Subject: Re: [PATCH v4 2/2] fpga: Add support for Lattice iCE40 FPGAs
To: Rob Herring <robh@kernel.org>
References: <1477776746-3678-1-git-send-email-joel@airwebreathe.org.uk>
 <1477776746-3678-2-git-send-email-joel@airwebreathe.org.uk>
 <20161031063317.fqoaqemoiqhrrjzg@rob-hp-laptop>
Cc: atull@opensource.altera.com, moritz.fischer@ettus.com,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-spi@vger.kernel.org
From: Joel Holdsworth <joel@airwebreathe.org.uk>
Message-ID: <f3c6dac1-bf10-c945-3e8a-9146e07253fd@airwebreathe.org.uk>
Date: Mon, 31 Oct 2016 10:58:16 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101
 Thunderbird/45.3.0
MIME-Version: 1.0
In-Reply-To: <20161031063317.fqoaqemoiqhrrjzg@rob-hp-laptop>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1545
Lines: 51

Hi Rob,

Thanks for taking the time review the patches.

>>  .../bindings/fpga/lattice-ice40-fpga-mgr.txt       |  23 +++
>
> It's preferred that bindings are a separate patch.

Can you just clarify a little? I'm happy to split the patch up, but I 
don't understand how it could work without the bindings. For example, in 
ice40_fpga_probe, I have to get the GPIOs with devm_gpiod_get for the 
driver to work.

Maybe I'm missing something. Or do you just mean the documentation?


>
> -gpios is preferred.
>
> Please state direction and polarity.

Thanks, I'll fix that up.

>
>> +- creset_b-gpio:	GPIO connected to CRESET_B pin. Note that CRESET_B is
>
> Don't use '_'. In this case, I'd just do cresetb-gpios.

So the pin is called CRESET_B in the datasheet. I think the _B refers to 
the active-low polarity of the line.

So I would think it should be creset-b-gpios or creset-gpios. I'm not so 
convinced cresetb-gpios is ideal, but it's a minor point.

>
>> +			treated as an active-low output because the signal is
>> +			treated as an enable signal, rather than a reset. This
>
> Though for enable signals, enable-gpios is fairly standard even if that
> deviates from the pin name.

I would think that would just confuse the user, unless they dig out the 
binding docs. The FPGA doesn't have an enable pin, and it's not at all 
obvious that a "reset" pin means "enable" in this driver.

Again, if you're adamant this is the correct convention it's no problem 
to make the change - just seems weird to me. What do you think?


Thanks
Joel