diff mbox series

[net-next,v2,2/2] net: phy: Add driver for Motorcomm yt8821 2.5G ethernet phy

Message ID 20240816060955.47076-3-Frank.Sae@motor-comm.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series Add driver for Motorcomm yt8821 2.5G ethernet phy | expand

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netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 16 this patch: 16
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 16 this patch: 16
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 16 this patch: 16
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 731 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 35 this patch: 35
netdev/source_inline success Was 0 now: 0
netdev/contest success net-next-2024-08-16--21-00 (tests: 710)

Commit Message

Frank Sae Aug. 16, 2024, 6:09 a.m. UTC 
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..

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).

Signed-off-by: Frank Sae <Frank.Sae@motor-comm.com>
---
v2:
  - removed motorcomm,chip-mode property in DT.
  - modified the magic numbers of _SETTING macro.
  - added ":" after returns in function's DOC.
  - updated YTPHY_SSR_SPEED_2500M val from 0x4 ((0x0 << 14) | BIT(9)).
  - yt8821gen_init_paged(phydev, YT8521_RSSR_FIBER_SPACE) and
    yt8821gen_init_paged(phydev, YT8521_RSSR_UTP_SPACE) updated to
    yt8821_serdes_init() and yt8821_utp_init().
  - removed phydev->irq = PHY_POLL; in yt8821_config_init().
  - instead of phydev_info(), phydev_dbg() used in yt8821_read_status().
  - instead of __assign_bit(), __set_bit() used.
v1:
  - https://lore.kernel.org/netdev/20240727091906.1108588-1-Frank.Sae@motor-comm.com/
  - https://lore.kernel.org/netdev/20240727092009.1108640-1-Frank.Sae@motor-comm.com/
  - https://lore.kernel.org/netdev/20240727092031.1108690-1-Frank.Sae@motor-comm.com/
---
 drivers/net/phy/motorcomm.c | 680 +++++++++++++++++++++++++++++++++++-
 1 file changed, 676 insertions(+), 4 deletions(-)

Comments

Andrew Lunn Aug. 16, 2024, 10:32 p.m. UTC | #1 
> +/**
> + * yt8821_get_features - read mmd register to get 2.5G capability
> + * @phydev: target phy_device struct
> + *
> + * Returns: 0 or negative errno code
> + */
> +static int yt8821_get_features(struct phy_device *phydev)
> +{
> +	int val;
> +
> +	val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_PMA_NG_EXTABLE);
> +	if (val < 0)
> +		return val;
> +
> +	linkmode_mod_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
> +			 phydev->supported,
> +			 val & MDIO_PMA_NG_EXTABLE_2_5GBT);

genphy_c45_pma_read_ext_abilities() ?

> +static int yt8821_read_status(struct phy_device *phydev)
> +{
> +	int link;
> +	int ret;
> +	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);

genphy_c45_read_lpa() ?

	Andrew
Russell King (Oracle) Aug. 17, 2024, 11:36 a.m. UTC | #2 
On Thu, Aug 15, 2024 at 11:09:55PM -0700, Frank Sae wrote:
> +static int yt8821_get_rate_matching(struct phy_device *phydev,
> +				    phy_interface_t iface)
> +{
> +	int val;
> +
> +	val = ytphy_read_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG);
> +	if (val < 0)
> +		return val;
> +
> +	if (FIELD_GET(YT8521_CCR_MODE_SEL_MASK, val) ==
> +	    YT8821_CHIP_MODE_FORCE_BX2500)
> +		return RATE_MATCH_PAUSE;

Does this device do rate matching for _any_ interface mode if it has
this bit set - because that's what you're saying here by not testing
"iface". From what I understand from your previous posting which
included a DT update, this only applies when 2500base-X is being
used as the interface mode.

> +static int yt8821_aneg_done(struct phy_device *phydev)
> +{
> +	int link;
> +
> +	link = yt8521_aneg_done_paged(phydev, YT8521_RSSR_UTP_SPACE);
> +
> +	return link;
> +}

Why not just:

	return yt8521_aneg_done_paged(phydev, YT8521_RSSR_UTP_SPACE);

?

> +/**
> + * 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)
> +{
> +	u8 mode = YT8821_CHIP_MODE_AUTO_BX2500_SGMII;
> +	int ret;
> +	u16 set;
> +
> +	if (phydev->interface == PHY_INTERFACE_MODE_2500BASEX)
> +		mode = YT8821_CHIP_MODE_FORCE_BX2500;

Hmm, I think this is tying us into situations we don't want. What if the
host supports 2500base-X and SGMII, but does not support pause (for
example, Marvell PP2 based hosts.) In that situation, we don't want to
lock-in to using pause based rate adaption, which I fear will become
a behaviour that would be risky to change later on.

> +
> +	set = FIELD_PREP(YT8521_CCR_MODE_SEL_MASK, mode);
> +	ret = ytphy_modify_ext_with_lock(phydev,
> +					 YT8521_CHIP_CONFIG_REG,
> +					 YT8521_CCR_MODE_SEL_MASK,
> +					 set);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (mode == YT8821_CHIP_MODE_AUTO_BX2500_SGMII) {
> +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> +			  phydev->possible_interfaces);
> +		__set_bit(PHY_INTERFACE_MODE_SGMII,
> +			  phydev->possible_interfaces);
> +
> +		phydev->rate_matching = RATE_MATCH_NONE;
> +	} else if (mode == YT8821_CHIP_MODE_FORCE_BX2500) {

		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
			  phydev->possible_interfaces);

so that phylink knows you're only going to be using a single interface
mode. Even better, since this is always supported, move it out of these
if() statements?


Also, it would be nice to have phydev->supported_interfaces populated
(which has to be done when the PHY is probed) so that phylink knows
before connecting with the PHY which interface modes are supported by
the PHY. (Andrew - please can we make this a condition for any new PHYs
supported by phylib in the future?)

Note the point below in my signature.
Andrew Lunn Aug. 17, 2024, 3:38 p.m. UTC | #3 
> Also, it would be nice to have phydev->supported_interfaces populated
> (which has to be done when the PHY is probed) so that phylink knows
> before connecting with the PHY which interface modes are supported by
> the PHY. (Andrew - please can we make this a condition for any new PHYs
> supported by phylib in the future?)

O.K i will add it to my mental checklist.

	Andrew
Frank Sae Aug. 18, 2024, 6:36 a.m. UTC | #4 
On 8/17/24 04:36, Russell King (Oracle) wrote:
> On Thu, Aug 15, 2024 at 11:09:55PM -0700, Frank Sae wrote:
>> +static int yt8821_get_rate_matching(struct phy_device *phydev,
>> +				    phy_interface_t iface)
>> +{
>> +	int val;
>> +
>> +	val = ytphy_read_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG);
>> +	if (val < 0)
>> +		return val;
>> +
>> +	if (FIELD_GET(YT8521_CCR_MODE_SEL_MASK, val) ==
>> +	    YT8821_CHIP_MODE_FORCE_BX2500)
>> +		return RATE_MATCH_PAUSE;
> Does this device do rate matching for _any_ interface mode if it has
> this bit set - because that's what you're saying here by not testing
> "iface". From what I understand from your previous posting which
> included a DT update, this only applies when 2500base-X is being
> used as the interface mode.

Here not check parameter iface, it is not to say that iface has no relation
with rate matching. when interface is configed with phy-mode property in
DT, modify YT8521_CHIP_CONFIG_REG register bit2:0 dependent on
phydev->interface in yt8821_config_init(), if phy-mode = "sgmii", bit2:0
will be set 3'b000, if phy-mode = "2500base-x", bit2:0 will be set 3'b001.

so that YT8521_CHIP_CONFIG_REG register bit2:0 may decide enable or disable
rate matching feature in yt8821_get_rate_matching() and do not care input
parameter iface here.

>> +static int yt8821_aneg_done(struct phy_device *phydev)
>> +{
>> +	int link;
>> +
>> +	link = yt8521_aneg_done_paged(phydev, YT8521_RSSR_UTP_SPACE);
>> +
>> +	return link;
>> +}
> Why not just:
>
> 	return yt8521_aneg_done_paged(phydev, YT8521_RSSR_UTP_SPACE);
>
> ?
>
>> +/**
>> + * 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)
>> +{
>> +	u8 mode = YT8821_CHIP_MODE_AUTO_BX2500_SGMII;
>> +	int ret;
>> +	u16 set;
>> +
>> +	if (phydev->interface == PHY_INTERFACE_MODE_2500BASEX)
>> +		mode = YT8821_CHIP_MODE_FORCE_BX2500;
> Hmm, I think this is tying us into situations we don't want. What if the
> host supports 2500base-X and SGMII, but does not support pause (for
> example, Marvell PP2 based hosts.) In that situation, we don't want to
> lock-in to using pause based rate adaption, which I fear will become
> a behaviour that would be risky to change later on.

yt8821 is pin2pin realtek rtl8221.

please refer to description about interface force 2500base-x and auto
2500base-x_sgmii in datasheet.

In AUTO_BX2500_SGMII mode, The internal flow control buffer is disabled in
this mode.

In FORCE_BX2500, SerDes always works as 2500BASE-X, internal flow control
buffer will be activated if UTP doesn't work at 2.5GBASE-T.

>> +
>> +	set = FIELD_PREP(YT8521_CCR_MODE_SEL_MASK, mode);
>> +	ret = ytphy_modify_ext_with_lock(phydev,
>> +					 YT8521_CHIP_CONFIG_REG,
>> +					 YT8521_CCR_MODE_SEL_MASK,
>> +					 set);
>> +	if (ret < 0)
>> +		return ret;
>> +
>> +	if (mode == YT8821_CHIP_MODE_AUTO_BX2500_SGMII) {
>> +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
>> +			  phydev->possible_interfaces);
>> +		__set_bit(PHY_INTERFACE_MODE_SGMII,
>> +			  phydev->possible_interfaces);
>> +
>> +		phydev->rate_matching = RATE_MATCH_NONE;
>> +	} else if (mode == YT8821_CHIP_MODE_FORCE_BX2500) {
> 		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> 			  phydev->possible_interfaces);
>
> so that phylink knows you're only going to be using a single interface
> mode. Even better, since this is always supported, move it out of these
> if() statements?

it is ok.

>
>
> Also, it would be nice to have phydev->supported_interfaces populated
> (which has to be done when the PHY is probed) so that phylink knows
> before connecting with the PHY which interface modes are supported by
> the PHY. (Andrew - please can we make this a condition for any new PHYs
> supported by phylib in the future?)

now no supported_interfaces member in struct phy_device.

> Note the point below in my signature.
>
diff mbox series

Patch

diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
index fe0aabe12622..8f91ff1647cf 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@gmail.com>
  * Author: Frank <Frank.Sae@motor-comm.com>
@@ -16,8 +16,8 @@ 
 #define PHY_ID_YT8521		0x0000011a
 #define PHY_ID_YT8531		0x4f51e91b
 #define PHY_ID_YT8531S		0x4f51e91a
-
-/* YT8521/YT8531S Register Overview
+#define PHY_ID_YT8821		0x4f51ea19
+/* YT8521/YT8531S/YT8821 Register Overview
  *	UTP Register space	|	FIBER Register space
  *  ------------------------------------------------------------
  * |	UTP MII			|	FIBER MII		|
@@ -50,6 +50,8 @@ 
 #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 YTPHY_SSR_SPEED_2500M			((0x0 << 14) | BIT(9))
 #define YTPHY_SSR_DUPLEX_OFFSET			13
 #define YTPHY_SSR_DUPLEX			BIT(13)
 #define YTPHY_SSR_PAGE_RECEIVED			BIT(12)
@@ -268,12 +270,89 @@ 
 #define YT8531_SCR_CLK_SRC_REF_25M		4
 #define YT8531_SCR_CLK_SRC_SSC_25M		5
 
+#define YT8821_SDS_EXT_CSR_CTRL_REG			0x23
+#define YT8821_SDS_EXT_CSR_VCO_LDO_EN			BIT(15)
+#define YT8821_SDS_EXT_CSR_VCO_BIAS_LPF_EN		BIT(8)
+
+#define YT8821_UTP_EXT_PI_CTRL_REG			0x56
+#define YT8821_UTP_EXT_PI_RST_N_FIFO			BIT(5)
+#define YT8821_UTP_EXT_PI_TX_CLK_SEL_AFE		BIT(4)
+#define YT8821_UTP_EXT_PI_RX_CLK_3_SEL_AFE		BIT(3)
+#define YT8821_UTP_EXT_PI_RX_CLK_2_SEL_AFE		BIT(2)
+#define YT8821_UTP_EXT_PI_RX_CLK_1_SEL_AFE		BIT(1)
+#define YT8821_UTP_EXT_PI_RX_CLK_0_SEL_AFE		BIT(0)
+
+#define YT8821_UTP_EXT_VCT_CFG6_CTRL_REG		0x97
+#define YT8821_UTP_EXT_FECHO_AMP_TH_HUGE		GENMASK(15, 8)
+
+#define YT8821_UTP_EXT_ECHO_CTRL_REG			0x336
+#define YT8821_UTP_EXT_TRACE_LNG_GAIN_THR_1000		GENMASK(14, 8)
+
+#define YT8821_UTP_EXT_GAIN_CTRL_REG			0x340
+#define YT8821_UTP_EXT_TRACE_MED_GAIN_THR_1000		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_RPDN_CTRL_REG			0x34E
+#define YT8821_UTP_EXT_RPDN_BP_FFE_LNG_2500		BIT(15)
+#define YT8821_UTP_EXT_RPDN_BP_FFE_SHT_2500		BIT(7)
+#define YT8821_UTP_EXT_RPDN_IPR_SHT_2500		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_TH_20DB_2500_CTRL_REG		0x36A
+#define YT8821_UTP_EXT_TH_20DB_2500			GENMASK(15, 0)
+
+#define YT8821_UTP_EXT_TRACE_CTRL_REG			0x372
+#define YT8821_UTP_EXT_TRACE_LNG_GAIN_THE_2500		GENMASK(14, 8)
+#define YT8821_UTP_EXT_TRACE_MED_GAIN_THE_2500		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_ALPHA_IPR_CTRL_REG		0x374
+#define YT8821_UTP_EXT_ALPHA_SHT_2500			GENMASK(14, 8)
+#define YT8821_UTP_EXT_IPR_LNG_2500			GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_PLL_CTRL_REG			0x450
+#define YT8821_UTP_EXT_PLL_SPARE_CFG			GENMASK(7, 0)
+
+#define YT8821_UTP_EXT_DAC_IMID_CH_2_3_CTRL_REG		0x466
+#define YT8821_UTP_EXT_DAC_IMID_CH_3_10_ORG		GENMASK(14, 8)
+#define YT8821_UTP_EXT_DAC_IMID_CH_2_10_ORG		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_DAC_IMID_CH_0_1_CTRL_REG		0x467
+#define YT8821_UTP_EXT_DAC_IMID_CH_1_10_ORG		GENMASK(14, 8)
+#define YT8821_UTP_EXT_DAC_IMID_CH_0_10_ORG		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_DAC_IMSB_CH_2_3_CTRL_REG		0x468
+#define YT8821_UTP_EXT_DAC_IMSB_CH_3_10_ORG		GENMASK(14, 8)
+#define YT8821_UTP_EXT_DAC_IMSB_CH_2_10_ORG		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_DAC_IMSB_CH_0_1_CTRL_REG		0x469
+#define YT8821_UTP_EXT_DAC_IMSB_CH_1_10_ORG		GENMASK(14, 8)
+#define YT8821_UTP_EXT_DAC_IMSB_CH_0_10_ORG		GENMASK(6, 0)
+
+#define YT8821_UTP_EXT_MU_COARSE_FR_CTRL_REG		0x4B3
+#define YT8821_UTP_EXT_MU_COARSE_FR_F_FFE		GENMASK(14, 12)
+#define YT8821_UTP_EXT_MU_COARSE_FR_F_FBE		GENMASK(10, 8)
+
+#define YT8821_UTP_EXT_MU_FINE_FR_CTRL_REG		0x4B5
+#define YT8821_UTP_EXT_MU_FINE_FR_F_FFE			GENMASK(14, 12)
+#define YT8821_UTP_EXT_MU_FINE_FR_F_FBE			GENMASK(10, 8)
+
+#define YT8821_UTP_EXT_VGA_LPF1_CAP_CTRL_REG		0x4D2
+#define YT8821_UTP_EXT_VGA_LPF1_CAP_OTHER		GENMASK(7, 4)
+#define YT8821_UTP_EXT_VGA_LPF1_CAP_2500		GENMASK(3, 0)
+
+#define YT8821_UTP_EXT_VGA_LPF2_CAP_CTRL_REG		0x4D3
+#define YT8821_UTP_EXT_VGA_LPF2_CAP_OTHER		GENMASK(7, 4)
+#define YT8821_UTP_EXT_VGA_LPF2_CAP_2500		GENMASK(3, 0)
+
+#define YT8821_UTP_EXT_TXGE_NFR_FR_THP_CTRL_REG		0x660
+#define YT8821_UTP_EXT_NFR_TX_ABILITY			BIT(3)
 /* Extended Register  end */
 
 #define YTPHY_DTS_OUTPUT_CLK_DIS		0
 #define YTPHY_DTS_OUTPUT_CLK_25M		25000000
 #define YTPHY_DTS_OUTPUT_CLK_125M		125000000
 
+#define YT8821_CHIP_MODE_AUTO_BX2500_SGMII	0
+#define YT8821_CHIP_MODE_FORCE_BX2500		1
+
 struct yt8521_priv {
 	/* combo_advertising is used for case of YT8521 in combo mode,
 	 * this means that yt8521 may work in utp or fiber mode which depends
@@ -2249,6 +2328,581 @@  static int yt8521_get_features(struct phy_device *phydev)
 	return ret;
 }
 
+/**
+ * yt8821_get_features - read mmd register to get 2.5G capability
+ * @phydev: target phy_device struct
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_get_features(struct phy_device *phydev)
+{
+	int val;
+
+	val = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_PMA_NG_EXTABLE);
+	if (val < 0)
+		return val;
+
+	linkmode_mod_bit(ETHTOOL_LINK_MODE_2500baseT_Full_BIT,
+			 phydev->supported,
+			 val & MDIO_PMA_NG_EXTABLE_2_5GBT);
+
+	return genphy_read_abilities(phydev);
+}
+
+/**
+ * yt8821_get_rate_matching - read register to get phy chip mode
+ * @phydev: target phy_device struct
+ * @iface: PHY data interface type
+ *
+ * Returns: rate matching type or negative errno code
+ */
+static int yt8821_get_rate_matching(struct phy_device *phydev,
+				    phy_interface_t iface)
+{
+	int val;
+
+	val = ytphy_read_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG);
+	if (val < 0)
+		return val;
+
+	if (FIELD_GET(YT8521_CCR_MODE_SEL_MASK, val) ==
+	    YT8821_CHIP_MODE_FORCE_BX2500)
+		return RATE_MATCH_PAUSE;
+
+	return RATE_MATCH_NONE;
+}
+
+/**
+ * yt8821_aneg_done() - determines the auto negotiation result
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0(no link)or 1(utp link) or negative errno code
+ */
+static int yt8821_aneg_done(struct phy_device *phydev)
+{
+	int link;
+
+	link = yt8521_aneg_done_paged(phydev, YT8521_RSSR_UTP_SPACE);
+
+	return link;
+}
+
+/**
+ * yt8821_serdes_init() - serdes init
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_serdes_init(struct phy_device *phydev)
+{
+	int old_page;
+	int ret = 0;
+	u16 mask;
+	u16 set;
+
+	old_page = phy_select_page(phydev, YT8521_RSSR_FIBER_SPACE);
+	if (old_page < 0)
+		goto err_restore_page;
+
+	ret = __phy_modify(phydev, MII_BMCR, BMCR_ANENABLE, 0);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_SDS_EXT_CSR_VCO_LDO_EN |
+		YT8821_SDS_EXT_CSR_VCO_BIAS_LPF_EN;
+	set = YT8821_SDS_EXT_CSR_VCO_LDO_EN;
+	ret = ytphy_modify_ext(phydev, YT8821_SDS_EXT_CSR_CTRL_REG, mask,
+			       set);
+	if (ret < 0)
+		goto err_restore_page;
+
+err_restore_page:
+	return phy_restore_page(phydev, old_page, ret);
+}
+
+/**
+ * yt8821_utp_init() - utp init
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_utp_init(struct phy_device *phydev)
+{
+	int old_page;
+	int ret = 0;
+	u16 mask;
+	u16 save;
+	u16 set;
+
+	old_page = phy_select_page(phydev, YT8521_RSSR_UTP_SPACE);
+	if (old_page < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_RPDN_BP_FFE_LNG_2500 |
+		YT8821_UTP_EXT_RPDN_BP_FFE_SHT_2500 |
+		YT8821_UTP_EXT_RPDN_IPR_SHT_2500;
+	set = YT8821_UTP_EXT_RPDN_BP_FFE_LNG_2500 |
+		YT8821_UTP_EXT_RPDN_BP_FFE_SHT_2500;
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_RPDN_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_VGA_LPF1_CAP_OTHER |
+		YT8821_UTP_EXT_VGA_LPF1_CAP_2500;
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_VGA_LPF1_CAP_CTRL_REG,
+			       mask, 0);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_VGA_LPF2_CAP_OTHER |
+		YT8821_UTP_EXT_VGA_LPF2_CAP_2500;
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_VGA_LPF2_CAP_CTRL_REG,
+			       mask, 0);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_TRACE_LNG_GAIN_THE_2500 |
+		YT8821_UTP_EXT_TRACE_MED_GAIN_THE_2500;
+	set = FIELD_PREP(YT8821_UTP_EXT_TRACE_LNG_GAIN_THE_2500, 0x5a) |
+		FIELD_PREP(YT8821_UTP_EXT_TRACE_MED_GAIN_THE_2500, 0x3c);
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_TRACE_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_IPR_LNG_2500;
+	set = FIELD_PREP(YT8821_UTP_EXT_IPR_LNG_2500, 0x6c);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_ALPHA_IPR_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_TRACE_LNG_GAIN_THR_1000;
+	set = FIELD_PREP(YT8821_UTP_EXT_TRACE_LNG_GAIN_THR_1000, 0x2a);
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_ECHO_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_TRACE_MED_GAIN_THR_1000;
+	set = FIELD_PREP(YT8821_UTP_EXT_TRACE_MED_GAIN_THR_1000, 0x22);
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_GAIN_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_TH_20DB_2500;
+	set = FIELD_PREP(YT8821_UTP_EXT_TH_20DB_2500, 0x8000);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_TH_20DB_2500_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_MU_COARSE_FR_F_FFE |
+		YT8821_UTP_EXT_MU_COARSE_FR_F_FBE;
+	set = FIELD_PREP(YT8821_UTP_EXT_MU_COARSE_FR_F_FFE, 0x7) |
+		FIELD_PREP(YT8821_UTP_EXT_MU_COARSE_FR_F_FBE, 0x7);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_MU_COARSE_FR_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_MU_FINE_FR_F_FFE |
+		YT8821_UTP_EXT_MU_FINE_FR_F_FBE;
+	set = FIELD_PREP(YT8821_UTP_EXT_MU_FINE_FR_F_FFE, 0x2) |
+		FIELD_PREP(YT8821_UTP_EXT_MU_FINE_FR_F_FBE, 0x2);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_MU_FINE_FR_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	/* save YT8821_UTP_EXT_PI_CTRL_REG's val for use later */
+	ret = ytphy_read_ext(phydev, YT8821_UTP_EXT_PI_CTRL_REG);
+	if (ret < 0)
+		goto err_restore_page;
+
+	save = ret;
+
+	mask = YT8821_UTP_EXT_PI_TX_CLK_SEL_AFE |
+		YT8821_UTP_EXT_PI_RX_CLK_3_SEL_AFE |
+		YT8821_UTP_EXT_PI_RX_CLK_2_SEL_AFE |
+		YT8821_UTP_EXT_PI_RX_CLK_1_SEL_AFE |
+		YT8821_UTP_EXT_PI_RX_CLK_0_SEL_AFE;
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_PI_CTRL_REG,
+			       mask, 0);
+	if (ret < 0)
+		goto err_restore_page;
+
+	/* restore YT8821_UTP_EXT_PI_CTRL_REG's val */
+	ret = ytphy_write_ext(phydev, YT8821_UTP_EXT_PI_CTRL_REG, save);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_FECHO_AMP_TH_HUGE;
+	set = FIELD_PREP(YT8821_UTP_EXT_FECHO_AMP_TH_HUGE, 0x38);
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_VCT_CFG6_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_NFR_TX_ABILITY;
+	set = YT8821_UTP_EXT_NFR_TX_ABILITY;
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_TXGE_NFR_FR_THP_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_PLL_SPARE_CFG;
+	set = FIELD_PREP(YT8821_UTP_EXT_PLL_SPARE_CFG, 0xe9);
+	ret = ytphy_modify_ext(phydev, YT8821_UTP_EXT_PLL_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_DAC_IMID_CH_3_10_ORG |
+		YT8821_UTP_EXT_DAC_IMID_CH_2_10_ORG;
+	set = FIELD_PREP(YT8821_UTP_EXT_DAC_IMID_CH_3_10_ORG, 0x64) |
+		FIELD_PREP(YT8821_UTP_EXT_DAC_IMID_CH_2_10_ORG, 0x64);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_DAC_IMID_CH_2_3_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_DAC_IMID_CH_1_10_ORG |
+		YT8821_UTP_EXT_DAC_IMID_CH_0_10_ORG;
+	set = FIELD_PREP(YT8821_UTP_EXT_DAC_IMID_CH_1_10_ORG, 0x64) |
+		FIELD_PREP(YT8821_UTP_EXT_DAC_IMID_CH_0_10_ORG, 0x64);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_DAC_IMID_CH_0_1_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_DAC_IMSB_CH_3_10_ORG |
+		YT8821_UTP_EXT_DAC_IMSB_CH_2_10_ORG;
+	set = FIELD_PREP(YT8821_UTP_EXT_DAC_IMSB_CH_3_10_ORG, 0x64) |
+		FIELD_PREP(YT8821_UTP_EXT_DAC_IMSB_CH_2_10_ORG, 0x64);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_DAC_IMSB_CH_2_3_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+	mask = YT8821_UTP_EXT_DAC_IMSB_CH_1_10_ORG |
+		YT8821_UTP_EXT_DAC_IMSB_CH_0_10_ORG;
+	set = FIELD_PREP(YT8821_UTP_EXT_DAC_IMSB_CH_1_10_ORG, 0x64) |
+		FIELD_PREP(YT8821_UTP_EXT_DAC_IMSB_CH_0_10_ORG, 0x64);
+	ret = ytphy_modify_ext(phydev,
+			       YT8821_UTP_EXT_DAC_IMSB_CH_0_1_CTRL_REG,
+			       mask, set);
+	if (ret < 0)
+		goto err_restore_page;
+
+err_restore_page:
+	return phy_restore_page(phydev, old_page, ret);
+}
+
+/**
+ * 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);
+	if (ret < 0)
+		goto err_restore_page;
+
+err_restore_page:
+	return phy_restore_page(phydev, old_page, ret);
+}
+
+/**
+ * yt8821_soft_reset() - soft reset utp and serdes
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_soft_reset(struct phy_device *phydev)
+{
+	return ytphy_modify_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG,
+					  YT8521_CCR_SW_RST, 0);
+}
+
+/**
+ * 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)
+{
+	u8 mode = YT8821_CHIP_MODE_AUTO_BX2500_SGMII;
+	int ret;
+	u16 set;
+
+	if (phydev->interface == PHY_INTERFACE_MODE_2500BASEX)
+		mode = YT8821_CHIP_MODE_FORCE_BX2500;
+
+	set = FIELD_PREP(YT8521_CCR_MODE_SEL_MASK, mode);
+	ret = ytphy_modify_ext_with_lock(phydev,
+					 YT8521_CHIP_CONFIG_REG,
+					 YT8521_CCR_MODE_SEL_MASK,
+					 set);
+	if (ret < 0)
+		return ret;
+
+	if (mode == YT8821_CHIP_MODE_AUTO_BX2500_SGMII) {
+		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
+			  phydev->possible_interfaces);
+		__set_bit(PHY_INTERFACE_MODE_SGMII,
+			  phydev->possible_interfaces);
+
+		phydev->rate_matching = RATE_MATCH_NONE;
+	} else if (mode == YT8821_CHIP_MODE_FORCE_BX2500) {
+		phydev->rate_matching = RATE_MATCH_PAUSE;
+	}
+
+	ret = yt8821_serdes_init(phydev);
+	if (ret < 0)
+		return ret;
+
+	ret = yt8821_utp_init(phydev);
+	if (ret < 0)
+		return ret;
+
+	/* disable auto sleep */
+	ret = yt8821_auto_sleep_config(phydev, false);
+	if (ret < 0)
+		return ret;
+
+	/* soft reset */
+	return yt8821_soft_reset(phydev);
+}
+
+/**
+ * yt8821_adjust_status() - update speed and duplex to phydev
+ * @phydev: a pointer to a &struct phy_device
+ * @val: read from YTPHY_SPECIFIC_STATUS_REG
+ */
+static void yt8821_adjust_status(struct phy_device *phydev, int val)
+{
+	int speed, duplex;
+	int speed_mode;
+
+	duplex = FIELD_GET(YTPHY_SSR_DUPLEX, val);
+	speed_mode = val & YTPHY_SSR_SPEED_MASK;
+	switch (speed_mode) {
+	case YTPHY_SSR_SPEED_10M:
+		speed = SPEED_10;
+		break;
+	case YTPHY_SSR_SPEED_100M:
+		speed = SPEED_100;
+		break;
+	case YTPHY_SSR_SPEED_1000M:
+		speed = SPEED_1000;
+		break;
+	case YTPHY_SSR_SPEED_2500M:
+		speed = SPEED_2500;
+		break;
+	default:
+		speed = SPEED_UNKNOWN;
+		break;
+	}
+
+	phydev->speed = speed;
+	phydev->duplex = duplex;
+}
+
+/**
+ * yt8821_update_interface() - update interface per current speed
+ * @phydev: a pointer to a &struct phy_device
+ */
+static void yt8821_update_interface(struct phy_device *phydev)
+{
+	if (!phydev->link)
+		return;
+
+	switch (phydev->speed) {
+	case SPEED_2500:
+		phydev->interface = PHY_INTERFACE_MODE_2500BASEX;
+		break;
+	case SPEED_1000:
+	case SPEED_100:
+	case SPEED_10:
+		phydev->interface = PHY_INTERFACE_MODE_SGMII;
+		break;
+	default:
+		phydev_warn(phydev, "phy speed err :%d\n", phydev->speed);
+		break;
+	}
+}
+
+/**
+ * yt8821_read_status() -  determines the negotiated speed and duplex
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_read_status(struct phy_device *phydev)
+{
+	int link;
+	int ret;
+	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;
+
+	ret = phy_read(phydev, YTPHY_SPECIFIC_STATUS_REG);
+	if (ret < 0)
+		return ret;
+
+	val = ret;
+
+	link = val & YTPHY_SSR_LINK;
+	if (link)
+		yt8821_adjust_status(phydev, val);
+
+	if (link) {
+		if (phydev->link == 0)
+			phydev_dbg(phydev,
+				   "%s, phy addr: %d, link up\n",
+				   __func__, phydev->mdio.addr);
+		phydev->link = 1;
+	} else {
+		if (phydev->link == 1)
+			phydev_dbg(phydev,
+				   "%s, phy addr: %d, link down\n",
+				   __func__, phydev->mdio.addr);
+		phydev->link = 0;
+	}
+
+	val = ytphy_read_ext_with_lock(phydev, YT8521_CHIP_CONFIG_REG);
+	if (val < 0)
+		return val;
+
+	if (FIELD_GET(YT8521_CCR_MODE_SEL_MASK, val) ==
+	    YT8821_CHIP_MODE_AUTO_BX2500_SGMII)
+		yt8821_update_interface(phydev);
+
+	return 0;
+}
+
+/**
+ * yt8821_modify_utp_fiber_bmcr - bits modify a PHY's BMCR register
+ * @phydev: the phy_device struct
+ * @mask: bit mask of bits to clear
+ * @set: bit mask of bits to set
+ *
+ * NOTE: Convenience function which allows a PHY's BMCR register to be
+ * modified as new register value = (old register value & ~mask) | set.
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_modify_utp_fiber_bmcr(struct phy_device *phydev,
+					u16 mask, u16 set)
+{
+	int ret;
+
+	ret = yt8521_modify_bmcr_paged(phydev, YT8521_RSSR_UTP_SPACE,
+				       mask, set);
+	if (ret < 0)
+		return ret;
+
+	return yt8521_modify_bmcr_paged(phydev, YT8521_RSSR_FIBER_SPACE,
+					mask, set);
+}
+
+/**
+ * yt8821_suspend() - suspend the hardware
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_suspend(struct phy_device *phydev)
+{
+	int wol_config;
+
+	wol_config = ytphy_read_ext_with_lock(phydev,
+					      YTPHY_WOL_CONFIG_REG);
+	if (wol_config < 0)
+		return wol_config;
+
+	/* if wol enable, do nothing */
+	if (wol_config & YTPHY_WCR_ENABLE)
+		return 0;
+
+	return yt8821_modify_utp_fiber_bmcr(phydev, 0, BMCR_PDOWN);
+}
+
+/**
+ * yt8821_resume() - resume the hardware
+ * @phydev: a pointer to a &struct phy_device
+ *
+ * Returns: 0 or negative errno code
+ */
+static int yt8821_resume(struct phy_device *phydev)
+{
+	int wol_config;
+	int ret;
+
+	/* disable auto sleep */
+	ret = yt8821_auto_sleep_config(phydev, false);
+	if (ret < 0)
+		return ret;
+
+	wol_config = ytphy_read_ext_with_lock(phydev,
+					      YTPHY_WOL_CONFIG_REG);
+	if (wol_config < 0)
+		return wol_config;
+
+	/* if wol enable, do nothing */
+	if (wol_config & YTPHY_WCR_ENABLE)
+		return 0;
+
+	return yt8821_modify_utp_fiber_bmcr(phydev, BMCR_PDOWN, 0);
+}
+
 static struct phy_driver motorcomm_phy_drvs[] = {
 	{
 		PHY_ID_MATCH_EXACT(PHY_ID_YT8511),
@@ -2304,11 +2958,28 @@  static struct phy_driver motorcomm_phy_drvs[] = {
 		.suspend	= yt8521_suspend,
 		.resume		= yt8521_resume,
 	},
+	{
+		PHY_ID_MATCH_EXACT(PHY_ID_YT8821),
+		.name			= "YT8821 2.5Gbps PHY",
+		.get_features		= yt8821_get_features,
+		.read_page		= yt8521_read_page,
+		.write_page		= yt8521_write_page,
+		.get_wol		= ytphy_get_wol,
+		.set_wol		= ytphy_set_wol,
+		.config_aneg		= genphy_config_aneg,
+		.aneg_done		= yt8821_aneg_done,
+		.config_init		= yt8821_config_init,
+		.get_rate_matching	= yt8821_get_rate_matching,
+		.read_status		= yt8821_read_status,
+		.soft_reset		= yt8821_soft_reset,
+		.suspend		= yt8821_suspend,
+		.resume			= yt8821_resume,
+	},
 };
 
 module_phy_driver(motorcomm_phy_drvs);
 
-MODULE_DESCRIPTION("Motorcomm 8511/8521/8531/8531S PHY driver");
+MODULE_DESCRIPTION("Motorcomm 8511/8521/8531/8531S/8821 PHY driver");
 MODULE_AUTHOR("Peter Geis");
 MODULE_AUTHOR("Frank");
 MODULE_LICENSE("GPL");
@@ -2318,6 +2989,7 @@  static const struct mdio_device_id __maybe_unused motorcomm_tbl[] = {
 	{ PHY_ID_MATCH_EXACT(PHY_ID_YT8521) },
 	{ PHY_ID_MATCH_EXACT(PHY_ID_YT8531) },
 	{ PHY_ID_MATCH_EXACT(PHY_ID_YT8531S) },
+	{ PHY_ID_MATCH_EXACT(PHY_ID_YT8821) },
 	{ /* sentinel */ }
 };