Re: [PATCH net-next v5 2/4] net: phy: mediatek: add phy driver for MT7628 built-in Fast Ethernet PHYs

[Daniel Golle <daniel@makrotopia.org>]

On Sat, Jun 13, 2026 at 09:18:43PM +0300, Joris Vaisvila wrote:
> The Fast Ethernet PHYs present in the MT7628 SoCs require an
> undocumented bit to be set before they can establish 100mbps links.
> 
> This commit adds the Kconfig option MEDIATEK_FE_SOC_PHY and the
> corresponding driver mtk-fe-soc.c.
> 
> Signed-off-by: Joris Vaisvila <joey@tinyisr.com>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>

Reviewed-by: Daniel Golle <daniel@makrotopia.org>

> [...]
> diff --git a/drivers/net/phy/mediatek/mtk-fe-soc.c b/drivers/net/phy/mediatek/mtk-fe-soc.c
> new file mode 100644
> index 000000000000..9eb4960bcaad
> --- /dev/null
> +++ b/drivers/net/phy/mediatek/mtk-fe-soc.c
> @@ -0,0 +1,50 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Driver for MT7628 Embedded Switch internal Fast Ethernet PHYs
> + */
> +#include <linux/module.h>
> +#include <linux/phy.h>
> +
> +#define MTK_FPHY_ID_MT7628	0x03a29410
> +#define MTK_EXT_PAGE_ACCESS	0x1f
> +
> +static int mt7628_phy_read_page(struct phy_device *phydev)
> +{
> +	return __phy_read(phydev, MTK_EXT_PAGE_ACCESS);
> +}
> +
> +static int mt7628_phy_write_page(struct phy_device *phydev, int page)
> +{
> +	return __phy_write(phydev, MTK_EXT_PAGE_ACCESS, page);
> +}
> +
> +static int mt7628_phy_config_init(struct phy_device *phydev)
> +{
> +	/*
> +	 * This undocumented bit is required for the PHYs to be able to
> +	 * establish 100mbps links.
> +	 */
> +	return phy_modify_paged(phydev, 0x8000, 30, BIT(13), BIT(13));

As there is only that single use I don't think it justifies introducing
a phy_set_bits_paged helper just for that, but that's my opinion...