net: ethernet: oa_tc6: implement error interrupts unmasking

This will unmask the following error interrupts from the MAC-PHY.
  tx protocol error
  rx buffer overflow error
  loss of framing error
  header error
The MAC-PHY will signal an error by setting the EXST bit in the receive
data footer which will then allow the host to read the STATUS0 register
to find the source of the error.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Parthiban Veerasooran <Parthiban.Veerasooran@microchip.com>
Link: https://patch.msgid.link/20240909082514.262942-6-Parthiban.Veerasooran@microchip.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/oa_tc6.c

@@ -18,6 +18,13 @@
 #define OA_TC6_REG_STATUS0			0x0008
 #define STATUS0_RESETC				BIT(6)	/* Reset Complete */
 
+/* Interrupt Mask Register #0 */
+#define OA_TC6_REG_INT_MASK0			0x000C
+#define INT_MASK0_HEADER_ERR_MASK		BIT(5)
+#define INT_MASK0_LOSS_OF_FRAME_ERR_MASK	BIT(4)
+#define INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK	BIT(3)
+#define INT_MASK0_TX_PROTOCOL_ERR_MASK		BIT(0)
+
 /* Control command header */
 #define OA_TC6_CTRL_HEADER_DATA_NOT_CTRL	BIT(31)
 #define OA_TC6_CTRL_HEADER_WRITE_NOT_READ	BIT(29)
@@ -327,6 +334,23 @@ static int oa_tc6_sw_reset_macphy(struct oa_tc6 *tc6)
 	return oa_tc6_write_register(tc6, OA_TC6_REG_STATUS0, regval);
 }
 
+static int oa_tc6_unmask_macphy_error_interrupts(struct oa_tc6 *tc6)
+{
+	u32 regval;
+	int ret;
+
+	ret = oa_tc6_read_register(tc6, OA_TC6_REG_INT_MASK0, &regval);
+	if (ret)
+		return ret;
+
+	regval &= ~(INT_MASK0_TX_PROTOCOL_ERR_MASK |
+		    INT_MASK0_RX_BUFFER_OVERFLOW_ERR_MASK |
+		    INT_MASK0_LOSS_OF_FRAME_ERR_MASK |
+		    INT_MASK0_HEADER_ERR_MASK);
+
+	return oa_tc6_write_register(tc6, OA_TC6_REG_INT_MASK0, regval);
+}
+
 /**
  * oa_tc6_init - allocates and initializes oa_tc6 structure.
  * @spi: device with which data will be exchanged.
@@ -369,6 +393,13 @@ struct oa_tc6 *oa_tc6_init(struct spi_device *spi)
 		return NULL;
 	}
 
+	ret = oa_tc6_unmask_macphy_error_interrupts(tc6);
+	if (ret) {
+		dev_err(&tc6->spi->dev,
+			"MAC-PHY error interrupts unmask failed: %d\n", ret);
+		return NULL;
+	}
+
 	return tc6;
 }
 EXPORT_SYMBOL_GPL(oa_tc6_init);