realtek: rtl931x: Support enable/disable SMI Polling for SerDes ports

During PHY matching, the SMI polling must be disabled to avoid conflicts
during the complex detection routine. Only after this finished, SMI polling
is allowed again.

This was implemented for all realtek families besides RTL931x.

Signed-off-by: Harshal Gohel <hg@simonwunderlich.de>
Signed-off-by: Sharadanand Karanjkar <sk@simonwunderlich.de>
Link: openwrt#19603
Signed-off-by: Robert Marko <robimarko@gmail.com>

Author: 0xharshal

target/linux/realtek/files-6.12/drivers/net/phy/rtl83xx-phy.c

@@ -120,7 +120,10 @@ static u64 disable_polling(int port)
 		sw_w32_mask(BIT(port), 0, RTL930X_SMI_POLL_CTRL);
 		break;
 	case RTL9310_FAMILY_ID:
-		pr_warn("%s not implemented for RTL931X\n", __func__);
+		saved_state = sw_r32(RTL931X_SMI_PORT_POLLING_CTRL + 4);
+		saved_state <<= 32;
+		saved_state |= sw_r32(RTL931X_SMI_PORT_POLLING_CTRL);
+		sw_w32_mask(BIT(port % 32), 0, RTL931X_SMI_PORT_POLLING_CTRL + ((port >> 5) << 2));
 		break;
 	}
 
@@ -145,7 +148,8 @@ static int resume_polling(u64 saved_state)
 		sw_w32(saved_state, RTL930X_SMI_POLL_CTRL);
 		break;
 	case RTL9310_FAMILY_ID:
-		pr_warn("%s not implemented for RTL931X\n", __func__);
+		sw_w32(saved_state >> 32, RTL931X_SMI_PORT_POLLING_CTRL + 4);
+		sw_w32(saved_state, RTL931X_SMI_PORT_POLLING_CTRL);
 		break;
 	}