can: mcp251x: add LED trigger support

Add support for canbus activity led indicators on mcp251x devices by
calling appropriate can_led functions.

These are only enabled when CONFIG_CAN_LEDS is Y, becomes no-op
otherwise.

Cc: Christian Pellegrin <[e-mail]>
Cc: Wolfgang Grandegger <[e-mail]>
Cc: Marc Kleine-Budde <[e-mail]>
Signed-off-by: Fabio Baltieri <[e-mail]>
Signed-off-by: Marc Kleine-Budde <[e-mail]>

drivers/net/can/mcp251x.c

···
 
 #include <linux/can/core.h>
 #include <linux/can/dev.h>
+#include <linux/can/led.h>
 #include <linux/can/platform/mcp251x.h>
 #include <linux/completion.h>
 #include <linux/delay.h>
···
 
 	priv->net->stats.rx_packets++;
 	priv->net->stats.rx_bytes += frame->can_dlc;
+
+	can_led_event(priv->net, CAN_LED_EVENT_RX);
+
 	netif_rx_ni(skb);
 }
 
···
 
 	mutex_unlock(&priv->mcp_lock);
 
+	can_led_event(net, CAN_LED_EVENT_STOP);
+
 	return 0;
 }
 
···
 		if (intf & CANINTF_TX) {
 			net->stats.tx_packets++;
 			net->stats.tx_bytes += priv->tx_len - 1;
+			can_led_event(net, CAN_LED_EVENT_TX);
 			if (priv->tx_len) {
 				can_get_echo_skb(net, 0);
 				priv->tx_len = 0;
···
 		mcp251x_open_clean(net);
 		goto open_unlock;
 	}
+
+	can_led_event(net, CAN_LED_EVENT_OPEN);
+
 	netif_wake_queue(net);
 
 open_unlock:
···
 		pdata->transceiver_enable(0);
 
 	ret = register_candev(net);
-	if (!ret) {
-		dev_info(&spi->dev, "probed\n");
-		return ret;
-	}
+	if (ret)
+		goto error_probe;
+
+	devm_can_led_init(net);
+
+	dev_info(&spi->dev, "probed\n");
+
+	return ret;
+
 error_probe:
 	if (!mcp251x_enable_dma)
 		kfree(priv->spi_rx_buf);