projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| de55d871 | 1 | What: /sys/class/extcon/.../ |
| 806d9dd7 | 2 | Date: February 2012 |
| de55d871 MH |
3 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> |
| 4 | Description: | |
| 5 | Provide a place in sysfs for the extcon objects. | |
| 6 | This allows accessing extcon specific variables. | |
| 7 | The name of extcon object denoted as ... is the name given | |
| 8 | with extcon_dev_register. | |
| 9 | ||
| 806d9dd7 MH |
10 | One extcon device denotes a single external connector |
| 11 | port. An external connector may have multiple cables | |
| 12 | attached simultaneously. Many of docks, cradles, and | |
| 13 | accessory cables have such capability. For example, | |
| 14 | the 30-pin port of Nuri board (/arch/arm/mach-exynos) | |
| 15 | may have both HDMI and Charger attached, or analog audio, | |
| f28d5a01 | 16 | video, and USB cables attached simultaneously. |
| 806d9dd7 | 17 | |
| bde68e60 MH |
18 | If there are cables mutually exclusive with each other, |
| 19 | such binary relations may be expressed with extcon_dev's | |
| 20 | mutually_exclusive array. | |
| 21 | ||
| de55d871 | 22 | What: /sys/class/extcon/.../name |
| 806d9dd7 | 23 | Date: February 2012 |
| de55d871 MH |
24 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> |
| 25 | Description: | |
| 26 | The /sys/class/extcon/.../name shows the name of the extcon | |
| 27 | object. If the extcon object has an optional callback | |
| 28 | "show_name" defined, the callback will provide the name with | |
| 29 | this sysfs node. | |
| 30 | ||
| 31 | What: /sys/class/extcon/.../state | |
| 806d9dd7 MH |
32 | Date: February 2012 |
| 33 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> | |
| 34 | Description: | |
| 35 | The /sys/class/extcon/.../state shows and stores the cable | |
| 36 | attach/detach information of the corresponding extcon object. | |
| 37 | If the extcon object has an optional callback "show_state" | |
| f28d5a01 | 38 | defined, the showing function is overridden with the optional |
| 806d9dd7 MH |
39 | callback. |
| 40 | ||
| 41 | If the default callback for showing function is used, the | |
| 54a19b4d MCC |
42 | format is like this:: |
| 43 | ||
| 44 | # cat state | |
| 45 | USB_OTG=1 | |
| 46 | HDMI=0 | |
| 47 | TA=1 | |
| 48 | EAR_JACK=0 | |
| 49 | # | |
| 50 | ||
| f28d5a01 | 51 | In this example, the extcon device has USB_OTG and TA |
| 806d9dd7 MH |
52 | cables attached and HDMI and EAR_JACK cables detached. |
| 53 | ||
| 54 | In order to update the state of an extcon device, enter a hex | |
| 54a19b4d MCC |
55 | state number starting with 0x:: |
| 56 | ||
| 57 | # echo 0xHEX > state | |
| 806d9dd7 | 58 | |
| f28d5a01 | 59 | This updates the whole state of the extcon device. |
| 806d9dd7 | 60 | Inputs of all the methods are required to meet the |
| f28d5a01 | 61 | mutually_exclusive conditions if they exist. |
| 806d9dd7 MH |
62 | |
| 63 | It is recommended to use this "global" state interface if | |
| f28d5a01 | 64 | you need to set the value atomically. The later state |
| 806d9dd7 MH |
65 | interface associated with each cable cannot update |
| 66 | multiple cable states of an extcon device simultaneously. | |
| 67 | ||
| 4aa5216c | 68 | What: /sys/class/extcon/.../cable.X/name |
| 806d9dd7 MH |
69 | Date: February 2012 |
| 70 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> | |
| 71 | Description: | |
| 4aa5216c MCC |
72 | The /sys/class/extcon/.../cable.X/name shows the name of cable |
| 73 | "X" (integer between 0 and 31) of an extcon device. | |
| 806d9dd7 | 74 | |
| 4aa5216c | 75 | What: /sys/class/extcon/.../cable.X/state |
| 806d9dd7 | 76 | Date: February 2012 |
| de55d871 MH |
77 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> |
| 78 | Description: | |
| 4aa5216c MCC |
79 | The /sys/class/extcon/.../cable.X/state shows and stores the |
| 80 | state of cable "X" (integer between 0 and 31) of an extcon | |
| 806d9dd7 MH |
81 | device. The state value is either 0 (detached) or 1 |
| 82 | (attached). | |
| bde68e60 MH |
83 | |
| 84 | What: /sys/class/extcon/.../mutually_exclusive/... | |
| 85 | Date: December 2011 | |
| 86 | Contact: MyungJoo Ham <myungjoo.ham@samsung.com> | |
| 87 | Description: | |
| 88 | Shows the relations of mutually exclusiveness. For example, | |
| f28d5a01 | 89 | if the mutually_exclusive array of extcon device is |
| 54a19b4d MCC |
90 | {0x3, 0x5, 0xC, 0x0}, then the output is:: |
| 91 | ||
| 92 | # ls mutually_exclusive/ | |
| 93 | 0x3 | |
| 94 | 0x5 | |
| 95 | 0xc | |
| 96 | # | |
| bde68e60 MH |
97 | |
| 98 | Note that mutually_exclusive is a sub-directory of the extcon | |
| 99 | device and the file names under the mutually_exclusive | |
| 100 | directory show the mutually-exclusive sets, not the contents | |
| 101 | of the files. |