Re: [PATCH net-next 3/3] net: phy: mediatek: add driver for built-in 2.5G ethernet PHY on MT7988

From: Andrew Lunn
Date: Sun Jan 19 2025 - 12:32:09 EST


> + np = of_find_compatible_node(NULL, NULL, "mediatek,2p5gphy-fw");
> + if (!np)
> + return -ENOENT;

The device tree binding need documenting.

> + /* Write magic number to safely stall MCU */
> + phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800e, 0x1100);
> + phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800f, 0x00df);

0x1100 and 0x00df are magic numbers, bit 0x800e and 0x800f are
not. Please add #defines.


> +
> + for (i = 0; i < MT7988_2P5GE_PMB_FW_SIZE - 1; i += 4)
> + writel(*((uint32_t *)(fw->data + i)), pmb_addr + i);
> + dev_info(dev, "Firmware date code: %x/%x/%x, version: %x.%x\n",
> + be16_to_cpu(*((__be16 *)(fw->data +
> + MT7988_2P5GE_PMB_FW_SIZE - 8))),
> + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 6),
> + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 5),
> + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 2),
> + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 1));
> +
> + writew(reg & ~MD32_EN, mcu_csr_base + MD32_EN_CFG);
> + writew(reg | MD32_EN, mcu_csr_base + MD32_EN_CFG);
> + phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
> + /* We need a delay here to stabilize initialization of MCU */
> + usleep_range(7000, 8000);
> + dev_info(dev, "Firmware loading/trigger ok.\n");

We generally don't spam the log for "Happy Days" conditions. Please
only log if firmware download fails.

> +static int mt798x_2p5ge_phy_get_features(struct phy_device *phydev)
> +{
> + int ret;
> +
> + ret = genphy_c45_pma_read_abilities(phydev);
> + if (ret)
> + return ret;
> +
> + /* This phy can't handle collision, and neither can (XFI)MAC it's
> + * connected to. Although it can do HDX handshake, it doesn't support
> + * CSMA/CD that HDX requires.
> + */
> + linkmode_clear_bit(ETHTOOL_LINK_MODE_100baseT_Half_BIT,
> + phydev->supported);

So it can do 10BaseT_Half? What about 1000BaseT_Half?

As you said somewhere, 10/100/1G are not in the C45 space. So does
genphy_c45_pma_read_abilities() report these features?

Andrew