[PATCH 2/2] input: samsung-keypad: Add device tree support

[Thomas Abraham]

On 15 September 2011 00:40, Grant Likely <grant.likely at secretlab.ca> wrote:
> On Wed, Sep 14, 2011 at 12:09 PM, Thomas Abraham
> <thomas.abraham at linaro.org> wrote:
>> On 14 September 2011 22:43, Grant Likely <grant.likely at secretlab.ca> wrote:
>>> On Wed, Sep 14, 2011 at 10:19:22PM +0530, Thomas Abraham wrote:
>>>> On 14 September 2011 21:41, Grant Likely <grant.likely at secretlab.ca> wrote:
>>>> > On Tue, Sep 13, 2011 at 05:56:19PM +0530, Thomas Abraham wrote:
>>>> >> +- Keys represented as child nodes: Each key connected to the keypad
>>>> >> +  controller is represented as a child node to the keypad controller
>>>> >> +  device node and should include the following properties.
>>>> >> +  - keypad,row: the row number to which the key is connected.
>>>> >> +  - keypad,column: the column number to which the key is connected.
>>>> >> +  - keypad,key-code: the key-code to be reported when the key is pressed
>>>> >> +    and released.
>>>> >
>>>> > What defines the meanings of the key codes?
>>>>
>>>> The key-code could be any value which the system would want the keypad
>>>> driver to report when that key is pressed.
>>>
>>> Are they linux keycodes?  If so, then this property name can
>>> probably be linux,code.  There is already precedence for that
>>> usage in Documentation/devicetree/bindings/gpio/gpio-keys.txt.  (I
>>> would personally prefer "linux,key-code", but sometimes it is better
>>> to go with existing precidence) You could also use linux,input-type as
>>> specified in that binding.
>>
>> Ok. For linux, "keypad,key-code" would mean linux keycodes. The
>> property name 'keypad,key-code' was chosen since it can be reused on
>> non-linux platforms as well. I did have a look at
>> Documentation/devicetree/bindings/gpio/gpio-keys.txt while doing this,
>> but preferred using 'keypad,key-code' since it would be generic. Given
>> a choice, I would like to retain this.
>
> This was debated a bit on the gpio-keys binding.  The binding *must*
> specify where it is getting the keycodes from.  For the gpio-keys
> binding, it was decided that the Linux keycodes were sufficient since
> they are exported to userspace, and therefore part of the stable
> kernel ABI (they will never change).  "keypad,key-code" is completely
> useless as a generic binding since it doesn't specify where the
> keycode meanings come from.  Besides, "linux,code" can be reused on
> non-linux platforms too, it just means that the authoritative source
> of the keycodes is the Linux kernel.
>
> g
>

Ok. I understand this now. I will change this to "linux,code" in the
next submission.

Thanks,
Thomas.