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" },
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
show_temp(struct device * dev,struct device_attribute * devattr,char * buf)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 */
w83l785ts_detect(struct i2c_client * client,struct i2c_board_info * info)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
w83l785ts_probe(struct i2c_client * client)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
w83l785ts_remove(struct i2c_client * client)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
w83l785ts_read_value(struct i2c_client * client,u8 reg,u8 defval)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
w83l785ts_update_device(struct device * dev)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