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9410700b AP |
1 | /* tmp421.c |
2 | * | |
3 | * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de> | |
4 | * Preliminary support by: | |
5 | * Melvin Rook, Raymond Ng | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
22 | /* | |
23 | * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC. | |
24 | * Supported models: TMP421, TMP422, TMP423 | |
25 | */ | |
26 | ||
27 | #include <linux/module.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/slab.h> | |
30 | #include <linux/jiffies.h> | |
31 | #include <linux/i2c.h> | |
32 | #include <linux/hwmon.h> | |
33 | #include <linux/hwmon-sysfs.h> | |
34 | #include <linux/err.h> | |
35 | #include <linux/mutex.h> | |
36 | #include <linux/sysfs.h> | |
37 | ||
38 | /* Addresses to scan */ | |
918ee91c JD |
39 | static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, |
40 | I2C_CLIENT_END }; | |
9410700b | 41 | |
e5e9f44c | 42 | enum chips { tmp421, tmp422, tmp423 }; |
9410700b AP |
43 | |
44 | /* The TMP421 registers */ | |
45 | #define TMP421_CONFIG_REG_1 0x09 | |
46 | #define TMP421_CONVERSION_RATE_REG 0x0B | |
47 | #define TMP421_MANUFACTURER_ID_REG 0xFE | |
48 | #define TMP421_DEVICE_ID_REG 0xFF | |
49 | ||
50 | static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 }; | |
51 | static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 }; | |
52 | ||
53 | /* Flags */ | |
54 | #define TMP421_CONFIG_SHUTDOWN 0x40 | |
55 | #define TMP421_CONFIG_RANGE 0x04 | |
56 | ||
57 | /* Manufacturer / Device ID's */ | |
58 | #define TMP421_MANUFACTURER_ID 0x55 | |
59 | #define TMP421_DEVICE_ID 0x21 | |
60 | #define TMP422_DEVICE_ID 0x22 | |
61 | #define TMP423_DEVICE_ID 0x23 | |
62 | ||
63 | static const struct i2c_device_id tmp421_id[] = { | |
8d59582a JD |
64 | { "tmp421", 2 }, |
65 | { "tmp422", 3 }, | |
66 | { "tmp423", 4 }, | |
9410700b AP |
67 | { } |
68 | }; | |
69 | MODULE_DEVICE_TABLE(i2c, tmp421_id); | |
70 | ||
71 | struct tmp421_data { | |
276dac80 | 72 | struct i2c_client *client; |
9410700b AP |
73 | struct mutex update_lock; |
74 | char valid; | |
75 | unsigned long last_updated; | |
8d59582a | 76 | int channels; |
9410700b AP |
77 | u8 config; |
78 | s16 temp[4]; | |
79 | }; | |
80 | ||
81 | static int temp_from_s16(s16 reg) | |
82 | { | |
a44908d7 JD |
83 | /* Mask out status bits */ |
84 | int temp = reg & ~0xf; | |
9410700b AP |
85 | |
86 | return (temp * 1000 + 128) / 256; | |
87 | } | |
88 | ||
89 | static int temp_from_u16(u16 reg) | |
90 | { | |
a44908d7 JD |
91 | /* Mask out status bits */ |
92 | int temp = reg & ~0xf; | |
9410700b AP |
93 | |
94 | /* Add offset for extended temperature range. */ | |
95 | temp -= 64 * 256; | |
96 | ||
97 | return (temp * 1000 + 128) / 256; | |
98 | } | |
99 | ||
100 | static struct tmp421_data *tmp421_update_device(struct device *dev) | |
101 | { | |
276dac80 GR |
102 | struct tmp421_data *data = dev_get_drvdata(dev); |
103 | struct i2c_client *client = data->client; | |
9410700b AP |
104 | int i; |
105 | ||
106 | mutex_lock(&data->update_lock); | |
107 | ||
108 | if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) { | |
109 | data->config = i2c_smbus_read_byte_data(client, | |
110 | TMP421_CONFIG_REG_1); | |
111 | ||
8d59582a | 112 | for (i = 0; i < data->channels; i++) { |
9410700b AP |
113 | data->temp[i] = i2c_smbus_read_byte_data(client, |
114 | TMP421_TEMP_MSB[i]) << 8; | |
115 | data->temp[i] |= i2c_smbus_read_byte_data(client, | |
116 | TMP421_TEMP_LSB[i]); | |
117 | } | |
118 | data->last_updated = jiffies; | |
119 | data->valid = 1; | |
120 | } | |
121 | ||
122 | mutex_unlock(&data->update_lock); | |
123 | ||
124 | return data; | |
125 | } | |
126 | ||
127 | static ssize_t show_temp_value(struct device *dev, | |
128 | struct device_attribute *devattr, char *buf) | |
129 | { | |
130 | int index = to_sensor_dev_attr(devattr)->index; | |
131 | struct tmp421_data *data = tmp421_update_device(dev); | |
132 | int temp; | |
133 | ||
134 | mutex_lock(&data->update_lock); | |
135 | if (data->config & TMP421_CONFIG_RANGE) | |
136 | temp = temp_from_u16(data->temp[index]); | |
137 | else | |
138 | temp = temp_from_s16(data->temp[index]); | |
139 | mutex_unlock(&data->update_lock); | |
140 | ||
141 | return sprintf(buf, "%d\n", temp); | |
142 | } | |
143 | ||
144 | static ssize_t show_fault(struct device *dev, | |
145 | struct device_attribute *devattr, char *buf) | |
146 | { | |
147 | int index = to_sensor_dev_attr(devattr)->index; | |
148 | struct tmp421_data *data = tmp421_update_device(dev); | |
149 | ||
150 | /* | |
151 | * The OPEN bit signals a fault. This is bit 0 of the temperature | |
152 | * register (low byte). | |
153 | */ | |
154 | if (data->temp[index] & 0x01) | |
155 | return sprintf(buf, "1\n"); | |
156 | else | |
157 | return sprintf(buf, "0\n"); | |
158 | } | |
159 | ||
587a1f16 | 160 | static umode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a, |
9410700b AP |
161 | int n) |
162 | { | |
163 | struct device *dev = container_of(kobj, struct device, kobj); | |
164 | struct tmp421_data *data = dev_get_drvdata(dev); | |
165 | struct device_attribute *devattr; | |
166 | unsigned int index; | |
167 | ||
168 | devattr = container_of(a, struct device_attribute, attr); | |
169 | index = to_sensor_dev_attr(devattr)->index; | |
170 | ||
8d59582a | 171 | if (index < data->channels) |
9410700b AP |
172 | return a->mode; |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0); | |
178 | static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1); | |
179 | static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1); | |
180 | static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2); | |
181 | static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2); | |
182 | static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3); | |
183 | static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3); | |
184 | ||
185 | static struct attribute *tmp421_attr[] = { | |
186 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
187 | &sensor_dev_attr_temp2_input.dev_attr.attr, | |
188 | &sensor_dev_attr_temp2_fault.dev_attr.attr, | |
189 | &sensor_dev_attr_temp3_input.dev_attr.attr, | |
190 | &sensor_dev_attr_temp3_fault.dev_attr.attr, | |
191 | &sensor_dev_attr_temp4_input.dev_attr.attr, | |
192 | &sensor_dev_attr_temp4_fault.dev_attr.attr, | |
193 | NULL | |
194 | }; | |
195 | ||
196 | static const struct attribute_group tmp421_group = { | |
197 | .attrs = tmp421_attr, | |
198 | .is_visible = tmp421_is_visible, | |
199 | }; | |
200 | ||
276dac80 GR |
201 | static const struct attribute_group *tmp421_groups[] = { |
202 | &tmp421_group, | |
203 | NULL | |
204 | }; | |
205 | ||
9410700b AP |
206 | static int tmp421_init_client(struct i2c_client *client) |
207 | { | |
208 | int config, config_orig; | |
209 | ||
210 | /* Set the conversion rate to 2 Hz */ | |
211 | i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05); | |
212 | ||
213 | /* Start conversions (disable shutdown if necessary) */ | |
214 | config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1); | |
215 | if (config < 0) { | |
b55f3757 GR |
216 | dev_err(&client->dev, |
217 | "Could not read configuration register (%d)\n", config); | |
010a166a | 218 | return config; |
9410700b AP |
219 | } |
220 | ||
221 | config_orig = config; | |
222 | config &= ~TMP421_CONFIG_SHUTDOWN; | |
223 | ||
224 | if (config != config_orig) { | |
225 | dev_info(&client->dev, "Enable monitoring chip\n"); | |
226 | i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config); | |
227 | } | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
310ec792 | 232 | static int tmp421_detect(struct i2c_client *client, |
9410700b AP |
233 | struct i2c_board_info *info) |
234 | { | |
dbe73c8f | 235 | enum chips kind; |
9410700b AP |
236 | struct i2c_adapter *adapter = client->adapter; |
237 | const char *names[] = { "TMP421", "TMP422", "TMP423" }; | |
dbe73c8f | 238 | u8 reg; |
9410700b AP |
239 | |
240 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
241 | return -ENODEV; | |
242 | ||
dbe73c8f JD |
243 | reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG); |
244 | if (reg != TMP421_MANUFACTURER_ID) | |
245 | return -ENODEV; | |
246 | ||
247 | reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG); | |
248 | switch (reg) { | |
249 | case TMP421_DEVICE_ID: | |
250 | kind = tmp421; | |
251 | break; | |
252 | case TMP422_DEVICE_ID: | |
253 | kind = tmp422; | |
254 | break; | |
255 | case TMP423_DEVICE_ID: | |
256 | kind = tmp423; | |
257 | break; | |
258 | default: | |
259 | return -ENODEV; | |
9410700b | 260 | } |
dbe73c8f | 261 | |
dc71afe5 | 262 | strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE); |
9410700b | 263 | dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n", |
dc71afe5 | 264 | names[kind], client->addr); |
9410700b AP |
265 | |
266 | return 0; | |
267 | } | |
268 | ||
269 | static int tmp421_probe(struct i2c_client *client, | |
270 | const struct i2c_device_id *id) | |
271 | { | |
276dac80 GR |
272 | struct device *dev = &client->dev; |
273 | struct device *hwmon_dev; | |
9410700b AP |
274 | struct tmp421_data *data; |
275 | int err; | |
276 | ||
276dac80 | 277 | data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL); |
9410700b AP |
278 | if (!data) |
279 | return -ENOMEM; | |
280 | ||
9410700b | 281 | mutex_init(&data->update_lock); |
8d59582a | 282 | data->channels = id->driver_data; |
276dac80 | 283 | data->client = client; |
9410700b AP |
284 | |
285 | err = tmp421_init_client(client); | |
286 | if (err) | |
f625e0fd | 287 | return err; |
9410700b | 288 | |
276dac80 GR |
289 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, |
290 | data, tmp421_groups); | |
291 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
9410700b AP |
292 | } |
293 | ||
294 | static struct i2c_driver tmp421_driver = { | |
295 | .class = I2C_CLASS_HWMON, | |
296 | .driver = { | |
297 | .name = "tmp421", | |
298 | }, | |
299 | .probe = tmp421_probe, | |
9410700b AP |
300 | .id_table = tmp421_id, |
301 | .detect = tmp421_detect, | |
c3813d6a | 302 | .address_list = normal_i2c, |
9410700b AP |
303 | }; |
304 | ||
f0967eea | 305 | module_i2c_driver(tmp421_driver); |
9410700b AP |
306 | |
307 | MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>"); | |
b55f3757 | 308 | MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor driver"); |
9410700b | 309 | MODULE_LICENSE("GPL"); |