// SPDX-License-Identifier: GPL-2.0 /* * Hwmon client for disk and solid state drives with temperature sensors * Copyright (C) 2019 Zodiac Inflight Innovations * * With input from: * Hwmon client for S.M.A.R.T. hard disk drives with temperature sensors. * (C) 2018 Linus Walleij * * hwmon: Driver for SCSI/ATA temperature sensors * by Constantin Baranov <[email protected]>, submitted September 2009 * * This drive supports reporting the temperature of SATA drives. It can be * easily extended to report the temperature of SCSI drives. * * The primary means to read drive temperatures and temperature limits * for ATA drives is the SCT Command Transport feature set as specified in * ATA8-ACS. * It can be used to read the current drive temperature, temperature limits, * and historic minimum and maximum temperatures. The SCT Command Transport * feature set is documented in "AT Attachment 8 - ATA/ATAPI Command Set * (ATA8-ACS)". * * If the SCT Command Transport feature set is not available, drive temperatures * may be readable through SMART attributes. Since SMART attributes are not well * defined, this method is only used as fallback mechanism. * * There are three SMART attributes which may report drive temperatures. * Those are defined as follows (from * http://www.cropel.com/library/smart-attribute-list.aspx). * * 190 Temperature Temperature, monitored by a sensor somewhere inside * the drive. Raw value typicaly holds the actual * temperature (hexadecimal) in its rightmost two digits. * * 194 Temperature Temperature, monitored by a sensor somewhere inside * the drive. Raw value typicaly holds the actual * temperature (hexadecimal) in its rightmost two digits. * * 231 Temperature Temperature, monitored by a sensor somewhere inside * the drive. Raw value typicaly holds the actual * temperature (hexadecimal) in its rightmost two digits. * * Wikipedia defines attributes a bit differently. * * 190 Temperature Value is equal to (100-temp. °C), allowing manufacturer * Difference or to set a minimum threshold which corresponds to a * Airflow maximum temperature. This also follows the convention of * Temperature 100 being a best-case value and lower values being * undesirable. However, some older drives may instead * report raw Temperature (identical to 0xC2) or * Temperature minus 50 here. * 194 Temperature or Indicates the device temperature, if the appropriate * Temperature sensor is fitted. Lowest byte of the raw value contains * Celsius the exact temperature value (Celsius degrees). * 231 Life Left Indicates the approximate SSD life left, in terms of * (SSDs) or program/erase cycles or available reserved blocks. * Temperature A normalized value of 100 represents a new drive, with * a threshold value at 10 indicating a need for * replacement. A value of 0 may mean that the drive is * operating in read-only mode to allow data recovery. * Previously (pre-2010) occasionally used for Drive * Temperature (more typically reported at 0xC2). * * Common denominator is that the first raw byte reports the temperature * in degrees C on almost all drives. Some drives may report a fractional * temperature in the second raw byte. * * Known exceptions (from libatasmart): * - SAMSUNG SV0412H and SAMSUNG SV1204H) report the temperature in 10th * degrees C in the first two raw bytes. * - A few Maxtor drives report an unknown or bad value in attribute 194. * - Certain Apple SSD drives report an unknown value in attribute 190. * Only certain firmware versions are affected. * * Those exceptions affect older ATA drives and are currently ignored. * Also, the second raw byte (possibly reporting the fractional temperature) * is currently ignored. * * Many drives also report temperature limits in additional SMART data raw * bytes. The format of those is not well defined and varies widely. * The driver does not currently attempt to report those limits. * * According to data in smartmontools, attribute 231 is rarely used to report * drive temperatures. At the same time, several drives report SSD life left * in attribute 231, but do not support temperature sensors. For this reason, * attribute 231 is currently ignored. * * Following above definitions, temperatures are reported as follows. * If SCT Command Transport is supported, it is used to read the * temperature and, if available, temperature limits. * - Otherwise, if SMART attribute 194 is supported, it is used to read * the temperature. * - Otherwise, if SMART attribute 190 is supported, it is used to read * the temperature. */ #include <linux/ata.h> #include <linux/bits.h> #include <linux/device.h> #include <linux/hwmon.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> #include <linux/mutex.h> #include <scsi/scsi_cmnd.h> #include <scsi/scsi_device.h> #include <scsi/scsi_driver.h> #include <scsi/scsi_proto.h> struct drivetemp_data { … }; static LIST_HEAD(drivetemp_devlist); #define ATA_MAX_SMART_ATTRS … #define SMART_TEMP_PROP_190 … #define SMART_TEMP_PROP_194 … #define SCT_STATUS_REQ_ADDR … #define SCT_STATUS_VERSION_LOW … #define SCT_STATUS_VERSION_HIGH … #define SCT_STATUS_TEMP … #define SCT_STATUS_TEMP_LOWEST … #define SCT_STATUS_TEMP_HIGHEST … #define SCT_READ_LOG_ADDR … #define SMART_READ_LOG … #define SMART_WRITE_LOG … #define INVALID_TEMP … #define temp_is_valid(temp) … #define temp_from_sct(temp) … static inline bool ata_id_smart_supported(u16 *id) { … } static inline bool ata_id_smart_enabled(u16 *id) { … } static int drivetemp_scsi_command(struct drivetemp_data *st, u8 ata_command, u8 feature, u8 lba_low, u8 lba_mid, u8 lba_high) { … } static int drivetemp_ata_command(struct drivetemp_data *st, u8 feature, u8 select) { … } static int drivetemp_get_smarttemp(struct drivetemp_data *st, u32 attr, long *temp) { … } static int drivetemp_get_scttemp(struct drivetemp_data *st, u32 attr, long *val) { … } static const char * const sct_avoid_models[] = …; static bool drivetemp_sct_avoid(struct drivetemp_data *st) { … } static int drivetemp_identify_sata(struct drivetemp_data *st) { … } static int drivetemp_identify(struct drivetemp_data *st) { … } static int drivetemp_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { … } static umode_t drivetemp_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { … } static const struct hwmon_channel_info * const drivetemp_info[] = …; static const struct hwmon_ops drivetemp_ops = …; static const struct hwmon_chip_info drivetemp_chip_info = …; /* * The device argument points to sdev->sdev_dev. Its parent is * sdev->sdev_gendev, which we can use to get the scsi_device pointer. */ static int drivetemp_add(struct device *dev) { … } static void drivetemp_remove(struct device *dev) { … } static struct class_interface drivetemp_interface = …; static int __init drivetemp_init(void) { … } static void __exit drivetemp_exit(void) { … } module_init(…) …; module_exit(drivetemp_exit); MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; MODULE_ALIAS(…) …;
Codebase Browser
linux