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14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/jiffies.h>
18#include <linux/i2c.h>
19#include <linux/hwmon.h>
20#include <linux/hwmon-sysfs.h>
21#include <linux/err.h>
22#include <linux/mutex.h>
23#include <linux/of_device.h>
24#include <linux/sysfs.h>
25
26
27static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
28 I2C_CLIENT_END };
29
30enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
31
32
33#define TMP421_STATUS_REG 0x08
34#define TMP421_CONFIG_REG_1 0x09
35#define TMP421_CONVERSION_RATE_REG 0x0B
36#define TMP421_MANUFACTURER_ID_REG 0xFE
37#define TMP421_DEVICE_ID_REG 0xFF
38
39static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
40static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
41
42
43#define TMP421_CONFIG_SHUTDOWN 0x40
44#define TMP421_CONFIG_RANGE 0x04
45
46
47#define TMP421_MANUFACTURER_ID 0x55
48#define TMP421_DEVICE_ID 0x21
49#define TMP422_DEVICE_ID 0x22
50#define TMP423_DEVICE_ID 0x23
51#define TMP441_DEVICE_ID 0x41
52#define TMP442_DEVICE_ID 0x42
53
54static const struct i2c_device_id tmp421_id[] = {
55 { "tmp421", 2 },
56 { "tmp422", 3 },
57 { "tmp423", 4 },
58 { "tmp441", 2 },
59 { "tmp442", 3 },
60 { }
61};
62MODULE_DEVICE_TABLE(i2c, tmp421_id);
63
64static const struct of_device_id __maybe_unused tmp421_of_match[] = {
65 {
66 .compatible = "ti,tmp421",
67 .data = (void *)2
68 },
69 {
70 .compatible = "ti,tmp422",
71 .data = (void *)3
72 },
73 {
74 .compatible = "ti,tmp423",
75 .data = (void *)4
76 },
77 {
78 .compatible = "ti,tmp441",
79 .data = (void *)2
80 },
81 {
82 .compatible = "ti,tmp442",
83 .data = (void *)3
84 },
85 { },
86};
87MODULE_DEVICE_TABLE(of, tmp421_of_match);
88
89struct tmp421_data {
90 struct i2c_client *client;
91 struct mutex update_lock;
92 u32 temp_config[5];
93 struct hwmon_channel_info temp_info;
94 const struct hwmon_channel_info *info[2];
95 struct hwmon_chip_info chip;
96 char valid;
97 unsigned long last_updated;
98 unsigned long channels;
99 u8 config;
100 s16 temp[4];
101};
102
103static int temp_from_s16(s16 reg)
104{
105
106 int temp = reg & ~0xf;
107
108 return (temp * 1000 + 128) / 256;
109}
110
111static int temp_from_u16(u16 reg)
112{
113
114 int temp = reg & ~0xf;
115
116
117 temp -= 64 * 256;
118
119 return (temp * 1000 + 128) / 256;
120}
121
122static struct tmp421_data *tmp421_update_device(struct device *dev)
123{
124 struct tmp421_data *data = dev_get_drvdata(dev);
125 struct i2c_client *client = data->client;
126 int i;
127
128 mutex_lock(&data->update_lock);
129
130 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
131 data->config = i2c_smbus_read_byte_data(client,
132 TMP421_CONFIG_REG_1);
133
134 for (i = 0; i < data->channels; i++) {
135 data->temp[i] = i2c_smbus_read_byte_data(client,
136 TMP421_TEMP_MSB[i]) << 8;
137 data->temp[i] |= i2c_smbus_read_byte_data(client,
138 TMP421_TEMP_LSB[i]);
139 }
140 data->last_updated = jiffies;
141 data->valid = 1;
142 }
143
144 mutex_unlock(&data->update_lock);
145
146 return data;
147}
148
149static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
150 u32 attr, int channel, long *val)
151{
152 struct tmp421_data *tmp421 = tmp421_update_device(dev);
153
154 switch (attr) {
155 case hwmon_temp_input:
156 if (tmp421->config & TMP421_CONFIG_RANGE)
157 *val = temp_from_u16(tmp421->temp[channel]);
158 else
159 *val = temp_from_s16(tmp421->temp[channel]);
160 return 0;
161 case hwmon_temp_fault:
162
163
164
165
166 *val = tmp421->temp[channel] & 0x01;
167 return 0;
168 default:
169 return -EOPNOTSUPP;
170 }
171
172}
173
174static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
175 u32 attr, int channel)
176{
177 switch (attr) {
178 case hwmon_temp_fault:
179 if (channel == 0)
180 return 0;
181 return 0444;
182 case hwmon_temp_input:
183 return 0444;
184 default:
185 return 0;
186 }
187}
188
189static int tmp421_init_client(struct i2c_client *client)
190{
191 int config, config_orig;
192
193
194 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
195
196
197 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
198 if (config < 0) {
199 dev_err(&client->dev,
200 "Could not read configuration register (%d)\n", config);
201 return config;
202 }
203
204 config_orig = config;
205 config &= ~TMP421_CONFIG_SHUTDOWN;
206
207 if (config != config_orig) {
208 dev_info(&client->dev, "Enable monitoring chip\n");
209 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
210 }
211
212 return 0;
213}
214
215static int tmp421_detect(struct i2c_client *client,
216 struct i2c_board_info *info)
217{
218 enum chips kind;
219 struct i2c_adapter *adapter = client->adapter;
220 static const char * const names[] = {
221 "TMP421", "TMP422", "TMP423",
222 "TMP441", "TMP442"
223 };
224 int addr = client->addr;
225 u8 reg;
226
227 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
228 return -ENODEV;
229
230 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
231 if (reg != TMP421_MANUFACTURER_ID)
232 return -ENODEV;
233
234 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
235 if (reg & 0xf8)
236 return -ENODEV;
237
238 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
239 if (reg & 0x7f)
240 return -ENODEV;
241
242 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
243 switch (reg) {
244 case TMP421_DEVICE_ID:
245 kind = tmp421;
246 break;
247 case TMP422_DEVICE_ID:
248 if (addr == 0x2a)
249 return -ENODEV;
250 kind = tmp422;
251 break;
252 case TMP423_DEVICE_ID:
253 if (addr != 0x4c && addr != 0x4d)
254 return -ENODEV;
255 kind = tmp423;
256 break;
257 case TMP441_DEVICE_ID:
258 kind = tmp441;
259 break;
260 case TMP442_DEVICE_ID:
261 if (addr != 0x4c && addr != 0x4d)
262 return -ENODEV;
263 kind = tmp442;
264 break;
265 default:
266 return -ENODEV;
267 }
268
269 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
270 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
271 names[kind], client->addr);
272
273 return 0;
274}
275
276static const struct hwmon_ops tmp421_ops = {
277 .is_visible = tmp421_is_visible,
278 .read = tmp421_read,
279};
280
281static int tmp421_probe(struct i2c_client *client,
282 const struct i2c_device_id *id)
283{
284 struct device *dev = &client->dev;
285 struct device *hwmon_dev;
286 struct tmp421_data *data;
287 int i, err;
288
289 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
290 if (!data)
291 return -ENOMEM;
292
293 mutex_init(&data->update_lock);
294 if (client->dev.of_node)
295 data->channels = (unsigned long)
296 of_device_get_match_data(&client->dev);
297 else
298 data->channels = id->driver_data;
299 data->client = client;
300
301 err = tmp421_init_client(client);
302 if (err)
303 return err;
304
305 for (i = 0; i < data->channels; i++)
306 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
307
308 data->chip.ops = &tmp421_ops;
309 data->chip.info = data->info;
310
311 data->info[0] = &data->temp_info;
312
313 data->temp_info.type = hwmon_temp;
314 data->temp_info.config = data->temp_config;
315
316 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
317 data,
318 &data->chip,
319 NULL);
320 return PTR_ERR_OR_ZERO(hwmon_dev);
321}
322
323static struct i2c_driver tmp421_driver = {
324 .class = I2C_CLASS_HWMON,
325 .driver = {
326 .name = "tmp421",
327 .of_match_table = of_match_ptr(tmp421_of_match),
328 },
329 .probe = tmp421_probe,
330 .id_table = tmp421_id,
331 .detect = tmp421_detect,
332 .address_list = normal_i2c,
333};
334
335module_i2c_driver(tmp421_driver);
336
337MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
338MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
339MODULE_LICENSE("GPL");
340
