Subject: Re: [PATCH v3 2/5] reset: socfpga: use the reset-simple driver
To: Philipp Zabel <p.zabel@pengutronix.de>, linux-kernel@vger.kernel.org
References: <20170816094701.30678-1-p.zabel@pengutronix.de>
 <20170816094701.30678-3-p.zabel@pengutronix.de>
Cc: Andre Przywara <andre.przywara@arm.com>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Maxime Ripard <maxime.ripard@free-electrons.com>,
        Chen-Yu Tsai <wens@csie.org>, Baoyou Xie <baoyou.xie@linaro.org>,
        Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>,
        Steffen Trumtrar <s.trumtrar@pengutronix.de>,
        Dinh Nguyen <dinguyen@kernel.org>,
        =?UTF-8?Q?Andreas_F=c3=a4rber?= <afaerber@suse.de>,
        linux-arm-kernel@lists.infradead.org, kernel@pengutronix.de
From: Alexandru Gagniuc <alex.g@adaptrum.com>
Message-ID: <900b3dad-7340-6ad9-d996-d2f0e389bd58@adaptrum.com>
Date: Wed, 16 Aug 2017 13:46:07 -0700
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Hi Phillip,

On 08/16/2017 02:46 AM, Philipp Zabel wrote:
[snip]
> @@ -118,8 +151,23 @@ static int reset_simple_probe(struct platform_device *pdev)
>  	data->rcdev.ops = &reset_simple_ops;
>  	data->rcdev.of_node = dev->of_node;
>
> -	if (devdata)
> +	if (devdata) {
> +		u32 reg_offset = devdata->reg_offset;
> +
> +		if (reg_offset &&
> +		    of_property_read_u32(dev->of_node, "altr,modrst-offset",
> +					 &reg_offset)) {
> +			dev_warn(dev,
> +				 "missing altr,modrst-offset property, assuming 0x%x!\n",
> +				 reg_offset);
> +		}

I would not make reading dt properties dependent on the presence of 
devdata. That breaks being able to configure the reset controller from 
dt. I would either just read the "altr,modrst-offset" property, or read 
it when

	of_device_is_compatible(dev->of_node, "altr,rst-mgr"));

Ideally, we could have a more generic "reg-offset" binding for new reset 
controllers, but that is beyond the scope of this patch.

Alex