Re: [PATCH v2 2/2] hwmon: ltc4282: add support for the LTC4282 chip

From: Guenter Roeck <linux@roeck-us.net>
To: "Andy Shevchenko" <andy@kernel.org>, "Nuno Sá" <noname.nuno@gmail.com>
Cc: Linus Walleij <linus.walleij@linaro.org>,
	nuno.sa@analog.com, linux-hwmon@vger.kernel.org,
	devicetree@vger.kernel.org, linux-doc@vger.kernel.org,
	Jean Delvare <jdelvare@suse.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Jonathan Corbet <corbet@lwn.net>,
	Bartosz Golaszewski <brgl@bgdev.pl>
Subject: Re: [PATCH v2 2/2] hwmon: ltc4282: add support for the LTC4282 chip
Date: Fri, 1 Dec 2023 08:04:12 -0800	[thread overview]
Message-ID: <7dc3f137-6073-4262-afb5-439d024bbbd2@roeck-us.net> (raw)
In-Reply-To: <ZWoABzufPkdXnrMT@smile.fi.intel.com>

On 12/1/23 07:47, Andy Shevchenko wrote:
> On Fri, Dec 01, 2023 at 04:24:35PM +0100, Nuno Sá wrote:
>> On Fri, 2023-12-01 at 14:40 +0100, Linus Walleij wrote:
> 
> ...
> 
>> Yes, that is the only thing we have. Meaning that there is no hw setting to set the
>> pins to open drain. Open drain is what they are. That is why I'm not seeing the point
>> in having PIN_CONFIG_DRIVE_OPEN_DRAIN implemented.
> 
> At least you have to implement error for PUSH_PULL mode and other modes,
> so from the (core) software point of view the user should be able to ask for
> anything and get an answer from the certain driver that "hey, i do support OD",
> or "hey, push-pull can't be supported with this hw".
> 

It seems to me that this is heading towards a mfd driver. I don't feel comfortable
with all that gpio specific code in the hwmon subsystem.

Maybe I should request that all hwmon chips with gpio support must be implemented
as mfd drivers. I'll have to think about that.

Guenter