toshiba_haps.txt 2.5 KB

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