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References: <20210824164801.28896-1-lakshmi.sowjanya.d@intel.com> <20210824164801.28896-11-lakshmi.sowjanya.d@intel.com>
In-Reply-To: <20210824164801.28896-11-lakshmi.sowjanya.d@intel.com>
From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Thu, 16 Sep 2021 23:52:18 +0200
Message-ID: <CACRpkda5Y-Dxb4SkwyUcqKwsTd_c9Emgt0Z6OME5pQYz-WiC_Q@mail.gmail.com>
Subject: Re: [RFC PATCH v1 10/20] tools: gpio: Add GPIO output generation user application
To:     "D, Lakshmi Sowjanya" <lakshmi.sowjanya.d@intel.com>,
        "thierry.reding@gmail.com" <thierry.reding@gmail.com>,
        =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= 
        <u.kleine-koenig@pengutronix.de>, Lee Jones <lee.jones@linaro.org>
Cc:     "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Mark Gross <mgross@linux.intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        "Saha, Tamal" <tamal.saha@intel.com>, bala.senthil@intel.com,
        Dipen Patel <dipenp@nvidia.com>
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On Tue, Aug 24, 2021 at 6:48 PM <lakshmi.sowjanya.d@intel.com> wrote:

> From: Christopher Hall <christopher.s.hall@intel.com>
>
> Add GPIO user application - gpio_event_gen - to generate output using
> output methods added to GPIO lib. The output produced is 1 Hz clock
> aligned to the system clock using singly scheduled edges.
>
> gpio_event_gen accepts similar arguments to gpio-event-mon.
>
> Example output:
>         $ gpio-event-gen -n gpiochip0 -o 0 -c 3
>         Generating events on line 0 on gpiochip1
>         clock realtime : 1612453529996832765
>         GPIO EVENT TRIGGER: 1612453531000000000
>         clock realtime 2 2 : 1612453531500000000
>         GPIO EVENT TRIGGER: 1612453531500000000
>         clock realtime 2 2 : 1612453532000000000
>         GPIO EVENT TRIGGER: 1612453532000000000
>         clock realtime 2 2 : 1612453532500000000
>
> Produces 3 events of 1 Hz output on line 0 of chip/device 0.
>
> Signed-off-by: Christopher Hall <christopher.s.hall@intel.com>
> Signed-off-by: Tamal Saha <tamal.saha@intel.com>
> Co-developed-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
> Signed-off-by: Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>
> Reviewed-by: Mark Gross <mgross@linux.intel.com>

To me this looks as very similar to what the PWM subsystem
is doing, just with a restricted number of periods.
Especially with that command line example.

Yours,
Linus Walleij