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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 u32 temp_config[5];
76 struct hwmon_channel_info temp_info;
77 const struct hwmon_channel_info *info[2];
78 struct hwmon_chip_info chip;
79 char valid;
80 unsigned long last_updated;
81 int channels;
82 u8 config;
83 s16 temp[4];
84};
85
86static int temp_from_s16(s16 reg)
87{
88
89 int temp = reg & ~0xf;
90
91 return (temp * 1000 + 128) / 256;
92}
93
94static int temp_from_u16(u16 reg)
95{
96
97 int temp = reg & ~0xf;
98
99
100 temp -= 64 * 256;
101
102 return (temp * 1000 + 128) / 256;
103}
104
105static struct tmp421_data *tmp421_update_device(struct device *dev)
106{
107 struct tmp421_data *data = dev_get_drvdata(dev);
108 struct i2c_client *client = data->client;
109 int i;
110
111 mutex_lock(&data->update_lock);
112
113 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
114 data->config = i2c_smbus_read_byte_data(client,
115 TMP421_CONFIG_REG_1);
116
117 for (i = 0; i < data->channels; i++) {
118 data->temp[i] = i2c_smbus_read_byte_data(client,
119 TMP421_TEMP_MSB[i]) << 8;
120 data->temp[i] |= i2c_smbus_read_byte_data(client,
121 TMP421_TEMP_LSB[i]);
122 }
123 data->last_updated = jiffies;
124 data->valid = 1;
125 }
126
127 mutex_unlock(&data->update_lock);
128
129 return data;
130}
131
132static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
133 u32 attr, int channel, long *val)
134{
135 struct tmp421_data *tmp421 = tmp421_update_device(dev);
136
137 switch (attr) {
138 case hwmon_temp_input:
139 if (tmp421->config & TMP421_CONFIG_RANGE)
140 *val = temp_from_u16(tmp421->temp[channel]);
141 else
142 *val = temp_from_s16(tmp421->temp[channel]);
143 return 0;
144 case hwmon_temp_fault:
145
146
147
148
149 *val = tmp421->temp[channel] & 0x01;
150 return 0;
151 default:
152 return -EOPNOTSUPP;
153 }
154
155}
156
157static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
158 u32 attr, int channel)
159{
160 switch (attr) {
161 case hwmon_temp_fault:
162 if (channel == 0)
163 return 0;
164 return S_IRUGO;
165 case hwmon_temp_input:
166 return S_IRUGO;
167 default:
168 return 0;
169 }
170}
171
172static int tmp421_init_client(struct i2c_client *client)
173{
174 int config, config_orig;
175
176
177 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
178
179
180 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
181 if (config < 0) {
182 dev_err(&client->dev,
183 "Could not read configuration register (%d)\n", config);
184 return config;
185 }
186
187 config_orig = config;
188 config &= ~TMP421_CONFIG_SHUTDOWN;
189
190 if (config != config_orig) {
191 dev_info(&client->dev, "Enable monitoring chip\n");
192 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
193 }
194
195 return 0;
196}
197
198static int tmp421_detect(struct i2c_client *client,
199 struct i2c_board_info *info)
200{
201 enum chips kind;
202 struct i2c_adapter *adapter = client->adapter;
203 const char * const names[] = { "TMP421", "TMP422", "TMP423",
204 "TMP441", "TMP442" };
205 int addr = client->addr;
206 u8 reg;
207
208 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
209 return -ENODEV;
210
211 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
212 if (reg != TMP421_MANUFACTURER_ID)
213 return -ENODEV;
214
215 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
216 if (reg & 0xf8)
217 return -ENODEV;
218
219 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
220 if (reg & 0x7f)
221 return -ENODEV;
222
223 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
224 switch (reg) {
225 case TMP421_DEVICE_ID:
226 kind = tmp421;
227 break;
228 case TMP422_DEVICE_ID:
229 if (addr == 0x2a)
230 return -ENODEV;
231 kind = tmp422;
232 break;
233 case TMP423_DEVICE_ID:
234 if (addr != 0x4c && addr != 0x4d)
235 return -ENODEV;
236 kind = tmp423;
237 break;
238 case TMP441_DEVICE_ID:
239 kind = tmp441;
240 break;
241 case TMP442_DEVICE_ID:
242 if (addr != 0x4c && addr != 0x4d)
243 return -ENODEV;
244 kind = tmp442;
245 break;
246 default:
247 return -ENODEV;
248 }
249
250 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
251 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
252 names[kind], client->addr);
253
254 return 0;
255}
256
257static const struct hwmon_ops tmp421_ops = {
258 .is_visible = tmp421_is_visible,
259 .read = tmp421_read,
260};
261
262static int tmp421_probe(struct i2c_client *client,
263 const struct i2c_device_id *id)
264{
265 struct device *dev = &client->dev;
266 struct device *hwmon_dev;
267 struct tmp421_data *data;
268 int i, err;
269
270 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
271 if (!data)
272 return -ENOMEM;
273
274 mutex_init(&data->update_lock);
275 data->channels = id->driver_data;
276 data->client = client;
277
278 err = tmp421_init_client(client);
279 if (err)
280 return err;
281
282 for (i = 0; i < data->channels; i++)
283 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
284
285 data->chip.ops = &tmp421_ops;
286 data->chip.info = data->info;
287
288 data->info[0] = &data->temp_info;
289
290 data->temp_info.type = hwmon_temp;
291 data->temp_info.config = data->temp_config;
292
293 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
294 data,
295 &data->chip,
296 NULL);
297 return PTR_ERR_OR_ZERO(hwmon_dev);
298}
299
300static struct i2c_driver tmp421_driver = {
301 .class = I2C_CLASS_HWMON,
302 .driver = {
303 .name = "tmp421",
304 },
305 .probe = tmp421_probe,
306 .id_table = tmp421_id,
307 .detect = tmp421_detect,
308 .address_list = normal_i2c,
309};
310
311module_i2c_driver(tmp421_driver);
312
313MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
314MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
315MODULE_LICENSE("GPL");
316
