linux-kernel - Re: [PATCH v4 1/5] gpio-f7188x: Add GPIO support for Nuvoton NCT6116

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Message-ID: <20220824155038.5aa19495@md1za8fc.ad001.siemens.net>
Date:   Wed, 24 Aug 2022 15:50:38 +0200
From:   Henning Schild <henning.schild@...mens.com>
To:     simon.guinot@...uanux.org
Cc:     Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
        Linus Walleij <linus.walleij@...aro.org>,
        Bartosz Golaszewski <brgl@...ev.pl>,
        Pavel Machek <pavel@....cz>,
        Hans de Goede <hdegoede@...hat.com>,
        Mark Gross <markgross@...nel.org>, Lee Jones <lee@...nel.org>,
        linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-leds@...r.kernel.org, platform-driver-x86@...r.kernel.org,
        Sheng-Yuan Huang <syhuang3@...oton.com>,
        Tasanakorn Phaipool <tasanakorn@...il.com>
Subject: Re: [PATCH v4 1/5] gpio-f7188x: Add GPIO support for Nuvoton
 NCT6116

Am Wed, 24 Aug 2022 15:10:55 +0200
schrieb simon.guinot@...uanux.org:

> On Tue, Aug 23, 2022 at 04:54:59PM +0200, Henning Schild wrote:
> > Am Tue, 23 Aug 2022 17:47:38 +0300
> > schrieb Andy Shevchenko <andriy.shevchenko@...ux.intel.com>:  
> 
> Hi Andy,
> 
> Thanks for this new version. It is looking good to me.
> 
> >   
> > > On Tue, Aug 23, 2022 at 12:23:40PM +0200, Henning Schild wrote:  
> > > > Add GPIO support for Nuvoton NCT6116 chip. Nuvoton SuperIO
> > > > chips are very similar to the ones from Fintek. In other
> > > > subsystems they also share drivers and are called a family of
> > > > drivers.
> > > > 
> > > > For the GPIO subsystem the only difference is that the direction
> > > > bit is reversed and that there is only one data bit per pin. On
> > > > the SuperIO level the logical device is another one.
> > > > 
> > > > On a chip level we do not have a manufacturer ID to check and
> > > > also no revision.    
> > > 
> > > ...
> > >   
> > > > - * GPIO driver for Fintek Super-I/O F71869, F71869A, F71882,
> > > > F71889 and F81866
> > > > + * GPIO driver for Fintek and Nuvoton Super-I/O chips    
> > > 
> > > I'm not sure it's good idea to drop it from here. It means reader
> > > has to get this info in a hard way.
> > > 
> > > ...  
> > 
> > Let us see what others say. I wanted to keep this in line with what
> > Kconfig says and the oneliner in the Kconfig was getting pretty
> > longish. Hence i decided to shorten that. Other drivers also seem to
> > not list all the possible chips in many places, it is all maint
> > effort when a new chips is added and the list is in like 5 places.  
> 
> I agree with you that we can drop this line. It was already incomplete
> and the information is quite readable a few lines below in both the
> define list and the chip enumeration.
> 
> >   
> > > > +#define gpio_dir_invert(type)	((type) == nct6116d)
> > > > +#define gpio_data_single(type)	((type) == nct6116d)    
> > > 
> > > What's prevents us to add a proper prefix to these? I don't like
> > > the idea of them having "gpio" prefix.
> > > 
> > > ...
> > >   
> > > > +		pr_info(DRVNAME ": Unsupported device
> > > > 0x%04x\n", devid);
> > > > +			pr_debug(DRVNAME ": Not a Fintek
> > > > device at 0x%08x\n", addr);
> > > > +	pr_info(DRVNAME ": Found %s at %#x\n",
> > > > +		pr_info(DRVNAME ":   revision %d\n",    
> > > 
> > > Can we, please, utilize pr_fmt()?
> > >   
> > > > +			(int)superio_inb(addr,
> > > > SIO_FINTEK_DEVREV));    
> > > 
> > > Explicit casting in printf() means wrong specifier in 99% of
> > > cases. 
> > 
> > For all the other comments i will wait for a second opinion. I
> > specifically did not change existing code for more than the
> > functional changes needed. And a bit of checkpatch.pl fixing.
> > Beautification could be done on the way but would only cause
> > inconsistency. That driver is what it is, if someone wants to
> > overhaul the style ... that should be another patch. One likely not
> > coming from me.  
> 
> About the int cast, I think you can drop it while you are updating
> this line. It is unneeded.

Ok two voices for doing that one fix along the way. I will send a v5
and hope nobody insists on me fixing the other findings in code i never
wrote.

regards,
Henning

> I have no opinion on the other comments and I am OK with the rest of
> the patch.
> 
> Simon