can: ifi: Add more detailed error reporting

The updated specification for the IFI CANFD core contains description
of more detailed error reporting capability of the core. Implement
support for this detailed error reporting.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/ifi_canfd/ifi_canfd.c

@@ -52,7 +52,8 @@
 #define IFI_CANFD_TXSTCMD_OVERFLOW		BIT(13)
 
 #define IFI_CANFD_INTERRUPT			0xc
-#define IFI_CANFD_INTERRUPT_ERROR_WARNING	((u32)BIT(1))
+#define IFI_CANFD_INTERRUPT_ERROR_WARNING	BIT(1)
+#define IFI_CANFD_INTERRUPT_ERROR_COUNTER	BIT(10)
 #define IFI_CANFD_INTERRUPT_TXFIFO_EMPTY	BIT(16)
 #define IFI_CANFD_INTERRUPT_TXFIFO_REMOVE	BIT(22)
 #define IFI_CANFD_INTERRUPT_RXFIFO_NEMPTY	BIT(24)
@@ -103,7 +104,26 @@
 
 #define IFI_CANFD_RES1				0x40
 
-#define IFI_CANFD_RES2				0x44
+#define IFI_CANFD_ERROR_CTR			0x44
+#define IFI_CANFD_ERROR_CTR_UNLOCK_MAGIC	0x21302899
+#define IFI_CANFD_ERROR_CTR_OVERLOAD_FIRST	BIT(0)
+#define IFI_CANFD_ERROR_CTR_ACK_ERROR_FIRST	BIT(1)
+#define IFI_CANFD_ERROR_CTR_BIT0_ERROR_FIRST	BIT(2)
+#define IFI_CANFD_ERROR_CTR_BIT1_ERROR_FIRST	BIT(3)
+#define IFI_CANFD_ERROR_CTR_STUFF_ERROR_FIRST	BIT(4)
+#define IFI_CANFD_ERROR_CTR_CRC_ERROR_FIRST	BIT(5)
+#define IFI_CANFD_ERROR_CTR_FORM_ERROR_FIRST	BIT(6)
+#define IFI_CANFD_ERROR_CTR_OVERLOAD_ALL	BIT(8)
+#define IFI_CANFD_ERROR_CTR_ACK_ERROR_ALL	BIT(9)
+#define IFI_CANFD_ERROR_CTR_BIT0_ERROR_ALL	BIT(10)
+#define IFI_CANFD_ERROR_CTR_BIT1_ERROR_ALL	BIT(11)
+#define IFI_CANFD_ERROR_CTR_STUFF_ERROR_ALL	BIT(12)
+#define IFI_CANFD_ERROR_CTR_CRC_ERROR_ALL	BIT(13)
+#define IFI_CANFD_ERROR_CTR_FORM_ERROR_ALL	BIT(14)
+#define IFI_CANFD_ERROR_CTR_BITPOSITION_OFFSET	16
+#define IFI_CANFD_ERROR_CTR_BITPOSITION_MASK	0xff
+#define IFI_CANFD_ERROR_CTR_ER_RESET		BIT(30)
+#define IFI_CANFD_ERROR_CTR_ER_ENABLE		((u32)BIT(31))
 
 #define IFI_CANFD_PAR				0x48
 
@@ -197,6 +217,8 @@ static void ifi_canfd_irq_enable(struct net_device *ndev, bool enable)
 	if (enable) {
 		enirq = IFI_CANFD_IRQMASK_TXFIFO_EMPTY |
 			IFI_CANFD_IRQMASK_RXFIFO_NEMPTY;
+		if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+			enirq |= IFI_CANFD_INTERRUPT_ERROR_COUNTER;
 	}
 
 	writel(IFI_CANFD_IRQMASK_SET_ERR |
@@ -335,6 +357,68 @@ static int ifi_canfd_handle_lost_msg(struct net_device *ndev)
 	return 1;
 }
 
+static int ifi_canfd_handle_lec_err(struct net_device *ndev, const u32 errctr)
+{
+	struct ifi_canfd_priv *priv = netdev_priv(ndev);
+	struct net_device_stats *stats = &ndev->stats;
+	struct can_frame *cf;
+	struct sk_buff *skb;
+	const u32 errmask = IFI_CANFD_ERROR_CTR_OVERLOAD_FIRST |
+			    IFI_CANFD_ERROR_CTR_ACK_ERROR_FIRST |
+			    IFI_CANFD_ERROR_CTR_BIT0_ERROR_FIRST |
+			    IFI_CANFD_ERROR_CTR_BIT1_ERROR_FIRST |
+			    IFI_CANFD_ERROR_CTR_STUFF_ERROR_FIRST |
+			    IFI_CANFD_ERROR_CTR_CRC_ERROR_FIRST |
+			    IFI_CANFD_ERROR_CTR_FORM_ERROR_FIRST;
+
+	if (!(errctr & errmask))	/* No error happened. */
+		return 0;
+
+	priv->can.can_stats.bus_error++;
+	stats->rx_errors++;
+
+	/* Propagate the error condition to the CAN stack. */
+	skb = alloc_can_err_skb(ndev, &cf);
+	if (unlikely(!skb))
+		return 0;
+
+	/* Read the error counter register and check for new errors. */
+	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_OVERLOAD_FIRST)
+		cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_ACK_ERROR_FIRST)
+		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_BIT0_ERROR_FIRST)
+		cf->data[2] |= CAN_ERR_PROT_BIT0;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_BIT1_ERROR_FIRST)
+		cf->data[2] |= CAN_ERR_PROT_BIT1;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_STUFF_ERROR_FIRST)
+		cf->data[2] |= CAN_ERR_PROT_STUFF;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_CRC_ERROR_FIRST)
+		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
+
+	if (errctr & IFI_CANFD_ERROR_CTR_FORM_ERROR_FIRST)
+		cf->data[2] |= CAN_ERR_PROT_FORM;
+
+	/* Reset the error counter, ack the IRQ and re-enable the counter. */
+	writel(IFI_CANFD_ERROR_CTR_ER_RESET, priv->base + IFI_CANFD_ERROR_CTR);
+	writel(IFI_CANFD_INTERRUPT_ERROR_COUNTER,
+	       priv->base + IFI_CANFD_INTERRUPT);
+	writel(IFI_CANFD_ERROR_CTR_ER_ENABLE, priv->base + IFI_CANFD_ERROR_CTR);
+
+	stats->rx_packets++;
+	stats->rx_bytes += cf->can_dlc;
+	netif_receive_skb(skb);
+
+	return 1;
+}
+
 static int ifi_canfd_get_berr_counter(const struct net_device *ndev,
 				      struct can_berr_counter *bec)
 {
@@ -470,6 +554,7 @@ static int ifi_canfd_poll(struct napi_struct *napi, int quota)
 
 	u32 stcmd = readl(priv->base + IFI_CANFD_STCMD);
 	u32 rxstcmd = readl(priv->base + IFI_CANFD_STCMD);
+	u32 errctr = readl(priv->base + IFI_CANFD_ERROR_CTR);
 
 	/* Handle bus state changes */
 	if ((stcmd & stcmd_state_mask) ||
@@ -480,6 +565,10 @@ static int ifi_canfd_poll(struct napi_struct *napi, int quota)
 	if (rxstcmd & IFI_CANFD_RXSTCMD_OVERFLOW)
 		work_done += ifi_canfd_handle_lost_msg(ndev);
 
+	/* Handle lec errors on the bus */
+	if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
+		work_done += ifi_canfd_handle_lec_err(ndev, errctr);
+
 	/* Handle normal messages on RX */
 	if (!(rxstcmd & IFI_CANFD_RXSTCMD_EMPTY))
 		work_done += ifi_canfd_do_rx_poll(ndev, quota - work_done);
@@ -499,11 +588,12 @@ static irqreturn_t ifi_canfd_isr(int irq, void *dev_id)
 	struct net_device_stats *stats = &ndev->stats;
 	const u32 rx_irq_mask = IFI_CANFD_INTERRUPT_RXFIFO_NEMPTY |
 				IFI_CANFD_INTERRUPT_RXFIFO_NEMPTY_PER |
-				IFI_CANFD_INTERRUPT_ERROR_WARNING;
+				IFI_CANFD_INTERRUPT_ERROR_WARNING |
+				IFI_CANFD_INTERRUPT_ERROR_COUNTER;
 	const u32 tx_irq_mask = IFI_CANFD_INTERRUPT_TXFIFO_EMPTY |
 				IFI_CANFD_INTERRUPT_TXFIFO_REMOVE;
-	const u32 clr_irq_mask = ~(IFI_CANFD_INTERRUPT_SET_IRQ |
-				   IFI_CANFD_INTERRUPT_ERROR_WARNING);
+	const u32 clr_irq_mask = ~((u32)(IFI_CANFD_INTERRUPT_SET_IRQ |
+					 IFI_CANFD_INTERRUPT_ERROR_WARNING));
 	u32 isr;
 
 	isr = readl(priv->base + IFI_CANFD_INTERRUPT);
@@ -657,6 +747,12 @@ static void ifi_canfd_start(struct net_device *ndev)
 
 	ifi_canfd_irq_enable(ndev, 1);
 
+	/* Unlock, reset and enable the error counter. */
+	writel(IFI_CANFD_ERROR_CTR_UNLOCK_MAGIC,
+	       priv->base + IFI_CANFD_ERROR_CTR);
+	writel(IFI_CANFD_ERROR_CTR_ER_RESET, priv->base + IFI_CANFD_ERROR_CTR);
+	writel(IFI_CANFD_ERROR_CTR_ER_ENABLE, priv->base + IFI_CANFD_ERROR_CTR);
+
 	/* Enable controller */
 	writel(stcmd, priv->base + IFI_CANFD_STCMD);
 }
@@ -665,6 +761,10 @@ static void ifi_canfd_stop(struct net_device *ndev)
 {
 	struct ifi_canfd_priv *priv = netdev_priv(ndev);
 
+	/* Reset and disable the error counter. */
+	writel(IFI_CANFD_ERROR_CTR_ER_RESET, priv->base + IFI_CANFD_ERROR_CTR);
+	writel(0, priv->base + IFI_CANFD_ERROR_CTR);
+
 	/* Reset the IP */
 	writel(IFI_CANFD_STCMD_HARDRESET, priv->base + IFI_CANFD_STCMD);
 
@@ -868,7 +968,8 @@ static int ifi_canfd_plat_probe(struct platform_device *pdev)
 	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 				       CAN_CTRLMODE_LISTENONLY |
 				       CAN_CTRLMODE_FD |
-				       CAN_CTRLMODE_FD_NON_ISO;
+				       CAN_CTRLMODE_FD_NON_ISO |
+				       CAN_CTRLMODE_BERR_REPORTING;
 
 	platform_set_drvdata(pdev, ndev);
 	SET_NETDEV_DEV(ndev, dev);