xref: /openbmc/linux/drivers/hwmon/emc6w201.c (revision 9aa2cba7)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * emc6w201.c - Hardware monitoring driver for the SMSC EMC6W201
4  * Copyright (C) 2011  Jean Delvare <jdelvare@suse.de>
5  */
6 
7 #include <linux/module.h>
8 #include <linux/init.h>
9 #include <linux/slab.h>
10 #include <linux/jiffies.h>
11 #include <linux/i2c.h>
12 #include <linux/hwmon.h>
13 #include <linux/hwmon-sysfs.h>
14 #include <linux/err.h>
15 #include <linux/mutex.h>
16 
17 /*
18  * Addresses to scan
19  */
20 
21 static const unsigned short normal_i2c[] = { 0x2c, 0x2d, 0x2e, I2C_CLIENT_END };
22 
23 /*
24  * The EMC6W201 registers
25  */
26 
27 #define EMC6W201_REG_IN(nr)		(0x20 + (nr))
28 #define EMC6W201_REG_TEMP(nr)		(0x26 + (nr))
29 #define EMC6W201_REG_FAN(nr)		(0x2C + (nr) * 2)
30 #define EMC6W201_REG_COMPANY		0x3E
31 #define EMC6W201_REG_VERSTEP		0x3F
32 #define EMC6W201_REG_CONFIG		0x40
33 #define EMC6W201_REG_IN_LOW(nr)		(0x4A + (nr) * 2)
34 #define EMC6W201_REG_IN_HIGH(nr)	(0x4B + (nr) * 2)
35 #define EMC6W201_REG_TEMP_LOW(nr)	(0x56 + (nr) * 2)
36 #define EMC6W201_REG_TEMP_HIGH(nr)	(0x57 + (nr) * 2)
37 #define EMC6W201_REG_FAN_MIN(nr)	(0x62 + (nr) * 2)
38 
39 enum subfeature { input, min, max };
40 
41 /*
42  * Per-device data
43  */
44 
45 struct emc6w201_data {
46 	struct i2c_client *client;
47 	struct mutex update_lock;
48 	bool valid; /* false until following fields are valid */
49 	unsigned long last_updated; /* in jiffies */
50 
51 	/* registers values */
52 	u8 in[3][6];
53 	s8 temp[3][6];
54 	u16 fan[2][5];
55 };
56 
57 /*
58  * Combine LSB and MSB registers in a single value
59  * Locking: must be called with data->update_lock held
60  */
61 static u16 emc6w201_read16(struct i2c_client *client, u8 reg)
62 {
63 	int lsb, msb;
64 
65 	lsb = i2c_smbus_read_byte_data(client, reg);
66 	msb = i2c_smbus_read_byte_data(client, reg + 1);
67 	if (unlikely(lsb < 0 || msb < 0)) {
68 		dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
69 			16, "read", reg);
70 		return 0xFFFF;	/* Arbitrary value */
71 	}
72 
73 	return (msb << 8) | lsb;
74 }
75 
76 /*
77  * Write 16-bit value to LSB and MSB registers
78  * Locking: must be called with data->update_lock held
79  */
80 static int emc6w201_write16(struct i2c_client *client, u8 reg, u16 val)
81 {
82 	int err;
83 
84 	err = i2c_smbus_write_byte_data(client, reg, val & 0xff);
85 	if (likely(!err))
86 		err = i2c_smbus_write_byte_data(client, reg + 1, val >> 8);
87 	if (unlikely(err < 0))
88 		dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
89 			16, "write", reg);
90 
91 	return err;
92 }
93 
94 /* Read 8-bit value from register */
95 static u8 emc6w201_read8(struct i2c_client *client, u8 reg)
96 {
97 	int val;
98 
99 	val = i2c_smbus_read_byte_data(client, reg);
100 	if (unlikely(val < 0)) {
101 		dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
102 			8, "read", reg);
103 		return 0x00;	/* Arbitrary value */
104 	}
105 
106 	return val;
107 }
108 
109 /* Write 8-bit value to register */
110 static int emc6w201_write8(struct i2c_client *client, u8 reg, u8 val)
111 {
112 	int err;
113 
114 	err = i2c_smbus_write_byte_data(client, reg, val);
115 	if (unlikely(err < 0))
116 		dev_err(&client->dev, "%d-bit %s failed at 0x%02x\n",
117 			8, "write", reg);
118 
119 	return err;
120 }
121 
122 static struct emc6w201_data *emc6w201_update_device(struct device *dev)
123 {
124 	struct emc6w201_data *data = dev_get_drvdata(dev);
125 	struct i2c_client *client = data->client;
126 	int nr;
127 
128 	mutex_lock(&data->update_lock);
129 
130 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
131 		for (nr = 0; nr < 6; nr++) {
132 			data->in[input][nr] =
133 				emc6w201_read8(client,
134 						EMC6W201_REG_IN(nr));
135 			data->in[min][nr] =
136 				emc6w201_read8(client,
137 						EMC6W201_REG_IN_LOW(nr));
138 			data->in[max][nr] =
139 				emc6w201_read8(client,
140 						EMC6W201_REG_IN_HIGH(nr));
141 		}
142 
143 		for (nr = 0; nr < 6; nr++) {
144 			data->temp[input][nr] =
145 				emc6w201_read8(client,
146 						EMC6W201_REG_TEMP(nr));
147 			data->temp[min][nr] =
148 				emc6w201_read8(client,
149 						EMC6W201_REG_TEMP_LOW(nr));
150 			data->temp[max][nr] =
151 				emc6w201_read8(client,
152 						EMC6W201_REG_TEMP_HIGH(nr));
153 		}
154 
155 		for (nr = 0; nr < 5; nr++) {
156 			data->fan[input][nr] =
157 				emc6w201_read16(client,
158 						EMC6W201_REG_FAN(nr));
159 			data->fan[min][nr] =
160 				emc6w201_read16(client,
161 						EMC6W201_REG_FAN_MIN(nr));
162 		}
163 
164 		data->last_updated = jiffies;
165 		data->valid = true;
166 	}
167 
168 	mutex_unlock(&data->update_lock);
169 
170 	return data;
171 }
172 
173 /*
174  * Sysfs callback functions
175  */
176 
177 static const s16 nominal_mv[6] = { 2500, 1500, 3300, 5000, 1500, 1500 };
178 
179 static ssize_t in_show(struct device *dev, struct device_attribute *devattr,
180 		       char *buf)
181 {
182 	struct emc6w201_data *data = emc6w201_update_device(dev);
183 	int sf = to_sensor_dev_attr_2(devattr)->index;
184 	int nr = to_sensor_dev_attr_2(devattr)->nr;
185 
186 	return sprintf(buf, "%u\n",
187 		       (unsigned)data->in[sf][nr] * nominal_mv[nr] / 0xC0);
188 }
189 
190 static ssize_t in_store(struct device *dev, struct device_attribute *devattr,
191 			const char *buf, size_t count)
192 {
193 	struct emc6w201_data *data = dev_get_drvdata(dev);
194 	struct i2c_client *client = data->client;
195 	int sf = to_sensor_dev_attr_2(devattr)->index;
196 	int nr = to_sensor_dev_attr_2(devattr)->nr;
197 	int err;
198 	long val;
199 	u8 reg;
200 
201 	err = kstrtol(buf, 10, &val);
202 	if (err < 0)
203 		return err;
204 
205 	val = clamp_val(val, 0, 255 * nominal_mv[nr] / 192);
206 	val = DIV_ROUND_CLOSEST(val * 192, nominal_mv[nr]);
207 	reg = (sf == min) ? EMC6W201_REG_IN_LOW(nr)
208 			  : EMC6W201_REG_IN_HIGH(nr);
209 
210 	mutex_lock(&data->update_lock);
211 	data->in[sf][nr] = val;
212 	err = emc6w201_write8(client, reg, data->in[sf][nr]);
213 	mutex_unlock(&data->update_lock);
214 
215 	return err < 0 ? err : count;
216 }
217 
218 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
219 			 char *buf)
220 {
221 	struct emc6w201_data *data = emc6w201_update_device(dev);
222 	int sf = to_sensor_dev_attr_2(devattr)->index;
223 	int nr = to_sensor_dev_attr_2(devattr)->nr;
224 
225 	return sprintf(buf, "%d\n", (int)data->temp[sf][nr] * 1000);
226 }
227 
228 static ssize_t temp_store(struct device *dev,
229 			  struct device_attribute *devattr, const char *buf,
230 			  size_t count)
231 {
232 	struct emc6w201_data *data = dev_get_drvdata(dev);
233 	struct i2c_client *client = data->client;
234 	int sf = to_sensor_dev_attr_2(devattr)->index;
235 	int nr = to_sensor_dev_attr_2(devattr)->nr;
236 	int err;
237 	long val;
238 	u8 reg;
239 
240 	err = kstrtol(buf, 10, &val);
241 	if (err < 0)
242 		return err;
243 
244 	val = clamp_val(val, -127000, 127000);
245 	val = DIV_ROUND_CLOSEST(val, 1000);
246 	reg = (sf == min) ? EMC6W201_REG_TEMP_LOW(nr)
247 			  : EMC6W201_REG_TEMP_HIGH(nr);
248 
249 	mutex_lock(&data->update_lock);
250 	data->temp[sf][nr] = val;
251 	err = emc6w201_write8(client, reg, data->temp[sf][nr]);
252 	mutex_unlock(&data->update_lock);
253 
254 	return err < 0 ? err : count;
255 }
256 
257 static ssize_t fan_show(struct device *dev, struct device_attribute *devattr,
258 			char *buf)
259 {
260 	struct emc6w201_data *data = emc6w201_update_device(dev);
261 	int sf = to_sensor_dev_attr_2(devattr)->index;
262 	int nr = to_sensor_dev_attr_2(devattr)->nr;
263 	unsigned rpm;
264 
265 	if (data->fan[sf][nr] == 0 || data->fan[sf][nr] == 0xFFFF)
266 		rpm = 0;
267 	else
268 		rpm = 5400000U / data->fan[sf][nr];
269 
270 	return sprintf(buf, "%u\n", rpm);
271 }
272 
273 static ssize_t fan_store(struct device *dev, struct device_attribute *devattr,
274 			 const char *buf, size_t count)
275 {
276 	struct emc6w201_data *data = dev_get_drvdata(dev);
277 	struct i2c_client *client = data->client;
278 	int sf = to_sensor_dev_attr_2(devattr)->index;
279 	int nr = to_sensor_dev_attr_2(devattr)->nr;
280 	int err;
281 	unsigned long val;
282 
283 	err = kstrtoul(buf, 10, &val);
284 	if (err < 0)
285 		return err;
286 
287 	if (val == 0) {
288 		val = 0xFFFF;
289 	} else {
290 		val = DIV_ROUND_CLOSEST(5400000U, val);
291 		val = clamp_val(val, 0, 0xFFFE);
292 	}
293 
294 	mutex_lock(&data->update_lock);
295 	data->fan[sf][nr] = val;
296 	err = emc6w201_write16(client, EMC6W201_REG_FAN_MIN(nr),
297 			       data->fan[sf][nr]);
298 	mutex_unlock(&data->update_lock);
299 
300 	return err < 0 ? err : count;
301 }
302 
303 static SENSOR_DEVICE_ATTR_2_RO(in0_input, in, 0, input);
304 static SENSOR_DEVICE_ATTR_2_RW(in0_min, in, 0, min);
305 static SENSOR_DEVICE_ATTR_2_RW(in0_max, in, 0, max);
306 static SENSOR_DEVICE_ATTR_2_RO(in1_input, in, 1, input);
307 static SENSOR_DEVICE_ATTR_2_RW(in1_min, in, 1, min);
308 static SENSOR_DEVICE_ATTR_2_RW(in1_max, in, 1, max);
309 static SENSOR_DEVICE_ATTR_2_RO(in2_input, in, 2, input);
310 static SENSOR_DEVICE_ATTR_2_RW(in2_min, in, 2, min);
311 static SENSOR_DEVICE_ATTR_2_RW(in2_max, in, 2, max);
312 static SENSOR_DEVICE_ATTR_2_RO(in3_input, in, 3, input);
313 static SENSOR_DEVICE_ATTR_2_RW(in3_min, in, 3, min);
314 static SENSOR_DEVICE_ATTR_2_RW(in3_max, in, 3, max);
315 static SENSOR_DEVICE_ATTR_2_RO(in4_input, in, 4, input);
316 static SENSOR_DEVICE_ATTR_2_RW(in4_min, in, 4, min);
317 static SENSOR_DEVICE_ATTR_2_RW(in4_max, in, 4, max);
318 static SENSOR_DEVICE_ATTR_2_RO(in5_input, in, 5, input);
319 static SENSOR_DEVICE_ATTR_2_RW(in5_min, in, 5, min);
320 static SENSOR_DEVICE_ATTR_2_RW(in5_max, in, 5, max);
321 
322 static SENSOR_DEVICE_ATTR_2_RO(temp1_input, temp, 0, input);
323 static SENSOR_DEVICE_ATTR_2_RW(temp1_min, temp, 0, min);
324 static SENSOR_DEVICE_ATTR_2_RW(temp1_max, temp, 0, max);
325 static SENSOR_DEVICE_ATTR_2_RO(temp2_input, temp, 1, input);
326 static SENSOR_DEVICE_ATTR_2_RW(temp2_min, temp, 1, min);
327 static SENSOR_DEVICE_ATTR_2_RW(temp2_max, temp, 1, max);
328 static SENSOR_DEVICE_ATTR_2_RO(temp3_input, temp, 2, input);
329 static SENSOR_DEVICE_ATTR_2_RW(temp3_min, temp, 2, min);
330 static SENSOR_DEVICE_ATTR_2_RW(temp3_max, temp, 2, max);
331 static SENSOR_DEVICE_ATTR_2_RO(temp4_input, temp, 3, input);
332 static SENSOR_DEVICE_ATTR_2_RW(temp4_min, temp, 3, min);
333 static SENSOR_DEVICE_ATTR_2_RW(temp4_max, temp, 3, max);
334 static SENSOR_DEVICE_ATTR_2_RO(temp5_input, temp, 4, input);
335 static SENSOR_DEVICE_ATTR_2_RW(temp5_min, temp, 4, min);
336 static SENSOR_DEVICE_ATTR_2_RW(temp5_max, temp, 4, max);
337 static SENSOR_DEVICE_ATTR_2_RO(temp6_input, temp, 5, input);
338 static SENSOR_DEVICE_ATTR_2_RW(temp6_min, temp, 5, min);
339 static SENSOR_DEVICE_ATTR_2_RW(temp6_max, temp, 5, max);
340 
341 static SENSOR_DEVICE_ATTR_2_RO(fan1_input, fan, 0, input);
342 static SENSOR_DEVICE_ATTR_2_RW(fan1_min, fan, 0, min);
343 static SENSOR_DEVICE_ATTR_2_RO(fan2_input, fan, 1, input);
344 static SENSOR_DEVICE_ATTR_2_RW(fan2_min, fan, 1, min);
345 static SENSOR_DEVICE_ATTR_2_RO(fan3_input, fan, 2, input);
346 static SENSOR_DEVICE_ATTR_2_RW(fan3_min, fan, 2, min);
347 static SENSOR_DEVICE_ATTR_2_RO(fan4_input, fan, 3, input);
348 static SENSOR_DEVICE_ATTR_2_RW(fan4_min, fan, 3, min);
349 static SENSOR_DEVICE_ATTR_2_RO(fan5_input, fan, 4, input);
350 static SENSOR_DEVICE_ATTR_2_RW(fan5_min, fan, 4, min);
351 
352 static struct attribute *emc6w201_attrs[] = {
353 	&sensor_dev_attr_in0_input.dev_attr.attr,
354 	&sensor_dev_attr_in0_min.dev_attr.attr,
355 	&sensor_dev_attr_in0_max.dev_attr.attr,
356 	&sensor_dev_attr_in1_input.dev_attr.attr,
357 	&sensor_dev_attr_in1_min.dev_attr.attr,
358 	&sensor_dev_attr_in1_max.dev_attr.attr,
359 	&sensor_dev_attr_in2_input.dev_attr.attr,
360 	&sensor_dev_attr_in2_min.dev_attr.attr,
361 	&sensor_dev_attr_in2_max.dev_attr.attr,
362 	&sensor_dev_attr_in3_input.dev_attr.attr,
363 	&sensor_dev_attr_in3_min.dev_attr.attr,
364 	&sensor_dev_attr_in3_max.dev_attr.attr,
365 	&sensor_dev_attr_in4_input.dev_attr.attr,
366 	&sensor_dev_attr_in4_min.dev_attr.attr,
367 	&sensor_dev_attr_in4_max.dev_attr.attr,
368 	&sensor_dev_attr_in5_input.dev_attr.attr,
369 	&sensor_dev_attr_in5_min.dev_attr.attr,
370 	&sensor_dev_attr_in5_max.dev_attr.attr,
371 
372 	&sensor_dev_attr_temp1_input.dev_attr.attr,
373 	&sensor_dev_attr_temp1_min.dev_attr.attr,
374 	&sensor_dev_attr_temp1_max.dev_attr.attr,
375 	&sensor_dev_attr_temp2_input.dev_attr.attr,
376 	&sensor_dev_attr_temp2_min.dev_attr.attr,
377 	&sensor_dev_attr_temp2_max.dev_attr.attr,
378 	&sensor_dev_attr_temp3_input.dev_attr.attr,
379 	&sensor_dev_attr_temp3_min.dev_attr.attr,
380 	&sensor_dev_attr_temp3_max.dev_attr.attr,
381 	&sensor_dev_attr_temp4_input.dev_attr.attr,
382 	&sensor_dev_attr_temp4_min.dev_attr.attr,
383 	&sensor_dev_attr_temp4_max.dev_attr.attr,
384 	&sensor_dev_attr_temp5_input.dev_attr.attr,
385 	&sensor_dev_attr_temp5_min.dev_attr.attr,
386 	&sensor_dev_attr_temp5_max.dev_attr.attr,
387 	&sensor_dev_attr_temp6_input.dev_attr.attr,
388 	&sensor_dev_attr_temp6_min.dev_attr.attr,
389 	&sensor_dev_attr_temp6_max.dev_attr.attr,
390 
391 	&sensor_dev_attr_fan1_input.dev_attr.attr,
392 	&sensor_dev_attr_fan1_min.dev_attr.attr,
393 	&sensor_dev_attr_fan2_input.dev_attr.attr,
394 	&sensor_dev_attr_fan2_min.dev_attr.attr,
395 	&sensor_dev_attr_fan3_input.dev_attr.attr,
396 	&sensor_dev_attr_fan3_min.dev_attr.attr,
397 	&sensor_dev_attr_fan4_input.dev_attr.attr,
398 	&sensor_dev_attr_fan4_min.dev_attr.attr,
399 	&sensor_dev_attr_fan5_input.dev_attr.attr,
400 	&sensor_dev_attr_fan5_min.dev_attr.attr,
401 	NULL
402 };
403 
404 ATTRIBUTE_GROUPS(emc6w201);
405 
406 /*
407  * Driver interface
408  */
409 
410 /* Return 0 if detection is successful, -ENODEV otherwise */
411 static int emc6w201_detect(struct i2c_client *client,
412 			   struct i2c_board_info *info)
413 {
414 	struct i2c_adapter *adapter = client->adapter;
415 	int company, verstep, config;
416 
417 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
418 		return -ENODEV;
419 
420 	/* Identification */
421 	company = i2c_smbus_read_byte_data(client, EMC6W201_REG_COMPANY);
422 	if (company != 0x5C)
423 		return -ENODEV;
424 	verstep = i2c_smbus_read_byte_data(client, EMC6W201_REG_VERSTEP);
425 	if (verstep < 0 || (verstep & 0xF0) != 0xB0)
426 		return -ENODEV;
427 	if ((verstep & 0x0F) > 2) {
428 		dev_dbg(&client->dev, "Unknown EMC6W201 stepping %d\n",
429 			verstep & 0x0F);
430 		return -ENODEV;
431 	}
432 
433 	/* Check configuration */
434 	config = i2c_smbus_read_byte_data(client, EMC6W201_REG_CONFIG);
435 	if (config < 0 || (config & 0xF4) != 0x04)
436 		return -ENODEV;
437 	if (!(config & 0x01)) {
438 		dev_err(&client->dev, "Monitoring not enabled\n");
439 		return -ENODEV;
440 	}
441 
442 	strscpy(info->type, "emc6w201", I2C_NAME_SIZE);
443 
444 	return 0;
445 }
446 
447 static int emc6w201_probe(struct i2c_client *client)
448 {
449 	struct device *dev = &client->dev;
450 	struct emc6w201_data *data;
451 	struct device *hwmon_dev;
452 
453 	data = devm_kzalloc(dev, sizeof(struct emc6w201_data), GFP_KERNEL);
454 	if (!data)
455 		return -ENOMEM;
456 
457 	data->client = client;
458 	mutex_init(&data->update_lock);
459 
460 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
461 							   data,
462 							   emc6w201_groups);
463 	return PTR_ERR_OR_ZERO(hwmon_dev);
464 }
465 
466 static const struct i2c_device_id emc6w201_id[] = {
467 	{ "emc6w201", 0 },
468 	{ }
469 };
470 MODULE_DEVICE_TABLE(i2c, emc6w201_id);
471 
472 static struct i2c_driver emc6w201_driver = {
473 	.class		= I2C_CLASS_HWMON,
474 	.driver = {
475 		.name	= "emc6w201",
476 	},
477 	.probe		= emc6w201_probe,
478 	.id_table	= emc6w201_id,
479 	.detect		= emc6w201_detect,
480 	.address_list	= normal_i2c,
481 };
482 
483 module_i2c_driver(emc6w201_driver);
484 
485 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
486 MODULE_DESCRIPTION("SMSC EMC6W201 hardware monitoring driver");
487 MODULE_LICENSE("GPL");
488