net: phy: marvell-88q2xxx: add driver for the Marvell 88Q2220 PHY

Add a driver for the Marvell 88Q2220. This driver allows to detect the
link, switch between 100BASE-T1 and 1000BASE-T1 and switch between
master and slave mode. Autonegotiation is supported.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Gregor Herburger <gregor.herburger@ew.tq-group.com>
Signed-off-by: Dimitri Fedrau <dima.fedrau@gmail.com>
Link: https://lore.kernel.org/r/20240218075753.18067-6-dima.fedrau@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/marvell-88q2xxx.c

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Marvell 88Q2XXX automotive 100BASE-T1/1000BASE-T1 PHY driver
+ *
+ * Derived from Marvell Q222x API
+ *
+ * Copyright (C) 2024 Liebherr-Electronics and Drives GmbH
  */
 #include <linux/ethtool_netlink.h>
 #include <linux/marvell_phy.h>
 #include <linux/phy.h>
 
+#define PHY_ID_88Q2220_REVB0	(MARVELL_PHY_ID_88Q2220 | 0x1)
+
 #define MDIO_MMD_AN_MV_STAT			32769
 #define MDIO_MMD_AN_MV_STAT_ANEG		0x0100
 #define MDIO_MMD_AN_MV_STAT_LOCAL_RX		0x1000
@@ -13,6 +19,11 @@
 #define MDIO_MMD_AN_MV_STAT_LOCAL_MASTER	0x4000
 #define MDIO_MMD_AN_MV_STAT_MS_CONF_FAULT	0x8000
 
+#define MDIO_MMD_AN_MV_STAT2			32794
+#define MDIO_MMD_AN_MV_STAT2_AN_RESOLVED	0x0800
+#define MDIO_MMD_AN_MV_STAT2_100BT1		0x2000
+#define MDIO_MMD_AN_MV_STAT2_1000BT1		0x4000
+
 #define MDIO_MMD_PCS_MV_100BT1_STAT1			33032
 #define MDIO_MMD_PCS_MV_100BT1_STAT1_IDLE_ERROR		0x00ff
 #define MDIO_MMD_PCS_MV_100BT1_STAT1_JABBER		0x0100
@@ -29,6 +40,42 @@
 
 #define MDIO_MMD_PCS_MV_RX_STAT			33328
 
+struct mmd_val {
+	int devad;
+	u32 regnum;
+	u16 val;
+};
+
+static const struct mmd_val mv88q222x_revb0_init_seq0[] = {
+	{ MDIO_MMD_PCS, 0x8033, 0x6801 },
+	{ MDIO_MMD_AN, MDIO_AN_T1_CTRL, 0x0 },
+	{ MDIO_MMD_PMAPMD, MDIO_CTRL1,
+	  MDIO_CTRL1_LPOWER | MDIO_PMA_CTRL1_SPEED1000 },
+	{ MDIO_MMD_PCS, 0xfe1b, 0x48 },
+	{ MDIO_MMD_PCS, 0xffe4, 0x6b6 },
+	{ MDIO_MMD_PMAPMD, MDIO_CTRL1, 0x0 },
+	{ MDIO_MMD_PCS, MDIO_CTRL1, 0x0 },
+};
+
+static const struct mmd_val mv88q222x_revb0_init_seq1[] = {
+	{ MDIO_MMD_PCS, 0xfe79, 0x0 },
+	{ MDIO_MMD_PCS, 0xfe07, 0x125a },
+	{ MDIO_MMD_PCS, 0xfe09, 0x1288 },
+	{ MDIO_MMD_PCS, 0xfe08, 0x2588 },
+	{ MDIO_MMD_PCS, 0xfe11, 0x1105 },
+	{ MDIO_MMD_PCS, 0xfe72, 0x042c },
+	{ MDIO_MMD_PCS, 0xfbba, 0xcb2 },
+	{ MDIO_MMD_PCS, 0xfbbb, 0xc4a },
+	{ MDIO_MMD_AN, 0x8032, 0x2020 },
+	{ MDIO_MMD_AN, 0x8031, 0xa28 },
+	{ MDIO_MMD_AN, 0x8031, 0xc28 },
+	{ MDIO_MMD_PCS, 0xffdb, 0xfc10 },
+	{ MDIO_MMD_PCS, 0xfe1b, 0x58 },
+	{ MDIO_MMD_PCS, 0xfe79, 0x4 },
+	{ MDIO_MMD_PCS, 0xfe5f, 0xe8 },
+	{ MDIO_MMD_PCS, 0xfe05, 0x755c },
+};
+
 static int mv88q2xxx_soft_reset(struct phy_device *phydev)
 {
 	int ret;
@@ -125,24 +172,90 @@ static int mv88q2xxx_read_link_100m(struct phy_device *phydev)
 
 static int mv88q2xxx_read_link(struct phy_device *phydev)
 {
-	int ret;
-
 	/* The 88Q2XXX PHYs do not have the PMA/PMD status register available,
 	 * therefore we need to read the link status from the vendor specific
 	 * registers depending on the speed.
 	 */
+
 	if (phydev->speed == SPEED_1000)
-		ret = mv88q2xxx_read_link_gbit(phydev);
+		return mv88q2xxx_read_link_gbit(phydev);
+	else if (phydev->speed == SPEED_100)
+		return mv88q2xxx_read_link_100m(phydev);
+
+	phydev->link = false;
+	return 0;
+}
+
+static int mv88q2xxx_read_master_slave_state(struct phy_device *phydev)
+{
+	int ret;
+
+	phydev->master_slave_state = MASTER_SLAVE_STATE_UNKNOWN;
+	ret = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_MMD_AN_MV_STAT);
+	if (ret < 0)
+		return ret;
+
+	if (ret & MDIO_MMD_AN_MV_STAT_LOCAL_MASTER)
+		phydev->master_slave_state = MASTER_SLAVE_STATE_MASTER;
 	else
-		ret = mv88q2xxx_read_link_100m(phydev);
+		phydev->master_slave_state = MASTER_SLAVE_STATE_SLAVE;
 
+	return 0;
+}
+
+static int mv88q2xxx_read_aneg_speed(struct phy_device *phydev)
+{
+	int ret;
+
+	phydev->speed = SPEED_UNKNOWN;
+	ret = phy_read_mmd(phydev, MDIO_MMD_AN, MDIO_MMD_AN_MV_STAT2);
+	if (ret < 0)
 		return ret;
+
+	if (!(ret & MDIO_MMD_AN_MV_STAT2_AN_RESOLVED))
+		return 0;
+
+	if (ret & MDIO_MMD_AN_MV_STAT2_100BT1)
+		phydev->speed = SPEED_100;
+	else if (ret & MDIO_MMD_AN_MV_STAT2_1000BT1)
+		phydev->speed = SPEED_1000;
+
+	return 0;
 }
 
 static int mv88q2xxx_read_status(struct phy_device *phydev)
 {
 	int ret;
 
+	if (phydev->autoneg == AUTONEG_ENABLE) {
+		/* We have to get the negotiated speed first, otherwise we are
+		 * not able to read the link.
+		 */
+		ret = mv88q2xxx_read_aneg_speed(phydev);
+		if (ret < 0)
+			return ret;
+
+		ret = mv88q2xxx_read_link(phydev);
+		if (ret < 0)
+			return ret;
+
+		ret = genphy_c45_read_lpa(phydev);
+		if (ret < 0)
+			return ret;
+
+		ret = genphy_c45_baset1_read_status(phydev);
+		if (ret < 0)
+			return ret;
+
+		ret = mv88q2xxx_read_master_slave_state(phydev);
+		if (ret < 0)
+			return ret;
+
+		phy_resolve_aneg_linkmode(phydev);
+
+		return 0;
+	}
+
 	ret = mv88q2xxx_read_link(phydev);
 	if (ret < 0)
 		return ret;
@@ -171,7 +284,9 @@ static int mv88q2xxx_get_features(struct phy_device *phydev)
 	 * sequence provided by Marvell. Disable it for now until a proper
 	 * workaround is found or a new PHY revision is released.
 	 */
-	linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, phydev->supported);
+	if (phydev->drv->phy_id == MARVELL_PHY_ID_88Q2110)
+		linkmode_clear_bit(ETHTOOL_LINK_MODE_Autoneg_BIT,
+				   phydev->supported);
 
 	return 0;
 }
@@ -241,6 +356,75 @@ static int mv88q2xxx_get_sqi_max(struct phy_device *phydev)
 	return 15;
 }
 
+static int mv88q222x_soft_reset(struct phy_device *phydev)
+{
+	int ret;
+
+	/* Enable RESET of DCL */
+	if (phydev->autoneg == AUTONEG_ENABLE || phydev->speed == SPEED_1000) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_PCS, 0xfe1b, 0x48);
+		if (ret < 0)
+			return ret;
+	}
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_1000BT1_CTRL,
+			    MDIO_PCS_1000BT1_CTRL_RESET);
+	if (ret < 0)
+		return ret;
+
+	ret = phy_write_mmd(phydev, MDIO_MMD_PCS, 0xffe4, 0xc);
+	if (ret < 0)
+		return ret;
+
+	/* Disable RESET of DCL */
+	if (phydev->autoneg == AUTONEG_ENABLE || phydev->speed == SPEED_1000)
+		return phy_write_mmd(phydev, MDIO_MMD_PCS, 0xfe1b, 0x58);
+
+	return 0;
+}
+
+static int mv88q222x_config_aneg(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = genphy_c45_config_aneg(phydev);
+	if (ret)
+		return ret;
+
+	return mv88q222x_soft_reset(phydev);
+}
+
+static int mv88q222x_revb0_config_init(struct phy_device *phydev)
+{
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(mv88q222x_revb0_init_seq0); i++) {
+		ret = phy_write_mmd(phydev, mv88q222x_revb0_init_seq0[i].devad,
+				    mv88q222x_revb0_init_seq0[i].regnum,
+				    mv88q222x_revb0_init_seq0[i].val);
+		if (ret < 0)
+			return ret;
+	}
+
+	usleep_range(5000, 10000);
+
+	for (i = 0; i < ARRAY_SIZE(mv88q222x_revb0_init_seq1); i++) {
+		ret = phy_write_mmd(phydev, mv88q222x_revb0_init_seq1[i].devad,
+				    mv88q222x_revb0_init_seq1[i].regnum,
+				    mv88q222x_revb0_init_seq1[i].val);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* The 88Q2XXX PHYs do have the extended ability register available, but
+	 * register MDIO_PMA_EXTABLE where they should signalize it does not
+	 * work according to specification. Therefore, we force it here.
+	 */
+	phydev->pma_extable = MDIO_PMA_EXTABLE_BT1;
+
+	return 0;
+}
+
 static struct phy_driver mv88q2xxx_driver[] = {
 	{
 		.phy_id			= MARVELL_PHY_ID_88Q2110,
@@ -255,12 +439,26 @@ static struct phy_driver mv88q2xxx_driver[] = {
 		.get_sqi		= mv88q2xxx_get_sqi,
 		.get_sqi_max		= mv88q2xxx_get_sqi_max,
 	},
+	{
+		PHY_ID_MATCH_EXACT(PHY_ID_88Q2220_REVB0),
+		.name			= "mv88q2220",
+		.get_features		= mv88q2xxx_get_features,
+		.config_aneg		= mv88q222x_config_aneg,
+		.aneg_done		= genphy_c45_aneg_done,
+		.config_init		= mv88q222x_revb0_config_init,
+		.read_status		= mv88q2xxx_read_status,
+		.soft_reset		= mv88q222x_soft_reset,
+		.set_loopback		= genphy_c45_loopback,
+		.get_sqi		= mv88q2xxx_get_sqi,
+		.get_sqi_max		= mv88q2xxx_get_sqi_max,
+	},
 };
 
 module_phy_driver(mv88q2xxx_driver);
 
 static struct mdio_device_id __maybe_unused mv88q2xxx_tbl[] = {
 	{ MARVELL_PHY_ID_88Q2110, MARVELL_PHY_ID_MASK },
+	{ PHY_ID_MATCH_EXACT(PHY_ID_88Q2220_REVB0), },
 	{ /*sentinel*/ }
 };
 MODULE_DEVICE_TABLE(mdio, mv88q2xxx_tbl);

include/linux/marvell_phy.h

@@ -26,6 +26,7 @@
 #define MARVELL_PHY_ID_88E2110		0x002b09b0
 #define MARVELL_PHY_ID_88X2222		0x01410f10
 #define MARVELL_PHY_ID_88Q2110		0x002b0980
+#define MARVELL_PHY_ID_88Q2220		0x002b0b20
 
 /* Marvel 88E1111 in Finisar SFP module with modified PHY ID */
 #define MARVELL_PHY_ID_88E1111_FINISAR	0x01ff0cc0