Re: [PATCH v2] net: phy: add driver for MotorComm PHY

[Yegor Yefremov <yegorslists@googlemail.com>]

Hi Sascha,


On Tue, Jun 6, 2023 at 10:17 AM <yegorslists@googlemail.com> wrote:
>
> From: Yegor Yefremov <yegorslists@googlemail.com>
>
> The driver corresponds to the kernel 6.1.27.
>
> Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
> ---
> Changes:
>         v1 -> v2: add the related kernel version
>
>  drivers/net/phy/Kconfig     |   5 ++
>  drivers/net/phy/Makefile    |   1 +
>  drivers/net/phy/motorcomm.c | 128 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 134 insertions(+)
>  create mode 100644 drivers/net/phy/motorcomm.c
>
> diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
> index cd20e1de27..e95e2a3228 100644
> --- a/drivers/net/phy/Kconfig
> +++ b/drivers/net/phy/Kconfig
> @@ -50,6 +50,11 @@ config MICREL_PHY
>         help
>           Supports the KSZ9021, VSC8201, KS8001 PHYs.
>
> +config MOTORCOMM_PHY
> +       bool "Driver for Motorcomm PHYs"
> +       help
> +         Currently supports the YT8511 PHY.
> +
>  config NATIONAL_PHY
>         bool "Driver for National Semiconductor PHYs"
>         help
> diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
> index 83f46f11d3..26e4ad884d 100644
> --- a/drivers/net/phy/Makefile
> +++ b/drivers/net/phy/Makefile
> @@ -6,6 +6,7 @@ obj-$(CONFIG_DAVICOM_PHY)       += davicom.o
>  obj-$(CONFIG_LXT_PHY)          += lxt.o
>  obj-$(CONFIG_MARVELL_PHY)      += marvell.o
>  obj-$(CONFIG_MICREL_PHY)       += micrel.o
> +obj-$(CONFIG_MOTORCOMM_PHY)    += motorcomm.o
>  obj-$(CONFIG_NATIONAL_PHY)     += national.o
>  obj-$(CONFIG_REALTEK_PHY)      += realtek.o
>  obj-$(CONFIG_SMSC_PHY)         += smsc.o
> diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
> new file mode 100644
> index 0000000000..4bcd84342c
> --- /dev/null
> +++ b/drivers/net/phy/motorcomm.c
> @@ -0,0 +1,128 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * drivers/net/phy/motorcomm.c
> + *
> + * Driver for Motorcomm PHYs
> + *
> + * Author: Peter Geis <pgwipeout@gmail.com>
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <linux/phy.h>
> +#include <linux/mdio.h>
> +
> +#define PHY_ID_YT8511          0x0000010a
> +
> +#define YT8511_PAGE_SELECT     0x1e
> +#define YT8511_PAGE            0x1f
> +#define YT8511_EXT_CLK_GATE    0x0c
> +#define YT8511_EXT_DELAY_DRIVE 0x0d
> +#define YT8511_EXT_SLEEP_CTRL  0x27
> +
> +/* 2b00 25m from pll
> + * 2b01 25m from xtl *default*
> + * 2b10 62.m from pll
> + * 2b11 125m from pll
> + */
> +#define YT8511_CLK_125M                (BIT(2) | BIT(1))
> +#define YT8511_PLLON_SLP       BIT(14)
> +
> +/* RX Delay enabled = 1.8ns 1000T, 8ns 10/100T */
> +#define YT8511_DELAY_RX                BIT(0)
> +
> +/* TX Gig-E Delay is bits 7:4, default 0x5
> + * TX Fast-E Delay is bits 15:12, default 0xf
> + * Delay = 150ps * N - 250ps
> + * On = 2000ps, off = 50ps
> + */
> +#define YT8511_DELAY_GE_TX_EN  (0xf << 4)
> +#define YT8511_DELAY_GE_TX_DIS (0x2 << 4)
> +#define YT8511_DELAY_FE_TX_EN  (0xf << 12)
> +#define YT8511_DELAY_FE_TX_DIS (0x2 << 12)
> +
> +static int yt8511_read_page(struct phy_device *phydev)
> +{
> +       return phy_read(phydev, YT8511_PAGE_SELECT);
> +};
> +
> +static int yt8511_write_page(struct phy_device *phydev, int page)
> +{
> +       return phy_write(phydev, YT8511_PAGE_SELECT, page);
> +};
> +
> +static int yt8511_config_init(struct phy_device *phydev)
> +{
> +       int oldpage, ret = 0;
> +       unsigned int ge, fe;
> +
> +       oldpage = phy_select_page(phydev, YT8511_EXT_CLK_GATE);
> +       if (oldpage < 0)
> +               goto err_restore_page;
> +
> +       /* set rgmii delay mode */
> +       switch (phydev->interface) {
> +       case PHY_INTERFACE_MODE_RGMII:
> +               ge = YT8511_DELAY_GE_TX_DIS;
> +               fe = YT8511_DELAY_FE_TX_DIS;
> +               break;
> +       case PHY_INTERFACE_MODE_RGMII_RXID:
> +               ge = YT8511_DELAY_RX | YT8511_DELAY_GE_TX_DIS;
> +               fe = YT8511_DELAY_FE_TX_DIS;
> +               break;
> +       case PHY_INTERFACE_MODE_RGMII_TXID:
> +               ge = YT8511_DELAY_GE_TX_EN;
> +               fe = YT8511_DELAY_FE_TX_EN;
> +               break;
> +       case PHY_INTERFACE_MODE_RGMII_ID:
> +               ge = YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN;
> +               fe = YT8511_DELAY_FE_TX_EN;
> +               break;
> +       default: /* do not support other modes */
> +               ret = -EOPNOTSUPP;
> +               goto err_restore_page;
> +       }
> +
> +       ret = phy_modify(phydev, YT8511_PAGE, (YT8511_DELAY_RX | YT8511_DELAY_GE_TX_EN), ge);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +       /* set clock mode to 125mhz */
> +       ret = phy_modify(phydev, YT8511_PAGE, 0, YT8511_CLK_125M);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +       /* fast ethernet delay is in a separate page */
> +       ret = phy_write(phydev, YT8511_PAGE_SELECT, YT8511_EXT_DELAY_DRIVE);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +       ret = phy_modify(phydev, YT8511_PAGE, YT8511_DELAY_FE_TX_EN, fe);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +       /* leave pll enabled in sleep */
> +       ret = phy_write(phydev, YT8511_PAGE_SELECT, YT8511_EXT_SLEEP_CTRL);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +       ret = phy_modify(phydev, YT8511_PAGE, 0, YT8511_PLLON_SLP);
> +       if (ret < 0)
> +               goto err_restore_page;
> +
> +err_restore_page:
> +       return phy_restore_page(phydev, oldpage, ret);

As for this approach, it is also used by some other drivers in the Linux kernel:

drivers/net/phy/realtek.c
drivers/net/phy/icplus.c

Regards,
Yegor

> +}
> +
> +static struct phy_driver motorcomm_phy_drvs[] = {
> +       {
> +               .phy_id         = PHY_ID_YT8511,
> +               .drv.name       = "YT8511 Gigabit Ethernet",
> +               .config_init    = yt8511_config_init,
> +               .features       = PHY_GBIT_FEATURES,
> +               .read_page      = yt8511_read_page,
> +               .write_page     = yt8511_write_page,
> +       },
> +};
> +
> +device_phy_drivers(motorcomm_phy_drvs);
> --
> 2.34.1
>