Message-ID: <54D12C84.9020505@broadcom.com>
Date: Tue, 3 Feb 2015 12:16:04 -0800
From: Ray Jui <rjui@broadcom.com>
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To: Dmitry Torokhov <dtor@google.com>
CC: Linus Walleij <linus.walleij@linaro.org>,
        Stephen Warren <swarren@wwwdotorg.org>,
        Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Ian Campbell <ijc+devicetree@hellion.org.uk>,
        Kumar Gala <galak@codeaurora.org>,
        "Grant Likely" <grant.likely@linaro.org>,
        Christian Daudt <bcm@fixthebug.org>, Matt Porter <mporter@linaro.org>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Russell King <linux@arm.linux.org.uk>,
        Scott Branden <sbranden@broadcom.com>,
        Anatol Pomazau <anatol@google.com>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>, <linux-gpio@vger.kernel.org>,
        <bcm-kernel-feedback-list@broadcom.com>, <devicetree@vger.kernel.org>
Subject: Re: [PATCH v3 3/4] pinctrl: cygnus: add initial IOMUX driver support
References: <rjui@broadcom.com> <1422928894-20716-1-git-send-email-rjui@broadcom.com> <1422928894-20716-4-git-send-email-rjui@broadcom.com> <20150203174042.GA15969@dtor-ws> <54D121A0.6070602@broadcom.com> <20150203200009.GB15969@dtor-ws>
In-Reply-To: <20150203200009.GB15969@dtor-ws>
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On 2/3/2015 12:00 PM, Dmitry Torokhov wrote:
> On Tue, Feb 03, 2015 at 11:29:36AM -0800, Ray Jui wrote:
>> On 2/3/2015 9:40 AM, Dmitry Torokhov wrote:
>>> On Mon, Feb 02, 2015 at 06:01:33PM -0800, Ray Jui wrote:
>>>> +
>>>> +/*
>>>> + * List of pins in Cygnus
>>>> + */
>>>> +static struct cygnus_pin cygnus_pins[] = {
>>>
>>> const?
>>>
>> I cannot make it const here, since the address of "gpio_mux" is later
>> passed to pinctrl_pin_desc's private data:
>>
>> pins[i].drv_data = &cygnus_pins[i].gpio_mux;
> 
> The pinctrl code says:
> 
> "@drv_data: driver-defined per-pin data. pinctrl core does not touch
> this"
> 
> so we could theoretically cast away the constness and restore it when
> we access drv_data in pin control methods, but I won't insist. I am
> not sure which way looks nicer.
> 
> Thanks.
> 
Yeah, I agreed that by declaring the cygnus_pins array const, it makes
it more obvious that "we do not expect any of its parameters to change."
But later if we cast &gpio_mux to void * before assigned to drv_data of
pinctrl_pin_desc, we sort of break it up...I'll keep this part of code
as it is for now.

Thanks,

Ray
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