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" , 0 }, |
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 | |
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, fmt: "%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 */ |
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(adap: adapter, I2C_FUNC_SMBUS_BYTE_DATA)) |
136 | return -ENODEV; |
137 | |
138 | /* detection */ |
139 | if ((w83l785ts_read_value(client, W83L785TS_REG_CONFIG, defval: 0) & 0x80) |
140 | || (w83l785ts_read_value(client, W83L785TS_REG_TYPE, defval: 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, defval: 0) << 8) |
149 | + w83l785ts_read_value(client, W83L785TS_REG_MAN_ID2, defval: 0); |
150 | chip_id = w83l785ts_read_value(client, W83L785TS_REG_CHIP_ID, defval: 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 | |
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, size: 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(device: dev, entry: &sensor_dev_attr_temp1_input.dev_attr); |
184 | if (err) |
185 | return err; |
186 | |
187 | err = device_create_file(device: dev, entry: &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(ptr: data->hwmon_dev)) { |
194 | err = PTR_ERR(ptr: data->hwmon_dev); |
195 | goto exit_remove; |
196 | } |
197 | |
198 | return 0; |
199 | |
200 | exit_remove: |
201 | device_remove_file(dev, attr: &sensor_dev_attr_temp1_input.dev_attr); |
202 | device_remove_file(dev, attr: &sensor_dev_attr_temp1_max.dev_attr); |
203 | return err; |
204 | } |
205 | |
206 | static void w83l785ts_remove(struct i2c_client *client) |
207 | { |
208 | struct w83l785ts_data *data = i2c_get_clientdata(client); |
209 | |
210 | hwmon_device_unregister(dev: data->hwmon_dev); |
211 | device_remove_file(dev: &client->dev, |
212 | attr: &sensor_dev_attr_temp1_input.dev_attr); |
213 | device_remove_file(dev: &client->dev, |
214 | attr: &sensor_dev_attr_temp1_max.dev_attr); |
215 | } |
216 | |
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, command: 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(msecs: i); |
249 | } |
250 | |
251 | dev_err(dev, "%sCouldn't read value from register 0x%02x.\n" , prefix, |
252 | reg); |
253 | return defval; |
254 | } |
255 | |
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, defval: data->temp[0]); |
267 | data->temp[1] = w83l785ts_read_value(client, |
268 | W83L785TS_REG_TEMP_OVER, defval: data->temp[1]); |
269 | |
270 | data->last_updated = jiffies; |
271 | data->valid = true; |
272 | } |
273 | |
274 | mutex_unlock(lock: &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 | |