Re: [PATCH 1/2] gpio: Rename devm_get_gpiod_from_child()

From: Boris Brezillon <boris.brezillon@free-electrons.com>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	Alexandre Courbot <gnurou@gmail.com>,
	linux-gpio@vger.kernel.org, linux-input@vger.kernel.org,
	Bryan Wu <cooloney@gmail.com>, Richard Purdie <rpurdie@rpsys.net>,
	Jacek Anaszewski <j.anaszewski@samsung.com>,
	linux-leds@vger.kernel.org,
	Tomi Valkeinen <tomi.valkeinen@ti.com>,
	linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	Russell King <linux@armlinux.org.uk>
Subject: Re: [PATCH 1/2] gpio: Rename devm_get_gpiod_from_child()
Date: Tue, 31 Jan 2017 10:24:24 +0100	[thread overview]
Message-ID: <20170131102424.7b68c0d4@bbrezillon> (raw)
In-Reply-To: <20170131091155.GH8311@dtor-ws>

On Tue, 31 Jan 2017 01:11:55 -0800
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:

> On Tue, Jan 31, 2017 at 10:07:21AM +0100, Boris Brezillon wrote:
> > On Tue, 31 Jan 2017 00:44:47 -0800
> > Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> >   
> > > On Tue, Jan 31, 2017 at 09:04:32AM +0100, Boris Brezillon wrote:  
> > > > On Mon, 30 Jan 2017 17:06:07 -0800
> > > > Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> > > >     
> > > > > On Mon, Jan 30, 2017 at 04:41:48PM +0100, Boris Brezillon wrote:    
> > > > > > Rename devm_get_gpiod_from_child() into
> > > > > > devm_fwnode_get_gpiod_from_child() to reflect the fact that this
> > > > > > function is operating on a fwnode object.      
> > > > > 
> > > > > I believe this is completely pointless rename. Are you planning on
> > > > > adding devm_of_get_gpiod_from_child()? Or
> > > > > devm_acpt_get_gpiod_from_child()? (I sure hope not).    
> > > > 
> > > > Of course not.
> > > >     
> > > > > 
> > > > > Also, on what object? Does it take fwnode as first argument? Or maybe we
> > > > > should call it devm_dev_const_charp_fwnode_get_gpiod_from_child() so we
> > > > > know types of all arguments?    
> > > > 
> > > > Linus suggested to rename this function [1]. I personally don't care
> > > > much about the name, though I agree with Linus that names should be
> > > > consistent and descriptive. Moreover, he's the maintainer, and I tend
> > > > to follow maintainers suggestion when I contribute to a specific
> > > > subsystem.    
> > > 
> > > OK, I did not know that that was Linus' request, my objection still
> > > stands.
> > >   
> > > > 
> > > > IIUC, you're concerned about the length of this function name. If I had
> > > > to drop something it would be the _from_child() suffix, because the
> > > > function is not even checking that the child parameter is actually a
> > > > direct child (or a descendant) of device->fwnode.    
> > > 
> > > OK, that sounds better. Actually, we already have
> > > fwnode_get_named_gpiod(), unfortunately it does not do suffixes
> > > permutations. There are also no users, except
> > > devm_get_gpiod_from_child(). So I would:
> > > 
> > > - rename fwnode_get_named_gpiod() -> static __fwnode_get_named_gpiod()
> > > - made new fwnode_get_named_gpiod() that did suffix permutation and
> > >   called __fwnode_get_named_gpiod() (or pulled its implementation
> > >   inline)  
> > 
> > Sorry but I don't follow you. Why do you need
> > __fwnode_get_named_gpiod(),  
> 
> You do not need it, it will just reduce size of the patch if you use
> it. I'd be perfectly fine not with having it and have everything in
> fwnode_get_named_gpiod().

Okay.

> 
> > and what is the suffix permutation you're
> > mentioning here?  
> 
> devm_get_gpiod_from_child() tries to apply "-gpio" and "-gpios" suffixes
> to the supplied GPIO ID while current fwnode_get_named_gpiod() takes
> property name literally.

fwnode_get_named_gpiod() just mimics what of_get_named_gpiod_flags(),
acpi_node_get_gpiod(), of_find_gpio() and acpi_find_gpio() do. It would
be weird/inconsistent to have the con_id suffixing logic moved in the
fwnode_get_named_gpiod() (if that's what you're suggesting, but I'm not
sure it is).