Re: [PATCH net-next 14/15] net: dsa: mt7530: introduce driver for MT7988 built-in switch

From: Andrew Lunn <andrew@lunn.ch>
To: "Arınç ÜNAL" <arinc.unal@arinc9.com>
Cc: Daniel Golle <daniel@makrotopia.org>,
	netdev@vger.kernel.org, linux-mediatek@lists.infradead.org,
	linux-arm-kernel@lists.infradead.org, linux@armlinux.org.uk,
	linux-kernel@vger.kernel.org,
	Florian Fainelli <f.fainelli@gmail.com>,
	Vladimir Oltean <olteanv@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	AngeloGioacchino Del Regno 
	<angelogioacchino.delregno@collabora.com>,
	Sean Wang <sean.wang@mediatek.com>,
	Landen Chao <Landen.Chao@mediatek.com>,
	DENG Qingfang <dqfext@gmail.com>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Sam Shih <Sam.Shih@mediatek.com>,
	Lorenzo Bianconi <lorenzo@kernel.org>,
	John Crispin <john@phrozen.org>, Felix Fietkau <nbd@nbd.name>,
	Luiz Angelo Daros de Luca <luizluca@gmail.com>
Subject: Re: [PATCH net-next 14/15] net: dsa: mt7530: introduce driver for MT7988 built-in switch
Date: Fri, 31 Mar 2023 14:45:01 +0200	[thread overview]
Message-ID: <387b3105-2d70-4906-9573-cfac20a55d3a@lunn.ch> (raw)
In-Reply-To: <7d0acaef-0cec-91b9-a5c6-d094b71e3dbd@arinc9.com>

> Firstly, all of the functions on the mt7530-mmio driver should be changed
> from mt7988_* to mt7530_mmio_*. Same goes for the mt7530-mdio driver too as
> some of the functions don't start with mt7530_mdio_*. The MDIO and MMIO
> drivers are supposed to be used for the switches the MT7530 DSA driver
> supports. The mt7530_ prefix is derived from that. The mmio_ or mdio_ prefix
> is derived from, well, the driver itself.

There are examples of similar naming schemes in other DSA drivers. For
the marvell mv88e6xxx driver, all generic functions use the mv88e6xxx_
prefix. For functions which are specific to a family of marvell
switches, we use a prefix for when the feature was introduced. So for
example we have mv88e6352_g1_reset(), where that method of resetting
the devices was introduced in the mv88e6352. This also gives us some
namespace space, so we can also have mv88e6185_g1_reset() which is
used for a different family.

So i personally don't have a problem using different prefixes within
one driver, if it helps with understanding and name space issues.

> What I'm going to say next depends on how generic the MMIO and MDIO drivers
> are so that they can be used on all MediaTek architecture switches. Let's
> say, a new MediaTek switch is introduced. It seems likely that either the
> MMIO or MDIO driver will be used to control the switch. Maybe the driver for
> this new switch won't be under mt7530.c, like on Realtek, but that doesn't
> change the outcome.

My experience with silicon vendors is that they like to change the
hardware in none backwards compatible ways. So i would actually avoid
generic names, it makes it harder to deal with different variants.

	Andrew