1 /*
2 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
3 * monitoring
4 * Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
5 *
6 * Inspired from the lm83 driver. The W83L785TS-S is a sensor chip made
7 * by Winbond. It reports a single external temperature with a 1 deg
8 * resolution and a 3 deg accuracy. Datasheet can be obtained from
9 * Winbond's website at:
10 * http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83L785TS-S.pdf
11 *
12 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
13 * <khali@linux-fr.org>.
14 *
15 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
16 * error handling mechanism.
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2 of the License, or
21 * (at your option) any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 * GNU General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program; if not, write to the Free Software
30 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
31 */
32
33 #include <linux/module.h>
34 #include <linux/delay.h>
35 #include <linux/init.h>
36 #include <linux/slab.h>
37 #include <linux/jiffies.h>
38 #include <linux/i2c.h>
39 #include <linux/hwmon.h>
40 #include <linux/hwmon-sysfs.h>
41 #include <linux/err.h>
42 #include <linux/mutex.h>
43
44 /* How many retries on register read error */
45 #define MAX_RETRIES 5
46
47 /*
48 * Address to scan
49 * Address is fully defined internally and cannot be changed.
50 */
51
52 static const unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
53
54 /*
55 * Insmod parameters
56 */
57
58 I2C_CLIENT_INSMOD_1(w83l785ts);
59
60 /*
61 * The W83L785TS-S registers
62 * Manufacturer ID is 0x5CA3 for Winbond.
63 */
64
65 #define W83L785TS_REG_MAN_ID1 0x4D
66 #define W83L785TS_REG_MAN_ID2 0x4C
67 #define W83L785TS_REG_CHIP_ID 0x4E
68 #define W83L785TS_REG_CONFIG 0x40
69 #define W83L785TS_REG_TYPE 0x52
70 #define W83L785TS_REG_TEMP 0x27
71 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */
72
73 /*
74 * Conversions
75 * The W83L785TS-S uses signed 8-bit values.
76 */
77
78 #define TEMP_FROM_REG(val) ((val) * 1000)
79
80 /*
81 * Functions declaration
82 */
83
84 static int w83l785ts_probe(struct i2c_client *client,
85 const struct i2c_device_id *id);
86 static int w83l785ts_detect(struct i2c_client *client, int kind,
87 struct i2c_board_info *info);
88 static int w83l785ts_remove(struct i2c_client *client);
89 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
90 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);
91
92 /*
93 * Driver data (common to all clients)
94 */
95
96 static const struct i2c_device_id w83l785ts_id[] = {
97 { "w83l785ts", w83l785ts },
98 { }
99 };
100 MODULE_DEVICE_TABLE(i2c, w83l785ts_id);
101
102 static struct i2c_driver w83l785ts_driver = {
103 .class = I2C_CLASS_HWMON,
104 .driver = {
105 .name = "w83l785ts",
106 },
107 .probe = w83l785ts_probe,
108 .remove = w83l785ts_remove,
109 .id_table = w83l785ts_id,
110 .detect = w83l785ts_detect,
111 .address_data = &addr_data,
112 };
113
114 /*
115 * Client data (each client gets its own)
116 */
117
118 struct w83l785ts_data {
119 struct device *hwmon_dev;
120 struct mutex update_lock;
121 char valid; /* zero until following fields are valid */
122 unsigned long last_updated; /* in jiffies */
123
124 /* registers values */
125 s8 temp[2]; /* 0: input
126 1: critical limit */
127 };
128
129 /*
130 * Sysfs stuff
131 */
132
133 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
134 char *buf)
135 {
136 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
137 struct w83l785ts_data *data = w83l785ts_update_device(dev);
138 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
139 }
140
141 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
142 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);
143
144 /*
145 * Real code
146 */
147
148 /* Return 0 if detection is successful, -ENODEV otherwise */
149 static int w83l785ts_detect(struct i2c_client *new_client, int kind,
150 struct i2c_board_info *info)
151 {
152 struct i2c_adapter *adapter = new_client->adapter;
153
154 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
155 return -ENODEV;
156
157 /*
158 * Now we do the remaining detection. A negative kind means that
159 * the driver was loaded with no force parameter (default), so we
160 * must both detect and identify the chip (actually there is only
161 * one possible kind of chip for now, W83L785TS-S). A zero kind means
162 * that the driver was loaded with the force parameter, the detection
163 * step shall be skipped. A positive kind means that the driver
164 * was loaded with the force parameter and a given kind of chip is
165 * requested, so both the detection and the identification steps
166 * are skipped.
167 */
168 if (kind < 0) { /* detection */
169 if (((w83l785ts_read_value(new_client,
170 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00)
171 || ((w83l785ts_read_value(new_client,
172 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) {
173 dev_dbg(&adapter->dev,
174 "W83L785TS-S detection failed at 0x%02x.\n",
175 new_client->addr);
176 return -ENODEV;
177 }
178 }
179
180 if (kind <= 0) { /* identification */
181 u16 man_id;
182 u8 chip_id;
183
184 man_id = (w83l785ts_read_value(new_client,
185 W83L785TS_REG_MAN_ID1, 0) << 8) +
186 w83l785ts_read_value(new_client,
187 W83L785TS_REG_MAN_ID2, 0);
188 chip_id = w83l785ts_read_value(new_client,
189 W83L785TS_REG_CHIP_ID, 0);
190
191 if (man_id == 0x5CA3) { /* Winbond */
192 if (chip_id == 0x70) { /* W83L785TS-S */
193 kind = w83l785ts;
194 }
195 }
196
197 if (kind <= 0) { /* identification failed */
198 dev_info(&adapter->dev,
199 "Unsupported chip (man_id=0x%04X, "
200 "chip_id=0x%02X).\n", man_id, chip_id);
201 return -ENODEV;
202 }
203 }
204
205 strlcpy(info->type, "w83l785ts", I2C_NAME_SIZE);
206
207 return 0;
208 }
209
210 static int w83l785ts_probe(struct i2c_client *new_client,
211 const struct i2c_device_id *id)
212 {
213 struct w83l785ts_data *data;
214 int err = 0;
215
216 data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL);
217 if (!data) {
218 err = -ENOMEM;
219 goto exit;
220 }
221
222 i2c_set_clientdata(new_client, data);
223 data->valid = 0;
224 mutex_init(&data->update_lock);
225
226 /* Default values in case the first read fails (unlikely). */
227 data->temp[1] = data->temp[0] = 0;
228
229 /*
230 * Initialize the W83L785TS chip
231 * Nothing yet, assume it is already started.
232 */
233
234 err = device_create_file(&new_client->dev,
235 &sensor_dev_attr_temp1_input.dev_attr);
236 if (err)
237 goto exit_remove;
238
239 err = device_create_file(&new_client->dev,
240 &sensor_dev_attr_temp1_max.dev_attr);
241 if (err)
242 goto exit_remove;
243
244 /* Register sysfs hooks */
245 data->hwmon_dev = hwmon_device_register(&new_client->dev);
246 if (IS_ERR(data->hwmon_dev)) {
247 err = PTR_ERR(data->hwmon_dev);
248 goto exit_remove;
249 }
250
251 return 0;
252
253 exit_remove:
254 device_remove_file(&new_client->dev,
255 &sensor_dev_attr_temp1_input.dev_attr);
256 device_remove_file(&new_client->dev,
257 &sensor_dev_attr_temp1_max.dev_attr);
258 kfree(data);
259 exit:
260 return err;
261 }
262
263 static int w83l785ts_remove(struct i2c_client *client)
264 {
265 struct w83l785ts_data *data = i2c_get_clientdata(client);
266
267 hwmon_device_unregister(data->hwmon_dev);
268 device_remove_file(&client->dev,
269 &sensor_dev_attr_temp1_input.dev_attr);
270 device_remove_file(&client->dev,
271 &sensor_dev_attr_temp1_max.dev_attr);
272
273 kfree(data);
274 return 0;
275 }
276
277 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
278 {
279 int value, i;
280 struct device *dev;
281 const char *prefix;
282
283 /* We might be called during detection, at which point the client
284 isn't yet fully initialized, so we can't use dev_dbg on it */
285 if (i2c_get_clientdata(client)) {
286 dev = &client->dev;
287 prefix = "";
288 } else {
289 dev = &client->adapter->dev;
290 prefix = "w83l785ts: ";
291 }
292
293 /* Frequent read errors have been reported on Asus boards, so we
294 * retry on read errors. If it still fails (unlikely), return the
295 * default value requested by the caller. */
296 for (i = 1; i <= MAX_RETRIES; i++) {
297 value = i2c_smbus_read_byte_data(client, reg);
298 if (value >= 0) {
299 dev_dbg(dev, "%sRead 0x%02x from register 0x%02x.\n",
300 prefix, value, reg);
301 return value;
302 }
303 dev_dbg(dev, "%sRead failed, will retry in %d.\n", prefix, i);
304 msleep(i);
305 }
306
307 dev_err(dev, "%sCouldn't read value from register 0x%02x.\n", prefix,
308 reg);
309 return defval;
310 }
311
312 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
313 {
314 struct i2c_client *client = to_i2c_client(dev);
315 struct w83l785ts_data *data = i2c_get_clientdata(client);
316
317 mutex_lock(&data->update_lock);
318
319 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
320 dev_dbg(&client->dev, "Updating w83l785ts data.\n");
321 data->temp[0] = w83l785ts_read_value(client,
322 W83L785TS_REG_TEMP, data->temp[0]);
323 data->temp[1] = w83l785ts_read_value(client,
324 W83L785TS_REG_TEMP_OVER, data->temp[1]);
325
326 data->last_updated = jiffies;
327 data->valid = 1;
328 }
329
330 mutex_unlock(&data->update_lock);
331
332 return data;
333 }
334
335 static int __init sensors_w83l785ts_init(void)
336 {
337 return i2c_add_driver(&w83l785ts_driver);
338 }
339
340 static void __exit sensors_w83l785ts_exit(void)
341 {
342 i2c_del_driver(&w83l785ts_driver);
343 }
344
345 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
346 MODULE_DESCRIPTION("W83L785TS-S driver");
347 MODULE_LICENSE("GPL");
348
349 module_init(sensors_w83l785ts_init);
350 module_exit(sensors_w83l785ts_exit);
351
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