1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * A hwmon driver for the IBM PowerExecutive temperature/power sensors
4  * Copyright (C) 2007 IBM
5  *
6  * Author: Darrick J. Wong <darrick.wong@oracle.com>
7  */
8 
9 #include <linux/ipmi.h>
10 #include <linux/module.h>
11 #include <linux/hwmon.h>
12 #include <linux/hwmon-sysfs.h>
13 #include <linux/jiffies.h>
14 #include <linux/mutex.h>
15 #include <linux/slab.h>
16 #include <linux/err.h>
17 
18 #define REFRESH_INTERVAL	(2 * HZ)
19 #define DRVNAME			"ibmpex"
20 
21 #define PEX_GET_VERSION		1
22 #define PEX_GET_SENSOR_COUNT	2
23 #define PEX_GET_SENSOR_NAME	3
24 #define PEX_RESET_HIGH_LOW	4
25 #define PEX_GET_SENSOR_DATA	6
26 
27 #define PEX_NET_FUNCTION	0x3A
28 #define PEX_COMMAND		0x3C
29 
extract_value(const char * data,int offset)30 static inline u16 extract_value(const char *data, int offset)
31 {
32 	return be16_to_cpup((__be16 *)&data[offset]);
33 }
34 
35 #define TEMP_SENSOR		1
36 #define POWER_SENSOR		2
37 
38 #define PEX_SENSOR_TYPE_LEN	3
39 static u8 const power_sensor_sig[] = {0x70, 0x77, 0x72};
40 static u8 const temp_sensor_sig[]  = {0x74, 0x65, 0x6D};
41 
42 #define PEX_MULT_LEN		2
43 static u8 const watt_sensor_sig[]  = {0x41, 0x43};
44 
45 #define PEX_NUM_SENSOR_FUNCS	3
46 static const char * const sensor_name_suffixes[] = {
47 	"",
48 	"_lowest",
49 	"_highest"
50 };
51 
52 static void ibmpex_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
53 static void ibmpex_register_bmc(int iface, struct device *dev);
54 static void ibmpex_bmc_gone(int iface);
55 
56 struct ibmpex_sensor_data {
57 	int			in_use;
58 	s16			values[PEX_NUM_SENSOR_FUNCS];
59 	int			multiplier;
60 
61 	struct sensor_device_attribute_2	attr[PEX_NUM_SENSOR_FUNCS];
62 };
63 
64 struct ibmpex_bmc_data {
65 	struct list_head	list;
66 	struct device		*hwmon_dev;
67 	struct device		*bmc_device;
68 	struct mutex		lock;
69 	bool			valid;
70 	unsigned long		last_updated;	/* In jiffies */
71 
72 	struct ipmi_addr	address;
73 	struct completion	read_complete;
74 	struct ipmi_user	*user;
75 	int			interface;
76 
77 	struct kernel_ipmi_msg	tx_message;
78 	unsigned char		tx_msg_data[IPMI_MAX_MSG_LENGTH];
79 	long			tx_msgid;
80 
81 	unsigned char		rx_msg_data[IPMI_MAX_MSG_LENGTH];
82 	unsigned long		rx_msg_len;
83 	unsigned char		rx_result;
84 	int			rx_recv_type;
85 
86 	unsigned char		sensor_major;
87 	unsigned char		sensor_minor;
88 
89 	unsigned char		num_sensors;
90 	struct ibmpex_sensor_data	*sensors;
91 };
92 
93 struct ibmpex_driver_data {
94 	struct list_head	bmc_data;
95 	struct ipmi_smi_watcher	bmc_events;
96 	struct ipmi_user_hndl	ipmi_hndlrs;
97 };
98 
99 static struct ibmpex_driver_data driver_data = {
100 	.bmc_data = LIST_HEAD_INIT(driver_data.bmc_data),
101 	.bmc_events = {
102 		.owner = THIS_MODULE,
103 		.new_smi = ibmpex_register_bmc,
104 		.smi_gone = ibmpex_bmc_gone,
105 	},
106 	.ipmi_hndlrs = {
107 		.ipmi_recv_hndl = ibmpex_msg_handler,
108 	},
109 };
110 
ibmpex_send_message(struct ibmpex_bmc_data * data)111 static int ibmpex_send_message(struct ibmpex_bmc_data *data)
112 {
113 	int err;
114 
115 	err = ipmi_validate_addr(&data->address, sizeof(data->address));
116 	if (err)
117 		goto out;
118 
119 	data->tx_msgid++;
120 	err = ipmi_request_settime(data->user, &data->address, data->tx_msgid,
121 				   &data->tx_message, data, 0, 0, 0);
122 	if (err)
123 		goto out1;
124 
125 	return 0;
126 out1:
127 	dev_err(data->bmc_device, "request_settime=%x\n", err);
128 	return err;
129 out:
130 	dev_err(data->bmc_device, "validate_addr=%x\n", err);
131 	return err;
132 }
133 
ibmpex_ver_check(struct ibmpex_bmc_data * data)134 static int ibmpex_ver_check(struct ibmpex_bmc_data *data)
135 {
136 	data->tx_msg_data[0] = PEX_GET_VERSION;
137 	data->tx_message.data_len = 1;
138 	ibmpex_send_message(data);
139 
140 	wait_for_completion(&data->read_complete);
141 
142 	if (data->rx_result || data->rx_msg_len != 6)
143 		return -ENOENT;
144 
145 	data->sensor_major = data->rx_msg_data[0];
146 	data->sensor_minor = data->rx_msg_data[1];
147 
148 	dev_info(data->bmc_device,
149 		 "Found BMC with sensor interface v%d.%d %d-%02d-%02d on interface %d\n",
150 		 data->sensor_major,
151 		 data->sensor_minor,
152 		 extract_value(data->rx_msg_data, 2),
153 		 data->rx_msg_data[4],
154 		 data->rx_msg_data[5],
155 		 data->interface);
156 
157 	return 0;
158 }
159 
ibmpex_query_sensor_count(struct ibmpex_bmc_data * data)160 static int ibmpex_query_sensor_count(struct ibmpex_bmc_data *data)
161 {
162 	data->tx_msg_data[0] = PEX_GET_SENSOR_COUNT;
163 	data->tx_message.data_len = 1;
164 	ibmpex_send_message(data);
165 
166 	wait_for_completion(&data->read_complete);
167 
168 	if (data->rx_result || data->rx_msg_len != 1)
169 		return -ENOENT;
170 
171 	return data->rx_msg_data[0];
172 }
173 
ibmpex_query_sensor_name(struct ibmpex_bmc_data * data,int sensor)174 static int ibmpex_query_sensor_name(struct ibmpex_bmc_data *data, int sensor)
175 {
176 	data->tx_msg_data[0] = PEX_GET_SENSOR_NAME;
177 	data->tx_msg_data[1] = sensor;
178 	data->tx_message.data_len = 2;
179 	ibmpex_send_message(data);
180 
181 	wait_for_completion(&data->read_complete);
182 
183 	if (data->rx_result || data->rx_msg_len < 1)
184 		return -ENOENT;
185 
186 	return 0;
187 }
188 
ibmpex_query_sensor_data(struct ibmpex_bmc_data * data,int sensor)189 static int ibmpex_query_sensor_data(struct ibmpex_bmc_data *data, int sensor)
190 {
191 	data->tx_msg_data[0] = PEX_GET_SENSOR_DATA;
192 	data->tx_msg_data[1] = sensor;
193 	data->tx_message.data_len = 2;
194 	ibmpex_send_message(data);
195 
196 	wait_for_completion(&data->read_complete);
197 
198 	if (data->rx_result || data->rx_msg_len < 26) {
199 		dev_err(data->bmc_device, "Error reading sensor %d.\n",
200 			sensor);
201 		return -ENOENT;
202 	}
203 
204 	return 0;
205 }
206 
ibmpex_reset_high_low_data(struct ibmpex_bmc_data * data)207 static int ibmpex_reset_high_low_data(struct ibmpex_bmc_data *data)
208 {
209 	data->tx_msg_data[0] = PEX_RESET_HIGH_LOW;
210 	data->tx_message.data_len = 1;
211 	ibmpex_send_message(data);
212 
213 	wait_for_completion(&data->read_complete);
214 
215 	return 0;
216 }
217 
ibmpex_update_device(struct ibmpex_bmc_data * data)218 static void ibmpex_update_device(struct ibmpex_bmc_data *data)
219 {
220 	int i, err;
221 
222 	mutex_lock(&data->lock);
223 	if (time_before(jiffies, data->last_updated + REFRESH_INTERVAL) &&
224 	    data->valid)
225 		goto out;
226 
227 	for (i = 0; i < data->num_sensors; i++) {
228 		if (!data->sensors[i].in_use)
229 			continue;
230 		err = ibmpex_query_sensor_data(data, i);
231 		if (err)
232 			continue;
233 		data->sensors[i].values[0] =
234 			extract_value(data->rx_msg_data, 16);
235 		data->sensors[i].values[1] =
236 			extract_value(data->rx_msg_data, 18);
237 		data->sensors[i].values[2] =
238 			extract_value(data->rx_msg_data, 20);
239 	}
240 
241 	data->last_updated = jiffies;
242 	data->valid = true;
243 
244 out:
245 	mutex_unlock(&data->lock);
246 }
247 
get_bmc_data(int iface)248 static struct ibmpex_bmc_data *get_bmc_data(int iface)
249 {
250 	struct ibmpex_bmc_data *p, *next;
251 
252 	list_for_each_entry_safe(p, next, &driver_data.bmc_data, list)
253 		if (p->interface == iface)
254 			return p;
255 
256 	return NULL;
257 }
258 
259 static DEVICE_STRING_ATTR_RO(name, 0444, DRVNAME);
260 
ibmpex_show_sensor(struct device * dev,struct device_attribute * devattr,char * buf)261 static ssize_t ibmpex_show_sensor(struct device *dev,
262 				  struct device_attribute *devattr,
263 				  char *buf)
264 {
265 	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
266 	struct ibmpex_bmc_data *data = dev_get_drvdata(dev);
267 	int mult = data->sensors[attr->index].multiplier;
268 	ibmpex_update_device(data);
269 
270 	return sprintf(buf, "%d\n",
271 		       data->sensors[attr->index].values[attr->nr] * mult);
272 }
273 
ibmpex_high_low_store(struct device * dev,struct device_attribute * devattr,const char * buf,size_t count)274 static ssize_t ibmpex_high_low_store(struct device *dev,
275 				     struct device_attribute *devattr,
276 				     const char *buf, size_t count)
277 {
278 	struct ibmpex_bmc_data *data = dev_get_drvdata(dev);
279 
280 	ibmpex_reset_high_low_data(data);
281 
282 	return count;
283 }
284 
285 static SENSOR_DEVICE_ATTR_WO(reset_high_low, ibmpex_high_low, 0);
286 
is_power_sensor(const char * sensor_id,int len)287 static int is_power_sensor(const char *sensor_id, int len)
288 {
289 	if (len < PEX_SENSOR_TYPE_LEN)
290 		return 0;
291 
292 	if (!memcmp(sensor_id, power_sensor_sig, PEX_SENSOR_TYPE_LEN))
293 		return 1;
294 	return 0;
295 }
296 
is_temp_sensor(const char * sensor_id,int len)297 static int is_temp_sensor(const char *sensor_id, int len)
298 {
299 	if (len < PEX_SENSOR_TYPE_LEN)
300 		return 0;
301 
302 	if (!memcmp(sensor_id, temp_sensor_sig, PEX_SENSOR_TYPE_LEN))
303 		return 1;
304 	return 0;
305 }
306 
power_sensor_multiplier(struct ibmpex_bmc_data * data,const char * sensor_id,int len)307 static int power_sensor_multiplier(struct ibmpex_bmc_data *data,
308 				   const char *sensor_id, int len)
309 {
310 	int i;
311 
312 	if (data->sensor_major == 2)
313 		return 1000000;
314 
315 	for (i = PEX_SENSOR_TYPE_LEN; i < len - 1; i++)
316 		if (!memcmp(&sensor_id[i], watt_sensor_sig, PEX_MULT_LEN))
317 			return 1000000;
318 
319 	return 100000;
320 }
321 
create_sensor(struct ibmpex_bmc_data * data,int type,int counter,int sensor,int func)322 static int create_sensor(struct ibmpex_bmc_data *data, int type,
323 			 int counter, int sensor, int func)
324 {
325 	int err;
326 	char *n;
327 
328 	n = kmalloc(32, GFP_KERNEL);
329 	if (!n)
330 		return -ENOMEM;
331 
332 	if (type == TEMP_SENSOR)
333 		sprintf(n, "temp%d_input%s",
334 			counter, sensor_name_suffixes[func]);
335 	else if (type == POWER_SENSOR)
336 		sprintf(n, "power%d_average%s",
337 			counter, sensor_name_suffixes[func]);
338 
339 	sysfs_attr_init(&data->sensors[sensor].attr[func].dev_attr.attr);
340 	data->sensors[sensor].attr[func].dev_attr.attr.name = n;
341 	data->sensors[sensor].attr[func].dev_attr.attr.mode = 0444;
342 	data->sensors[sensor].attr[func].dev_attr.show = ibmpex_show_sensor;
343 	data->sensors[sensor].attr[func].index = sensor;
344 	data->sensors[sensor].attr[func].nr = func;
345 
346 	err = device_create_file(data->bmc_device,
347 				 &data->sensors[sensor].attr[func].dev_attr);
348 	if (err) {
349 		data->sensors[sensor].attr[func].dev_attr.attr.name = NULL;
350 		kfree(n);
351 		return err;
352 	}
353 
354 	return 0;
355 }
356 
ibmpex_find_sensors(struct ibmpex_bmc_data * data)357 static int ibmpex_find_sensors(struct ibmpex_bmc_data *data)
358 {
359 	int i, j, err;
360 	int sensor_type;
361 	int sensor_counter;
362 	int num_power = 0;
363 	int num_temp = 0;
364 
365 	err = ibmpex_query_sensor_count(data);
366 	if (err <= 0)
367 		return -ENOENT;
368 	data->num_sensors = err;
369 
370 	data->sensors = kcalloc(data->num_sensors, sizeof(*data->sensors),
371 				GFP_KERNEL);
372 	if (!data->sensors)
373 		return -ENOMEM;
374 
375 	for (i = 0; i < data->num_sensors; i++) {
376 		err = ibmpex_query_sensor_name(data, i);
377 		if (err)
378 			continue;
379 
380 		if (is_power_sensor(data->rx_msg_data, data->rx_msg_len)) {
381 			sensor_type = POWER_SENSOR;
382 			num_power++;
383 			sensor_counter = num_power;
384 			data->sensors[i].multiplier =
385 				power_sensor_multiplier(data,
386 							data->rx_msg_data,
387 							data->rx_msg_len);
388 		} else if (is_temp_sensor(data->rx_msg_data,
389 					  data->rx_msg_len)) {
390 			sensor_type = TEMP_SENSOR;
391 			num_temp++;
392 			sensor_counter = num_temp;
393 			data->sensors[i].multiplier = 1000;
394 		} else
395 			continue;
396 
397 		data->sensors[i].in_use = 1;
398 
399 		/* Create attributes */
400 		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
401 			err = create_sensor(data, sensor_type, sensor_counter,
402 					    i, j);
403 			if (err)
404 				goto exit_remove;
405 		}
406 	}
407 
408 	err = device_create_file(data->bmc_device,
409 			&sensor_dev_attr_reset_high_low.dev_attr);
410 	if (err)
411 		goto exit_remove;
412 
413 	err = device_create_file(data->bmc_device, &dev_attr_name.attr);
414 	if (err)
415 		goto exit_remove;
416 
417 	return 0;
418 
419 exit_remove:
420 	device_remove_file(data->bmc_device,
421 			   &sensor_dev_attr_reset_high_low.dev_attr);
422 	device_remove_file(data->bmc_device, &dev_attr_name.attr);
423 	for (i = 0; i < data->num_sensors; i++)
424 		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
425 			if (!data->sensors[i].attr[j].dev_attr.attr.name)
426 				continue;
427 			device_remove_file(data->bmc_device,
428 				&data->sensors[i].attr[j].dev_attr);
429 			kfree(data->sensors[i].attr[j].dev_attr.attr.name);
430 		}
431 
432 	kfree(data->sensors);
433 	return err;
434 }
435 
ibmpex_register_bmc(int iface,struct device * dev)436 static void ibmpex_register_bmc(int iface, struct device *dev)
437 {
438 	struct ibmpex_bmc_data *data;
439 	int err;
440 
441 	data = kzalloc(sizeof(*data), GFP_KERNEL);
442 	if (!data)
443 		return;
444 
445 	data->address.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
446 	data->address.channel = IPMI_BMC_CHANNEL;
447 	data->address.data[0] = 0;
448 	data->interface = iface;
449 	data->bmc_device = dev;
450 
451 	/* Create IPMI messaging interface user */
452 	err = ipmi_create_user(data->interface, &driver_data.ipmi_hndlrs,
453 			       data, &data->user);
454 	if (err < 0) {
455 		dev_err(dev,
456 			"Unable to register user with IPMI interface %d\n",
457 			data->interface);
458 		goto out;
459 	}
460 
461 	mutex_init(&data->lock);
462 
463 	/* Initialize message */
464 	data->tx_msgid = 0;
465 	init_completion(&data->read_complete);
466 	data->tx_message.netfn = PEX_NET_FUNCTION;
467 	data->tx_message.cmd = PEX_COMMAND;
468 	data->tx_message.data = data->tx_msg_data;
469 
470 	/* Does this BMC support PowerExecutive? */
471 	err = ibmpex_ver_check(data);
472 	if (err)
473 		goto out_user;
474 
475 	/* Register the BMC as a HWMON class device */
476 	data->hwmon_dev = hwmon_device_register(data->bmc_device);
477 
478 	if (IS_ERR(data->hwmon_dev)) {
479 		dev_err(data->bmc_device,
480 			"Unable to register hwmon device for IPMI interface %d\n",
481 			data->interface);
482 		goto out_user;
483 	}
484 
485 	/* finally add the new bmc data to the bmc data list */
486 	dev_set_drvdata(dev, data);
487 	list_add_tail(&data->list, &driver_data.bmc_data);
488 
489 	/* Now go find all the sensors */
490 	err = ibmpex_find_sensors(data);
491 	if (err) {
492 		dev_err(data->bmc_device, "Error %d finding sensors\n", err);
493 		goto out_register;
494 	}
495 
496 	return;
497 
498 out_register:
499 	list_del(&data->list);
500 	hwmon_device_unregister(data->hwmon_dev);
501 out_user:
502 	ipmi_destroy_user(data->user);
503 out:
504 	kfree(data);
505 }
506 
ibmpex_bmc_delete(struct ibmpex_bmc_data * data)507 static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data)
508 {
509 	int i, j;
510 
511 	device_remove_file(data->bmc_device,
512 			   &sensor_dev_attr_reset_high_low.dev_attr);
513 	device_remove_file(data->bmc_device, &dev_attr_name.attr);
514 	for (i = 0; i < data->num_sensors; i++)
515 		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
516 			if (!data->sensors[i].attr[j].dev_attr.attr.name)
517 				continue;
518 			device_remove_file(data->bmc_device,
519 				&data->sensors[i].attr[j].dev_attr);
520 			kfree(data->sensors[i].attr[j].dev_attr.attr.name);
521 		}
522 
523 	list_del(&data->list);
524 	dev_set_drvdata(data->bmc_device, NULL);
525 	hwmon_device_unregister(data->hwmon_dev);
526 	ipmi_destroy_user(data->user);
527 	kfree(data->sensors);
528 	kfree(data);
529 }
530 
ibmpex_bmc_gone(int iface)531 static void ibmpex_bmc_gone(int iface)
532 {
533 	struct ibmpex_bmc_data *data = get_bmc_data(iface);
534 
535 	if (!data)
536 		return;
537 
538 	ibmpex_bmc_delete(data);
539 }
540 
ibmpex_msg_handler(struct ipmi_recv_msg * msg,void * user_msg_data)541 static void ibmpex_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
542 {
543 	struct ibmpex_bmc_data *data = user_msg_data;
544 
545 	if (msg->msgid != data->tx_msgid) {
546 		dev_err(data->bmc_device,
547 			"Mismatch between received msgid (%02x) and transmitted msgid (%02x)!\n",
548 			(int)msg->msgid,
549 			(int)data->tx_msgid);
550 		ipmi_free_recv_msg(msg);
551 		return;
552 	}
553 
554 	data->rx_recv_type = msg->recv_type;
555 	if (msg->msg.data_len > 0)
556 		data->rx_result = msg->msg.data[0];
557 	else
558 		data->rx_result = IPMI_UNKNOWN_ERR_COMPLETION_CODE;
559 
560 	if (msg->msg.data_len > 1) {
561 		data->rx_msg_len = msg->msg.data_len - 1;
562 		memcpy(data->rx_msg_data, msg->msg.data + 1, data->rx_msg_len);
563 	} else
564 		data->rx_msg_len = 0;
565 
566 	ipmi_free_recv_msg(msg);
567 	complete(&data->read_complete);
568 }
569 
ibmpex_init(void)570 static int __init ibmpex_init(void)
571 {
572 	return ipmi_smi_watcher_register(&driver_data.bmc_events);
573 }
574 
ibmpex_exit(void)575 static void __exit ibmpex_exit(void)
576 {
577 	struct ibmpex_bmc_data *p, *next;
578 
579 	ipmi_smi_watcher_unregister(&driver_data.bmc_events);
580 	list_for_each_entry_safe(p, next, &driver_data.bmc_data, list)
581 		ibmpex_bmc_delete(p);
582 }
583 
584 MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");
585 MODULE_DESCRIPTION("IBM PowerExecutive power/temperature sensor driver");
586 MODULE_LICENSE("GPL");
587 
588 module_init(ibmpex_init);
589 module_exit(ibmpex_exit);
590 
591 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3350-*");
592 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550-*");
593 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650-*");
594 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3655-*");
595 MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3755-*");
596