Add support for LAN8670/1/2 Rev.C1 as per the latest configuration note
AN1699 released (Revision E (DS60001699F - June 2024)).
https://www.microchip.com/en-us/application-notes/an1699

Signed-off-by: Parthiban Veerasooran <parthiban.veerasooran@microchip.com>
---
 drivers/net/phy/Kconfig         |  2 +-
 drivers/net/phy/microchip_t1s.c | 66 ++++++++++++++++++++++++++++++++-
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index f18defab70cf..04f605606a8a 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -292,7 +292,7 @@ config MICREL_PHY
 config MICROCHIP_T1S_PHY
 	tristate "Microchip 10BASE-T1S Ethernet PHYs"
 	help
-	  Currently supports the LAN8670/1/2 Rev.B1 and LAN8650/1 Rev.B0/B1
+	  Currently supports the LAN8670/1/2 Rev.B1/C1 and LAN8650/1 Rev.B0/B1
 	  Internal PHYs.
 
 config MICROCHIP_PHY
diff --git a/drivers/net/phy/microchip_t1s.c b/drivers/net/phy/microchip_t1s.c
index d9814a09a026..f4081886ac1e 100644
--- a/drivers/net/phy/microchip_t1s.c
+++ b/drivers/net/phy/microchip_t1s.c
@@ -3,7 +3,7 @@
  * Driver for Microchip 10BASE-T1S PHYs
  *
  * Support: Microchip Phys:
- *  lan8670/1/2 Rev.B1
+ *  lan8670/1/2 Rev.B1/C1
  *  lan8650/1 Rev.B0/B1 Internal PHYs
  */
 
@@ -12,6 +12,7 @@
 #include <linux/phy.h>
 
 #define PHY_ID_LAN867X_REVB1 0x0007C162
+#define PHY_ID_LAN867X_REVC1 0x0007C164
 /* Both Rev.B0 and B1 clause 22 PHYID's are same due to B1 chip limitation */
 #define PHY_ID_LAN865X_REVB 0x0007C1B3
 
@@ -291,6 +292,58 @@ static int lan867x_check_reset_complete(struct phy_device *phydev)
 	return 0;
 }
 
+static int lan867x_revc1_config_init(struct phy_device *phydev)
+{
+	s8 offsets[2];
+	int ret;
+
+	ret = lan867x_check_reset_complete(phydev);
+	if (ret)
+		return ret;
+
+	ret = lan865x_generate_cfg_offsets(phydev, offsets);
+	if (ret)
+		return ret;
+
+	/* LAN867x Rev.C1 configuration settings are equal to the first 9
+	 * configuration settings and all the sqi fixup settings from LAN865x
+	 * Rev.B0/B1. So the same fixup registers and values from LAN865x
+	 * Rev.B0/B1 are used for LAN867x Rev.C1 to avoid duplication.
+	 * Refer the below links for the comparison.
+	 * https://www.microchip.com/en-us/application-notes/an1760
+	 * Revision F (DS60001760G - June 2024)
+	 * https://www.microchip.com/en-us/application-notes/an1699
+	 * Revision E (DS60001699F - June 2024)
+	 */
+	for (int i = 0; i < 9; i++) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
+				    lan865x_revb_fixup_registers[i],
+				    lan865x_revb_fixup_values[i]);
+		if (ret)
+			return ret;
+
+		if (i == 1) {
+			ret = lan865x_setup_cfgparam(phydev, offsets);
+			if (ret)
+				return ret;
+		}
+	}
+
+	ret = lan865x_setup_sqi_cfgparam(phydev, offsets);
+	if (ret)
+		return ret;
+
+	for (int i = 0; i < ARRAY_SIZE(lan865x_revb_sqi_fixup_regs); i++) {
+		ret = phy_write_mmd(phydev, MDIO_MMD_VEND2,
+				    lan865x_revb_sqi_fixup_regs[i],
+				    lan865x_revb_sqi_fixup_values[i]);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 static int lan867x_revb1_config_init(struct phy_device *phydev)
 {
 	int err;
@@ -371,6 +424,16 @@ static struct phy_driver microchip_t1s_driver[] = {
 		.set_plca_cfg	    = genphy_c45_plca_set_cfg,
 		.get_plca_status    = genphy_c45_plca_get_status,
 	},
+	{
+		PHY_ID_MATCH_EXACT(PHY_ID_LAN867X_REVC1),
+		.name               = "LAN867X Rev.C1",
+		.features           = PHY_BASIC_T1S_P2MP_FEATURES,
+		.config_init        = lan867x_revc1_config_init,
+		.read_status        = lan86xx_read_status,
+		.get_plca_cfg	    = genphy_c45_plca_get_cfg,
+		.set_plca_cfg	    = genphy_c45_plca_set_cfg,
+		.get_plca_status    = genphy_c45_plca_get_status,
+	},
 	{
 		PHY_ID_MATCH_EXACT(PHY_ID_LAN865X_REVB),
 		.name               = "LAN865X Rev.B0/B1 Internal Phy",
@@ -389,6 +452,7 @@ module_phy_driver(microchip_t1s_driver);
 
 static struct mdio_device_id __maybe_unused tbl[] = {
 	{ PHY_ID_MATCH_EXACT(PHY_ID_LAN867X_REVB1) },
+	{ PHY_ID_MATCH_EXACT(PHY_ID_LAN867X_REVC1) },
 	{ PHY_ID_MATCH_EXACT(PHY_ID_LAN865X_REVB) },
 	{ }
 };
-- 
2.34.1