can: add tx/rx LED trigger support
This patch implements the functions to add two LED triggers, named
<ifname>-tx and <ifname>-rx, to a canbus device driver.
Triggers are called from specific handlers by each CAN device driver and
can be disabled altogether with a Kconfig option.
The implementation keeps the LED on when the interface is UP and blinks
the LED on network activity at a configurable rate.
This only supports can-dev based drivers, as it uses some support field
in the can_priv structure.
Supported drivers should call devm_can_led_init() and can_led_event() as
needed.
Cleanup is handled automatically by devres, so no *_exit function is
needed.
Supported events are:
- CAN_LED_EVENT_OPEN: turn on tx/rx LEDs
- CAN_LED_EVENT_STOP: turn off tx/rx LEDs
- CAN_LED_EVENT_TX: trigger tx LED blink
- CAN_LED_EVENT_RX: trigger tx LED blink
Cc: Wolfgang Grandegger <wg@grandegger.com>
Cc: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Fabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index 0c5a656..1cca19f 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -51,6 +51,17 @@
arguments "tq", "prop_seg", "phase_seg1", "phase_seg2" and "sjw".
If unsure, say Y.
+config CAN_LEDS
+ bool "Enable LED triggers for Netlink based drivers"
+ depends on LEDS_CLASS
+ select LEDS_TRIGGERS
+ ---help---
+ This option adds two LED triggers for packet receive and transmit
+ events on each supported CAN device.
+
+ Say Y here if you are working on a system with led-class supported
+ LEDs and you want to use them as canbus activity indicators.
+
config CAN_AT91
tristate "Atmel AT91 onchip CAN controller"
depends on ARCH_AT91SAM9263 || ARCH_AT91SAM9X5
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index 7de5986..c744039 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -8,6 +8,8 @@
obj-$(CONFIG_CAN_DEV) += can-dev.o
can-dev-y := dev.o
+can-dev-$(CONFIG_CAN_LEDS) += led.o
+
obj-y += usb/
obj-y += softing/
diff --git a/drivers/net/can/led.c b/drivers/net/can/led.c
new file mode 100644
index 0000000..c50a0d7
--- /dev/null
+++ b/drivers/net/can/led.c
@@ -0,0 +1,86 @@
+/*
+ * Copyright 2012, Fabio Baltieri <fabio.baltieri@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/netdevice.h>
+#include <linux/can/dev.h>
+
+#include <linux/can/led.h>
+
+static unsigned long led_delay = 50;
+module_param(led_delay, ulong, 0644);
+MODULE_PARM_DESC(led_delay,
+ "blink delay time for activity leds (msecs, default: 50).");
+
+/* Trigger a LED event in response to a CAN device event */
+void can_led_event(struct net_device *netdev, enum can_led_event event)
+{
+ struct can_priv *priv = netdev_priv(netdev);
+
+ switch (event) {
+ case CAN_LED_EVENT_OPEN:
+ led_trigger_event(priv->tx_led_trig, LED_FULL);
+ led_trigger_event(priv->rx_led_trig, LED_FULL);
+ break;
+ case CAN_LED_EVENT_STOP:
+ led_trigger_event(priv->tx_led_trig, LED_OFF);
+ led_trigger_event(priv->rx_led_trig, LED_OFF);
+ break;
+ case CAN_LED_EVENT_TX:
+ if (led_delay)
+ led_trigger_blink_oneshot(priv->tx_led_trig,
+ &led_delay, &led_delay, 1);
+ break;
+ case CAN_LED_EVENT_RX:
+ if (led_delay)
+ led_trigger_blink_oneshot(priv->rx_led_trig,
+ &led_delay, &led_delay, 1);
+ break;
+ }
+}
+EXPORT_SYMBOL_GPL(can_led_event);
+
+static void can_led_release(struct device *gendev, void *res)
+{
+ struct can_priv *priv = netdev_priv(to_net_dev(gendev));
+
+ led_trigger_unregister_simple(priv->tx_led_trig);
+ led_trigger_unregister_simple(priv->rx_led_trig);
+}
+
+/* Register CAN LED triggers for a CAN device
+ *
+ * This is normally called from a driver's probe function
+ */
+void devm_can_led_init(struct net_device *netdev)
+{
+ struct can_priv *priv = netdev_priv(netdev);
+ void *res;
+
+ res = devres_alloc(can_led_release, 0, GFP_KERNEL);
+ if (!res) {
+ netdev_err(netdev, "cannot register LED triggers\n");
+ return;
+ }
+
+ snprintf(priv->tx_led_trig_name, sizeof(priv->tx_led_trig_name),
+ "%s-tx", netdev->name);
+ snprintf(priv->rx_led_trig_name, sizeof(priv->rx_led_trig_name),
+ "%s-rx", netdev->name);
+
+ led_trigger_register_simple(priv->tx_led_trig_name,
+ &priv->tx_led_trig);
+ led_trigger_register_simple(priv->rx_led_trig_name,
+ &priv->rx_led_trig);
+
+ devres_add(&netdev->dev, res);
+}
+EXPORT_SYMBOL_GPL(devm_can_led_init);