2 * w83l785ts.c - Part of lm_sensors, Linux kernel modules for hardware
4 * Copyright (C) 2003-2004 Jean Delvare <khali@linux-fr.org>
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
12 * Ported to Linux 2.6 by Wolfgang Ziegler <nuppla@gmx.at> and Jean Delvare
13 * <khali@linux-fr.org>.
15 * Thanks to James Bolt <james@evilpenguin.com> for benchmarking the read
16 * error handling mechanism.
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.
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.
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.
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>
43 /* How many retries on register read error */
48 * Address is fully defined internally and cannot be changed.
51 static unsigned short normal_i2c[] = { 0x2e, I2C_CLIENT_END };
57 I2C_CLIENT_INSMOD_1(w83l785ts);
60 * The W83L785TS-S registers
61 * Manufacturer ID is 0x5CA3 for Winbond.
64 #define W83L785TS_REG_MAN_ID1 0x4D
65 #define W83L785TS_REG_MAN_ID2 0x4C
66 #define W83L785TS_REG_CHIP_ID 0x4E
67 #define W83L785TS_REG_CONFIG 0x40
68 #define W83L785TS_REG_TYPE 0x52
69 #define W83L785TS_REG_TEMP 0x27
70 #define W83L785TS_REG_TEMP_OVER 0x53 /* not sure about this one */
74 * The W83L785TS-S uses signed 8-bit values.
77 #define TEMP_FROM_REG(val) ((val) * 1000)
80 * Functions declaration
83 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter);
84 static int w83l785ts_detect(struct i2c_adapter *adapter, int address,
86 static int w83l785ts_detach_client(struct i2c_client *client);
87 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval);
88 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev);
91 * Driver data (common to all clients)
94 static struct i2c_driver w83l785ts_driver = {
97 .id = I2C_DRIVERID_W83L785TS,
98 .attach_adapter = w83l785ts_attach_adapter,
99 .detach_client = w83l785ts_detach_client,
103 * Client data (each client gets its own)
106 struct w83l785ts_data {
107 struct i2c_client client;
108 struct class_device *class_dev;
109 struct semaphore update_lock;
110 char valid; /* zero until following fields are valid */
111 unsigned long last_updated; /* in jiffies */
113 /* registers values */
114 s8 temp[2]; /* 0: input
122 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
125 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
126 struct w83l785ts_data *data = w83l785ts_update_device(dev);
127 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
130 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
131 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 1);
137 static int w83l785ts_attach_adapter(struct i2c_adapter *adapter)
139 if (!(adapter->class & I2C_CLASS_HWMON))
141 return i2c_probe(adapter, &addr_data, w83l785ts_detect);
145 * The following function does more than just detection. If detection
146 * succeeds, it also registers the new chip.
148 static int w83l785ts_detect(struct i2c_adapter *adapter, int address, int kind)
150 struct i2c_client *new_client;
151 struct w83l785ts_data *data;
155 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
158 if (!(data = kzalloc(sizeof(struct w83l785ts_data), GFP_KERNEL))) {
163 /* The common I2C client data is placed right before the
164 * W83L785TS-specific data. */
165 new_client = &data->client;
166 i2c_set_clientdata(new_client, data);
167 new_client->addr = address;
168 new_client->adapter = adapter;
169 new_client->driver = &w83l785ts_driver;
170 new_client->flags = 0;
173 * Now we do the remaining detection. A negative kind means that
174 * the driver was loaded with no force parameter (default), so we
175 * must both detect and identify the chip (actually there is only
176 * one possible kind of chip for now, W83L785TS-S). A zero kind means
177 * that the driver was loaded with the force parameter, the detection
178 * step shall be skipped. A positive kind means that the driver
179 * was loaded with the force parameter and a given kind of chip is
180 * requested, so both the detection and the identification steps
183 if (kind < 0) { /* detection */
184 if (((w83l785ts_read_value(new_client,
185 W83L785TS_REG_CONFIG, 0) & 0x80) != 0x00)
186 || ((w83l785ts_read_value(new_client,
187 W83L785TS_REG_TYPE, 0) & 0xFC) != 0x00)) {
188 dev_dbg(&adapter->dev,
189 "W83L785TS-S detection failed at 0x%02x.\n",
195 if (kind <= 0) { /* identification */
199 man_id = (w83l785ts_read_value(new_client,
200 W83L785TS_REG_MAN_ID1, 0) << 8) +
201 w83l785ts_read_value(new_client,
202 W83L785TS_REG_MAN_ID2, 0);
203 chip_id = w83l785ts_read_value(new_client,
204 W83L785TS_REG_CHIP_ID, 0);
206 if (man_id == 0x5CA3) { /* Winbond */
207 if (chip_id == 0x70) { /* W83L785TS-S */
212 if (kind <= 0) { /* identification failed */
213 dev_info(&adapter->dev,
214 "Unsupported chip (man_id=0x%04X, "
215 "chip_id=0x%02X).\n", man_id, chip_id);
220 /* We can fill in the remaining client fields. */
221 strlcpy(new_client->name, "w83l785ts", I2C_NAME_SIZE);
223 init_MUTEX(&data->update_lock);
225 /* Default values in case the first read fails (unlikely). */
226 data->temp[1] = data->temp[0] = 0;
228 /* Tell the I2C layer a new client has arrived. */
229 if ((err = i2c_attach_client(new_client)))
233 * Initialize the W83L785TS chip
234 * Nothing yet, assume it is already started.
237 /* Register sysfs hooks */
238 data->class_dev = hwmon_device_register(&new_client->dev);
239 if (IS_ERR(data->class_dev)) {
240 err = PTR_ERR(data->class_dev);
244 device_create_file(&new_client->dev,
245 &sensor_dev_attr_temp1_input.dev_attr);
246 device_create_file(&new_client->dev,
247 &sensor_dev_attr_temp1_max.dev_attr);
252 i2c_detach_client(new_client);
259 static int w83l785ts_detach_client(struct i2c_client *client)
261 struct w83l785ts_data *data = i2c_get_clientdata(client);
264 hwmon_device_unregister(data->class_dev);
266 if ((err = i2c_detach_client(client)))
273 static u8 w83l785ts_read_value(struct i2c_client *client, u8 reg, u8 defval)
277 /* Frequent read errors have been reported on Asus boards, so we
278 * retry on read errors. If it still fails (unlikely), return the
279 * default value requested by the caller. */
280 for (i = 1; i <= MAX_RETRIES; i++) {
281 value = i2c_smbus_read_byte_data(client, reg);
283 dev_dbg(&client->dev, "Read 0x%02x from register "
284 "0x%02x.\n", value, reg);
287 dev_dbg(&client->dev, "Read failed, will retry in %d.\n", i);
291 dev_err(&client->dev, "Couldn't read value from register 0x%02x. "
292 "Please report.\n", reg);
296 static struct w83l785ts_data *w83l785ts_update_device(struct device *dev)
298 struct i2c_client *client = to_i2c_client(dev);
299 struct w83l785ts_data *data = i2c_get_clientdata(client);
301 down(&data->update_lock);
303 if (!data->valid || time_after(jiffies, data->last_updated + HZ * 2)) {
304 dev_dbg(&client->dev, "Updating w83l785ts data.\n");
305 data->temp[0] = w83l785ts_read_value(client,
306 W83L785TS_REG_TEMP, data->temp[0]);
307 data->temp[1] = w83l785ts_read_value(client,
308 W83L785TS_REG_TEMP_OVER, data->temp[1]);
310 data->last_updated = jiffies;
314 up(&data->update_lock);
319 static int __init sensors_w83l785ts_init(void)
321 return i2c_add_driver(&w83l785ts_driver);
324 static void __exit sensors_w83l785ts_exit(void)
326 i2c_del_driver(&w83l785ts_driver);
329 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
330 MODULE_DESCRIPTION("W83L785TS-S driver");
331 MODULE_LICENSE("GPL");
333 module_init(sensors_w83l785ts_init);
334 module_exit(sensors_w83l785ts_exit);