[PATCH net-next 4/8] net: dsa: realtek: rtl8365mb: set RGMII mode for family D

[Mieczyslaw Nalewaj]

Forcing RGMII mode on extension interface 1 within family D silicon
demands an alternative muxing and clock delay path. The driver needs
to explicitly reset the hardware TX clock delay line
(EXT1_RGMII_TX_DLY) and evaluate the top-level configuration register
mux. If the internal MAC4 block is not occupying extension 1, the
RGMII/MII pin mux matrix must be bound to MAC7, disabling the
conflicting SerDes 1 lane in the process.

Signed-off-by: Mieczyslaw Nalewaj <namiltd@xxxxxxxxx>
---
 drivers/net/dsa/realtek/rtl8365mb_main.c | 42 ++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/drivers/net/dsa/realtek/rtl8365mb_main.c b/drivers/net/dsa/realtek/rtl8365mb_main.c
index 910e868..c638c20 100644
--- a/drivers/net/dsa/realtek/rtl8365mb_main.c
+++ b/drivers/net/dsa/realtek/rtl8365mb_main.c
@@ -334,6 +334,12 @@
 #define   RTL8365MB_SDS_OPTION_ARM_KEY		0x0249
 #define RTL8365MB_SDS_OPTION_REG		0x13C1
 
+#define RTL8365MB_D_SDS_MISC_MODE_FIELD_MASK		GENMASK(4, 0)
+/* Shared "disable" encoding for both SDS_MISC's and SDS1_MISC0's
+ * 5-bit mode fields.
+ */
+#define RTL8365MB_D_PORT_SDS_MODE_DISABLE		0x1f
+
 /* Embedded DW8051 microcontroller control registers. The microcontroller
  * can run firmware to manage the SerDes link, but this driver keeps it in
  * reset and disabled: phylink already performs the link management that
@@ -459,6 +465,15 @@
 #define   RTL8365MB_PORT_MISC_CFG_VLAN_EGRESS_MODE_MASK		GENMASK(5, 4)
 #define   RTL8365MB_PORT_MISC_CFG_CONGESTION_SUSTAIN_TIME_MASK	GENMASK(3, 0)
 
+#define RTL8365MB_D_REG_EXT_TXC_DLY				0x13f9
+#define   RTL8365MB_D_EXT1_RGMII_TX_DLY_MASK			GENMASK(5, 3)
+
+#define RTL8365MB_D_REG_TOP_CON0				0x1d70
+#define   RTL8365MB_D_MAC7_SEL_EXT1_MASK			BIT(13)
+#define   RTL8365MB_D_MAC4_SEL_EXT1_MASK			BIT(12)
+
+#define RTL8365MB_D_REG_SDS1_MISC0				0x1d78
+
 /**
  * enum rtl8365mb_vlan_egress_mode - port VLAN egress mode
  * @RTL8365MB_VLAN_EGRESS_MODE_ORIGINAL: follow untag mask in VLAN4k table entry
@@ -1208,6 +1223,7 @@ static int rtl8365mb_ext_config_rgmii(struct realtek_priv *priv, int port,
 	struct dsa_port *dp;
 	int tx_delay = 0;
 	int rx_delay = 0;
+	u32 data;
 	u32 val;
 	int ret;
 
@@ -1277,6 +1293,32 @@ static int rtl8365mb_ext_config_rgmii(struct realtek_priv *priv, int port,
 	if (ret)
 		return ret;
 
+	if (rtl8365mb_get_family(priv) == RTL8365MB_FAMILY_D && extint->id == 1) {
+		ret = regmap_update_bits(priv->map,
+					 RTL8365MB_D_REG_EXT_TXC_DLY,
+					 RTL8365MB_D_EXT1_RGMII_TX_DLY_MASK, 0);
+		if (ret)
+			return ret;
+		/* Configure RGMII/MII mux to port 7 if UTP_PORT4 is not RGMII mode */
+		ret = regmap_read(priv->map, RTL8365MB_D_REG_TOP_CON0, &data);
+		if (ret)
+			return ret;
+		if ((data & RTL8365MB_D_MAC4_SEL_EXT1_MASK) == 0) {
+			ret = regmap_update_bits(priv->map,
+						 RTL8365MB_D_REG_TOP_CON0,
+						 RTL8365MB_D_MAC7_SEL_EXT1_MASK,
+						 RTL8365MB_D_MAC7_SEL_EXT1_MASK);
+			if (ret)
+				return ret;
+		}
+		ret = regmap_update_bits(priv->map,
+					 RTL8365MB_D_REG_SDS1_MISC0,
+					 RTL8365MB_D_SDS_MISC_MODE_FIELD_MASK,
+					 RTL8365MB_D_PORT_SDS_MODE_DISABLE);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
-- 
2.53.0