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/config.h>
34 #include <linux/module.h>
35 #include <linux/delay.h>
36 #include <linux/init.h>
37 #include <linux/slab.h>
38 #include <linux/i2c.h>
39 #include <linux/i2c-sensor.h>
40
41 /* How many retries on register read error */
42 #define MAX_RETRIES 5
43
44 /*
45 * Address to scan
46 * Address is fully defined internally and cannot be changed.
47 */
48
49 static unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
50 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
51
52 /*
53 * Insmod parameters
54 */
55
56 SENSORS_INSMOD_1(w83l785ts);
57
58 /*
59 * The W83L785TS-S registers
60 * Manufacturer ID is 0x5CA3 for Winbond.
61 */
62
63 #define W83L785TS_REG_MAN_ID1 0x4D
64 #define W83L785TS_REG_MAN_ID2 0x4C
65 #define W83L785TS_REG_CHIP_ID 0x4E
66 #define W83L785TS_REG_CONFIG 0x40
67 #define W83L785TS_REG_TYPE 0x52
68 #define W83L785TS_REG_TEMP 0x27
69 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */
70
71 /*
72 * Conversions
73 * The W83L785TS-S uses signed 8-bit values.
74 */
75
76 #define TEMP_FROM_REG(val) ((val & 0x80 ? val-0x100 : val) * 1000)
77
78 /*
79 * Functions declaration
80 */
81
82 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter);
83 static int w83l785ts_detect(struct i2c_adapter *adapter, int address,
84 int kind);
85 static int w83l785ts_detach_client(struct i2c_client *client);
86 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
87 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);
88
89 /*
90 * Driver data (common to all clients)
91 */
92
93 static struct i2c_driver w83l785ts_driver = {
94 .owner = THIS_MODULE,
95 .name = "w83l785ts",
96 .id = I2C_DRIVERID_W83L785TS,
97 .flags = I2C_DF_NOTIFY,
98 .attach_adapter = w83l785ts_attach_adapter,
99 .detach_client = w83l785ts_detach_client,
100 };
101
102 /*
103 * Client data (each client gets its own)
104 */
105
106 struct w83l785ts_data {
107 struct i2c_client client;
108 struct semaphore update_lock;
109 char valid; /* zero until following fields are valid */
110 unsigned long last_updated; /* in jiffies */
111
112 /* registers values */
113 u8 temp, temp_over;
114 };
115
116 /*
117 * Internal variables
118 */
119
120 static int w83l785ts_id = 0;
121
122 /*
123 * Sysfs stuff
124 */
125
126 static ssize_t show_temp(struct device *dev, char *buf)
127 {
128 struct w83l785ts_data *data = w83l785ts_update_device(dev);
129 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp));
130 }
131
132 static ssize_t show_temp_over(struct device *dev, char *buf)
133 {
134 struct w83l785ts_data *data = w83l785ts_update_device(dev);
135 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_over));
136 }
137
138 static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
139 static DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_over, NULL);
140
141 /*
142 * Real code
143 */
144
145 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter)
146 {
147 if (!(adapter->class & I2C_CLASS_HWMON))
148 return 0;
149 return i2c_detect(adapter, &addr_data, w83l785ts_detect);
150 }
151
152 /*
153 * The following function does more than just detection. If detection
154 * succeeds, it also registers the new chip.
155 */
156 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind)
157 {
158 struct i2c_client *new_client;
159 struct w83l785ts_data *data;
160 int err = 0;
161
162
163 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
164 goto exit;
165
166 if (!(data = kmalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) {
167 err = -ENOMEM;
168 goto exit;
169 }
170 memset(data, 0, sizeof(struct w83l785ts_data));
171
172
173 /* The common I2C client data is placed right before the
174 * W83L785TS-specific data. */
175 new_client = &data->client;
176 i2c_set_clientdata(new_client, data);
177 new_client->addr = address;
178 new_client->adapter = adapter;
179 new_client->driver = &w83l785ts_driver;
180 new_client->flags = 0;
181
182 /*
183 * Now we do the remaining detection. A negative kind means that
184 * the driver was loaded with no force parameter (default), so we
185 * must both detect and identify the chip (actually there is only
186 * one possible kind of chip for now, W83L785TS-S). A zero kind means
187 * that the driver was loaded with the force parameter, the detection
188 * step shall be skipped. A positive kind means that the driver
189 * was loaded with the force parameter and a given kind of chip is
190 * requested, so both the detection and the identification steps
191 * are skipped.
192 */
193 if (kind < 0) { /* detection */
194 if (((w83l785ts_read_value(new_client,
195 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00)
196 || ((w83l785ts_read_value(new_client,
197 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) {
198 dev_dbg(&adapter->dev,
199 "W83L785TS-S detection failed at 0x%02x.\n",
200 address);
201 goto exit_free;
202 }
203 }
204
205 if (kind <= 0) { /* identification */
206 u16 man_id;
207 u8 chip_id;
208
209 man_id = (w83l785ts_read_value(new_client,
210 W83L785TS_REG_MAN_ID1, 0) << 8) +
211 w83l785ts_read_value(new_client,
212 W83L785TS_REG_MAN_ID2, 0);
213 chip_id = w83l785ts_read_value(new_client,
214 W83L785TS_REG_CHIP_ID, 0);
215
216 if (man_id == 0x5CA3) { /* Winbond */
217 if (chip_id == 0x70) { /* W83L785TS-S */
218 kind = w83l785ts;
219 }
220 }
221
222 if (kind <= 0) { /* identification failed */
223 dev_info(&adapter->dev,
224 "Unsupported chip (man_id=0x%04X, "
225 "chip_id=0x%02X).\n", man_id, chip_id);
226 goto exit_free;
227 }
228 }
229
230 /* We can fill in the remaining client fields. */
231 strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE);
232 new_client->id = w83l785ts_id++;
233 data->valid = 0;
234 init_MUTEX(&data->update_lock);
235
236 /* Default values in case the first read fails (unlikely). */
237 data->temp_over = data->temp = 0;
238
239 /* Tell the I2C layer a new client has arrived. */
240 if ((err = i2c_attach_client(new_client)))
241 goto exit_free;
242
243 /*
244 * Initialize the W83L785TS chip
245 * Nothing yet, assume it is already started.
246 */
247
248 /* Register sysfs hooks */
249 device_create_file(&new_client->dev, &dev_attr_temp1_input);
250 device_create_file(&new_client->dev, &dev_attr_temp1_max);
251
252 return 0;
253
254 exit_free:
255 kfree(data);
256 exit:
257 return err;
258 }
259
260 static int w83l785ts_detach_client(struct i2c_client *client)
261 {
262 int err;
263
264 if ((err = i2c_detach_client(client))) {
265 dev_err(&client->dev, "Client deregistration failed, "
266 "client not detached.\n");
267 return err;
268 }
269
270 kfree(i2c_get_clientdata(client));
271 return 0;
272 }
273
274 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
275 {
276 int value, i;
277
278 /* Frequent read errors have been reported on Asus boards, so we
279 * retry on read errors. If it still fails (unlikely), return the
280 * default value requested by the caller. */
281 for (i = 1; i <= MAX_RETRIES; i++) {
282 value = i2c_smbus_read_byte_data(client, reg);
283 if (value >= 0) {
284 dev_dbg(&client->dev, "Read 0x%02x from register "
285 "0x%02x.\n", value, reg);
286 return value;
287 }
288 dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i);
289 msleep(i);
290 }
291
292 dev_err(&client->dev, "Couldn't read value from register 0x%02x. "
293 "Please report.\n", reg);
294 return defval;
295 }
296
297 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
298 {
299 struct i2c_client *client = to_i2c_client(dev);
300 struct w83l785ts_data *data = i2c_get_clientdata(client);
301
302 down(&data->update_lock);
303
304 if (!data->valid
305 || (jiffies - data->last_updated > HZ * 2)
306 || (jiffies < data->last_updated)) {
307 dev_dbg(&client->dev, "Updating w83l785ts data.\n");
308 data->temp = w83l785ts_read_value(client,
309 W83L785TS_REG_TEMP, data->temp);
310 data->temp_over = w83l785ts_read_value(client,
311 W83L785TS_REG_TEMP_OVER, data->temp_over);
312
313 data->last_updated = jiffies;
314 data->valid = 1;
315 }
316
317 up(&data->update_lock);
318
319 return data;
320 }
321
322 static int __init sensors_w83l785ts_init(void)
323 {
324 return i2c_add_driver(&w83l785ts_driver);
325 }
326
327 static void __exit sensors_w83l785ts_exit(void)
328 {
329 i2c_del_driver(&w83l785ts_driver);
330 }
331
332 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
333 MODULE_DESCRIPTION("W83L785TS-S driver");
334 MODULE_LICENSE("GPL");
335
336 module_init(sensors_w83l785ts_init);
337 module_exit(sensors_w83l785ts_exit);
338
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