_SHIFT 5 44 #define LM73_CTRL_RES_MASK (BIT(5) | BIT(6)) 45 #define LM73_CTRL_TO_MASK BIT(7) 46 47 #define LM73_CTRL_HI_SHIFT 2 48 #define LM73_CTRL_LO_SHIFT 1 49 50 static const unsigned short lm73_convrates[] = { 51 14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */ 52 28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */ 53 56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */ 54 112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */ 55 }; 56 57 struct lm73_data { 58 struct device *hwmon_dev; 59 struct mutex lock; 60 u8 ctrl; /* control register value */ 61 }; 62 63 /*-----------------------------------------------------------------------*/ 64 65 static ssize_t set_temp(struct device *dev, struct device_attribute *da, 66 const char *buf, size_t count) 67 { 68 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 69 struct i2c_client *client = to_i2c_client(dev); 70 long temp; 71 short value; 72 s32 err; 73 74 int status = kstrtol(buf, 10, &temp); 75 if (status < 0) 76 return status; 77 78 /* Write value */ 79 value = clamp_val(temp / 250, LM73_TEMP_MIN, LM73_TEMP_MAX) << 5; 80 err = i2c_smbus_write_word_swapped(client, attr->index, value); 81 return (err < 0) ? err : count; 82 } 83 84 static ssize_t show_temp(struct device *dev, struct device_attribute *da, 85 char *buf) 86 { 87 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 88 struct i2c_client *client = to_i2c_client(dev); 89 int temp; 90 91 s32 err = i2c_smbus_read_word_swapped(client, attr->index); 92 if (err < 0) 93 return err; 94 95 /* use integer division instead of equivalent right shift to 96 guarantee arithmetic shift and preserve the sign */ 97 temp = (((s16) err) * 250) / 32; 98 return scnprintf(buf, PAGE_SIZE, "%d\n", temp); 99 } 100 101 static ssize_t set_convrate(struct device *dev, struct device_attribute *da, 102 const char *buf, size_t count) 103 { 104 struct i2c_client *client = to_i2c_client(dev); 105 struct lm73_data *data = i2c_get_clientdata(client); 106 unsigned long convrate; 107 s32 err; 108 int res = 0; 109 110 err = kstrtoul(buf, 10, &convrate); 111 if (err < 0) 112 return err; 113 114 /* 115 * Convert the desired conversion rate into register bits. 116 * res is already initialized, and everything past the second-to-last 117 * value in the array is treated as belonging to the last value 118 * in the array. 119 */ 120 while (res < (ARRAY_SIZE(lm73_convrates) - 1) && 121 convrate > lm73_convrates[res]) 122 res++; 123 124 mutex_lock(&data->lock); 125 data->ctrl &= LM73_CTRL_TO_MASK; 126 data->ctrl |= res << LM73_CTRL_RES_SHIFT; 127 err = i2c_smbus_write_byte_data(client, LM73_REG_CTRL, data->ctrl); 128 mutex_unlock(&data->lock); 129 130 if (err < 0) 131 return err; 132 133 return count; 134 } 135 136 static ssize_t show_convrate(struct device *dev, struct device_attribute *da, 137 char *buf) 138 { 139 struct i2c_client *client = to_i2c_client(dev); 140 struct lm73_data *data = i2c_get_clientdata(client); 141 int res; 142 143 res = (data->ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT; 144 return scnprintf(buf, PAGE_SIZE, "%hu\n", lm73_convrates[res]); 145 } 146 147 static ssize_t show_maxmin_alarm(struct device *dev, 148 struct device_attribute *da, char *buf) 149 { 150 struct i2c_client *client = to_i2c_client(dev); 151 struct sensor_device_attribute *attr = to_sensor_dev_attr(da); 152 struct lm73_data *data = i2c_get_clientdata(client); 153 s32 ctrl; 154 155 mutex_lock(&data->lock); 156 ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL); 157 if (ctrl < 0) 158 goto abort; 159 data->ctrl = ctrl; 160 mutex_unlock(&data->lock); 161 162 return scnprintf(buf, PAGE_SIZE, "%d\n", (ctrl >> attr->index) & 1); 163 164 abort: 165 mutex_unlock(&data->lock); 166 return ctrl; 167 } 168 169 /*-----------------------------------------------------------------------*/ 170 171 /* sysfs attributes for hwmon */ 172 173 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, 174 show_temp, set_temp, LM73_REG_MAX); 175 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, 176 show_temp, set_temp, LM73_REG_MIN); 177 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, 178 show_temp, NULL, LM73_REG_INPUT); 179 static SENSOR_DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, 180 show_convrate, set_convrate, 0); 181 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, 182 show_maxmin_alarm, NULL, LM73_CTRL_HI_SHIFT); 183 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, 184 show_maxmin_alarm, NULL, LM73_CTRL_LO_SHIFT); 185 186 static struct attribute *lm73_attributes[] = { 187 &sensor_dev_attr_temp1_input.dev_attr.attr, 188 &sensor_dev_attr_temp1_max.dev_attr.attr, 189 &sensor_dev_attr_temp1_min.dev_attr.attr, 190 &sensor_dev_attr_update_interval.dev_attr.attr, 191 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, 192 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, 193 NULL 194 }; 195 196 static const struct attribute_group lm73_group = { 197 .attrs = lm73_attributes, 198 }; 199 200 /*-----------------------------------------------------------------------*/ 201 202 /* device probe and removal */ 203 204 static int 205 lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) 206 { 207 int status; 208 struct lm73_data *data; 209 int ctrl; 210 211 data = devm_kzalloc(&client->dev, sizeof(struct lm73_data), 212 GFP_KERNEL); 213 if (!data) 214 return -ENOMEM; 215 216 i2c_set_clientdata(client, data); 217 mutex_init(&data->lock); 218 219 ctrl = i2c_smbus_read_byte_data(client, LM73_REG_CTRL); 220 if (ctrl < 0) 221 return ctrl; 222 data->ctrl = ctrl; 223 224 /* Register sysfs hooks */ 225 status = sysfs_create_group(&client->dev.kobj, &lm73_group); 226 if (status) 227 return status; 228 229 data->hwmon_dev = hwmon_device_register(&client->dev); 230 if (IS_ERR(data->hwmon_dev)) { 231 status = PTR_ERR(data->hwmon_dev); 232 goto exit_remove; 233 } 234 235 dev_info(&client->dev, "%s: sensor '%s'\n", 236 dev_name(data->hwmon_dev), client->name); 237 238 return 0; 239 240 exit_remove: 241 sysfs_remove_group(&client->dev.kobj, &lm73_group); 242 return status; 243 } 244 245 static int lm73_remove(struct i2c_client *client) 246 { 247 struct lm73_data *data = i2c_get_clientdata(client); 248 249 hwmon_device_unregister(data->hwmon_dev); 250 sysfs_remove_group(&client->dev.kobj, &lm73_group); 251 return 0; 252 } 253 254 static const struct i2c_device_id lm73_ids[] = { 255 { "lm73", 0 }, 256 { /* LIST END */ } 257 }; 258 MODULE_DEVICE_TABLE(i2c, lm73_ids); 259 260 /* Return 0 if detection is successful, -ENODEV otherwise */ 261 static int lm73_detect(struct i2c_client *new_client, 262 struct i2c_board_info *info) 263 { 264 struct i2c_adapter *adapter = new_client->adapter; 265 int id, ctrl, conf; 266 267 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | 268 I2C_FUNC_SMBUS_WORD_DATA)) 269 return -ENODEV; 270 271 /* 272 * Do as much detection as possible with byte reads first, as word 273 * reads can confuse other devices. 274 */ 275 ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL); 276 if (ctrl < 0 || (ctrl & 0x10)) 277 return -ENODEV; 278 279 conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF); 280 if (conf < 0 || (conf & 0x0c)) 281 return -ENODEV; 282 283 id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID); 284 if (id < 0 || id != (LM73_ID & 0xff)) 285 return -ENODEV; 286 287 /* Check device ID */ 288 id = i2c_smbus_read_word_data(new_client, LM73_REG_ID); 289 if (id < 0 || id != LM73_ID) 290 return -ENODEV; 291 292 strlcpy(info->type, "lm73", I2C_NAME_SIZE); 293 294 return 0; 295 } 296 297 static struct i2c_driver lm73_driver = { 298 .class = I2C_CLASS_HWMON, 299 .driver = { 300 .name = "lm73", 301 }, 302 .probe = lm73_probe, 303 .remove = lm73_remove, 304 .id_table = lm73_ids, 305 .detect = lm73_detect, 306 .address_list = normal_i2c, 307 }; 308 309 module_i2c_driver(lm73_driver); 310 311 MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>"); 312 MODULE_DESCRIPTION("LM73 driver"); 313 MODULE_LICENSE("GPL"); 314