Re: [PATCH 2/2] net: phy: Add driver for Motorcomm yt8821 2.5G ethernet phy

From: Andrew Lunn
Date: Sat Jul 27 2024 - 07:36:53 EST

On Sat, Jul 27, 2024 at 02:20:31AM -0700, Frank.Sae wrote:
> Add a driver for the motorcomm yt8821 2.5G ethernet phy.
> Verified the driver on
> BPI-R3(with MediaTek MT7986(Filogic 830) SoC) development board,
> which is developed by Guangdong Bipai Technology Co., Ltd..
> On the board, yt8821 2.5G ethernet phy works in
> AUTO_BX2500_SGMII or FORCE_BX2500 interface,
> supports 2.5G/1000M/100M/10M speeds, and wol(magic package).
> Since some functions of yt8821 are similar to YT8521
> so some functions for yt8821 can be reused.

No leading space please.

>
> Signed-off-by: Frank.Sae <Frank.Sae@xxxxxxxxxxxxxx>
> ---
> drivers/net/phy/motorcomm.c | 639 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 636 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
> index 7a11fdb687cc..a432b27dd849 100644
> --- a/drivers/net/phy/motorcomm.c
> +++ b/drivers/net/phy/motorcomm.c
> @@ -1,6 +1,6 @@
> // SPDX-License-Identifier: GPL-2.0+
> /*
> - * Motorcomm 8511/8521/8531/8531S PHY driver.
> + * Motorcomm 8511/8521/8531/8531S/8821 PHY driver.
> *
> * Author: Peter Geis <pgwipeout@xxxxxxxxx>
> * Author: Frank <Frank.Sae@xxxxxxxxxxxxxx>
> @@ -16,7 +16,7 @@
> #define PHY_ID_YT8521 0x0000011a
> #define PHY_ID_YT8531 0x4f51e91b
> #define PHY_ID_YT8531S 0x4f51e91a
> -
> +#define PHY_ID_YT8821 0x4f51ea19
> /* YT8521/YT8531S Register Overview
> * UTP Register space | FIBER Register space
> * ------------------------------------------------------------
> @@ -52,6 +52,15 @@
> #define YTPHY_SSR_SPEED_10M 0x0
> #define YTPHY_SSR_SPEED_100M 0x1
> #define YTPHY_SSR_SPEED_1000M 0x2
> +/* bit9 as speed_mode[2], bit15:14 as Speed_mode[1:0]
> + * Speed_mode[2:0]:
> + * 100 = 2P5G
> + * 011 = 10G
> + * 010 = 1000 Mbps
> + * 001 = 100 Mbps
> + * 000 = 10 Mbps
> + */
> +#define YT8821_SSR_SPEED_2500M 0x4

If these bits are spread around, why 0x4? Ahh, because you extract the
bits and reform the value. Maybe:

#define YTPHY_SSR_SPEED_10M (0x0 << 14)
#define YTPHY_SSR_SPEED_100M (0x1 << 14)
#define YTPHY_SSR_SPEED_1000M (0x2 << 14)
#define YTPHY_SSR_SPEED_10G (0x3 << 14)
#define YT8821_SSR_SPEED_2500M (0x0 << 14) | BIT(9)
#define YTPHY_SSR_SPEED_MASK (0x3 << 14) | BIT(9)

> +#define YT8821_SDS_EXT_CSR_CTRL_REG 0x23
> +#define YT8821_SDS_EXT_CSR_PLL_SETTING 0x8605
> +#define YT8821_UTP_EXT_FFE_IPR_CTRL_REG 0x34E
> +#define YT8821_UTP_EXT_FFE_SETTING 0x8080
> +#define YT8821_UTP_EXT_VGA_LPF1_CAP_CTRL_REG 0x4D2
> +#define YT8821_UTP_EXT_VGA_LPF1_CAP_SHT_SETTING 0x5200
> +#define YT8821_UTP_EXT_VGA_LPF2_CAP_CTRL_REG 0x4D3
> +#define YT8821_UTP_EXT_VGA_LPF2_CAP_SHT_SETTING 0x5200
> +#define YT8821_UTP_EXT_TRACE_CTRL_REG 0x372
> +#define YT8821_UTP_EXT_TRACE_LNG_MED_GAIN_THR_SETTING 0x5A3C
> +#define YT8821_UTP_EXT_IPR_CTRL_REG 0x374
> +#define YT8821_UTP_EXT_IPR_ALPHA_IPR_SETTING 0x7C6C
> +#define YT8821_UTP_EXT_ECHO_CTRL_REG 0x336
> +#define YT8821_UTP_EXT_ECHO_SETTING 0xAA0A
> +#define YT8821_UTP_EXT_GAIN_CTRL_REG 0x340
> +#define YT8821_UTP_EXT_AGC_MED_GAIN_SETTING 0x3022
> +#define YT8821_UTP_EXT_TH_20DB_2500_CTRL_REG 0x36A
> +#define YT8821_UTP_EXT_TH_20DB_2500_SETTING 0x8000
> +#define YT8821_UTP_EXT_MU_COARSE_FR_CTRL_REG 0x4B3
> +#define YT8821_UTP_EXT_MU_COARSE_FR_FFE_GN_DC_SETTING 0x7711
> +#define YT8821_UTP_EXT_MU_FINE_FR_CTRL_REG 0x4B5
> +#define YT8821_UTP_EXT_MU_FINE_FR_FFE_GN_DC_SETTING 0x2211
> +#define YT8821_UTP_EXT_ANALOG_CFG7_CTRL_REG 0x56
> +#define YT8821_UTP_EXT_ANALOG_CFG7_RESET 0x20
> +#define YT8821_UTP_EXT_ANALOG_CFG7_PI_CLK_SEL_AFE 0x3F
> +#define YT8821_UTP_EXT_VCT_CFG6_CTRL_REG 0x97
> +#define YT8821_UTP_EXT_VCT_CFG6_FECHO_AMP_TH_SETTING 0x380C
> +#define YT8821_UTP_EXT_TXGE_NFR_FR_THP_CTRL_REG 0x660
> +#define YT8821_UTP_EXT_TXGE_NFR_FR_SETTING 0x112A
> +#define YT8821_UTP_EXT_PLL_CTRL_REG 0x450
> +#define YT8821_UTP_EXT_PLL_SPARE_SETTING 0xE9
> +#define YT8821_UTP_EXT_DAC_IMID_CHANNEL23_CTRL_REG 0x466
> +#define YT8821_UTP_EXT_DAC_IMID_CHANNEL23_SETTING 0x6464
> +#define YT8821_UTP_EXT_DAC_IMID_CHANNEL01_CTRL_REG 0x467
> +#define YT8821_UTP_EXT_DAC_IMID_CHANNEL01_SETTING 0x6464
> +#define YT8821_UTP_EXT_DAC_IMSB_CHANNEL23_CTRL_REG 0x468
> +#define YT8821_UTP_EXT_DAC_IMSB_CHANNEL23_SETTING 0x6464
> +#define YT8821_UTP_EXT_DAC_IMSB_CHANNEL01_CTRL_REG 0x469
> +#define YT8821_UTP_EXT_DAC_IMSB_CHANNEL01_SETTING 0x6464

All these _SETTING are magic numbers. Can you document any of them?

> +/**
> + * yt8821_probe() - read dts to get chip mode
> + * @phydev: a pointer to a &struct phy_device
> + *
> + * returns 0 or negative errno code

kerneldoc requires a : after returns.

> + */
> +static int yt8821_probe(struct phy_device *phydev)
> +{
> + struct device_node *node = phydev->mdio.dev.of_node;
> + struct device *dev = &phydev->mdio.dev;
> + struct yt8821_priv *priv;
> + u8 chip_mode;
> +
> + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + phydev->priv = priv;
> +
> + if (of_property_read_u8(node, "motorcomm,chip-mode", &chip_mode))
> + chip_mode = YT8821_CHIP_MODE_FORCE_BX2500;
> +
> + switch (chip_mode) {
> + case YT8821_CHIP_MODE_AUTO_BX2500_SGMII:
> + priv->chip_mode = YT8821_CHIP_MODE_AUTO_BX2500_SGMII;
> + break;
> + case YT8821_CHIP_MODE_FORCE_BX2500:
> + priv->chip_mode = YT8821_CHIP_MODE_FORCE_BX2500;
> + break;
> + default:
> + phydev_warn(phydev, "chip_mode err:%d\n", chip_mode);
> + return -EINVAL;

Didn't the binding say it defaults to forced? Yet here it gives an
error?

> + * yt8821_get_rate_matching - read register to get phy chip mode

Why? You have it in priv?

> +/**
> + * yt8821gen_init_paged() - generic initialization according to page
> + * @phydev: a pointer to a &struct phy_device
> + * @page: The reg page(YT8521_RSSR_FIBER_SPACE/YT8521_RSSR_UTP_SPACE) to
> + * operate.
> + *
> + * returns 0 or negative errno code
> + */
> +static int yt8821gen_init_paged(struct phy_device *phydev, int page)
> +{
> + int old_page;
> + int ret = 0;
> +
> + old_page = phy_select_page(phydev, page & YT8521_RSSR_SPACE_MASK);
> + if (old_page < 0)
> + goto err_restore_page;
> +
> + if (page & YT8521_RSSR_SPACE_MASK) {
> + /* sds init */
> + ret = __phy_modify(phydev, MII_BMCR, BMCR_ANENABLE, 0);
> + if (ret < 0)
> + goto err_restore_page;
> +
> + ret = ytphy_write_ext(phydev, YT8821_SDS_EXT_CSR_CTRL_REG,
> + YT8821_SDS_EXT_CSR_PLL_SETTING);
> + if (ret < 0)
> + goto err_restore_page;
> + } else {
> + /* utp init */
> + ret = ytphy_write_ext(phydev, YT8821_UTP_EXT_FFE_IPR_CTRL_REG,
> + YT8821_UTP_EXT_FFE_SETTING);
> + if (ret < 0)
> + goto err_restore_page;
> +

...

> + }
> +
> +err_restore_page:
> + return phy_restore_page(phydev, old_page, ret);
> +}
> +
> +/**
> + * yt8821gen_init() - generic initialization
> + * @phydev: a pointer to a &struct phy_device
> + *
> + * returns 0 or negative errno code
> + */
> +static int yt8821gen_init(struct phy_device *phydev)
> +{
> + int ret = 0;
> +
> + ret = yt8821gen_init_paged(phydev, YT8521_RSSR_FIBER_SPACE);
> + if (ret < 0)
> + return ret;
> +
> + return yt8821gen_init_paged(phydev, YT8521_RSSR_UTP_SPACE);

That is odd. Why not have two functions, rather than one with a
parameter. You get better functions names then, making it clearer what
each function is doing.

> +}
> +
> +/**
> + * yt8821_auto_sleep_config() - phy auto sleep config
> + * @phydev: a pointer to a &struct phy_device
> + * @enable: true enable auto sleep, false disable auto sleep
> + *
> + * returns 0 or negative errno code
> + */
> +static int yt8821_auto_sleep_config(struct phy_device *phydev, bool enable)
> +{
> + int old_page;
> + int ret = 0;
> +
> + old_page = phy_select_page(phydev, YT8521_RSSR_UTP_SPACE);
> + if (old_page < 0)
> + goto err_restore_page;
> +
> + ret = ytphy_modify_ext(phydev,
> + YT8521_EXTREG_SLEEP_CONTROL1_REG,
> + YT8521_ESC1R_SLEEP_SW,
> + enable ? 1 : 0);

So each page has its own extension registers?

> + if (ret < 0)
> + goto err_restore_page;
> +
> +err_restore_page:
> + return phy_restore_page(phydev, old_page, ret);
> +}
> +

> +/**
> + * yt8821_config_init() - phy initializatioin
> + * @phydev: a pointer to a &struct phy_device
> + *
> + * returns 0 or negative errno code
> + */
> +static int yt8821_config_init(struct phy_device *phydev)
> +{
> + struct yt8821_priv *priv = phydev->priv;
> + int ret, val;
> +
> + phydev->irq = PHY_POLL;

Why do this?

> +
> + val = ytphy_read_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG);
> + if (priv->chip_mode == YT8821_CHIP_MODE_AUTO_BX2500_SGMII) {
> + ret = ytphy_modify_ext_with_lock(phydev,
> + YT8521_CHIP_CONFIG_REG,
> + YT8521_CCR_MODE_SEL_MASK,
> + FIELD_PREP(YT8521_CCR_MODE_SEL_MASK, 0));
> + if (ret < 0)
> + return ret;
> +
> + __assign_bit(PHY_INTERFACE_MODE_2500BASEX,
> + phydev->possible_interfaces,
> + true);
> + __assign_bit(PHY_INTERFACE_MODE_SGMII,
> + phydev->possible_interfaces,
> + true);
> +
> + phydev->rate_matching = RATE_MATCH_NONE;
> + } else if (priv->chip_mode == YT8821_CHIP_MODE_FORCE_BX2500) {
> + ret = ytphy_modify_ext_with_lock(phydev,
> + YT8521_CHIP_CONFIG_REG,
> + YT8521_CCR_MODE_SEL_MASK,
> + FIELD_PREP(YT8521_CCR_MODE_SEL_MASK, 1));
> + if (ret < 0)
> + return ret;
> +
> + phydev->rate_matching = RATE_MATCH_PAUSE;
> + }

The idea of this phydev->possible_interfaces is to allow the core to
figure out what mode is most appropriate. So i would drop the mode in
DT, default to auto, and let the core tell you it wants 2500 BaseX if
that is all the MAC can do.

> +static int yt8821_read_status(struct phy_device *phydev)
> +{
> + struct yt8821_priv *priv = phydev->priv;
> + int old_page;
> + int ret = 0;
> + int link;
> + int val;
> +
> + if (phydev->autoneg == AUTONEG_ENABLE) {
> + int lpadv = phy_read_mmd(phydev,
> + MDIO_MMD_AN, MDIO_AN_10GBT_STAT);
> +
> + if (lpadv < 0)
> + return lpadv;
> +
> + mii_10gbt_stat_mod_linkmode_lpa_t(phydev->lp_advertising,
> + lpadv);
> + }
> +
> + ret = ytphy_write_ext_with_lock(phydev,
> + YT8521_REG_SPACE_SELECT_REG,
> + YT8521_RSSR_UTP_SPACE);
> + if (ret < 0)
> + return ret;
> +
> + ret = genphy_read_status(phydev);
> + if (ret < 0)
> + return ret;
> +
> + old_page = phy_select_page(phydev, YT8521_RSSR_UTP_SPACE);
> + if (old_page < 0)
> + goto err_restore_page;
> +
> + val = __phy_read(phydev, YTPHY_SPECIFIC_STATUS_REG);
> + if (val < 0) {
> + ret = val;
> + goto err_restore_page;
> + }
> +
> + link = val & YTPHY_SSR_LINK;
> + if (link)
> + yt8821_adjust_status(phydev, val);
> +
> + if (link) {
> + if (phydev->link == 0)
> + phydev_info(phydev,
> + "%s, phy addr: %d, link up, mii reg 0x%x = 0x%x\n",
> + __func__, phydev->mdio.addr,
> + YTPHY_SPECIFIC_STATUS_REG,
> + (unsigned int)val);

phydev_dbg()?


> + phydev->link = 1;
> + } else {
> + if (phydev->link == 1)
> + phydev_info(phydev, "%s, phy addr: %d, link down\n",
> + __func__, phydev->mdio.addr);

phydev_dbg()?

Andrew