net: ethernet: oa_tc6: enable open alliance tc6 data communication

Enabling Configuration Synchronization bit (SYNC) in the Configuration
Register #0 enables data communication in the MAC-PHY. The state of this
bit is reflected in the data footer SYNC bit.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
Link: https://patch.msgid.link/20240909082514.262942-9-Parthiban.Veerasooran@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/oa_tc6.c

@@ -20,6 +20,10 @@
 #define OA_TC6_REG_RESET			0x0003
 #define RESET_SWRESET				BIT(0)	/* Software Reset */
 
+/* Configuration Register #0 */
+#define OA_TC6_REG_CONFIG0			0x0004
+#define CONFIG0_SYNC				BIT(15)
+
 /* Status Register #0 */
 #define OA_TC6_REG_STATUS0			0x0008
 #define STATUS0_RESETC				BIT(6)	/* Reset Complete */
@@ -559,6 +563,21 @@ static int oa_tc6_unmask_macphy_error_interrupts(struct oa_tc6 *tc6)
 	return oa_tc6_write_register(tc6, OA_TC6_REG_INT_MASK0, regval);
 }
 
+static int oa_tc6_enable_data_transfer(struct oa_tc6 *tc6)
+{
+	u32 value;
+	int ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_REG_CONFIG0, &value);
+	if (ret)
+		return ret;
+
+	/* Enable configuration synchronization for data transfer */
+	value |= CONFIG0_SYNC;
+
+	return oa_tc6_write_register(tc6, OA_TC6_REG_CONFIG0, value);
+}
+
 /**
  * oa_tc6_init - allocates and initializes oa_tc6 structure.
  * @spi: device with which data will be exchanged.
@@ -618,7 +637,18 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi, struct net_device *netdev)
 		return NULL;
 	}
 
+	ret = oa_tc6_enable_data_transfer(tc6);
+	if (ret) {
+		dev_err(&tc6->spi->dev, "Failed to enable data transfer: %d\n",
+			ret);
+		goto phy_exit;
+	}
+
 	return tc6;
+
+phy_exit:
+	oa_tc6_phy_exit(tc6);
+	return NULL;
 }
 EXPORT_SYMBOL_GPL(oa_tc6_init);