From mboxrd@z Thu Jan  1 00:00:00 1970
From: ladis@linux-mips.org (Ladislav Michl)
Date: Mon, 8 Jan 2018 23:06:02 +0100
Subject: [RFC 5/5] pwm: pwm-omap-dmtimer: Add capture functionality
In-Reply-To: <20180108215931.GV3875@atomide.com>
References: <20180108153926.GA3916@lenoch> <20180108154336.GE4077@lenoch>
 <20180108215931.GV3875@atomide.com>
Message-ID: <20180108220602.GA17615@lenoch>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Mon, Jan 08, 2018 at 01:59:31PM -0800, Tony Lindgren wrote:
> * Ladislav Michl <ladis@linux-mips.org> [180108 15:46]:
> > Here it seems hardware can capture both edges, but I do not see a way
> > how to tell it I want start from either low to high or high to low
> > transition. Clues?
> 
> At least dm3730 TRM documents TCM bits [9:8] for TCLR, but you
> probably know that already..
> 
> If you're having hard time getting things starting, maybe something
> like this helps:
> 
> stop timer in TCLR register
> configure timer in TCLR
> write some value to TLDR, maybe 0?
> set ST bit in TCLR to start

Let me clarify it a bit more. I have no problem starting timer and capture
events. I just didn't find a way how to tell hardware I want to start
with for example rising edge, so rising edge goes to TCAR1 and failing edge
to TCAR2. Substracting those gives pulse width.

	ladis