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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware4 * monitoring5 * Copyright (C) 2003-2009 Jean Delvare <jdelvare@suse.de>6 *7 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made8 * by Winbond. It reports a single external temperature with a 1 deg9 * resolution and a 3 deg accuracy. Datasheet can be obtained from10 * Winbond's website at:11 * http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf12 *13 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare14 * <jdelvare@suse.de>.15 *16 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read17 * 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 533 34/*35 * Address to scan36 * Address is fully defined internally and cannot be changed.37 */38 39static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };40 41/*42 * The W83L785TS-S registers43 * Manufacturer ID is 0x5CA3 for Winbond.44 */45 46#define W83L785TS_REG_MAN_ID1 0x4D47#define W83L785TS_REG_MAN_ID2 0x4C48#define W83L785TS_REG_CHIP_ID 0x4E49#define W83L785TS_REG_CONFIG 0x4050#define W83L785TS_REG_TYPE 0x5251#define W83L785TS_REG_TEMP 0x2752#define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */53 54/*55 * Conversions56 * The W83L785TS-S uses signed 8-bit values.57 */58 59#define TEMP_FROM_REG(val) ((val) * 1000)60 61/*62 * Functions declaration63 */64 65static int w83l785ts_probe(struct i2c_client *client);66static int w83l785ts_detect(struct i2c_client *client,67 struct i2c_board_info *info);68static void w83l785ts_remove(struct i2c_client *client);69static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);70static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);71 72/*73 * Driver data (common to all clients)74 */75 76static const struct i2c_device_id w83l785ts_id[] = {77 { "w83l785ts" },78 { }79};80MODULE_DEVICE_TABLE(i2c, w83l785ts_id);81 82static 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 98struct 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 stuff110 */111 112static 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 120static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);121static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);122 123/*124 * Real code125 */126 127/* Return 0 if detection is successful, -ENODEV otherwise */128static 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 165static 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 chip180 * 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 200exit_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 206static 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 217static 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 client225 * isn't yet fully initialized, so we can't use dev_dbg on it226 */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 we237 * retry on read errors. If it still fails (unlikely), return the238 * 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 256static 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 279module_i2c_driver(w83l785ts_driver);280 281MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");282MODULE_DESCRIPTION("W83L785TS-S driver");283MODULE_LICENSE("GPL");284