Re: [PATCH 2/4] Input: mt-matrix-keypad: Add Bosch mt matrix keypad driver

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 04/05/2022 16:14, Marco Felsch wrote:
> On 22-05-04, Gireesh.Hiremath@in.bosch.com wrote:
>> From: Gireesh Hiremath <Gireesh.Hiremath@in.bosch.com>
>>
>> The existing matric_keypad.c use different gpio line for row and colunm,
>> where in mt_matrix_kepad.c use same gpio line for row as well as column.
>> a key can be placed at each intersection of a unique row number 
>> not equal to a unique column and they are diagonally symmetric.
>> Advantage of this is with existed gpio line we can get more keys
>>   
>> example: in matrix_keypad.c for 5 gpio line possible matrix is 2X3 or 3X2
>> and maximum possible keys are 6 but 
>> in mt_matrix_kepad.c for same 5 gpio line possible matrix is 5X5 and maximum
>> possible buttons are 10, below table will discribe that
> 
> Nobody should stop you to increase the amount of max. possible keys, so
> this isn't a real block.
> 
>> 	------------------------------------------------------
>> 	|Row\Col |GPIO 0 | GPIO 1 | GPIO 2 | GPIO 3 | GPIO 4 |
>> 	------------------------------------------------------
>> 	| GPIO 0 |  X    | KEY_9  | KEY_2  | KEY_3  | KEY_1  |
>> 	------------------------------------------------------
>> 	| GPIO 1 | KEY_9 |  X     | KEY_6  | KEY_5  |  KEY_0 |
>> 	------------------------------------------------------
>> 	| GPIO 2 | KEY_2 | KEY_6  |  X     | KEY_4  | KEY_7  |
>> 	------------------------------------------------------
>> 	| GPIO 3 | KEY_3 | KEY_5  | KEY_4  |  X     | KEY_8  |
>> 	------------------------------------------------------
>> 	| GPIO 4 | KEY_1 |  KEY_0 | KEY_7  | KEY_8  |  X     |
>> 	------------------------------------------------------
>> 	X - invalid key
>> 	KEY_x - preferred key code
> 
> That should be pointed somewhere very clearly, thanks for the
> description. Also what is than the benefit of the original matrix_keypad
> driver?

It looks like this driver has smaller number of features than
matrix-keypad, so it should be integrated into the matrix-keypad.
matrix-keypad features are superset to this one.

Best regards,
Krzysztof