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 capable of giving back the values of the rx/tx errors
counters, to provide more details and statistics to the linux-can layer.
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 any
CAN_STATE_ERROR_xxx state.
Signed-off-by: Stephane Grosjean <s.grosjean@xxxxxxxxxxxxxxx>
---
drivers/net/can/usb/peak_usb/pcan_usb.c | 133 +++++++++++++++++++++---
1 file changed, 117 insertions(+), 16 deletions(-)
diff --git a/drivers/net/can/usb/peak_usb/pcan_usb.c b/drivers/net/can/usb/peak_usb/pcan_usb.c
index fedfa6f7a5e8..419cf2953a0d 100644
--- a/drivers/net/can/usb/peak_usb/pcan_usb.c
+++ b/drivers/net/can/usb/peak_usb/pcan_usb.c
@@ -41,6 +41,7 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
#define PCAN_USB_CMD_SN 6
#define PCAN_USB_CMD_REGISTER 9
#define PCAN_USB_CMD_EXT_VCC 10
+#define PCAN_USB_CMD_ERR_FR 11
/* PCAN_USB_CMD_SET_BUS number arg */
#define PCAN_USB_BUS_XCVER 2
@@ -82,6 +83,10 @@ 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
@@ -101,11 +106,25 @@ MODULE_SUPPORTED_DEVICE("PEAK-System PCAN-USB adapter");
#define PCAN_USB_REC_TS 4
#define PCAN_USB_REC_BUSEVT 5
+/* CAN bus events notifications selection mask */
+#define PCAN_USB_ERR_RXERR 0x02 /* ask for rxerr counter */
+#define PCAN_USB_ERR_TXERR 0x04 /* ask for txerr counter */
+
+/* This mask generates an usb packet each time the state of the bus changes.
+ * In other words, its interest is to know which side among rx and tx is
+ * responsible of the change of the bus state.
+ */
+#define PCAN_USB_BERR_MASK (PCAN_USB_ERR_RXERR | PCAN_USB_ERR_TXERR)
+
+/* identify bus event packets with rx/tx error counters */
+#define PCAN_USB_ERR_CNT 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 */
@@ -212,6 +231,16 @@ static int pcan_usb_set_silent(struct peak_usb_device *dev, u8 onoff)
PCAN_USB_BUS_SILENT_MODE, 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, PCAN_USB_CMD_ERR_FR, PCAN_USB_SET, args);
+}
+
static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
{
u8 args[PCAN_USB_CMD_ARGS_LEN] = {
@@ -445,7 +474,7 @@ 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
@@ -469,7 +498,7 @@ 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
@@ -508,29 +537,50 @@ 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;
case CAN_STATE_ERROR_ACTIVE:
cf->can_id |= CAN_ERR_CRTL;
cf->data[1] = CAN_ERR_CRTL_ACTIVE;
+
+ /* sync local copies of rxerr/txerr counters */
+ mc->pdev->bec.txerr = 0;
+ mc->pdev->bec.rxerr = 0;
break;
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;
@@ -552,6 +602,30 @@ static int pcan_usb_decode_error(struct pcan_usb_msg_context *mc, u8 n,
return 0;
}
+/* decode bus event usb packet: first byte contains rxerr while 2nd one contains
+ * txerr.
+ */
+static int pcan_usb_handle_bus_evt(struct pcan_usb_msg_context *mc, u8 ir)
+{
+ struct pcan_usb *pdev = mc->pdev;
+
+ /* acccording to the content of the packet */
+ switch (ir) {
+ case PCAN_USB_ERR_CNT:
+
+ /* save rx/tx error counters from in the device context */
+ pdev->bec.rxerr = mc->ptr[0];
+ pdev->bec.txerr = mc->ptr[1];
+ break;
+
+ default:
+ /* reserved */
+ break;
+ }
+
+ return 0;
+}
+
/*
* decode non-data usb message
*/
@@ -606,9 +680,10 @@ 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");
+ /* bus event notifications (get rxerr/txerr) */
+ err = pcan_usb_handle_bus_evt(mc, n);
+ if (err)
+ return err;
break;
default:
netdev_err(mc->netdev, "unexpected function %u\n", f);
@@ -792,20 +867,44 @@ 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 received 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 error counter changes (if requested by user) */
+ if (dev->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) {
+ err = pcan_usb_set_err_frame(dev, PCAN_USB_BERR_MASK);
+ if (err)
+ netdev_warn(dev->netdev,
+ "Asking for BERR reporting error %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)
@@ -892,7 +991,8 @@ const struct peak_usb_adapter pcan_usb = {
.name = "PCAN-USB",
.device_id = PCAN_USB_PRODUCT_ID,
.ctrl_count = 1,
- .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY,
+ .ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LISTENONLY |
+ CAN_CTRLMODE_BERR_REPORTING,
.clock = {
.freq = PCAN_USB_CRYSTAL_HZ / 2 ,
},
@@ -925,4 +1025,5 @@ 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
