Add bus error, state change, lost message handling mechanism.

Signed-off-by: Dong Aisheng <redacted>
---
 drivers/net/can/m_can.c |  271 +++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 240 insertions(+), 31 deletions(-)

diff --git a/drivers/net/can/m_can.c b/drivers/net/can/m_can.c
index 61e9a8e..e4aed71 100644
--- a/drivers/net/can/m_can.c
+++ b/drivers/net/can/m_can.c

@@ -83,6 +83,18 @@ enum m_can_reg {
 	M_CAN_TXEFA	= 0xf8,
 };
 
+/* m_can lec values */
+enum m_can_lec_type {
+	LEC_NO_ERROR = 0,
+	LEC_STUFF_ERROR,
+	LEC_FORM_ERROR,
+	LEC_ACK_ERROR,
+	LEC_BIT1_ERROR,
+	LEC_BIT0_ERROR,
+	LEC_CRC_ERROR,
+	LEC_UNUSED,
+};
+
 /* CC Control Register(CCCR) */
 #define CCCR_CCE	BIT(1)
 #define CCCR_INIT	BIT(0)

@@ -97,6 +109,19 @@ enum m_can_reg {
 #define BTR_SJW_SHIFT		0
 #define BTR_SJW_MASK		0xf
 
+/* Error Counter Register(ECR) */
+#define ECR_RP			BIT(15)
+#define ECR_REC_SHIFT		8
+#define ECR_REC_MASK		(0x7f << ECR_REC_SHIFT)
+#define ECR_TEC_SHIFT		0
+#define ECR_TEC_MASK		0xff
+
+/* Protocol Status Register(PSR) */
+#define PSR_BO		BIT(7)
+#define PSR_EW		BIT(6)
+#define PSR_EP		BIT(5)
+#define PSR_LEC_MASK	0x7
+
 /* Interrupt Register(IR) */
 #define IR_ALL_INT	0xffffffff
 #define IR_STE		BIT(31)

@@ -131,10 +156,11 @@ enum m_can_reg {
 #define IR_RF0F		BIT(2)
 #define IR_RF0W		BIT(1)
 #define IR_RF0N		BIT(0)
-#define IR_ERR_ALL	(IR_STE	| IR_FOE | IR_ACKE | IR_BE | IR_CRCE | \
-		IR_WDI | IR_BO | IR_EW | IR_EP | IR_ELO | IR_BEU | \
-		IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | IR_RF1L | \
-		IR_RF0L)
+#define IR_ERR_STATE	(IR_BO | IR_EW | IR_EP)
+#define IR_ERR_BUS	(IR_STE	| IR_FOE | IR_ACKE | IR_BE | IR_CRCE | \
+		IR_WDI | IR_ELO | IR_BEU | IR_BEC | IR_TOO | IR_MRAF | \
+		IR_TSW | IR_TEFL | IR_RF1L | IR_RF0L)
+#define IR_ERR_ALL	(IR_ERR_STATE | IR_ERR_BUS)
 
 /* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
 #define RXFC_FWM_OFF	24

@@ -320,12 +346,175 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 	return num_rx_pkts;
 }
 
+static int m_can_handle_lost_msg(struct net_device *dev)
+{
+	struct net_device_stats *stats = &dev->stats;
+	struct sk_buff *skb;
+	struct can_frame *frame;
+
+	netdev_err(dev, "msg lost in rxf0\n");
+
+	skb = alloc_can_err_skb(dev, &frame);
+	if (unlikely(!skb))
+		return 0;

+
+	return 1;
+}
+
 static int m_can_poll(struct napi_struct *napi, int quota)
 {
 	struct net_device *dev = napi->dev;
 	struct m_can_priv *priv = netdev_priv(dev);
 	u32 work_done = 0;
-	u32 irqstatus;
+	u32 irqstatus, psr;
 
 	irqstatus = m_can_read(priv, M_CAN_IR);
 	if (irqstatus)

@@ -337,6 +526,48 @@ static int m_can_poll(struct napi_struct *napi, int quota)
 	if (!irqstatus)
 		goto end;
 
+	psr = m_can_read(priv, M_CAN_PSR);
+	if (irqstatus & IR_ERR_STATE) {
+		if ((psr & PSR_EW) &&
+			(priv->can.state != CAN_STATE_ERROR_WARNING)) {
+			netdev_dbg(dev, "entered error warning state\n");
+			work_done += m_can_handle_state_change(dev,
+					CAN_STATE_ERROR_WARNING);
+		}
+
+		if ((psr & PSR_EP) &&
+			(priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
+			netdev_dbg(dev, "entered error warning state\n");
+			work_done += m_can_handle_state_change(dev,
+					CAN_STATE_ERROR_PASSIVE);
+		}
+
+		if ((psr & PSR_BO) &&
+			(priv->can.state != CAN_STATE_BUS_OFF)) {
+			netdev_dbg(dev, "entered error warning state\n");
+			work_done += m_can_handle_state_change(dev,
+					CAN_STATE_BUS_OFF);
+		}

+	}
+
 	if (irqstatus & IR_RF0N)
 		/* handle events corresponding to receive message objects */
 		work_done += m_can_do_rx_poll(dev, (quota - work_done));

@@ -369,31 +600,18 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	if (ir & IR_ALL_INT)
 		m_can_write(priv, M_CAN_IR, ir);
 
-	if (ir & IR_ERR_ALL) {
-		netdev_dbg(dev, "bus error\n");
-		/* TODO: handle bus error */
-	}
-
-	/* save irqstatus for later using */
-	priv->irqstatus = ir;
-
 	/*
 	 * schedule NAPI in case of
 	 * - rx IRQ
-	 * - state change IRQ(TODO)
-	 * - bus error IRQ and bus error reporting (TODO)
+	 * - state change IRQ
+	 * - bus error IRQ and bus error reporting
 	 */
-	if (ir & IR_RF0N) {
+	if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) {
+		priv->irqstatus = ir;
 		m_can_enable_all_interrupts(priv, false);
 		napi_schedule(&priv->napi);
 	}
 
-	/* FIFO overflow */
-	if (ir & IR_RF0L) {
-		dev->stats.rx_over_errors++;
-		dev->stats.rx_errors++;
-	}
-
 	/* transmission complete interrupt */
 	if (ir & IR_TC) {
 		netdev_dbg(dev, "tx complete\n");

@@ -446,7 +664,6 @@ static int m_can_set_bittiming(struct net_device *dev)
  * - setup bittiming
  * - TODO:
  *   1) other working modes support like monitor, loopback...
- *   2) lec error status report enable
  */
 static void m_can_chip_config(struct net_device *dev)
 {

@@ -515,14 +732,6 @@ static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
 	return 0;
 }
 
-static int m_can_get_berr_counter(const struct net_device *dev,
-				  struct can_berr_counter *bec)
-{
-	/* TODO */
-
-	return 0;
-}
-
 static void free_m_can_dev(struct net_device *dev)
 {
 	free_candev(dev);