From: Bjorn Andersson <andersson@kernel•org>
To: Alex Elder <elder@riscstar•com>
Cc: andrew+netdev@lunn•ch, davem@davemloft•net, edumazet@google•com,
kuba@kernel•org, pabeni@redhat•com,
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Subject: Re: [PATCH net-next 08/12] dt-bindings: net: toshiba,tc965x-dwmac: add TC956x Ethernet bridge
Date: Sat, 9 May 2026 21:25:16 -0500 [thread overview]
Message-ID: <af_sarCs9E5M7NLE@baldur> (raw)
In-Reply-To: <3c78f48c-6478-46d0-87c2-581bb58637dd@riscstar.com>
On Thu, May 07, 2026 at 01:37:09PM -0500, Alex Elder wrote:
> On 5/7/26 9:12 AM, Bjorn Andersson wrote:
> > On Fri, May 01, 2026 at 10:54:16AM -0500, Alex Elder wrote:
> > > diff --git a/Documentation/devicetree/bindings/net/toshiba,tc956x-dwmac.yaml b/Documentation/devicetree/bindings/net/toshiba,tc956x-dwmac.yaml
> > [..]
> > > +
> > > + gpio-controller: true
> >
> > I don't have any concern with the use of a proper gpio driver to model
> > the implementation, but if I understand correctly this relationship
> > between gpio controller and gpio consumer is strictly internal to "the
> > PCI device".
>
> (I think you're already cool with this but I still wanted to respond.)
>
Thank you for the further clarifications, and added details, Alex. This
does look reasonable to me.
Regards,
Bjorn
> That is not correct. These GPIO lines are used two ways for the
> RB3gen2:
> - drivers/pci/pwrctrl/pci-pwrctrl-tc9563.c uses GPIOs 2 and 3 to
> assert/deassert the reset lines associated with the two exposed
> downstream PCIe ports on the PCIe switch within the TC956x.
>
> - Each of the Ethernet PHYs has a reset GPIO. On the RB3gen2, the
> GPIOs used for the purpose come from the GPIO controller embedded
> in the TC9564 (00 and 01).
>
> These are therefore "exposed" (they are *not* strictly internal).
>
> > Is this connection variable or is the link merely expressed in
> > DeviceTree to mitigate the fact that you choose to implement the
> > responsibilities of the two parts split into two device drivers?
>
> It is variable. These resets might be implemented by other GPIO
> controllers on other platforms.
>
> > Are there other consumers of these TC956x gpios which would result in a
> > board designer (and hence dts author) to ever reference this
> > gpio-controller in a different way?
>
> They could. Nine of these GPIOs are exposed by the TC956x pins
> (GPIO00-06, GPIO12, GPIO35 and GPIO36). The RB3gen2 uses 00-03
> (and possibly 04 but that's for a PHY we haven't tested yet).
>
> -Alex
>
> > Regards,
> > Bjorn
>
next prev parent reply other threads:[~2026-05-10 2:25 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260501155421.3329862-1-elder@riscstar.com>
[not found] ` <20260501155421.3329862-12-elder@riscstar.com>
2026-05-02 16:45 ` [PATCH net-next 11/12] misc: tc956x_pci: add TC956x/QPS615 support Jakub Kicinski
2026-05-03 2:06 ` Alex Elder
2026-05-03 2:14 ` Jakub Kicinski
2026-05-03 2:23 ` Alex Elder
2026-05-02 16:47 ` [PATCH net-next 00/12] net: enable TC956x support Jakub Kicinski
2026-05-03 2:07 ` Alex Elder
[not found] ` <20260501155421.3329862-10-elder@riscstar.com>
2026-05-03 3:42 ` [PATCH net-next 09/12] gpio: tc956x: add TC956x/QPS615 support Julian Braha
2026-05-06 18:51 ` Alex Elder
[not found] ` <CAMRc=McWXCqyv1LmWMuEMmE3HqaURx_eMD8rkDs9AJT+7W2aYw@mail.gmail.com>
2026-05-04 13:07 ` Alex Elder
[not found] ` <736fb3b7-c88a-4ec4-96ad-d1b79cc48d30@lunn.ch>
[not found] ` <30cec7dd-ac3c-47ab-896a-c29992bd5ba5@riscstar.com>
[not found] ` <3666e3e6-e6f3-4cbf-b9fe-caa394fbab7c@lunn.ch>
[not found] ` <0751a051-9894-45be-92d6-0d46f2c39293@riscstar.com>
[not found] ` <7d7b6b89-3ef4-4891-a794-c8b11f39db34@lunn.ch>
[not found] ` <79684efa-4ba9-4144-a99b-dab935007a2f@riscstar.com>
[not found] ` <ec5765aa-b830-468b-8965-a95fbe020065@lunn.ch>
2026-05-06 22:41 ` Alex Elder
2026-05-07 12:15 ` Linus Walleij
2026-05-07 12:20 ` Alex Elder
[not found] ` <20260501155421.3329862-11-elder@riscstar.com>
2026-05-05 16:38 ` [PATCH net-next 10/12] net: stmmac: " Mohd Ayaan Anwar
2026-05-05 16:46 ` Alex Elder
[not found] ` <20260501155421.3329862-13-elder@riscstar.com>
2026-05-05 16:42 ` [PATCH net-next 12/12] arm64: dts: qcom: qcs6490-rb3gen2: enable TC9564 with a single QCS8081 phy Mohd Ayaan Anwar
2026-05-05 16:46 ` Alex Elder
[not found] ` <20260501155421.3329862-9-elder@riscstar.com>
2026-05-07 14:12 ` [PATCH net-next 08/12] dt-bindings: net: toshiba,tc965x-dwmac: add TC956x Ethernet bridge Bjorn Andersson
2026-05-07 18:37 ` Alex Elder
2026-05-10 2:25 ` Bjorn Andersson [this message]
2026-05-07 23:41 ` Rob Herring
2026-05-15 17:59 ` [PATCH net-next 00/12] net: enable TC956x support Alex Elder
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