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From: Grygorii Strashko <grygorii.strashko@ti.com>
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
Subject: Re: [PATCH] gpio: omap: fix debounce time calculation
Date: Thu, 12 Nov 2015 21:28:28 +0200	[thread overview]
Message-ID: <5644E85C.8010807@ti.com> (raw)
In-Reply-To: <87egfvqecr.fsf@saruman.tx.rr.com>

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

  reply	other threads:[~2015-11-12 19:29 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-11-12 17:50 [PATCH] gpio: omap: fix debounce time calculation Felipe Balbi
2015-11-12 18:05 ` Grygorii Strashko
2015-11-12 18:09   ` Felipe Balbi
2015-11-12 19:28     ` Grygorii Strashko [this message]
2015-11-12 19:33       ` Felipe Balbi
2015-11-12 20:02         ` santosh shilimkar

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