From: Florian Fainelli <f.fainelli@gmail.com>
To: Marco Felsch <m.felsch@pengutronix.de>,
Marek Vasut <marex@denx.de>, Rob Herring <robh+dt@kernel.org>
Cc: Oleksij Rempel <o.rempel@pengutronix.de>,
Andrew Lunn <andrew@lunn.ch>,
netdev@vger.kernel.org, Russell King <linux@armlinux.org.uk>,
linux-kernel@vger.kernel.org, mkl@pengutronix.de,
kernel@pengutronix.de, David Jander <david@protonic.nl>
Subject: Re: PHY reset question
Date: Wed, 7 Oct 2020 08:44:53 -0700 [thread overview]
Message-ID: <c6bce70b-c97a-1696-2113-61bd3ba6ae99@gmail.com> (raw)
In-Reply-To: <20201007104757.fntgjiwt4tst3w3f@pengutronix.de>
On 10/7/2020 3:47 AM, Marco Felsch wrote:
> Florian did you send a new version of those patches?
I did not because we had a good conversation with Rob over IRC and the
conclusion was that the only solution that scaled across drivers,
subsystems and type of resources (regulators, clocks, resets, etc.) was
to have a compatible string for the given device that contains the ID.
For Ethernet PHY or MDIO device nodes that is "ethernet-phyAAAA.BBBB".
When the bus determines the presence of such a compatible string it
needs to bypass the dynamic identification of the device and needs to
bind the PHY driver and the device instance directly. MDIO does that,
and so does I2C and SPI AFAICT with the modalias/compatible (there is
not a standardized way to runtime detect an I2C or SPI client anyway),
while PCI and USB do not, but arguably could in the future.
For the specific use case that I had which required turning on a clock
to the Ethernet PHY, I ended up modifying the firmware to provide that
compatible string "ethernetAAAA.BBBB" and have the driver request the
clock from its probe function:
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git/commit/drivers/net/phy/bcm7xxx.c?id=ba4ee3c053659119472135231dbef8f6880ce1fb
--
Florian
next prev parent reply other threads:[~2020-10-07 15:45 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-06 8:04 PHY reset question Oleksij Rempel
2020-10-06 19:36 ` Florian Fainelli
2020-10-06 20:24 ` Marek Vasut
2020-10-06 21:11 ` Florian Fainelli
2020-10-06 22:24 ` Marek Vasut
2020-10-07 8:14 ` Marco Felsch
2020-10-07 8:23 ` Marek Vasut
2020-10-07 9:06 ` Marco Felsch
2020-10-07 9:20 ` Marek Vasut
2020-10-07 10:47 ` Marco Felsch
2020-10-07 15:44 ` Florian Fainelli [this message]
2020-10-07 9:50 ` Fabio Estevam
2020-10-09 14:25 ` Bruno Thomsen
2020-10-12 5:48 ` Oleksij Rempel
2020-10-12 8:25 ` Marek Vasut
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