[PATCH v2 02/22] net: sunxi_emac: chase DT nodes to find PHY regulator

[Samuel Holland]

Hi Andre,

On 9/28/23 16:54, Andre Przywara wrote:
> At the moment the sun4i EMAC driver relies on hardcoded CONFIG_MACPWR
> Kconfig symbols to enable potential PHY regulators. As we want to get rid
> of those, we need to find the regulator by chasing up the DT.
> 
> The sun4i-emac binding puts the PHY regulator into the MDIO node, which
> is the parent of the PHY device. U-Boot does not have (and does not
> need) an MDIO driver, so we need to chase down the regulator through the
> EMAC node: we follow the "phy-handle" property to find the PHY node,
> then go up to its parent, where we find the "phy-supply" link to the
> regulator. Let U-Boot find the associated regulator device, and put that
> into the private device struct, so we can find and enable the regulator
> at probe time, later.

This does somewhat duplicate the logic from dm_eth_connect_phy_handle(),
and putting the regulator in a UCLASS_MDIO device's probe function would
work out cleanly (albeit with the usual DM overhead). But that can be a
later refactoring.

> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> Reviewed-by: Sam Edwards <CFSworks at gmail.com>
> ---
>  drivers/net/sunxi_emac.c | 39 +++++++++++++++++++++++++++++++++++++++
>  1 file changed, 39 insertions(+)
> 
> diff --git a/drivers/net/sunxi_emac.c b/drivers/net/sunxi_emac.c
> index 4c90d4b4981..f1f0e5bbbb2 100644
> --- a/drivers/net/sunxi_emac.c
> +++ b/drivers/net/sunxi_emac.c
> @@ -17,6 +17,7 @@
>  #include <net.h>
>  #include <asm/io.h>
>  #include <asm/arch/clock.h>
> +#include <power/regulator.h>
>  
>  /* EMAC register  */
>  struct emac_regs {
> @@ -165,6 +166,7 @@ struct emac_eth_dev {
>  	struct phy_device *phydev;
>  	int link_printed;
>  	uchar rx_buf[EMAC_RX_BUFSIZE];
> +	struct udevice *phy_reg;
>  };
>  
>  struct emac_rxhdr {
> @@ -572,6 +574,9 @@ static int sunxi_emac_eth_probe(struct udevice *dev)
>  	if (ret)
>  		return ret;
>  
> +	if (priv->phy_reg)
> +		regulator_set_enable(priv->phy_reg, true);
> +
>  	return sunxi_emac_init_phy(priv, dev);
>  }
>  
> @@ -585,9 +590,43 @@ static const struct eth_ops sunxi_emac_eth_ops = {
>  static int sunxi_emac_eth_of_to_plat(struct udevice *dev)
>  {
>  	struct eth_pdata *pdata = dev_get_plat(dev);
> +	struct emac_eth_dev *priv = dev_get_priv(dev);
> +	struct ofnode_phandle_args args;
> +	ofnode mdio_node;
> +	int ret;
>  
>  	pdata->iobase = dev_read_addr(dev);
>  
> +	/* The PHY regulator is in the MDIO node, not the EMAC or PHY node. */
> +	ret = dev_read_phandle_with_args(dev, "phy-handle", NULL, 0, 0, &args);

You can use dev_get_phy_node() here. Either way:

Reviewed-by: Samuel Holland <samuel at sholland.org>

> +	if (ret) {
> +		dev_err(dev, "failed to get PHY node\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * U-Boot does not have (and does not need) a device driver for the
> +	 * MDIO device, so just "pass through" that DT node to get to the
> +	 * regulator phandle.
> +	 * The PHY regulator is optional, though: ignore if we cannot find
> +	 * a phy-supply property.
> +	 */
> +	mdio_node = ofnode_get_parent(args.node);
> +	ret= ofnode_parse_phandle_with_args(mdio_node, "phy-supply", NULL, 0, 0,
> +					    &args);
> +	if (ret && ret != -ENOENT) {
> +		dev_err(dev, "failed to get PHY supply node\n");
> +		return ret;
> +	}
> +	if (!ret) {
> +		ret = uclass_get_device_by_ofnode(UCLASS_REGULATOR, args.node,
> +						  &priv->phy_reg);
> +		if (ret) {
> +			dev_err(dev, "failed to get PHY regulator node\n");
> +			return ret;
> +		}
> +	}
> +
>  	return 0;
>  }
>