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 <chripell@fsfe.org>
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/mcp251x.c

@@ -60,6 +60,7 @@
 
 #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>
@@ -494,6 +495,9 @@ static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 
 	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);
 }
 
@@ -707,6 +711,8 @@ static int mcp251x_stop(struct net_device *net)
 
 	mutex_unlock(&priv->mcp_lock);
 
+	can_led_event(net, CAN_LED_EVENT_STOP);
+
 	return 0;
 }
 
@@ -905,6 +911,7 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
 		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;
@@ -968,6 +975,9 @@ static int mcp251x_open(struct net_device *net)
 		mcp251x_open_clean(net);
 		goto open_unlock;
 	}
+
+	can_led_event(net, CAN_LED_EVENT_OPEN);
+
 	netif_wake_queue(net);
 
 open_unlock:
@@ -1077,10 +1087,15 @@ static int mcp251x_can_probe(struct spi_device *spi)
 		pdata->transceiver_enable(0);
 
 	ret = register_candev(net);
-	if (!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);