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23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/jiffies.h>
27#include <linux/i2c.h>
28#include <linux/hwmon.h>
29#include <linux/hwmon-sysfs.h>
30#include <linux/err.h>
31#include <linux/mutex.h>
32#include <linux/sysfs.h>
33
34
35static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
36 I2C_CLIENT_END };
37
38enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
39
40
41#define TMP421_STATUS_REG 0x08
42#define TMP421_CONFIG_REG_1 0x09
43#define TMP421_CONVERSION_RATE_REG 0x0B
44#define TMP421_MANUFACTURER_ID_REG 0xFE
45#define TMP421_DEVICE_ID_REG 0xFF
46
47static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
48static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
49
50
51#define TMP421_CONFIG_SHUTDOWN 0x40
52#define TMP421_CONFIG_RANGE 0x04
53
54
55#define TMP421_MANUFACTURER_ID 0x55
56#define TMP421_DEVICE_ID 0x21
57#define TMP422_DEVICE_ID 0x22
58#define TMP423_DEVICE_ID 0x23
59#define TMP441_DEVICE_ID 0x41
60#define TMP442_DEVICE_ID 0x42
61
62static const struct i2c_device_id tmp421_id[] = {
63 { "tmp421", 2 },
64 { "tmp422", 3 },
65 { "tmp423", 4 },
66 { "tmp441", 2 },
67 { "tmp442", 3 },
68 { }
69};
70MODULE_DEVICE_TABLE(i2c, tmp421_id);
71
72struct tmp421_data {
73 struct i2c_client *client;
74 struct mutex update_lock;
75 char valid;
76 unsigned long last_updated;
77 int channels;
78 u8 config;
79 s16 temp[4];
80};
81
82static int temp_from_s16(s16 reg)
83{
84
85 int temp = reg & ~0xf;
86
87 return (temp * 1000 + 128) / 256;
88}
89
90static int temp_from_u16(u16 reg)
91{
92
93 int temp = reg & ~0xf;
94
95
96 temp -= 64 * 256;
97
98 return (temp * 1000 + 128) / 256;
99}
100
101static struct tmp421_data *tmp421_update_device(struct device *dev)
102{
103 struct tmp421_data *data = dev_get_drvdata(dev);
104 struct i2c_client *client = data->client;
105 int i;
106
107 mutex_lock(&data->update_lock);
108
109 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
110 data->config = i2c_smbus_read_byte_data(client,
111 TMP421_CONFIG_REG_1);
112
113 for (i = 0; i < data->channels; i++) {
114 data->temp[i] = i2c_smbus_read_byte_data(client,
115 TMP421_TEMP_MSB[i]) << 8;
116 data->temp[i] |= i2c_smbus_read_byte_data(client,
117 TMP421_TEMP_LSB[i]);
118 }
119 data->last_updated = jiffies;
120 data->valid = 1;
121 }
122
123 mutex_unlock(&data->update_lock);
124
125 return data;
126}
127
128static ssize_t show_temp_value(struct device *dev,
129 struct device_attribute *devattr, char *buf)
130{
131 int index = to_sensor_dev_attr(devattr)->index;
132 struct tmp421_data *data = tmp421_update_device(dev);
133 int temp;
134
135 mutex_lock(&data->update_lock);
136 if (data->config & TMP421_CONFIG_RANGE)
137 temp = temp_from_u16(data->temp[index]);
138 else
139 temp = temp_from_s16(data->temp[index]);
140 mutex_unlock(&data->update_lock);
141
142 return sprintf(buf, "%d\n", temp);
143}
144
145static ssize_t show_fault(struct device *dev,
146 struct device_attribute *devattr, char *buf)
147{
148 int index = to_sensor_dev_attr(devattr)->index;
149 struct tmp421_data *data = tmp421_update_device(dev);
150
151
152
153
154
155 if (data->temp[index] & 0x01)
156 return sprintf(buf, "1\n");
157 else
158 return sprintf(buf, "0\n");
159}
160
161static umode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
162 int n)
163{
164 struct device *dev = container_of(kobj, struct device, kobj);
165 struct tmp421_data *data = dev_get_drvdata(dev);
166 struct device_attribute *devattr;
167 unsigned int index;
168
169 devattr = container_of(a, struct device_attribute, attr);
170 index = to_sensor_dev_attr(devattr)->index;
171
172 if (index < data->channels)
173 return a->mode;
174
175 return 0;
176}
177
178static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
179static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
180static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
181static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
182static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
183static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
184static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
185
186static struct attribute *tmp421_attr[] = {
187 &sensor_dev_attr_temp1_input.dev_attr.attr,
188 &sensor_dev_attr_temp2_input.dev_attr.attr,
189 &sensor_dev_attr_temp2_fault.dev_attr.attr,
190 &sensor_dev_attr_temp3_input.dev_attr.attr,
191 &sensor_dev_attr_temp3_fault.dev_attr.attr,
192 &sensor_dev_attr_temp4_input.dev_attr.attr,
193 &sensor_dev_attr_temp4_fault.dev_attr.attr,
194 NULL
195};
196
197static const struct attribute_group tmp421_group = {
198 .attrs = tmp421_attr,
199 .is_visible = tmp421_is_visible,
200};
201
202static const struct attribute_group *tmp421_groups[] = {
203 &tmp421_group,
204 NULL
205};
206
207static int tmp421_init_client(struct i2c_client *client)
208{
209 int config, config_orig;
210
211
212 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
213
214
215 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
216 if (config < 0) {
217 dev_err(&client->dev,
218 "Could not read configuration register (%d)\n", config);
219 return config;
220 }
221
222 config_orig = config;
223 config &= ~TMP421_CONFIG_SHUTDOWN;
224
225 if (config != config_orig) {
226 dev_info(&client->dev, "Enable monitoring chip\n");
227 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
228 }
229
230 return 0;
231}
232
233static int tmp421_detect(struct i2c_client *client,
234 struct i2c_board_info *info)
235{
236 enum chips kind;
237 struct i2c_adapter *adapter = client->adapter;
238 const char * const names[] = { "TMP421", "TMP422", "TMP423",
239 "TMP441", "TMP442" };
240 int addr = client->addr;
241 u8 reg;
242
243 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
244 return -ENODEV;
245
246 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
247 if (reg != TMP421_MANUFACTURER_ID)
248 return -ENODEV;
249
250 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
251 if (reg & 0xf8)
252 return -ENODEV;
253
254 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
255 if (reg & 0x7f)
256 return -ENODEV;
257
258 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
259 switch (reg) {
260 case TMP421_DEVICE_ID:
261 kind = tmp421;
262 break;
263 case TMP422_DEVICE_ID:
264 if (addr == 0x2a)
265 return -ENODEV;
266 kind = tmp422;
267 break;
268 case TMP423_DEVICE_ID:
269 if (addr != 0x4c && addr != 0x4d)
270 return -ENODEV;
271 kind = tmp423;
272 break;
273 case TMP441_DEVICE_ID:
274 kind = tmp441;
275 break;
276 case TMP442_DEVICE_ID:
277 if (addr != 0x4c && addr != 0x4d)
278 return -ENODEV;
279 kind = tmp442;
280 break;
281 default:
282 return -ENODEV;
283 }
284
285 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
286 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
287 names[kind], client->addr);
288
289 return 0;
290}
291
292static int tmp421_probe(struct i2c_client *client,
293 const struct i2c_device_id *id)
294{
295 struct device *dev = &client->dev;
296 struct device *hwmon_dev;
297 struct tmp421_data *data;
298 int err;
299
300 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
301 if (!data)
302 return -ENOMEM;
303
304 mutex_init(&data->update_lock);
305 data->channels = id->driver_data;
306 data->client = client;
307
308 err = tmp421_init_client(client);
309 if (err)
310 return err;
311
312 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
313 data, tmp421_groups);
314 return PTR_ERR_OR_ZERO(hwmon_dev);
315}
316
317static struct i2c_driver tmp421_driver = {
318 .class = I2C_CLASS_HWMON,
319 .driver = {
320 .name = "tmp421",
321 },
322 .probe = tmp421_probe,
323 .id_table = tmp421_id,
324 .detect = tmp421_detect,
325 .address_list = normal_i2c,
326};
327
328module_i2c_driver(tmp421_driver);
329
330MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
331MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
332MODULE_LICENSE("GPL");
333
