This patch adds the support of the rx/tx errors CAN counters to the
driver of the PCAN-USB PC-CAN interface from PEAK-System GmbH.
The PCAN-USB is internally equipped with a SJA1000 -like CAN controller,
therefore it is capable of giving back the values of the rx/tx errors
counters, to provide more details and statistics to the linux-can layer.
Moreover, getting these values allows the driver to better tune
CAN_ERR_CRTL_TX_xxx and CAN_ERR_CRTL_RX_xxx bits in case of
the interface enters the CAN_STATE_ERROR_xxx state.
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
---
drivers/net/can/usb/peak_usb/pcan_usb.c | 175 ++++++++++++++++++++++--
1 file changed, 160 insertions(+), 15 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
index d2539c95adb6..b0b722cb327c 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
@@ -66,6 +66,10 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
#define PCAN_USB_ERROR_QOVR 0x40
#define PCAN_USB_ERROR_TXQFULL 0x80
+#define PCAN_USB_ERROR_BUS (PCAN_USB_ERROR_BUS_LIGHT | \
+ PCAN_USB_ERROR_BUS_HEAVY | \
+ PCAN_USB_ERROR_BUS_OFF)
+
/* SJA1000 modes */
#define SJA1000_MODE_NORMAL 0x00
#define SJA1000_MODE_INIT 0x01
@@ -85,11 +89,31 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
#define PCAN_USB_REC_TS 4
#define PCAN_USB_REC_BUSEVT 5
+/* CAN bus errors notifications */
+#define PCAN_USB_ERR_ECC 0x01
+#define PCAN_USB_ERR_RXERR 0x02
+#define PCAN_USB_ERR_TXERR 0x04
+#define PCAN_USB_ERR_RXERR_CNT 0x08
+#define PCAN_USB_ERR_TXERR_CNT 0x10
+
+/* SJA1000 ECC register */
+#define ECC_SEG 0x1f
+#define ECC_DIR 0x20
+#define ECC_ERR 6
+#define ECC_BIT 0x00
+#define ECC_FORM 0x40
+#define ECC_STUFF 0x80
+#define ECC_MASK 0xc0
+
+/* SJA1000 Bus Error Interrupt */
+#define IRQ_BEI 0x80
+
/* private to PCAN-USB adapter */
struct pcan_usb {
struct peak_usb_device dev;
struct peak_time_ref time_ref;
struct timer_list restart_timer;
+ struct can_berr_counter bec;
};
/* incoming message context for decoding */
@@ -193,6 +217,16 @@ static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff)
return pcan_usb_send_cmd(dev, 3, 3, args);
}
+/* send the cmd to be notified from bus errors */
+static int pcan_usb_set_err_frame(struct peak_usb_device *dev, u8 err_mask)
+{
+ u8 args[PCAN_USB_CMD_ARGS_LEN] = {
+ [0] = err_mask,
+ };
+
+ return pcan_usb_send_cmd(dev, 11, 2, args);
+}
+
static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
{
u8 args[PCAN_USB_CMD_ARGS_LEN] = {
@@ -426,7 +460,7 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
new_state = CAN_STATE_BUS_OFF;
break;
}
- if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
+ if (n & ~PCAN_USB_ERROR_BUS) {
/*
* trick to bypass next comparison and process other
* errors
@@ -450,7 +484,7 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
new_state = CAN_STATE_ERROR_WARNING;
break;
}
- if (n & (PCAN_USB_ERROR_RXQOVR | PCAN_USB_ERROR_QOVR)) {
+ if (n & ~PCAN_USB_ERROR_BUS) {
/*
* trick to bypass next comparison and process other
* errors
@@ -489,15 +523,23 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
case CAN_STATE_ERROR_PASSIVE:
cf->can_id |= CAN_ERR_CRTL;
- cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE |
- CAN_ERR_CRTL_RX_PASSIVE;
+ cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?
+ CAN_ERR_CRTL_TX_PASSIVE :
+ CAN_ERR_CRTL_RX_PASSIVE;
+ cf->data[6] = mc->pdev->bec.txerr;
+ cf->data[7] = mc->pdev->bec.rxerr;
+
mc->pdev->dev.can.can_stats.error_passive++;
break;
case CAN_STATE_ERROR_WARNING:
cf->can_id |= CAN_ERR_CRTL;
- cf->data[1] |= CAN_ERR_CRTL_TX_WARNING |
- CAN_ERR_CRTL_RX_WARNING;
+ cf->data[1] = (mc->pdev->bec.txerr > mc->pdev->bec.rxerr) ?
+ CAN_ERR_CRTL_TX_WARNING :
+ CAN_ERR_CRTL_RX_WARNING;
+ cf->data[6] = mc->pdev->bec.txerr;
+ cf->data[7] = mc->pdev->bec.rxerr;
+
mc->pdev->dev.can.can_stats.error_warning++;
break;
@@ -508,10 +550,19 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
default:
/* CAN_STATE_MAX (trick to handle other errors) */
- cf->can_id |= CAN_ERR_CRTL;
- cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
- mc->netdev->stats.rx_over_errors++;
- mc->netdev->stats.rx_errors++;
+ if (n & PCAN_USB_ERROR_TXQFULL)
+ netdev_dbg(mc->netdev, "device Tx queue full)\n");
+
+ if (n & PCAN_USB_ERROR_RXQOVR) {
+ netdev_dbg(mc->netdev, "data overrun interrupt\n");
+ cf->can_id |= CAN_ERR_CRTL;
+ cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
+ mc->netdev->stats.rx_over_errors++;
+ mc->netdev->stats.rx_errors++;
+ }
+
+ cf->data[6] = mc->pdev->bec.txerr;
+ cf->data[7] = mc->pdev->bec.rxerr;
new_state = mc->pdev->dev.can.state;
break;
@@ -533,6 +584,74 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
return 0;
}
+static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir,
+ u8 status_len)
+{
+ struct pcan_usb *pdev = mc->pdev;
+
+ /* process bus error interrupt */
+ if (ir & IRQ_BEI) {
+ struct net_device_stats *stats = &mc->netdev->stats;
+ struct sk_buff *skb;
+ struct can_frame *cf;
+ u8 ecc = mc->ptr[0];
+
+ /* save rx/tx error counters from data bytes */
+ pdev->bec.rxerr = mc->ptr[1];
+ pdev->bec.txerr = mc->ptr[2];
+
+ /* allocate an skb to store the error frame */
+ skb = alloc_can_err_skb(mc->netdev, &cf);
+ if (!skb)
+ return -ENOMEM;
+
+ cf->data[6] = pdev->bec.txerr;
+ cf->data[7] = pdev->bec.rxerr;
+
+ /* The PCAN-USB is equipped with a SJA1000, thus copy from
+ * sja1000.c how to handle the BEI:
+ */
+ pdev->dev.can.can_stats.bus_error++;
+ stats->rx_errors++;
+
+ cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
+
+ /* set error type according to 1st data byte (ECC) */
+ switch (ecc & ECC_MASK) {
+ case ECC_BIT:
+ cf->data[2] |= CAN_ERR_PROT_BIT;
+ break;
+ case ECC_FORM:
+ cf->data[2] |= CAN_ERR_PROT_FORM;
+ break;
+ case ECC_STUFF:
+ cf->data[2] |= CAN_ERR_PROT_STUFF;
+ break;
+ default:
+ break;
+ }
+
+ /* set error location */
+ cf->data[3] = ecc & ECC_SEG;
+
+ /* Error occurred during transmission? */
+ if ((ecc & ECC_DIR) == 0)
+ cf->data[2] |= CAN_ERR_PROT_TX;
+ if (status_len & PCAN_USB_STATUSLEN_TIMESTAMP) {
+ struct skb_shared_hwtstamps *hwts = skb_hwtstamps(skb);
+
+ peak_usb_get_ts_time(&mc->pdev->time_ref, mc->ts16,
+ &hwts->hwtstamp);
+ }
+
+ stats->rx_packets++;
+ stats->rx_bytes += cf->can_dlc;
+ netif_rx(skb);
+ }
+
+ return 0;
+}
+
/*
* decode non-data usb message
*/
@@ -587,9 +706,9 @@ static int pcan_usb_decode_status(struct pcan_usb_msg_context *mc,
break;
case PCAN_USB_REC_BUSEVT:
- /* error frame/bus event */
- if (n & PCAN_USB_ERROR_TXQFULL)
- netdev_dbg(mc->netdev, "device Tx queue full)\n");
+ err = pcan_usb_handle_bus_evt(mc, n, status_len);
+ if (err)
+ return err;
break;
default:
netdev_err(mc->netdev, "unexpected function %u\n", f);
@@ -773,20 +892,45 @@ static int pcan_usb_encode_msg(struct peak_usb_device *dev, struct sk_buff *skb,
return 0;
}
+/* socket callback used to copy berr counters values receieved through USB */
+static int pcan_usb_get_berr_counter(const struct net_device *netdev,
+ struct can_berr_counter *bec)
+{
+ struct peak_usb_device *dev = netdev_priv(netdev);
+ struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
+
+ *bec = pdev->bec;
+
+ /* must return 0 */
+ return 0;
+}
+
/*
* start interface
*/
static int pcan_usb_start(struct peak_usb_device *dev)
{
struct pcan_usb *pdev = container_of(dev, struct pcan_usb, dev);
+ int err;
/* number of bits used in timestamps read from adapter struct */
peak_usb_init_time_ref(&pdev->time_ref, &pcan_usb);
+ pdev->bec.rxerr = 0;
+ pdev->bec.txerr = 0;
+
+ /* be notified on any error counter change */
+ err = pcan_usb_set_err_frame(dev, PCAN_USB_ERR_ECC |
+ PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR |
+ PCAN_USB_ERR_RXERR_CNT |
+ PCAN_USB_ERR_TXERR_CNT);
+ if (err)
+ netdev_warn(dev->netdev,
+ "CAN bus error counters not available (err %u)\n",
+ err);
+
/* if revision greater than 3, can put silent mode on/off */
if (dev->device_rev > 3) {
- int err;
-
err = pcan_usb_set_silent(dev,
dev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY);
if (err)
@@ -906,4 +1050,5 @@ const struct peak_usb_adapter pcan_usb = {
.dev_encode_msg = pcan_usb_encode_msg,
.dev_start = pcan_usb_start,
.dev_restart_async = pcan_usb_restart_async,
+ .do_get_berr_counter = pcan_usb_get_berr_counter,
};
--
2.20.1
