From mboxrd@z Thu Jan  1 00:00:00 1970
From: Grygorii Strashko <grygorii.strashko@ti.com>
Subject: Re: [PATCH] gpio: omap: fix debounce time calculation
Date: Thu, 12 Nov 2015 21:28:28 +0200
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To: Felipe Balbi <balbi@ti.com>, Javier Martinez Canillas <javier@dowhile0.org>, Santosh Shilimkar <ssantosh@kernel.org>, Kevin Hilman <khilman@deeprootsystems.com>, Linus Walleij <linus.walleij@linaro.org>, Alexandre Courbot <gnurou@gmail.com>
Cc: Linux OMAP Mailing List <linux-omap@vger.kernel.org>, Linux ARM Kernel Mailing List <linux-arm-kernel@lists.infradead.org>, Tony Lindgren <tony@atomide.com>, linux-gpio@vger.kernel.org

On 11/12/2015 08:09 PM, Felipe Balbi wrote:
>
> Hi,
>
> Grygorii Strashko <grygorii.strashko@ti.com> writes:
>> On 11/12/2015 07:50 PM, Felipe Balbi wrote:
>>> According to TRM, debounce is measured in periods of
>>> the functional clock of the GPIO IP. This means that
>>
>>
>> What TRM? link pls.
>>
>> http://www.ti.com/lit/ug/spruhl7d/spruhl7d.pdf
>>
>> 28.4.1.24 GPIO_DEBOUNCINGTIME Register (offset = 154h) [reset = 0h]
>>
>> The GPIO_DEBOUNCINGTIME register controls debouncing time (the value is
>> global for all ports). The debouncing cell is running with the
>> debouncing clock (32 kHz), this register represents the number of the
>> clock cycle(s) (31 s long) to be used.
>>
>> Debouncing Value in 31 microsecond steps.
>> Debouncing Value = (DEBOUNCETIME + 1) * 31 microseconds.
>
> DRA7xx:
>
> "
> 8-bit values specifying the debouncing time. It is n-
> periods of the muxed clock, which can come from either
> a true 32k oscillator/pad of from the system clock. It
> depends on which boot mode is selected. For more
> information see Chapter 32, Initialization.
> "
>

See
http://www.ti.com/lit/ug/spruhz6d/spruhz6d.pdf
27.4.3 General-Purpose Interface Clock Configuration
27.4.3.1 Clocking

This completely unclear. Sry, I think this patch can't be used as is,
first of all because of backward compatibility issues.

-- 
regards,
-grygorii