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Message-ID: <7674659c-20f4-68da-5a62-5c8e8ebdfe5a@linaro.org>
Date:   Thu, 5 May 2022 10:27:43 +0200
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Subject: Re: [PATCH 2/4] Input: mt-matrix-keypad: Add Bosch mt matrix keypad
 driver
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To:     Marco Felsch <m.felsch@pengutronix.de>,
        Gireesh.Hiremath@in.bosch.com
Cc:     linux-omap@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-input@vger.kernel.org,
        bcousson@baylibre.com, tony@atomide.com, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, dmitry.torokhov@gmail.com,
        mkorpershoek@baylibre.com, davidgow@google.com,
        swboyd@chromium.org, fengping.yu@mediatek.com,
        y.oudjana@protonmail.com, rdunlap@infradead.org,
        colin.king@intel.com, sjoerd.simons@collabora.co.uk,
        VinayKumar.Shettar@in.bosch.com,
        Govindaraji.Sivanantham@in.bosch.com, anaclaudia.dias@de.bosch.com
References: <20220504105254.1576-2-Gireesh.Hiremath@in.bosch.com>
 <20220504134817.1490-1-Gireesh.Hiremath@in.bosch.com>
 <20220504141404.onom7x5lycyg3b22@pengutronix.de>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20220504141404.onom7x5lycyg3b22@pengutronix.de>
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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