1==================================== 2Toshiba HDD Active Protection Sensor 3==================================== 4 5Kernel driver: toshiba_haps 6 7Author: Azael Avalos <coproscefalo@gmail.com> 8 9 10.. 0. Contents 11 12 1. Description 13 2. Interface 14 3. Accelerometer axes 15 4. Supported devices 16 5. Usage 17 18 191. Description 20-------------- 21 22This driver provides support for the accelerometer found in various Toshiba 23laptops, being called "Toshiba HDD Protection - Shock Sensor" officially, 24and detects laptops automatically with this device. 25On Windows, Toshiba provided software monitors this device and provides 26automatic HDD protection (head unload) on sudden moves or harsh vibrations, 27however, this driver only provides a notification via a sysfs file to let 28userspace tools or daemons act accordingly, as well as providing a sysfs 29file to set the desired protection level or sensor sensibility. 30 31 322. Interface 33------------ 34 35This device comes with 3 methods: 36 37==== ===================================================================== 38_STA Checks existence of the device, returning Zero if the device does not 39 exists or is not supported. 40PTLV Sets the desired protection level. 41RSSS Shuts down the HDD protection interface for a few seconds, 42 then restores normal operation. 43==== ===================================================================== 44 45Note: 46 The presence of Solid State Drives (SSD) can make this driver to fail loading, 47 given the fact that such drives have no movable parts, and thus, not requiring 48 any "protection" as well as failing during the evaluation of the _STA method 49 found under this device. 50 51 523. Accelerometer axes 53--------------------- 54 55This device does not report any axes, however, to query the sensor position 56a couple HCI (Hardware Configuration Interface) calls (0x6D and 0xA6) are 57provided to query such information, handled by the kernel module toshiba_acpi 58since kernel version 3.15. 59 60 614. Supported devices 62-------------------- 63 64This driver binds itself to the ACPI device TOS620A, and any Toshiba laptop 65with this device is supported, given the fact that they have the presence of 66conventional HDD and not only SSD, or a combination of both HDD and SSD. 67 68 695. Usage 70-------- 71 72The sysfs files under /sys/devices/LNXSYSTM:00/LNXSYBUS:00/TOS620A:00/ are: 73 74================ ============================================================ 75protection_level The protection_level is readable and writeable, and 76 provides a way to let userspace query the current protection 77 level, as well as set the desired protection level, the 78 available protection levels are:: 79 80 ============ ======= ========== ======== 81 0 - Disabled 1 - Low 2 - Medium 3 - High 82 ============ ======= ========== ======== 83 84reset_protection The reset_protection entry is writeable only, being "1" 85 the only parameter it accepts, it is used to trigger 86 a reset of the protection interface. 87================ ============================================================ 88