[U-Boot] [PATCH v2 2/2] net: eth-uclass: Support device tree MAC addresses

[Grygorii Strashko]

On 16.04.19 19:24, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> Add the standard Ethernet device tree bindings (imported from v5.0 of
> the Linux kernel) and implement support for reading the MAC address for
> Ethernet devices in the Ethernet uclass. If the "mac-address" property
> exists, the MAC address will be parsed from that. If that property does
> not exist, the "local-mac-address" property will be tried as fallback.
> 
> MAC addresses from device tree take precedence over the ones stored in
> a network interface card's ROM.
> 
> Acked-by: Joe Hershberger <joe.hershberger at ni.com>
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
> Changes in v2:
> - use dev_read_u8_array_ptr()
> 
>  .../devicetree/bindings/net/ethernet.txt      | 66 +++++++++++++++++++
>  net/eth-uclass.c                              | 26 +++++++-
>  2 files changed, 89 insertions(+), 3 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/net/ethernet.txt
> 
> diff --git a/Documentation/devicetree/bindings/net/ethernet.txt b/Documentation/devicetree/bindings/net/ethernet.txt
> new file mode 100644
> index 000000000000..cfc376bc977a
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/ethernet.txt
> @@ -0,0 +1,66 @@
> +The following properties are common to the Ethernet controllers:
> +
> +NOTE: All 'phy*' properties documented below are Ethernet specific. For the
> +generic PHY 'phys' property, see
> +Documentation/devicetree/bindings/phy/phy-bindings.txt.
> +
> +- local-mac-address: array of 6 bytes, specifies the MAC address that was
> +  assigned to the network device;
> +- mac-address: array of 6 bytes, specifies the MAC address that was last used by
> +  the boot program; should be used in cases where the MAC address assigned to
> +  the device by the boot program is different from the "local-mac-address"
> +  property;
> +- nvmem-cells: phandle, reference to an nvmem node for the MAC address;
> +- nvmem-cell-names: string, should be "mac-address" if nvmem is to be used;
> +- max-speed: number, specifies maximum speed in Mbit/s supported by the device;
> +- max-frame-size: number, maximum transfer unit (IEEE defined MTU), rather than
> +  the maximum frame size (there's contradiction in the Devicetree
> +  Specification).
> +- phy-mode: string, operation mode of the PHY interface. This is now a de-facto
> +  standard property; supported values are:
> +  * "internal"
> +  * "mii"
> +  * "gmii"
> +  * "sgmii"
> +  * "qsgmii"
> +  * "tbi"
> +  * "rev-mii"
> +  * "rmii"
> +  * "rgmii" (RX and TX delays are added by the MAC when required)
> +  * "rgmii-id" (RGMII with internal RX and TX delays provided by the PHY, the
> +     MAC should not add the RX or TX delays in this case)
> +  * "rgmii-rxid" (RGMII with internal RX delay provided by the PHY, the MAC
> +     should not add an RX delay in this case)
> +  * "rgmii-txid" (RGMII with internal TX delay provided by the PHY, the MAC
> +     should not add an TX delay in this case)
> +  * "rtbi"
> +  * "smii"
> +  * "xgmii"
> +  * "trgmii"
> +  * "2000base-x",
> +  * "2500base-x",
> +  * "rxaui"
> +  * "xaui"
> +  * "10gbase-kr" (10GBASE-KR, XFI, SFI)
> +- phy-connection-type: the same as "phy-mode" property but described in the
> +  Devicetree Specification;
> +- phy-handle: phandle, specifies a reference to a node representing a PHY
> +  device; this property is described in the Devicetree Specification and so
> +  preferred;
> +- phy: the same as "phy-handle" property, not recommended for new bindings.
> +- phy-device: the same as "phy-handle" property, not recommended for new
> +  bindings.
> +- rx-fifo-depth: the size of the controller's receive fifo in bytes. This
> +  is used for components that can have configurable receive fifo sizes,
> +  and is useful for determining certain configuration settings such as
> +  flow control thresholds.
> +- tx-fifo-depth: the size of the controller's transmit fifo in bytes. This
> +  is used for components that can have configurable fifo sizes.
> +- managed: string, specifies the PHY management type. Supported values are:
> +  "auto", "in-band-status". "auto" is the default, it usess MDIO for
> +  management if fixed-link is not specified.
> +
> +Child nodes of the Ethernet controller are typically the individual PHY devices
> +connected via the MDIO bus (sometimes the MDIO bus controller is separate).
> +They are described in the phy.txt file in this same directory.
> +For non-MDIO PHY management see fixed-link.txt.
> diff --git a/net/eth-uclass.c b/net/eth-uclass.c
> index 4225aabf1fa1..c6d5ec013bd8 100644
> --- a/net/eth-uclass.c
> +++ b/net/eth-uclass.c
> @@ -455,6 +455,23 @@ static int eth_pre_unbind(struct udevice *dev)
>  	return 0;
>  }
>  
> +static bool eth_dev_get_mac_address(struct udevice *dev, u8 mac[ARP_HLEN])
> +{
> +	const uint8_t *p;
> +
> +	p = dev_read_u8_array_ptr(dev, "mac-address", ARP_HLEN);
> +	if (!p)
> +		p = dev_read_u8_array_ptr(dev, "local-mac-address", ARP_HLEN);
> +
> +	if (!p) {
> +		memset(mac, 0, ARP_HLEN);
> +		return false;
> +	}
> +
> +	memcpy(mac, p, ARP_HLEN);
> +	return true;
> +}

There are set of DT files in u-boot which have
mac-address = [ 00 00 00 00 00 00 ];

How will it work for them? 
Wouldn't cause unexpected skipping eth_get_ops(dev)->read_rom_hwaddr(dev) call?

> +
>  static int eth_post_probe(struct udevice *dev)
>  {
>  	struct eth_device_priv *priv = dev->uclass_priv;
> @@ -489,9 +506,12 @@ static int eth_post_probe(struct udevice *dev)
>  
>  	priv->state = ETH_STATE_INIT;
>  
> -	/* Check if the device has a MAC address in ROM */
> -	if (eth_get_ops(dev)->read_rom_hwaddr)
> -		eth_get_ops(dev)->read_rom_hwaddr(dev);
> +	/* Check if the device has a MAC address in device tree */
> +	if (!eth_dev_get_mac_address(dev, pdata->enetaddr)) {
> +		/* Check if the device has a MAC address in ROM */
> +		if (eth_get_ops(dev)->read_rom_hwaddr)
> +			eth_get_ops(dev)->read_rom_hwaddr(dev);
> +	}
>  
>  	eth_env_get_enetaddr_by_index("eth", dev->seq, env_enetaddr);
>  	if (!is_zero_ethaddr(env_enetaddr)) {
> 

-- 
Best regards,
grygorii