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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
39static unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
40 I2C_CLIENT_END };
41
42
43I2C_CLIENT_INSMOD_3(tmp421, tmp422, tmp423);
44
45
46#define TMP421_CONFIG_REG_1 0x09
47#define TMP421_CONVERSION_RATE_REG 0x0B
48#define TMP421_MANUFACTURER_ID_REG 0xFE
49#define TMP421_DEVICE_ID_REG 0xFF
50
51static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
52static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
53
54
55#define TMP421_CONFIG_SHUTDOWN 0x40
56#define TMP421_CONFIG_RANGE 0x04
57
58
59#define TMP421_MANUFACTURER_ID 0x55
60#define TMP421_DEVICE_ID 0x21
61#define TMP422_DEVICE_ID 0x22
62#define TMP423_DEVICE_ID 0x23
63
64static const struct i2c_device_id tmp421_id[] = {
65 { "tmp421", tmp421 },
66 { "tmp422", tmp422 },
67 { "tmp423", tmp423 },
68 { }
69};
70MODULE_DEVICE_TABLE(i2c, tmp421_id);
71
72struct tmp421_data {
73 struct device *hwmon_dev;
74 struct mutex update_lock;
75 char valid;
76 unsigned long last_updated;
77 int kind;
78 u8 config;
79 s16 temp[4];
80};
81
82static int temp_from_s16(s16 reg)
83{
84 int temp = reg;
85
86 return (temp * 1000 + 128) / 256;
87}
88
89static int temp_from_u16(u16 reg)
90{
91 int temp = reg;
92
93
94 temp -= 64 * 256;
95
96 return (temp * 1000 + 128) / 256;
97}
98
99static struct tmp421_data *tmp421_update_device(struct device *dev)
100{
101 struct i2c_client *client = to_i2c_client(dev);
102 struct tmp421_data *data = i2c_get_clientdata(client);
103 int i;
104
105 mutex_lock(&data->update_lock);
106
107 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
108 data->config = i2c_smbus_read_byte_data(client,
109 TMP421_CONFIG_REG_1);
110
111 for (i = 0; i <= data->kind; i++) {
112 data->temp[i] = i2c_smbus_read_byte_data(client,
113 TMP421_TEMP_MSB[i]) << 8;
114 data->temp[i] |= i2c_smbus_read_byte_data(client,
115 TMP421_TEMP_LSB[i]);
116 }
117 data->last_updated = jiffies;
118 data->valid = 1;
119 }
120
121 mutex_unlock(&data->update_lock);
122
123 return data;
124}
125
126static ssize_t show_temp_value(struct device *dev,
127 struct device_attribute *devattr, char *buf)
128{
129 int index = to_sensor_dev_attr(devattr)->index;
130 struct tmp421_data *data = tmp421_update_device(dev);
131 int temp;
132
133 mutex_lock(&data->update_lock);
134 if (data->config & TMP421_CONFIG_RANGE)
135 temp = temp_from_u16(data->temp[index]);
136 else
137 temp = temp_from_s16(data->temp[index]);
138 mutex_unlock(&data->update_lock);
139
140 return sprintf(buf, "%d\n", temp);
141}
142
143static ssize_t show_fault(struct device *dev,
144 struct device_attribute *devattr, char *buf)
145{
146 int index = to_sensor_dev_attr(devattr)->index;
147 struct tmp421_data *data = tmp421_update_device(dev);
148
149
150
151
152
153 if (data->temp[index] & 0x01)
154 return sprintf(buf, "1\n");
155 else
156 return sprintf(buf, "0\n");
157}
158
159static mode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
160 int n)
161{
162 struct device *dev = container_of(kobj, struct device, kobj);
163 struct tmp421_data *data = dev_get_drvdata(dev);
164 struct device_attribute *devattr;
165 unsigned int index;
166
167 devattr = container_of(a, struct device_attribute, attr);
168 index = to_sensor_dev_attr(devattr)->index;
169
170 if (data->kind > index)
171 return a->mode;
172
173 return 0;
174}
175
176static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
177static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
178static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
179static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
180static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
181static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
182static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
183
184static struct attribute *tmp421_attr[] = {
185 &sensor_dev_attr_temp1_input.dev_attr.attr,
186 &sensor_dev_attr_temp2_input.dev_attr.attr,
187 &sensor_dev_attr_temp2_fault.dev_attr.attr,
188 &sensor_dev_attr_temp3_input.dev_attr.attr,
189 &sensor_dev_attr_temp3_fault.dev_attr.attr,
190 &sensor_dev_attr_temp4_input.dev_attr.attr,
191 &sensor_dev_attr_temp4_fault.dev_attr.attr,
192 NULL
193};
194
195static const struct attribute_group tmp421_group = {
196 .attrs = tmp421_attr,
197 .is_visible = tmp421_is_visible,
198};
199
200static int tmp421_init_client(struct i2c_client *client)
201{
202 int config, config_orig;
203
204
205 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
206
207
208 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
209 if (config < 0) {
210 dev_err(&client->dev, "Could not read configuration"
211 " register (%d)\n", config);
212 return -ENODEV;
213 }
214
215 config_orig = config;
216 config &= ~TMP421_CONFIG_SHUTDOWN;
217
218 if (config != config_orig) {
219 dev_info(&client->dev, "Enable monitoring chip\n");
220 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
221 }
222
223 return 0;
224}
225
226static int tmp421_detect(struct i2c_client *client, int kind,
227 struct i2c_board_info *info)
228{
229 struct i2c_adapter *adapter = client->adapter;
230 const char *names[] = { "TMP421", "TMP422", "TMP423" };
231
232 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
233 return -ENODEV;
234
235 if (kind <= 0) {
236 u8 reg;
237
238 reg = i2c_smbus_read_byte_data(client,
239 TMP421_MANUFACTURER_ID_REG);
240 if (reg != TMP421_MANUFACTURER_ID)
241 return -ENODEV;
242
243 reg = i2c_smbus_read_byte_data(client,
244 TMP421_DEVICE_ID_REG);
245 switch (reg) {
246 case TMP421_DEVICE_ID:
247 kind = tmp421;
248 break;
249 case TMP422_DEVICE_ID:
250 kind = tmp422;
251 break;
252 case TMP423_DEVICE_ID:
253 kind = tmp423;
254 break;
255 default:
256 return -ENODEV;
257 }
258 }
259 strlcpy(info->type, tmp421_id[kind - 1].name, I2C_NAME_SIZE);
260 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
261 names[kind - 1], client->addr);
262
263 return 0;
264}
265
266static int tmp421_probe(struct i2c_client *client,
267 const struct i2c_device_id *id)
268{
269 struct tmp421_data *data;
270 int err;
271
272 data = kzalloc(sizeof(struct tmp421_data), GFP_KERNEL);
273 if (!data)
274 return -ENOMEM;
275
276 i2c_set_clientdata(client, data);
277 mutex_init(&data->update_lock);
278 data->kind = id->driver_data;
279
280 err = tmp421_init_client(client);
281 if (err)
282 goto exit_free;
283
284 err = sysfs_create_group(&client->dev.kobj, &tmp421_group);
285 if (err)
286 goto exit_free;
287
288 data->hwmon_dev = hwmon_device_register(&client->dev);
289 if (IS_ERR(data->hwmon_dev)) {
290 err = PTR_ERR(data->hwmon_dev);
291 data->hwmon_dev = NULL;
292 goto exit_remove;
293 }
294 return 0;
295
296exit_remove:
297 sysfs_remove_group(&client->dev.kobj, &tmp421_group);
298
299exit_free:
300 i2c_set_clientdata(client, NULL);
301 kfree(data);
302
303 return err;
304}
305
306static int tmp421_remove(struct i2c_client *client)
307{
308 struct tmp421_data *data = i2c_get_clientdata(client);
309
310 hwmon_device_unregister(data->hwmon_dev);
311 sysfs_remove_group(&client->dev.kobj, &tmp421_group);
312
313 i2c_set_clientdata(client, NULL);
314 kfree(data);
315
316 return 0;
317}
318
319static struct i2c_driver tmp421_driver = {
320 .class = I2C_CLASS_HWMON,
321 .driver = {
322 .name = "tmp421",
323 },
324 .probe = tmp421_probe,
325 .remove = tmp421_remove,
326 .id_table = tmp421_id,
327 .detect = tmp421_detect,
328 .address_data = &addr_data,
329};
330
331static int __init tmp421_init(void)
332{
333 return i2c_add_driver(&tmp421_driver);
334}
335
336static void __exit tmp421_exit(void)
337{
338 i2c_del_driver(&tmp421_driver);
339}
340
341MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
342MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor"
343 " driver");
344MODULE_LICENSE("GPL");
345
346module_init(tmp421_init);
347module_exit(tmp421_exit);
348
