1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware 4 * monitoring 5 * Copyright (C) 2003-2009 Jean Delvare <jdelvare@suse.de> 6 * 7 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made 8 * by Winbond. It reports a single external temperature with a 1 deg 9 * resolution and a 3 deg accuracy. Datasheet can be obtained from 10 * Winbond's website at: 11 * http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf 12 * 13 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare 14 * <jdelvare@suse.de>. 15 * 16 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read 17 * error handling mechanism. 18 */ 19 20 #include <linux/module.h> 21 #include <linux/delay.h> 22 #include <linux/init.h> 23 #include <linux/slab.h> 24 #include <linux/jiffies.h> 25 #include <linux/i2c.h> 26 #include <linux/hwmon.h> 27 #include <linux/hwmon-sysfs.h> 28 #include <linux/err.h> 29 #include <linux/mutex.h> 30 31 /* How many retries on register read error */ 32 #define MAX_RETRIES 5 33 34 /* 35 * Address to scan 36 * Address is fully defined internally and cannot be changed. 37 */ 38 39 static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END }; 40 41 /* 42 * The W83L785TS-S registers 43 * Manufacturer ID is 0x5CA3 for Winbond. 44 */ 45 46 #define W83L785TS_REG_MAN_ID1 0x4D 47 #define W83L785TS_REG_MAN_ID2 0x4C 48 #define W83L785TS_REG_CHIP_ID 0x4E 49 #define W83L785TS_REG_CONFIG 0x40 50 #define W83L785TS_REG_TYPE 0x52 51 #define W83L785TS_REG_TEMP 0x27 52 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */ 53 54 /* 55 * Conversions 56 * The W83L785TS-S uses signed 8-bit values. 57 */ 58 59 #define TEMP_FROM_REG(val) ((val) * 1000) 60 61 /* 62 * Functions declaration 63 */ 64 65 static int w83l785ts_probe(struct i2c_client *client); 66 static int w83l785ts_detect(struct i2c_client *client, 67 struct i2c_board_info *info); 68 static void w83l785ts_remove(struct i2c_client *client); 69 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval); 70 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev); 71 72 /* 73 * Driver data (common to all clients) 74 */ 75 76 static const struct i2c_device_id w83l785ts_id[] = { 77 { "w83l785ts", 0 }, 78 { } 79 }; 80 MODULE_DEVICE_TABLE(i2c, w83l785ts_id); 81 82 static struct i2c_driver w83l785ts_driver = { 83 .class = I2C_CLASS_HWMON, 84 .driver = { 85 .name = "w83l785ts", 86 }, 87 .probe = w83l785ts_probe, 88 .remove = w83l785ts_remove, 89 .id_table = w83l785ts_id, 90 .detect = w83l785ts_detect, 91 .address_list = normal_i2c, 92 }; 93 94 /* 95 * Client data (each client gets its own) 96 */ 97 98 struct w83l785ts_data { 99 struct device *hwmon_dev; 100 struct mutex update_lock; 101 bool valid; /* false until following fields are valid */ 102 unsigned long last_updated; /* in jiffies */ 103 104 /* registers values */ 105 s8 temp[2]; /* 0: input, 1: critical limit */ 106 }; 107 108 /* 109 * Sysfs stuff 110 */ 111 112 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, 113 char *buf) 114 { 115 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); 116 struct w83l785ts_data *data = w83l785ts_update_device(dev); 117 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); 118 } 119 120 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); 121 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1); 122 123 /* 124 * Real code 125 */ 126 127 /* Return 0 if detection is successful, -ENODEV otherwise */ 128 static int w83l785ts_detect(struct i2c_client *client, 129 struct i2c_board_info *info) 130 { 131 struct i2c_adapter *adapter = client->adapter; 132 u16 man_id; 133 u8 chip_id; 134 135 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) 136 return -ENODEV; 137 138 /* detection */ 139 if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, 0) & 0x80) 140 || (w83l785ts_read_value(client, W83L785TS_REG_TYPE, 0) & 0xFC)) { 141 dev_dbg(&adapter->dev, 142 "W83L785TS-S detection failed at 0x%02x\n", 143 client->addr); 144 return -ENODEV; 145 } 146 147 /* Identification */ 148 man_id = (w83l785ts_read_value(client, W83L785TS_REG_MAN_ID1, 0) << 8) 149 + w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, 0); 150 chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, 0); 151 152 if (man_id != 0x5CA3 /* Winbond */ 153 || chip_id != 0x70) { /* W83L785TS-S */ 154 dev_dbg(&adapter->dev, 155 "Unsupported chip (man_id=0x%04X, chip_id=0x%02X)\n", 156 man_id, chip_id); 157 return -ENODEV; 158 } 159 160 strscpy(info->type, "w83l785ts", I2C_NAME_SIZE); 161 162 return 0; 163 } 164 165 static int w83l785ts_probe(struct i2c_client *client) 166 { 167 struct w83l785ts_data *data; 168 struct device *dev = &client->dev; 169 int err; 170 171 data = devm_kzalloc(dev, sizeof(struct w83l785ts_data), GFP_KERNEL); 172 if (!data) 173 return -ENOMEM; 174 175 i2c_set_clientdata(client, data); 176 mutex_init(&data->update_lock); 177 178 /* 179 * Initialize the W83L785TS chip 180 * Nothing yet, assume it is already started. 181 */ 182 183 err = device_create_file(dev, &sensor_dev_attr_temp1_input.dev_attr); 184 if (err) 185 return err; 186 187 err = device_create_file(dev, &sensor_dev_attr_temp1_max.dev_attr); 188 if (err) 189 goto exit_remove; 190 191 /* Register sysfs hooks */ 192 data->hwmon_dev = hwmon_device_register(dev); 193 if (IS_ERR(data->hwmon_dev)) { 194 err = PTR_ERR(data->hwmon_dev); 195 goto exit_remove; 196 } 197 198 return 0; 199 200 exit_remove: 201 device_remove_file(dev, &sensor_dev_attr_temp1_input.dev_attr); 202 device_remove_file(dev, &sensor_dev_attr_temp1_max.dev_attr); 203 return err; 204 } 205 206 static void w83l785ts_remove(struct i2c_client *client) 207 { 208 struct w83l785ts_data *data = i2c_get_clientdata(client); 209 210 hwmon_device_unregister(data->hwmon_dev); 211 device_remove_file(&client->dev, 212 &sensor_dev_attr_temp1_input.dev_attr); 213 device_remove_file(&client->dev, 214 &sensor_dev_attr_temp1_max.dev_attr); 215 } 216 217 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval) 218 { 219 int value, i; 220 struct device *dev; 221 const char *prefix; 222 223 /* 224 * We might be called during detection, at which point the client 225 * isn't yet fully initialized, so we can't use dev_dbg on it 226 */ 227 if (i2c_get_clientdata(client)) { 228 dev = &client->dev; 229 prefix = ""; 230 } else { 231 dev = &client->adapter->dev; 232 prefix = "w83l785ts: "; 233 } 234 235 /* 236 * Frequent read errors have been reported on Asus boards, so we 237 * retry on read errors. If it still fails (unlikely), return the 238 * default value requested by the caller. 239 */ 240 for (i = 1; i <= MAX_RETRIES; i++) { 241 value = i2c_smbus_read_byte_data(client, reg); 242 if (value >= 0) { 243 dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n", 244 prefix, value, reg); 245 return value; 246 } 247 dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i); 248 msleep(i); 249 } 250 251 dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix, 252 reg); 253 return defval; 254 } 255 256 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev) 257 { 258 struct i2c_client *client = to_i2c_client(dev); 259 struct w83l785ts_data *data = i2c_get_clientdata(client); 260 261 mutex_lock(&data->update_lock); 262 263 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) { 264 dev_dbg(&client->dev, "Updating w83l785ts data.\n"); 265 data->temp[0] = w83l785ts_read_value(client, 266 W83L785TS_REG_TEMP, data->temp[0]); 267 data->temp[1] = w83l785ts_read_value(client, 268 W83L785TS_REG_TEMP_OVER, data->temp[1]); 269 270 data->last_updated = jiffies; 271 data->valid = true; 272 } 273 274 mutex_unlock(&data->update_lock); 275 276 return data; 277 } 278 279 module_i2c_driver(w83l785ts_driver); 280 281 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); 282 MODULE_DESCRIPTION("W83L785TS-S driver"); 283 MODULE_LICENSE("GPL"); 284