From: Tony Lindgren <tony@atomide.com>
To: Ladislav Michl <ladis@linux-mips.org>
Cc: Keerthy <j-keerthy@ti.com>,
aaro.koskinen@iki.fi, thierry.reding@gmail.com,
daniel.lezcano@linaro.org, grygorii.strashko@ti.com,
linux-omap@vger.kernel.org, robh+dt@kernel.org,
linux-arm-kernel@lists.infradead.org, linux-pwm@vger.kernel.org,
sebastian.reichel@collabora.co.uk, t-kristo@ti.com
Subject: Re: [RFC 5/5] pwm: pwm-omap-dmtimer: Add capture functionality
Date: Mon, 8 Jan 2018 14:13:27 -0800 [thread overview]
Message-ID: <20180108221327.GW3875@atomide.com> (raw)
In-Reply-To: <20180108220602.GA17615@lenoch>
* Ladislav Michl <ladis@linux-mips.org> [180108 22:09]:
> 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.
Oh I see, yeah that would be cool :) Maybe you can first configure
an interrupt to trigger on rising edge, then configure things for
falling edge, then subtract..
Regards,
Tony
WARNING: multiple messages have this Message-ID (diff)
From: tony@atomide.com (Tony Lindgren)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 5/5] pwm: pwm-omap-dmtimer: Add capture functionality
Date: Mon, 8 Jan 2018 14:13:27 -0800 [thread overview]
Message-ID: <20180108221327.GW3875@atomide.com> (raw)
In-Reply-To: <20180108220602.GA17615@lenoch>
* Ladislav Michl <ladis@linux-mips.org> [180108 22:09]:
> 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.
Oh I see, yeah that would be cool :) Maybe you can first configure
an interrupt to trigger on rising edge, then configure things for
falling edge, then subtract..
Regards,
Tony
next prev parent reply other threads:[~2018-01-08 22:13 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-08 15:39 [PATCH 0/5] Add capture functionality to OMAP pwm driver Ladislav Michl
2018-01-08 15:39 ` Ladislav Michl
2018-01-08 15:40 ` [PATCH 1/5] clocksource: timer-dm: Make unexported functions static Ladislav Michl
2018-01-08 15:40 ` Ladislav Michl
2018-01-08 15:41 ` [PATCH 2/5] clocksource: timer-dm: Check prescaler value Ladislav Michl
2018-01-08 15:41 ` Ladislav Michl
2018-01-08 15:41 ` [PATCH 3/5] pwm: pwm-omap-dmtimer: Fix frequency when using prescaler Ladislav Michl
2018-01-08 15:41 ` Ladislav Michl
2018-01-08 15:42 ` [PATCH 4/5] clocksource: timer-dm: Add event capture Ladislav Michl
2018-01-08 15:42 ` Ladislav Michl
2018-01-08 15:43 ` [RFC 5/5] pwm: pwm-omap-dmtimer: Add capture functionality Ladislav Michl
2018-01-08 21:59 ` Tony Lindgren
2018-01-08 21:59 ` Tony Lindgren
2018-01-08 22:06 ` Ladislav Michl
2018-01-08 22:06 ` Ladislav Michl
2018-01-08 22:13 ` Tony Lindgren [this message]
2018-01-08 22:13 ` Tony Lindgren
2018-01-08 22:26 ` Ladislav Michl
2018-01-08 22:26 ` Ladislav Michl
2018-01-08 21:51 ` [PATCH 0/5] Add capture functionality to OMAP pwm driver Tony Lindgren
2018-01-08 21:51 ` Tony Lindgren
2018-01-08 21:57 ` Ladislav Michl
2018-01-08 21:57 ` Ladislav Michl
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20180108221327.GW3875@atomide.com \
--to=tony@atomide.com \
--cc=aaro.koskinen@iki.fi \
--cc=daniel.lezcano@linaro.org \
--cc=grygorii.strashko@ti.com \
--cc=j-keerthy@ti.com \
--cc=ladis@linux-mips.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-omap@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=robh+dt@kernel.org \
--cc=sebastian.reichel@collabora.co.uk \
--cc=t-kristo@ti.com \
--cc=thierry.reding@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.