From mboxrd@z Thu Jan 1 00:00:00 1970
From: Philipp Zabel
Subject: Re: [PATCH v2 07/18] drivers: reset: Add STM32 reset driver
Date: Wed, 11 Mar 2015 14:08:28 +0100
Message-ID: <1426079308.3101.57.camel@pengutronix.de>
References: <1424455277-29983-1-git-send-email-mcoquelin.stm32@gmail.com>
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Sender: linux-doc-owner@vger.kernel.org
To: Maxime Coquelin
Cc: Arnd Bergmann , Uwe =?ISO-8859-1?Q?Kleine-K=F6nig?= , Andreas =?ISO-8859-1?Q?F=E4rber?= , Geert Uytterhoeven , Rob Herring , Jonathan Corbet , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , Daniel Lezcano , Thomas Gleixner , Linus Walleij , Greg Kroah-Hartman , Jiri Slaby , Andrew Morton , "David S. Miller" , Mauro Carvalho Chehab , Joe Perches , Antti Palosaari , Tejun Heo
List-Id: linux-api@vger.kernel.org
Am Dienstag, den 10.03.2015, 22:20 +0100 schrieb Maxime Coquelin:
> 2015-03-10 21:21 GMT+01:00 Arnd Bergmann :
> > On Tuesday 10 March 2015 16:44:24 Maxime Coquelin wrote:
> >> 2015-03-10 16:02 GMT+01:00 Arnd Bergmann :
> >> > On Friday 20 February 2015 19:01:06 Maxime Coquelin wrote:
> >> >> +/* AHB1 */
> >> >> +#define GPIOA_RESET 0
> >> >> +#define GPIOB_RESET 1
> >> >> +#define GPIOC_RESET 2
> >> >> +#define GPIOD_RESET 3
> >> >> +#define GPIOE_RESET 4
> >> >> +#define GPIOF_RESET 5
> >> >> +#define GPIOG_RESET 6
> >> >> +#define GPIOH_RESET 7
> >> >> +#define GPIOI_RESET 8
> >> >> +#define GPIOJ_RESET 9
> >> >> +#define GPIOK_RESET 10
> >> >>
> >> >
> >> > As these are just the hardware numbers, it's better to not make =
them
> >> > part of the binding at all. Instead, just document in the bindin=
g that
> >> > one is supposed to pass the hardware number as the argument.
> >>
> >> The reset controller is part of the RCC (Reset & Clock Controller)=
IP.
> >> In this version, I only provided the reset registers to the reset
> >> controller driver, but as per Andreas F=C3=A4rber remark, I should=
avec a
> >> single DT node for both the resets and clocks.
> >>
> >> In the next version I am preparing, the defines doesn't look as
> >> trivial as in this version, GPIOA_RESET being 128 for instance.
> >>
> >> Is it fine for you if I keep the defines part of the binding?
> >>
> >>
> >
> > It's always better to avoid these files entirely, as they are
> > a frequent source of merge dependencies, and they make it less
> > obvious what's going on than having binary values in the dtb
> > that make sense.
>=20
> I agree it is always painful to have to have to manage these merge de=
pendencies.
> What I will do, if Philipp agrees, is to list all the values in the
> binding documentation.
>=20
> Doing that, the user of a reset won't have to do the calculation, and
> no more merge dependencies.
I'd prefer to have #defines for the reset bits if they are named in the
documentation and use the names in the dts. But if you want to referenc=
e
reset bits by number in the device tree instead, I won't insist.
Consider using two cells in the phandle for register and bit offset
instead of a single number that arbitrarily starts at 128.
regards
Philipp