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From:   Arnd Bergmann <arnd@arndb.de>
Date:   Tue, 3 May 2022 20:51:57 +0200
Message-ID: <CAK8P3a3t7-ozDHu18vMKEWxfNS4yd_BNHUh7hQ24rfS20tssDg@mail.gmail.com>
Subject: Re: [PATCH v6 3/8] watchdog: hpe-wdt: Introduce HPE GXP Watchdog
To:     Guenter Roeck <linux@roeck-us.net>
Cc:     "Hawkins, Nick" <nick.hawkins@hpe.com>,
        "Verdun, Jean-Marie" <verdun@hpe.com>,
        "joel@jms.id.au" <joel@jms.id.au>, "arnd@arndb.de" <arnd@arndb.de>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Wim Van Sebroeck <wim@linux-watchdog.org>,
        "linux-watchdog@vger.kernel.org" <linux-watchdog@vger.kernel.org>
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On Tue, May 3, 2022 at 6:53 PM Guenter Roeck <linux@roeck-us.net> wrote:

> > Just to clarify for my understanding are you asking that in the device structure I use the "void *platform_data" to pass "struct *resource"? If I am incorrect here can you elaborate on what you would like to be done? Based on feedback in review for the device tree; the watchdog is being created as a child to the timer. Therefore the conclusion reached was there should not be a gxp-wdt listed in the device tree files. I took this implementation based on what I found in ixp4xx_wdt.c.
> >
>
> One bad deed tends to multiply.
>
> No, I didn't ask to pass a struct resource as platform data.
> That would be no different to the current code. Resources
> can be added to a platform device using
> platform_device_add_resources(), and the platform driver
> can then use platform_get_resource() to use it. This
> would make it independent of a "private" mechanism.

Unfortunately there is no resource type for __iomem tokens,
only for physical addresses, so you'd end up having to do
ioremap() of the same address twice to map it into both the
timer and the watchdog driver . Not the end of the world
of course, but that doesn't seem much better than abusing the
device private data.

       Arnd