Re: [PATCH 2/2] Input: matrix_keymap - wire up device tree support

[Stephen Warren <swarren@wwwdotorg.org>]

On 05/08/2012 11:25 PM, Dmitry Torokhov wrote:
> On Mon, Apr 30, 2012 at 10:00:42AM -0600, Stephen Warren wrote:
>> On 04/29/2012 10:19 PM, Dmitry Torokhov wrote:
>>> On Thu, Apr 26, 2012 at 09:05:18AM -0600, Stephen Warren wrote:
>>>> On 04/26/2012 02:19 AM, Dmitry Torokhov wrote:
>>>>> When platform keymap is not supplied to matrix_keypad_build_keymap()
>>>>> and device tree support is enabled, try locating specified property
>>>>> and load keymap from it. If property name is not defined, try using
>>>>> "linux,keymap".
>>>>>
>>>>> Based on earlier patch by Viresh Kumar <viresh.kumar@st.com>
>>>>
>>>> I think this series looks mostly OK. A few comments below.
>>>>
>>>> We don't actually have the KBC driver hooked up on any boards yet, so I
>>>> can't actually test this yet.
>>>>
>>>> How will the linux,fn-keymap handling work? It looks like this code is
>>>> allocating a keymap data structure with one additional row to represent
>>>> fn-not-pressed vs. fn-pressed.
>>>
>>> No, it loads 2x rows (therefore giving you twice original keymap size).
>>
>> Yes, I mean an extra row signal, so therefore twice as many rows.
>>
>>>> I assume this will work without issue
>>>> even though the second half is not filled in. Won't this allow the
>>>> linux,keymap property entries to pass validation "if (row >= rows)" for
>>>> one more row than it should?
>>>
>>> Maybe... I think we should revisit this when you actually have
>>> linux,fn-keymap. Probably will need to export matrix_keypad_parse_
>>
>> Would it be better to just drop the support for the linux,fn-keymap
>> property, until the full support is there? That wouldn't lose any
>> functionality, but would avoid this potential error-checking issue.
> 
> Fair enough, how about the version below?

Yes, I think that will work.

I would expect that when linux,fn-keymap support gets added, perhaps the
"keymap_rows *= 2" would move into the DT keymap parsing code, since
only it will know whether its going to parse the second property. But I
don't think that influences the current patch.