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| -rw-r--r-- | Documentation/laptops/toshiba_haps.txt | 76 |
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diff --git a/Documentation/laptops/toshiba_haps.txt b/Documentation/laptops/toshiba_haps.txt new file mode 100644 index 000000000..0c1d88ded --- /dev/null +++ b/Documentation/laptops/toshiba_haps.txt @@ -0,0 +1,76 @@ +Kernel driver toshiba_haps +Toshiba HDD Active Protection Sensor +==================================== + +Author: Azael Avalos <coproscefalo@gmail.com> + + +0. Contents +----------- + +1. Description +2. Interface +3. Accelerometer axes +4. Supported devices +5. Usage + + +1. Description +-------------- + +This driver provides support for the accelerometer found in various Toshiba +laptops, being called "Toshiba HDD Protection - Shock Sensor" officially, +and detects laptops automatically with this device. +On Windows, Toshiba provided software monitors this device and provides +automatic HDD protection (head unload) on sudden moves or harsh vibrations, +however, this driver only provides a notification via a sysfs file to let +userspace tools or daemons act accordingly, as well as providing a sysfs +file to set the desired protection level or sensor sensibility. + + +2. Interface +------------ + +This device comes with 3 methods: +_STA - Checks existence of the device, returning Zero if the device does not + exists or is not supported. +PTLV - Sets the desired protection level. +RSSS - Shuts down the HDD protection interface for a few seconds, + then restores normal operation. + +Note: +The presence of Solid State Drives (SSD) can make this driver to fail loading, +given the fact that such drives have no movable parts, and thus, not requiring +any "protection" as well as failing during the evaluation of the _STA method +found under this device. + + +3. Accelerometer axes +--------------------- + +This device does not report any axes, however, to query the sensor position +a couple HCI (Hardware Configuration Interface) calls (0x6D and 0xA6) are +provided to query such information, handled by the kernel module toshiba_acpi +since kernel version 3.15. + + +4. Supported devices +-------------------- + +This driver binds itself to the ACPI device TOS620A, and any Toshiba laptop +with this device is supported, given the fact that they have the presence of +conventional HDD and not only SSD, or a combination of both HDD and SSD. + + +5. Usage +-------- + +The sysfs files under /sys/devices/LNXSYSTM:00/LNXSYBUS:00/TOS620A:00/ are: +protection_level - The protection_level is readable and writeable, and + provides a way to let userspace query the current protection + level, as well as set the desired protection level, the + available protection levels are: + 0 - Disabled | 1 - Low | 2 - Medium | 3 - High +reset_protection - The reset_protection entry is writeable only, being "1" + the only parameter it accepts, it is used to trigger + a reset of the protection interface. |