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Subject: Re: [PATCH V5 0/4] gpio: tegra: Cleanups and support for debounce
To: Linus Walleij <linus.walleij@linaro.org>,
        Laxman Dewangan <ldewangan@nvidia.com>
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Cc: Alexandre Courbot <gnurou@gmail.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
        "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
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From: Stephen Warren <swarren@wwwdotorg.org>
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Date: Mon, 2 May 2016 10:12:32 -0600
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On 04/30/2016 05:07 AM, Linus Walleij wrote:
> On Fri, Apr 29, 2016 at 11:20 AM, Laxman Dewangan <ldewangan@nvidia.com> wrote:
>> On Friday 29 April 2016 02:37 PM, Linus Walleij wrote:
>>> On Mon, Apr 25, 2016 at 12:38 PM, Laxman Dewangan <ldewangan@nvidia.com>
>>> wrote:
>>>
>>>> Add support for the debounce as Tegra210 support debounce in HW.
>>>> Also do the clenaups to remove all global variables.
>>>
>>> OK this v5 is applied.
>>>
>>> Laxman does this GPIO also have open drain and/or open source
>>> handling?
>>
>>
>> Some of the pins support the open drain and these are part of pinmux
>> register set.
>> For that we have property for setting open drain.

IIRC, Tegra has open-drain control in both the GPIO controller for all 
pins (OE bit) and in the pinmux controller for a small subset of pins. 
For GPIOs, why wouldn't we just use the control bit in the GPIO 
controller for all GPIOs. This would avoid any special-cases, and 
minimize coupling between the GPIO and pinctrl drivers.