1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Hwmon client for disk and solid state drives with temperature sensors
4 * Copyright (C) 2019 Zodiac Inflight Innovations
5 *
6 * With input from:
7 *    Hwmon client for S.M.A.R.T. hard disk drives with temperature sensors.
8 *    (C) 2018 Linus Walleij
9 *
10 *    hwmon: Driver for SCSI/ATA temperature sensors
11 *    by Constantin Baranov <const@mimas.ru>, submitted September 2009
12 *
13 * This drive supports reporting the temperature of SATA drives. It can be
14 * easily extended to report the temperature of SCSI drives.
15 *
16 * The primary means to read drive temperatures and temperature limits
17 * for ATA drives is the SCT Command Transport feature set as specified in
18 * ATA8-ACS.
19 * It can be used to read the current drive temperature, temperature limits,
20 * and historic minimum and maximum temperatures. The SCT Command Transport
21 * feature set is documented in "AT Attachment 8 - ATA/ATAPI Command Set
22 * (ATA8-ACS)".
23 *
24 * If the SCT Command Transport feature set is not available, drive temperatures
25 * may be readable through SMART attributes. Since SMART attributes are not well
26 * defined, this method is only used as fallback mechanism.
27 *
28 * There are three SMART attributes which may report drive temperatures.
29 * Those are defined as follows (from
30 * http://www.cropel.com/library/smart-attribute-list.aspx).
31 *
32 * 190	Temperature	Temperature, monitored by a sensor somewhere inside
33 *			the drive. Raw value typicaly holds the actual
34 *			temperature (hexadecimal) in its rightmost two digits.
35 *
36 * 194	Temperature	Temperature, monitored by a sensor somewhere inside
37 *			the drive. Raw value typicaly holds the actual
38 *			temperature (hexadecimal) in its rightmost two digits.
39 *
40 * 231	Temperature	Temperature, monitored by a sensor somewhere inside
41 *			the drive. Raw value typicaly holds the actual
42 *			temperature (hexadecimal) in its rightmost two digits.
43 *
44 * Wikipedia defines attributes a bit differently.
45 *
46 * 190	Temperature	Value is equal to (100-temp. ��C), allowing manufacturer
47 *	Difference or	to set a minimum threshold which corresponds to a
48 *	Airflow		maximum temperature. This also follows the convention of
49 *	Temperature	100 being a best-case value and lower values being
50 *			undesirable. However, some older drives may instead
51 *			report raw Temperature (identical to 0xC2) or
52 *			Temperature minus 50 here.
53 * 194	Temperature or	Indicates the device temperature, if the appropriate
54 *	Temperature	sensor is fitted. Lowest byte of the raw value contains
55 *	Celsius		the exact temperature value (Celsius degrees).
56 * 231	Life Left	Indicates the approximate SSD life left, in terms of
57 *	(SSDs) or	program/erase cycles or available reserved blocks.
58 *	Temperature	A normalized value of 100 represents a new drive, with
59 *			a threshold value at 10 indicating a need for
60 *			replacement. A value of 0 may mean that the drive is
61 *			operating in read-only mode to allow data recovery.
62 *			Previously (pre-2010) occasionally used for Drive
63 *			Temperature (more typically reported at 0xC2).
64 *
65 * Common denominator is that the first raw byte reports the temperature
66 * in degrees C on almost all drives. Some drives may report a fractional
67 * temperature in the second raw byte.
68 *
69 * Known exceptions (from libatasmart):
70 * - SAMSUNG SV0412H and SAMSUNG SV1204H) report the temperature in 10th
71 *   degrees C in the first two raw bytes.
72 * - A few Maxtor drives report an unknown or bad value in attribute 194.
73 * - Certain Apple SSD drives report an unknown value in attribute 190.
74 *   Only certain firmware versions are affected.
75 *
76 * Those exceptions affect older ATA drives and are currently ignored.
77 * Also, the second raw byte (possibly reporting the fractional temperature)
78 * is currently ignored.
79 *
80 * Many drives also report temperature limits in additional SMART data raw
81 * bytes. The format of those is not well defined and varies widely.
82 * The driver does not currently attempt to report those limits.
83 *
84 * According to data in smartmontools, attribute 231 is rarely used to report
85 * drive temperatures. At the same time, several drives report SSD life left
86 * in attribute 231, but do not support temperature sensors. For this reason,
87 * attribute 231 is currently ignored.
88 *
89 * Following above definitions, temperatures are reported as follows.
90 *   If SCT Command Transport is supported, it is used to read the
91 *   temperature and, if available, temperature limits.
92 * - Otherwise, if SMART attribute 194 is supported, it is used to read
93 *   the temperature.
94 * - Otherwise, if SMART attribute 190 is supported, it is used to read
95 *   the temperature.
96 */
97
98#include <linux/ata.h>
99#include <linux/bits.h>
100#include <linux/device.h>
101#include <linux/hwmon.h>
102#include <linux/kernel.h>
103#include <linux/list.h>
104#include <linux/module.h>
105#include <linux/mutex.h>
106#include <scsi/scsi_cmnd.h>
107#include <scsi/scsi_device.h>
108#include <scsi/scsi_driver.h>
109#include <scsi/scsi_proto.h>
110
111struct drivetemp_data {
112	struct list_head list;		/* list of instantiated devices */
113	struct mutex lock;		/* protect data buffer accesses */
114	struct scsi_device *sdev;	/* SCSI device */
115	struct device *dev;		/* instantiating device */
116	struct device *hwdev;		/* hardware monitoring device */
117	u8 smartdata[ATA_SECT_SIZE];	/* local buffer */
118	int (*get_temp)(struct drivetemp_data *st, u32 attr, long *val);
119	bool have_temp_lowest;		/* lowest temp in SCT status */
120	bool have_temp_highest;		/* highest temp in SCT status */
121	bool have_temp_min;		/* have min temp */
122	bool have_temp_max;		/* have max temp */
123	bool have_temp_lcrit;		/* have lower critical limit */
124	bool have_temp_crit;		/* have critical limit */
125	int temp_min;			/* min temp */
126	int temp_max;			/* max temp */
127	int temp_lcrit;			/* lower critical limit */
128	int temp_crit;			/* critical limit */
129};
130
131static LIST_HEAD(drivetemp_devlist);
132
133#define ATA_MAX_SMART_ATTRS	30
134#define SMART_TEMP_PROP_190	190
135#define SMART_TEMP_PROP_194	194
136
137#define SCT_STATUS_REQ_ADDR	0xe0
138#define  SCT_STATUS_VERSION_LOW		0	/* log byte offsets */
139#define  SCT_STATUS_VERSION_HIGH	1
140#define  SCT_STATUS_TEMP		200
141#define  SCT_STATUS_TEMP_LOWEST		201
142#define  SCT_STATUS_TEMP_HIGHEST	202
143#define SCT_READ_LOG_ADDR	0xe1
144#define  SMART_READ_LOG			0xd5
145#define  SMART_WRITE_LOG		0xd6
146
147#define INVALID_TEMP		0x80
148
149#define temp_is_valid(temp)	((temp) != INVALID_TEMP)
150#define temp_from_sct(temp)	(((s8)(temp)) * 1000)
151
152static inline bool ata_id_smart_supported(u16 *id)
153{
154	return id[ATA_ID_COMMAND_SET_1] & BIT(0);
155}
156
157static inline bool ata_id_smart_enabled(u16 *id)
158{
159	return id[ATA_ID_CFS_ENABLE_1] & BIT(0);
160}
161
162static int drivetemp_scsi_command(struct drivetemp_data *st,
163				 u8 ata_command, u8 feature,
164				 u8 lba_low, u8 lba_mid, u8 lba_high)
165{
166	u8 scsi_cmd[MAX_COMMAND_SIZE];
167	enum req_op op;
168
169	memset(scsi_cmd, 0, sizeof(scsi_cmd));
170	scsi_cmd[0] = ATA_16;
171	if (ata_command == ATA_CMD_SMART && feature == SMART_WRITE_LOG) {
172		scsi_cmd[1] = (5 << 1);	/* PIO Data-out */
173		/*
174		 * No off.line or cc, write to dev, block count in sector count
175		 * field.
176		 */
177		scsi_cmd[2] = 0x06;
178		op = REQ_OP_DRV_OUT;
179	} else {
180		scsi_cmd[1] = (4 << 1);	/* PIO Data-in */
181		/*
182		 * No off.line or cc, read from dev, block count in sector count
183		 * field.
184		 */
185		scsi_cmd[2] = 0x0e;
186		op = REQ_OP_DRV_IN;
187	}
188	scsi_cmd[4] = feature;
189	scsi_cmd[6] = 1;	/* 1 sector */
190	scsi_cmd[8] = lba_low;
191	scsi_cmd[10] = lba_mid;
192	scsi_cmd[12] = lba_high;
193	scsi_cmd[14] = ata_command;
194
195	return scsi_execute_cmd(st->sdev, scsi_cmd, op, st->smartdata,
196				ATA_SECT_SIZE, HZ, 5, NULL);
197}
198
199static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature,
200				 u8 select)
201{
202	return drivetemp_scsi_command(st, ATA_CMD_SMART, feature, select,
203				     ATA_SMART_LBAM_PASS, ATA_SMART_LBAH_PASS);
204}
205
206static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr,
207				  long *temp)
208{
209	u8 *buf = st->smartdata;
210	bool have_temp = false;
211	u8 temp_raw;
212	u8 csum;
213	int err;
214	int i;
215
216	err = drivetemp_ata_command(st, ATA_SMART_READ_VALUES, 0);
217	if (err)
218		return err;
219
220	/* Checksum the read value table */
221	csum = 0;
222	for (i = 0; i < ATA_SECT_SIZE; i++)
223		csum += buf[i];
224	if (csum) {
225		dev_dbg(&st->sdev->sdev_gendev,
226			"checksum error reading SMART values\n");
227		return -EIO;
228	}
229
230	for (i = 0; i < ATA_MAX_SMART_ATTRS; i++) {
231		u8 *attr = buf + i * 12;
232		int id = attr[2];
233
234		if (!id)
235			continue;
236
237		if (id == SMART_TEMP_PROP_190) {
238			temp_raw = attr[7];
239			have_temp = true;
240		}
241		if (id == SMART_TEMP_PROP_194) {
242			temp_raw = attr[7];
243			have_temp = true;
244			break;
245		}
246	}
247
248	if (have_temp) {
249		*temp = temp_raw * 1000;
250		return 0;
251	}
252
253	return -ENXIO;
254}
255
256static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val)
257{
258	u8 *buf = st->smartdata;
259	int err;
260
261	err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
262	if (err)
263		return err;
264	switch (attr) {
265	case hwmon_temp_input:
266		if (!temp_is_valid(buf[SCT_STATUS_TEMP]))
267			return -ENODATA;
268		*val = temp_from_sct(buf[SCT_STATUS_TEMP]);
269		break;
270	case hwmon_temp_lowest:
271		if (!temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]))
272			return -ENODATA;
273		*val = temp_from_sct(buf[SCT_STATUS_TEMP_LOWEST]);
274		break;
275	case hwmon_temp_highest:
276		if (!temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]))
277			return -ENODATA;
278		*val = temp_from_sct(buf[SCT_STATUS_TEMP_HIGHEST]);
279		break;
280	default:
281		err = -EINVAL;
282		break;
283	}
284	return err;
285}
286
287static const char * const sct_avoid_models[] = {
288/*
289 * These drives will have WRITE FPDMA QUEUED command timeouts and sometimes just
290 * freeze until power-cycled under heavy write loads when their temperature is
291 * getting polled in SCT mode. The SMART mode seems to be fine, though.
292 *
293 * While only the 3 TB model (DT01ACA3) was actually caught exhibiting the
294 * problem let's play safe here to avoid data corruption and ban the whole
295 * DT01ACAx family.
296
297 * The models from this array are prefix-matched.
298 */
299	"TOSHIBA DT01ACA",
300};
301
302static bool drivetemp_sct_avoid(struct drivetemp_data *st)
303{
304	struct scsi_device *sdev = st->sdev;
305	unsigned int ctr;
306
307	if (!sdev->model)
308		return false;
309
310	/*
311	 * The "model" field contains just the raw SCSI INQUIRY response
312	 * "product identification" field, which has a width of 16 bytes.
313	 * This field is space-filled, but is NOT NULL-terminated.
314	 */
315	for (ctr = 0; ctr < ARRAY_SIZE(sct_avoid_models); ctr++)
316		if (!strncmp(sdev->model, sct_avoid_models[ctr],
317			     strlen(sct_avoid_models[ctr])))
318			return true;
319
320	return false;
321}
322
323static int drivetemp_identify_sata(struct drivetemp_data *st)
324{
325	struct scsi_device *sdev = st->sdev;
326	u8 *buf = st->smartdata;
327	struct scsi_vpd *vpd;
328	bool is_ata, is_sata;
329	bool have_sct_data_table;
330	bool have_sct_temp;
331	bool have_smart;
332	bool have_sct;
333	u16 *ata_id;
334	u16 version;
335	long temp;
336	int err;
337
338	/* SCSI-ATA Translation present? */
339	rcu_read_lock();
340	vpd = rcu_dereference(sdev->vpd_pg89);
341
342	/*
343	 * Verify that ATA IDENTIFY DEVICE data is included in ATA Information
344	 * VPD and that the drive implements the SATA protocol.
345	 */
346	if (!vpd || vpd->len < 572 || vpd->data[56] != ATA_CMD_ID_ATA ||
347	    vpd->data[36] != 0x34) {
348		rcu_read_unlock();
349		return -ENODEV;
350	}
351	ata_id = (u16 *)&vpd->data[60];
352	is_ata = ata_id_is_ata(ata_id);
353	is_sata = ata_id_is_sata(ata_id);
354	have_sct = ata_id_sct_supported(ata_id);
355	have_sct_data_table = ata_id_sct_data_tables(ata_id);
356	have_smart = ata_id_smart_supported(ata_id) &&
357				ata_id_smart_enabled(ata_id);
358
359	rcu_read_unlock();
360
361	/* bail out if this is not a SATA device */
362	if (!is_ata || !is_sata)
363		return -ENODEV;
364
365	if (have_sct && drivetemp_sct_avoid(st)) {
366		dev_notice(&sdev->sdev_gendev,
367			   "will avoid using SCT for temperature monitoring\n");
368		have_sct = false;
369	}
370
371	if (!have_sct)
372		goto skip_sct;
373
374	err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_STATUS_REQ_ADDR);
375	if (err)
376		goto skip_sct;
377
378	version = (buf[SCT_STATUS_VERSION_HIGH] << 8) |
379		  buf[SCT_STATUS_VERSION_LOW];
380	if (version != 2 && version != 3)
381		goto skip_sct;
382
383	have_sct_temp = temp_is_valid(buf[SCT_STATUS_TEMP]);
384	if (!have_sct_temp)
385		goto skip_sct;
386
387	st->have_temp_lowest = temp_is_valid(buf[SCT_STATUS_TEMP_LOWEST]);
388	st->have_temp_highest = temp_is_valid(buf[SCT_STATUS_TEMP_HIGHEST]);
389
390	if (!have_sct_data_table)
391		goto skip_sct_data;
392
393	/* Request and read temperature history table */
394	memset(buf, '\0', sizeof(st->smartdata));
395	buf[0] = 5;	/* data table command */
396	buf[2] = 1;	/* read table */
397	buf[4] = 2;	/* temperature history table */
398
399	err = drivetemp_ata_command(st, SMART_WRITE_LOG, SCT_STATUS_REQ_ADDR);
400	if (err)
401		goto skip_sct_data;
402
403	err = drivetemp_ata_command(st, SMART_READ_LOG, SCT_READ_LOG_ADDR);
404	if (err)
405		goto skip_sct_data;
406
407	/*
408	 * Temperature limits per AT Attachment 8 -
409	 * ATA/ATAPI Command Set (ATA8-ACS)
410	 */
411	st->have_temp_max = temp_is_valid(buf[6]);
412	st->have_temp_crit = temp_is_valid(buf[7]);
413	st->have_temp_min = temp_is_valid(buf[8]);
414	st->have_temp_lcrit = temp_is_valid(buf[9]);
415
416	st->temp_max = temp_from_sct(buf[6]);
417	st->temp_crit = temp_from_sct(buf[7]);
418	st->temp_min = temp_from_sct(buf[8]);
419	st->temp_lcrit = temp_from_sct(buf[9]);
420
421skip_sct_data:
422	if (have_sct_temp) {
423		st->get_temp = drivetemp_get_scttemp;
424		return 0;
425	}
426skip_sct:
427	if (!have_smart)
428		return -ENODEV;
429	st->get_temp = drivetemp_get_smarttemp;
430	return drivetemp_get_smarttemp(st, hwmon_temp_input, &temp);
431}
432
433static int drivetemp_identify(struct drivetemp_data *st)
434{
435	struct scsi_device *sdev = st->sdev;
436
437	/* Bail out immediately if there is no inquiry data */
438	if (!sdev->inquiry || sdev->inquiry_len < 16)
439		return -ENODEV;
440
441	/* Disk device? */
442	if (sdev->type != TYPE_DISK && sdev->type != TYPE_ZBC)
443		return -ENODEV;
444
445	return drivetemp_identify_sata(st);
446}
447
448static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type,
449			 u32 attr, int channel, long *val)
450{
451	struct drivetemp_data *st = dev_get_drvdata(dev);
452	int err = 0;
453
454	if (type != hwmon_temp)
455		return -EINVAL;
456
457	switch (attr) {
458	case hwmon_temp_input:
459	case hwmon_temp_lowest:
460	case hwmon_temp_highest:
461		mutex_lock(&st->lock);
462		err = st->get_temp(st, attr, val);
463		mutex_unlock(&st->lock);
464		break;
465	case hwmon_temp_lcrit:
466		*val = st->temp_lcrit;
467		break;
468	case hwmon_temp_min:
469		*val = st->temp_min;
470		break;
471	case hwmon_temp_max:
472		*val = st->temp_max;
473		break;
474	case hwmon_temp_crit:
475		*val = st->temp_crit;
476		break;
477	default:
478		err = -EINVAL;
479		break;
480	}
481	return err;
482}
483
484static umode_t drivetemp_is_visible(const void *data,
485				   enum hwmon_sensor_types type,
486				   u32 attr, int channel)
487{
488	const struct drivetemp_data *st = data;
489
490	switch (type) {
491	case hwmon_temp:
492		switch (attr) {
493		case hwmon_temp_input:
494			return 0444;
495		case hwmon_temp_lowest:
496			if (st->have_temp_lowest)
497				return 0444;
498			break;
499		case hwmon_temp_highest:
500			if (st->have_temp_highest)
501				return 0444;
502			break;
503		case hwmon_temp_min:
504			if (st->have_temp_min)
505				return 0444;
506			break;
507		case hwmon_temp_max:
508			if (st->have_temp_max)
509				return 0444;
510			break;
511		case hwmon_temp_lcrit:
512			if (st->have_temp_lcrit)
513				return 0444;
514			break;
515		case hwmon_temp_crit:
516			if (st->have_temp_crit)
517				return 0444;
518			break;
519		default:
520			break;
521		}
522		break;
523	default:
524		break;
525	}
526	return 0;
527}
528
529static const struct hwmon_channel_info * const drivetemp_info[] = {
530	HWMON_CHANNEL_INFO(chip,
531			   HWMON_C_REGISTER_TZ),
532	HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT |
533			   HWMON_T_LOWEST | HWMON_T_HIGHEST |
534			   HWMON_T_MIN | HWMON_T_MAX |
535			   HWMON_T_LCRIT | HWMON_T_CRIT),
536	NULL
537};
538
539static const struct hwmon_ops drivetemp_ops = {
540	.is_visible = drivetemp_is_visible,
541	.read = drivetemp_read,
542};
543
544static const struct hwmon_chip_info drivetemp_chip_info = {
545	.ops = &drivetemp_ops,
546	.info = drivetemp_info,
547};
548
549/*
550 * The device argument points to sdev->sdev_dev. Its parent is
551 * sdev->sdev_gendev, which we can use to get the scsi_device pointer.
552 */
553static int drivetemp_add(struct device *dev)
554{
555	struct scsi_device *sdev = to_scsi_device(dev->parent);
556	struct drivetemp_data *st;
557	int err;
558
559	st = kzalloc(sizeof(*st), GFP_KERNEL);
560	if (!st)
561		return -ENOMEM;
562
563	st->sdev = sdev;
564	st->dev = dev;
565	mutex_init(&st->lock);
566
567	if (drivetemp_identify(st)) {
568		err = -ENODEV;
569		goto abort;
570	}
571
572	st->hwdev = hwmon_device_register_with_info(dev->parent, "drivetemp",
573						    st, &drivetemp_chip_info,
574						    NULL);
575	if (IS_ERR(st->hwdev)) {
576		err = PTR_ERR(st->hwdev);
577		goto abort;
578	}
579
580	list_add(&st->list, &drivetemp_devlist);
581	return 0;
582
583abort:
584	kfree(st);
585	return err;
586}
587
588static void drivetemp_remove(struct device *dev)
589{
590	struct drivetemp_data *st, *tmp;
591
592	list_for_each_entry_safe(st, tmp, &drivetemp_devlist, list) {
593		if (st->dev == dev) {
594			list_del(&st->list);
595			hwmon_device_unregister(st->hwdev);
596			kfree(st);
597			break;
598		}
599	}
600}
601
602static struct class_interface drivetemp_interface = {
603	.add_dev = drivetemp_add,
604	.remove_dev = drivetemp_remove,
605};
606
607static int __init drivetemp_init(void)
608{
609	return scsi_register_interface(&drivetemp_interface);
610}
611
612static void __exit drivetemp_exit(void)
613{
614	scsi_unregister_interface(&drivetemp_interface);
615}
616
617module_init(drivetemp_init);
618module_exit(drivetemp_exit);
619
620MODULE_AUTHOR("Guenter Roeck <linus@roeck-us.net>");
621MODULE_DESCRIPTION("Hard drive temperature monitor");
622MODULE_LICENSE("GPL");
623MODULE_ALIAS("platform:drivetemp");
624