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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_raw(u16 reg, bool extended)
104{
105
106 int temp = reg & ~0xf;
107
108 if (extended)
109 temp = temp - 64 * 256;
110 else
111 temp = (s16)temp;
112
113 return DIV_ROUND_CLOSEST(temp * 1000, 256);
114}
115
116static int tmp421_update_device(struct tmp421_data *data)
117{
118 struct i2c_client *client = data->client;
119 int ret = 0;
120 int i;
121
122 mutex_lock(&data->update_lock);
123
124 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
125 !data->valid) {
126 ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
127 if (ret < 0)
128 goto exit;
129 data->config = ret;
130
131 for (i = 0; i < data->channels; i++) {
132 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
133 if (ret < 0)
134 goto exit;
135 data->temp[i] = ret << 8;
136
137 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
138 if (ret < 0)
139 goto exit;
140 data->temp[i] |= ret;
141 }
142 data->last_updated = jiffies;
143 data->valid = 1;
144 }
145
146exit:
147 mutex_unlock(&data->update_lock);
148
149 if (ret < 0) {
150 data->valid = 0;
151 return ret;
152 }
153
154 return 0;
155}
156
157static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
158 u32 attr, int channel, long *val)
159{
160 struct tmp421_data *tmp421 = dev_get_drvdata(dev);
161 int ret = 0;
162
163 ret = tmp421_update_device(tmp421);
164 if (ret)
165 return ret;
166
167 switch (attr) {
168 case hwmon_temp_input:
169 *val = temp_from_raw(tmp421->temp[channel],
170 tmp421->config & TMP421_CONFIG_RANGE);
171 return 0;
172 case hwmon_temp_fault:
173
174
175
176
177 *val = !!(tmp421->temp[channel] & 0x03);
178 return 0;
179 default:
180 return -EOPNOTSUPP;
181 }
182
183}
184
185static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
186 u32 attr, int channel)
187{
188 switch (attr) {
189 case hwmon_temp_fault:
190 case hwmon_temp_input:
191 return 0444;
192 default:
193 return 0;
194 }
195}
196
197static int tmp421_init_client(struct i2c_client *client)
198{
199 int config, config_orig;
200
201
202 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
203
204
205 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
206 if (config < 0) {
207 dev_err(&client->dev,
208 "Could not read configuration register (%d)\n", config);
209 return config;
210 }
211
212 config_orig = config;
213 config &= ~TMP421_CONFIG_SHUTDOWN;
214
215 if (config != config_orig) {
216 dev_info(&client->dev, "Enable monitoring chip\n");
217 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
218 }
219
220 return 0;
221}
222
223static int tmp421_detect(struct i2c_client *client,
224 struct i2c_board_info *info)
225{
226 enum chips kind;
227 struct i2c_adapter *adapter = client->adapter;
228 static const char * const names[] = {
229 "TMP421", "TMP422", "TMP423",
230 "TMP441", "TMP442"
231 };
232 int addr = client->addr;
233 u8 reg;
234
235 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
236 return -ENODEV;
237
238 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
239 if (reg != TMP421_MANUFACTURER_ID)
240 return -ENODEV;
241
242 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
243 if (reg & 0xf8)
244 return -ENODEV;
245
246 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
247 if (reg & 0x7f)
248 return -ENODEV;
249
250 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
251 switch (reg) {
252 case TMP421_DEVICE_ID:
253 kind = tmp421;
254 break;
255 case TMP422_DEVICE_ID:
256 if (addr == 0x2a)
257 return -ENODEV;
258 kind = tmp422;
259 break;
260 case TMP423_DEVICE_ID:
261 if (addr != 0x4c && addr != 0x4d)
262 return -ENODEV;
263 kind = tmp423;
264 break;
265 case TMP441_DEVICE_ID:
266 kind = tmp441;
267 break;
268 case TMP442_DEVICE_ID:
269 if (addr != 0x4c && addr != 0x4d)
270 return -ENODEV;
271 kind = tmp442;
272 break;
273 default:
274 return -ENODEV;
275 }
276
277 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
278 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
279 names[kind], client->addr);
280
281 return 0;
282}
283
284static const struct hwmon_ops tmp421_ops = {
285 .is_visible = tmp421_is_visible,
286 .read = tmp421_read,
287};
288
289static int tmp421_probe(struct i2c_client *client)
290{
291 struct device *dev = &client->dev;
292 struct device *hwmon_dev;
293 struct tmp421_data *data;
294 int i, err;
295
296 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
297 if (!data)
298 return -ENOMEM;
299
300 mutex_init(&data->update_lock);
301 if (client->dev.of_node)
302 data->channels = (unsigned long)
303 of_device_get_match_data(&client->dev);
304 else
305 data->channels = i2c_match_id(tmp421_id, client)->driver_data;
306 data->client = client;
307
308 err = tmp421_init_client(client);
309 if (err)
310 return err;
311
312 for (i = 0; i < data->channels; i++)
313 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
314
315 data->chip.ops = &tmp421_ops;
316 data->chip.info = data->info;
317
318 data->info[0] = &data->temp_info;
319
320 data->temp_info.type = hwmon_temp;
321 data->temp_info.config = data->temp_config;
322
323 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
324 data,
325 &data->chip,
326 NULL);
327 return PTR_ERR_OR_ZERO(hwmon_dev);
328}
329
330static struct i2c_driver tmp421_driver = {
331 .class = I2C_CLASS_HWMON,
332 .driver = {
333 .name = "tmp421",
334 .of_match_table = of_match_ptr(tmp421_of_match),
335 },
336 .probe_new = tmp421_probe,
337 .id_table = tmp421_id,
338 .detect = tmp421_detect,
339 .address_list = normal_i2c,
340};
341
342module_i2c_driver(tmp421_driver);
343
344MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
345MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
346MODULE_LICENSE("GPL");
347
