[2/6] net: phy: maxio: parse and enable PHY clock from generic DT binding
Commit Message
The generic PHY DT binding features a clocks property, which describes
the clock input to the PHY. Typically this is a crystal oscillator, so
it works without software interaction. But some boards want to save some
pennies on that part, and let a clock fanout pin from the SoC provide this
clock signal. In this case the PHY probe routine needs to enable this
clock explicitly.
Look for a "clocks" property inside the PHY node and enable that clock,
if one is provided.
This allows boards with a SoC-driven PHY clock to use the PHY. Please
note that without the clock enabled, the PHY will not be detected on the
MDIO bus, so the PHY-ID needs to be explicitly named in the PHY
compatible string:
compatible = "ethernet-phy-id7b74.4411";
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
---
drivers/net/phy/maxio.c | 7 +++++++
1 file changed, 7 insertions(+)
Comments
On Mon, Aug 03, 2026 at 12:14:48PM +0200, Andre Przywara wrote:
> The generic PHY DT binding features a clocks property, which describes
> the clock input to the PHY. Typically this is a crystal oscillator, so
> it works without software interaction. But some boards want to save some
> pennies on that part, and let a clock fanout pin from the SoC provide this
> clock signal. In this case the PHY probe routine needs to enable this
> clock explicitly.
>
> Look for a "clocks" property inside the PHY node and enable that clock,
> if one is provided.
>
> This allows boards with a SoC-driven PHY clock to use the PHY. Please
> note that without the clock enabled, the PHY will not be detected on the
> MDIO bus, so the PHY-ID needs to be explicitly named in the PHY
> compatible string:
> compatible = "ethernet-phy-id7b74.4411";
>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Andrew
@@ -2,6 +2,7 @@
/* Driver for Maxio Ethernet PHYs. */
#include <linux/bitops.h>
+#include <linux/clk.h>
#include <linux/module.h>
#include <linux/phy.h>
#include <linux/property.h>
@@ -15,6 +16,7 @@
#define MAXIO_MAE0621A_CLKOUT_ENABLE BIT(0)
struct maxio_priv {
+ struct clk *clk;
bool clk_out_125m;
};
@@ -55,6 +57,11 @@ static int maxio_mae0621a_probe(struct phy_device *phydev)
return ret;
}
+ /* PHY clock from the generic PHY binding */
+ priv->clk = devm_clk_get_optional_enabled(&phydev->mdio.dev, NULL);
+ if (IS_ERR(priv->clk))
+ return PTR_ERR(priv->clk);
+
return 0;
}