Re: [PATCH net-next 1/4] net: phy: add MediaTek PHY driver

[Vladimir Oltean <olteanv@gmail.com>]

On Thu, Apr 29, 2021 at 02:21:27PM +0800, DENG Qingfang wrote:
> Add support for MediaTek PHYs found in MT7530 and MT7531 switches.
> The initialization procedure is from the vendor driver, but due to lack
> of documentation, the function of some register values remains unknown.
> 
> Signed-off-by: DENG Qingfang <dqfext@gmail.com>
> ---
> RFC v4 -> PATCH v1:
> - No changes.
> 
>  drivers/net/phy/Kconfig    |   5 ++
>  drivers/net/phy/Makefile   |   1 +
>  drivers/net/phy/mediatek.c | 112 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 118 insertions(+)
>  create mode 100644 drivers/net/phy/mediatek.c
> 
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index 288bf405ebdb..9db39fb443e6 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -207,6 +207,11 @@ config MARVELL_88X2222_PHY
>  	  Support for the Marvell 88X2222 Dual-port Multi-speed Ethernet
>  	  Transceiver.
>  
> +config MEDIATEK_PHY
> +	tristate "MediaTek PHYs"
> +	help
> +	  Supports the MediaTek switch integrated PHYs.
> +
>  config MICREL_PHY
>  	tristate "Micrel PHYs"
>  	help
> diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> index bcda7ed2455d..ab512cb3592b 100644
> --- a/drivers/net/phy/Makefile
> +++ b/drivers/net/phy/Makefile
> @@ -64,6 +64,7 @@ obj-$(CONFIG_LXT_PHY)		+= lxt.o
>  obj-$(CONFIG_MARVELL_10G_PHY)	+= marvell10g.o
>  obj-$(CONFIG_MARVELL_PHY)	+= marvell.o
>  obj-$(CONFIG_MARVELL_88X2222_PHY)	+= marvell-88x2222.o
> +obj-$(CONFIG_MEDIATEK_PHY)	+= mediatek.o
>  obj-$(CONFIG_MESON_GXL_PHY)	+= meson-gxl.o
>  obj-$(CONFIG_MICREL_KS8995MA)	+= spi_ks8995.o
>  obj-$(CONFIG_MICREL_PHY)	+= micrel.o
> diff --git a/drivers/net/phy/mediatek.c b/drivers/net/phy/mediatek.c
> new file mode 100644
> index 000000000000..86e6c466b0e9
> --- /dev/null
> +++ b/drivers/net/phy/mediatek.c
> @@ -0,0 +1,112 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +#include <linux/bitfield.h>
> +#include <linux/module.h>
> +#include <linux/phy.h>
> +
> +#define MTK_EXT_PAGE_ACCESS		0x1f
> +#define MTK_PHY_PAGE_STANDARD		0x0000
> +#define MTK_PHY_PAGE_EXTENDED		0x0001
> +#define MTK_PHY_PAGE_EXTENDED_2		0x0002
> +#define MTK_PHY_PAGE_EXTENDED_3		0x0003
> +#define MTK_PHY_PAGE_EXTENDED_2A30	0x2a30
> +#define MTK_PHY_PAGE_EXTENDED_52B5	0x52b5
> +
> +static int mtk_phy_read_page(struct phy_device *phydev)
> +{
> +	return __phy_read(phydev, MTK_EXT_PAGE_ACCESS);
> +}
> +
> +static int mtk_phy_write_page(struct phy_device *phydev, int page)
> +{
> +	return __phy_write(phydev, MTK_EXT_PAGE_ACCESS, page);
> +}
> +
> +static void mtk_phy_config_init(struct phy_device *phydev)
> +{
> +	/* Disable EEE */
> +	phy_write_mmd(phydev, MDIO_MMD_AN, MDIO_AN_EEE_ADV, 0);

Is there any ERR around this (i.e. is the feature universally broken or
just on your setup)? There is a function called of_set_phy_eee_broken,
you can let the PHY core disable EEE advertisement based on device tree.

> +
> +	/* Enable HW auto downshift */
> +	phy_modify_paged(phydev, MTK_PHY_PAGE_EXTENDED, 0x14, 0, BIT(4));
> +
> +	/* Increase SlvDPSready time */
> +	phy_select_page(phydev, MTK_PHY_PAGE_EXTENDED_52B5);
> +	__phy_write(phydev, 0x10, 0xafae);
> +	__phy_write(phydev, 0x12, 0x2f);
> +	__phy_write(phydev, 0x10, 0x8fae);
> +	phy_restore_page(phydev, MTK_PHY_PAGE_STANDARD, 0);
> +
> +	/* Adjust 100_mse_threshold */
> +	phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x123, 0xffff);
> +
> +	/* Disable mcc */
> +	phy_write_mmd(phydev, MDIO_MMD_VEND1, 0xa6, 0x300);
> +}