2024-01-22 05:35:52

by Arınç ÜNAL

[permalink] [raw]
Subject: [PATCH net-next] net: dsa: mt7530: support OF-based registration of switch MDIO bus

Currently the MDIO bus of the switches the MT7530 DSA subdriver controls
can only be registered as non-OF-based. Bring support for registering the
bus OF-based.

The subdrivers that control switches [with MDIO bus] probed on OF must
follow this logic to support all cases properly:

No switch MDIO bus defined: Populate ds->user_mii_bus, register the MDIO
bus, set the interrupts for PHYs if "interrupt-controller" is defined at
the switch node. This case should only be covered for the switches which
their dt-bindings documentation didn't document the MDIO bus from the
start. This is to keep supporting the device trees that do not describe the
MDIO bus on the device tree but the MDIO bus is being used nonetheless.

Switch MDIO bus defined: Don't populate ds->user_mii_bus, register the MDIO
bus, set the interrupts for PHYs if ["interrupt-controller" is defined at
the switch node and "interrupts" is defined at the PHY nodes under the
switch MDIO bus node].

Switch MDIO bus defined but explicitly disabled: If the device tree says
status = "disabled" for the MDIO bus, we shouldn't need an MDIO bus at all.
Instead, just exit as early as possible and do not call any MDIO API.

The use of ds->user_mii_bus is inappropriate when the MDIO bus of the
switch is described on the device tree [1], which is why we don't populate
ds->user_mii_bus in that case.

Link: https://lore.kernel.org/netdev/20231213120656.x46fyad6ls7sqyzv@skbuf/ [1]
Suggested-by: David Bauer <[email protected]>
Signed-off-by: Arınç ÜNAL <[email protected]>
---
drivers/net/dsa/mt7530.c | 34 ++++++++++++++++++++++++++--------
1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 391c4dbdff42..cf2ff7680c15 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2146,24 +2146,40 @@ mt7530_free_irq_common(struct mt7530_priv *priv)
static void
mt7530_free_irq(struct mt7530_priv *priv)
{
- mt7530_free_mdio_irq(priv);
+ struct device_node *mnp, *np = priv->dev->of_node;
+
+ mnp = of_get_child_by_name(np, "mdio");
+ if (!mnp)
+ mt7530_free_mdio_irq(priv);
+ of_node_put(mnp);
+
mt7530_free_irq_common(priv);
}

static int
mt7530_setup_mdio(struct mt7530_priv *priv)
{
+ struct device_node *mnp, *np = priv->dev->of_node;
struct dsa_switch *ds = priv->ds;
struct device *dev = priv->dev;
struct mii_bus *bus;
static int idx;
- int ret;
+ int ret = 0;
+
+ mnp = of_get_child_by_name(np, "mdio");
+
+ if (mnp && !of_device_is_available(mnp))
+ goto out;

bus = devm_mdiobus_alloc(dev);
- if (!bus)
- return -ENOMEM;
+ if (!bus) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ if (!mnp)
+ ds->user_mii_bus = bus;

- ds->user_mii_bus = bus;
bus->priv = priv;
bus->name = KBUILD_MODNAME "-mii";
snprintf(bus->id, MII_BUS_ID_SIZE, KBUILD_MODNAME "-%d", idx++);
@@ -2174,16 +2190,18 @@ mt7530_setup_mdio(struct mt7530_priv *priv)
bus->parent = dev;
bus->phy_mask = ~ds->phys_mii_mask;

- if (priv->irq)
+ if (priv->irq && !mnp)
mt7530_setup_mdio_irq(priv);

- ret = devm_mdiobus_register(dev, bus);
+ ret = devm_of_mdiobus_register(dev, bus, mnp);
if (ret) {
dev_err(dev, "failed to register MDIO bus: %d\n", ret);
- if (priv->irq)
+ if (priv->irq && !mnp)
mt7530_free_mdio_irq(priv);
}

+out:
+ of_node_put(mnp);
return ret;
}

--
2.40.1



2024-01-25 09:30:58

by Vladimir Oltean

[permalink] [raw]
Subject: Re: [PATCH net-next] net: dsa: mt7530: support OF-based registration of switch MDIO bus

On Mon, Jan 22, 2024 at 08:34:31AM +0300, Arınç ÜNAL wrote:
> Currently the MDIO bus of the switches the MT7530 DSA subdriver controls
> can only be registered as non-OF-based. Bring support for registering the
> bus OF-based.
>
> The subdrivers that control switches [with MDIO bus] probed on OF must
> follow this logic to support all cases properly:
>
> No switch MDIO bus defined: Populate ds->user_mii_bus, register the MDIO
> bus, set the interrupts for PHYs if "interrupt-controller" is defined at
> the switch node. This case should only be covered for the switches which
> their dt-bindings documentation didn't document the MDIO bus from the
> start. This is to keep supporting the device trees that do not describe the
> MDIO bus on the device tree but the MDIO bus is being used nonetheless.
>
> Switch MDIO bus defined: Don't populate ds->user_mii_bus, register the MDIO
> bus, set the interrupts for PHYs if ["interrupt-controller" is defined at
> the switch node and "interrupts" is defined at the PHY nodes under the
> switch MDIO bus node].
>
> Switch MDIO bus defined but explicitly disabled: If the device tree says
> status = "disabled" for the MDIO bus, we shouldn't need an MDIO bus at all.
> Instead, just exit as early as possible and do not call any MDIO API.
>
> The use of ds->user_mii_bus is inappropriate when the MDIO bus of the
> switch is described on the device tree [1], which is why we don't populate
> ds->user_mii_bus in that case.
>
> Link: https://lore.kernel.org/netdev/20231213120656.x46fyad6ls7sqyzv@skbuf/ [1]
> Suggested-by: David Bauer <[email protected]>
> Signed-off-by: Arınç ÜNAL <[email protected]>
> ---

Reviewed-by: Vladimir Oltean <[email protected]>

2024-01-25 15:03:21

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net-next] net: dsa: mt7530: support OF-based registration of switch MDIO bus

Hello:

This patch was applied to netdev/net-next.git (main)
by Paolo Abeni <[email protected]>:

On Mon, 22 Jan 2024 08:34:31 +0300 you wrote:
> Currently the MDIO bus of the switches the MT7530 DSA subdriver controls
> can only be registered as non-OF-based. Bring support for registering the
> bus OF-based.
>
> The subdrivers that control switches [with MDIO bus] probed on OF must
> follow this logic to support all cases properly:
>
> [...]

Here is the summary with links:
- [net-next] net: dsa: mt7530: support OF-based registration of switch MDIO bus
https://git.kernel.org/netdev/net-next/c/91374ba537bd

You are awesome, thank you!
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