projects / linux-block.git / blame
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|---|---|---|
| b02f1651 | 1 | ==================================== |
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2 | Toshiba HDD Active Protection Sensor |
| 3 | ==================================== | |
| 4 | ||
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5 | Kernel driver: toshiba_haps |
| 6 | ||
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7 | Author: Azael Avalos <coproscefalo@gmail.com> |
| 8 | ||
| 9 | ||
| b02f1651 | 10 | .. 0. Contents |
| f369aa6d | 11 | |
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12 | 1. Description |
| 13 | 2. Interface | |
| 14 | 3. Accelerometer axes | |
| 15 | 4. Supported devices | |
| 16 | 5. Usage | |
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17 | |
| 18 | ||
| 19 | 1. Description | |
| 20 | -------------- | |
| 21 | ||
| 22 | This driver provides support for the accelerometer found in various Toshiba | |
| 2b4f4f3d | 23 | laptops, being called "Toshiba HDD Protection - Shock Sensor" officially, |
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24 | and detects laptops automatically with this device. |
| 25 | On Windows, Toshiba provided software monitors this device and provides | |
| 26 | automatic HDD protection (head unload) on sudden moves or harsh vibrations, | |
| 27 | however, this driver only provides a notification via a sysfs file to let | |
| 28 | userspace tools or daemons act accordingly, as well as providing a sysfs | |
| 29 | file to set the desired protection level or sensor sensibility. | |
| 30 | ||
| 31 | ||
| 32 | 2. Interface | |
| 33 | ------------ | |
| 34 | ||
| 35 | This device comes with 3 methods: | |
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36 | |
| 37 | ==== ===================================================================== | |
| 38 | _STA Checks existence of the device, returning Zero if the device does not | |
| f369aa6d | 39 | exists or is not supported. |
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40 | PTLV Sets the desired protection level. |
| 41 | RSSS Shuts down the HDD protection interface for a few seconds, | |
| f369aa6d | 42 | then restores normal operation. |
| b02f1651 | 43 | ==== ===================================================================== |
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44 | |
| 45 | Note: | |
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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. | |
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50 | |
| 51 | ||
| 52 | 3. Accelerometer axes | |
| 53 | --------------------- | |
| 54 | ||
| 55 | This device does not report any axes, however, to query the sensor position | |
| 56 | a couple HCI (Hardware Configuration Interface) calls (0x6D and 0xA6) are | |
| 57 | provided to query such information, handled by the kernel module toshiba_acpi | |
| 58 | since kernel version 3.15. | |
| 59 | ||
| 60 | ||
| 61 | 4. Supported devices | |
| 62 | -------------------- | |
| 63 | ||
| 64 | This driver binds itself to the ACPI device TOS620A, and any Toshiba laptop | |
| 65 | with this device is supported, given the fact that they have the presence of | |
| 66 | conventional HDD and not only SSD, or a combination of both HDD and SSD. | |
| 67 | ||
| 68 | ||
| 69 | 5. Usage | |
| 70 | -------- | |
| 71 | ||
| 72 | The sysfs files under /sys/devices/LNXSYSTM:00/LNXSYBUS:00/TOS620A:00/ are: | |
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73 | |
| 74 | ================ ============================================================ | |
| 75 | protection_level The protection_level is readable and writeable, and | |
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76 | provides a way to let userspace query the current protection |
| 77 | level, as well as set the desired protection level, the | |
| eddeed12 | 78 | available protection levels are:: |
| b02f1651 | 79 | |
| eddeed12 MCC |
80 | ============ ======= ========== ======== |
| 81 | 0 - Disabled 1 - Low 2 - Medium 3 - High | |
| 82 | ============ ======= ========== ======== | |
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83 | |
| 84 | reset_protection The reset_protection entry is writeable only, being "1" | |
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85 | the only parameter it accepts, it is used to trigger |
| 86 | a reset of the protection interface. | |
| b02f1651 | 87 | ================ ============================================================ |