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Date: Fri, 27 Jun 2014 18:00:45 +0800
From: Dong Aisheng <b29396@...escale.com>
To: <linux-can@...r.kernel.org>
CC: <netdev@...r.kernel.org>, <wg@...ndegger.com>,
<mkl@...gutronix.de>, <devicetree@...r.kernel.org>
Subject: [PATCH 2/3] can: m_can: add bus error handling
Add bus error, state change, lost message handling mechanism.
Signed-off-by: Dong Aisheng <b29396@...escale.com>
---
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;
+
+ frame->can_id |= CAN_ERR_CRTL;
+ frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
+ stats->rx_errors++;
+ stats->rx_over_errors++;
+
+ netif_receive_skb(skb);
+
+ return 1;
+}
+
+static int m_can_handle_bus_err(struct net_device *dev,
+ enum m_can_lec_type lec_type)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+ struct net_device_stats *stats = &dev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+
+ /* early exit if no lec update */
+ if (lec_type == LEC_UNUSED)
+ return 0;
+
+ /* propagate the error condition to the CAN stack */
+ skb = alloc_can_err_skb(dev, &cf);
+ if (unlikely(!skb))
+ return 0;
+
+ /*
+ * check for 'last error code' which tells us the
+ * type of the last error to occur on the CAN bus
+ */
+ priv->can.can_stats.bus_error++;
+ stats->rx_errors++;
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+ cf->data[2] |= CAN_ERR_PROT_UNSPEC;
+
+ switch (lec_type) {
+ case LEC_STUFF_ERROR:
+ netdev_dbg(dev, "stuff error\n");
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+ case LEC_FORM_ERROR:
+ netdev_dbg(dev, "form error\n");
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+ case LEC_ACK_ERROR:
+ netdev_dbg(dev, "ack error\n");
+ cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
+ CAN_ERR_PROT_LOC_ACK_DEL);
+ break;
+ case LEC_BIT1_ERROR:
+ netdev_dbg(dev, "bit1 error\n");
+ cf->data[2] |= CAN_ERR_PROT_BIT1;
+ break;
+ case LEC_BIT0_ERROR:
+ netdev_dbg(dev, "bit0 error\n");
+ cf->data[2] |= CAN_ERR_PROT_BIT0;
+ break;
+ case LEC_CRC_ERROR:
+ netdev_dbg(dev, "CRC error\n");
+ cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
+ CAN_ERR_PROT_LOC_CRC_DEL);
+ break;
+ default:
+ break;
+ }
+
+ netif_receive_skb(skb);
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+
+ return 1;
+}
+
+static int m_can_get_berr_counter(const struct net_device *dev,
+ struct can_berr_counter *bec)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+ unsigned int ecr;
+
+ ecr = m_can_read(priv, M_CAN_ECR);
+ bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
+ bec->txerr = ecr & ECR_TEC_MASK;
+
+ return 0;
+}
+
+static int m_can_handle_state_change(struct net_device *dev,
+ enum can_state new_state)
+{
+ struct m_can_priv *priv = netdev_priv(dev);
+ struct net_device_stats *stats = &dev->stats;
+ struct can_frame *cf;
+ struct sk_buff *skb;
+ struct can_berr_counter bec;
+ unsigned int ecr;
+
+ /* propagate the error condition to the CAN stack */
+ skb = alloc_can_err_skb(dev, &cf);
+ if (unlikely(!skb))
+ return 0;
+
+ m_can_get_berr_counter(dev, &bec);
+
+ switch (new_state) {
+ case CAN_STATE_ERROR_ACTIVE:
+ /* error warning state */
+ priv->can.can_stats.error_warning++;
+ priv->can.state = CAN_STATE_ERROR_WARNING;
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] = (bec.txerr > bec.rxerr) ?
+ CAN_ERR_CRTL_TX_WARNING :
+ CAN_ERR_CRTL_RX_WARNING;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ break;
+ case CAN_STATE_ERROR_PASSIVE:
+ /* error passive state */
+ priv->can.can_stats.error_passive++;
+ priv->can.state = CAN_STATE_ERROR_PASSIVE;
+ cf->can_id |= CAN_ERR_CRTL;
+ ecr = m_can_read(priv, M_CAN_ECR);
+ if (ecr & ECR_RP)
+ cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
+ if (bec.txerr > 127)
+ cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
+ cf->data[6] = bec.txerr;
+ cf->data[7] = bec.rxerr;
+ break;
+ case CAN_STATE_BUS_OFF:
+ /* bus-off state */
+ priv->can.state = CAN_STATE_BUS_OFF;
+ cf->can_id |= CAN_ERR_BUSOFF;
+ /*
+ * disable all interrupts in bus-off mode to ensure that
+ * the CPU is not hogged down
+ */
+ m_can_enable_all_interrupts(priv, false);
+ can_bus_off(dev);
+ break;
+ default:
+ break;
+ }
+
+ netif_receive_skb(skb);
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+
+ 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_ERR_BUS) {
+ if (irqstatus & IR_RF0L)
+ work_done += m_can_handle_lost_msg(dev);
+
+ /* handle lec errors on the bus */
+ if (psr & LEC_UNUSED)
+ work_done += m_can_handle_bus_err(dev,
+ psr & LEC_UNUSED);
+
+ /* other unproccessed error interrupts */
+ if (irqstatus & IR_WDI)
+ netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
+ if (irqstatus & IR_TOO)
+ netdev_err(dev, "Timeout reached\n");
+ if (irqstatus & IR_MRAF)
+ netdev_err(dev, "Message RAM access failure occurred\n");
+ }
+
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);
--
1.7.8
--
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