[PATCH 6/6] can: gs_usb: support reading error counters

[Marc Kleine-Budde <mkl@pengutronix.de>]

From: Jeroen Hofstee <jhofstee@victronenergy.com>

the format of this message is a bit weird, single bytes would be
sufficient. At the moment it uses the existing struct gs_device_state.

Not-Signed-off-by: Jeroen Hofstee <jhofstee@victronenergy.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 drivers/net/can/usb/gs_usb.c | 40 ++++++++++++++++++++++++++++++++++++
 1 file changed, 40 insertions(+)

diff --git a/drivers/net/can/usb/gs_usb.c b/drivers/net/can/usb/gs_usb.c
index fc5e8d08eb4d..dfabd9cec19b 100644
--- a/drivers/net/can/usb/gs_usb.c
+++ b/drivers/net/can/usb/gs_usb.c
@@ -961,6 +961,43 @@ static int gs_can_open(struct net_device *netdev)
 	return 0;
 }
 
+static int gs_usb_get_state(const struct net_device *netdev,
+			    struct can_berr_counter *bec,
+			    enum can_state *state)
+{
+	struct gs_can *dev = netdev_priv(netdev);
+	struct gs_device_state ds;
+	int rc;
+
+	rc = usb_control_msg_recv(interface_to_usbdev(dev->iface), 0,
+				  GS_USB_BREQ_GET_STATE,
+				  USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_INTERFACE,
+				  dev->channel, 0,
+				  &ds, sizeof(ds),
+				  USB_CTRL_GET_TIMEOUT,
+				  GFP_KERNEL);
+
+	if (rc)
+		return rc;
+
+	if (ds.state >= CAN_STATE_MAX)
+		return -EOPNOTSUPP;
+
+	*state = ds.state;
+	bec->txerr = ds.txerr;
+	bec->rxerr = ds.rxerr;
+
+	return 0;
+}
+
+static int gs_usb_can_get_berr_counter(const struct net_device *netdev,
+				       struct can_berr_counter *bec)
+{
+	enum can_state state;
+
+	return gs_usb_get_state(netdev, bec, &state);
+}
+
 static int gs_can_close(struct net_device *netdev)
 {
 	int rc;
@@ -1234,6 +1271,9 @@ static struct gs_can *gs_make_candev(unsigned int channel,
 	if (feature & GS_CAN_FEATURE_BERR_REPORTING)
 		dev->can.ctrlmode_supported |= CAN_CTRLMODE_BERR_REPORTING;
 
+	if (feature & GS_CAN_FEATURE_GET_STATE)
+		dev->can.do_get_berr_counter = gs_can_get_berr_counter;
+
 	/* The CANtact Pro from LinkLayer Labs is based on the
 	 * LPC54616 µC, which is affected by the NXP LPC USB transfer
 	 * erratum. However, the current firmware (version 2) doesn't
-- 
2.35.1