From: Tien Hock Loh <thloh@altera.com>
To: Josh Cartwright <joshc@codeaurora.org>
CC: Dinh Nguyen <dinguyen@altera.com>, Ley Foon Tan <lftan@altera.com>,
        "robh+dt@kernel.org" <robh+dt@kernel.org>,
        "pawel.moll@arm.com" <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        "ijc+devicetree@hellion.org.uk" <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>, Rob Landley <rob@landley.net>,
        Linus Walleij <linus.walleij@linaro.org>,
        Alexandre Courbot <gnurou@gmail.com>,
        "Grant Likely" <grant.likely@linaro.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
        "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-gpio@vger.kernel.org" <linux-gpio@vger.kernel.org>,
        "thloh.linux@gmail.com" <thloh.linux@gmail.com>
Subject: Re: [PATCH V7 1/1] drivers/gpio: Altera soft IP GPIO driver and
 devicetree binding
Thread-Topic: [PATCH V7 1/1] drivers/gpio: Altera soft IP GPIO driver and
 devicetree binding
Thread-Index: AQHPXQhcsq16BvDmc0+h1Q5oLf7Jvg==
Date: Mon, 21 Apr 2014 02:21:11 +0000
Message-ID: <1CCADEFFEC58A54CACEDCA3F6E1E1A4C01573F@PG-ITEXCH02.altera.priv.altera.com>
References: <1393842463-5206-1-git-send-email-thloh@altera.com>
 <20140307151455.GI18529@joshc.qualcomm.com>
 <CAOLUe6aspffO1PUjKWW7ejpbxnYtb+RKRQrK=y30kuF7KXUUhA@mail.gmail.com>
 <CAOLUe6aPWmkJJSiBLL8tmw2MNfpaeLpSp3CSwP1u7q+qXxCh9Q@mail.gmail.com>
 <20140407171115.GA3956@joshc.qualcomm.com>
In-Reply-To: <20140407171115.GA3956@joshc.qualcomm.com>
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On Isn, 2014-04-07 at 12:11 -0500, Josh Cartwright wrote:
> On Mon, Apr 07, 2014 at 04:00:43PM +0800, Tien Hock Loh wrote:
> > On Wed, Mar 19, 2014 at 6:09 PM, Tien Hock Loh <thloh@altera.com> wrote:
> > > On Fri, Mar 7, 2014 at 11:14 PM, Josh Cartwright <joshc@codeaurora.org> wrote:
> > >> On Mon, Mar 03, 2014 at 06:27:43PM +0800, thloh@altera.com wrote:
> > >>> From: Tien Hock Loh <thloh@altera.com>
> [..]
> > >>> +     altera_gc->mapped_irq = irq_of_parse_and_map(node, 0);
> > >>>
> > >>
> > >> platform_get_irq(pdev, 0);
> > >>
> > > OK.
> > >
> >
> > platform_get_irq doesn't create the irq mapping which is needed by the
> > driver. Since this driver is targeted at using of, should I be using
> > irq_of_parse_and_map or should I still redo the codes with
> > platform_get_irq and irq_create_mapping? I think the latter would be
> > introducing code redundancy. Please advice.
>
> Yes, it is technically true that platform_get_irq() doesn't do the
> mapping directly, but that's because the mapping is setup earlier, when
> of_device_alloc() (drivers/of/platform.c) allocates resources for your
> platform device.
>
> Calling irq_of_parse_and_map() should be unnecessary.

I checked and tried running the without irq_create_mapping but it seems
the mapping is not done. What I've seen other GPIO driver is doing is to
create the mapping during the gpio_to_irq call. However Linus suggested
we are avoiding that route, thus the use of irq_of_parse_and_map.

Do you agree with my findings?

>


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