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: Oliver Hartkopp <socket...@hartkopp.net>
Cc: Wolfgang Grandegger <w...@grandegger.com>
Cc: Marc Kleine-Budde <m...@pengutronix.de>
Signed-off-by: Fabio Baltieri <fabio.balti...@gmail.com>
---
Hi all,
so, v6, change trigger names for fixed size allocation capped to (IFNAMSIZ + 4)
and removed kasprintf as suggested by Oliver (thanks!).
This also has the side effect of reducing the error path to just one check to
devres_alloc return value... nice!
I've put CAN_LED_NAME_SZ definition with the active function declaration,
but used sizeof(priv->tx_led_trig_name) as snprintf length argument in the
code, as it looks cleaner to me.
I'm not reposting the flexcan patch as it's not affected by the change.
Fabio
drivers/net/can/Kconfig | 12 +++++++
drivers/net/can/Makefile | 2 ++
drivers/net/can/led.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/can/dev.h | 8 +++++
include/linux/can/led.h | 42 +++++++++++++++++++++++
5 files changed, 153 insertions(+)
create mode 100644 drivers/net/can/led.c
create mode 100644 include/linux/can/led.h
diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig
index bb709fd..19dec19 100644
--- a/drivers/net/can/Kconfig
+++ b/drivers/net/can/Kconfig
@@ -54,6 +54,18 @@ config CAN_CALC_BITTIMING
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 CAN_DEV
+ 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 CAN_DEV && (ARCH_AT91SAM9263 || ARCH_AT91SAM9X5)
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile
index 938be37..24ee98b 100644
--- a/drivers/net/can/Makefile
+++ b/drivers/net/can/Makefile
@@ -8,6 +8,8 @@ obj-$(CONFIG_CAN_SLCAN) += slcan.o
obj-$(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..eaa14ac
--- /dev/null
+++ b/drivers/net/can/led.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2012, Fabio Baltieri <fabio.balti...@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);
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 2b2fc34..7747d9b 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -16,6 +16,7 @@
#include <linux/can.h>
#include <linux/can/netlink.h>
#include <linux/can/error.h>
+#include <linux/can/led.h>
/*
* CAN mode
@@ -52,6 +53,13 @@ struct can_priv {
unsigned int echo_skb_max;
struct sk_buff **echo_skb;
+
+#ifdef CONFIG_CAN_LEDS
+ struct led_trigger *tx_led_trig;
+ char tx_led_trig_name[CAN_LED_NAME_SZ];
+ struct led_trigger *rx_led_trig;
+ char rx_led_trig_name[CAN_LED_NAME_SZ];
+#endif
};
/*
diff --git a/include/linux/can/led.h b/include/linux/can/led.h
new file mode 100644
index 0000000..12d5549
--- /dev/null
+++ b/include/linux/can/led.h
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2012, Fabio Baltieri <fabio.balti...@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.
+ */
+
+#ifndef CAN_LED_H
+#define CAN_LED_H
+
+#include <linux/if.h>
+#include <linux/leds.h>
+
+enum can_led_event {
+ CAN_LED_EVENT_OPEN,
+ CAN_LED_EVENT_STOP,
+ CAN_LED_EVENT_TX,
+ CAN_LED_EVENT_RX,
+};
+
+#ifdef CONFIG_CAN_LEDS
+
+/* keep space for interface name + "-tx"/"-rx" suffix and null terminator */
+#define CAN_LED_NAME_SZ (IFNAMSIZ + 4)
+
+void can_led_event(struct net_device *netdev, enum can_led_event event);
+void devm_can_led_init(struct net_device *netdev);
+
+#else
+
+static inline void can_led_event(struct net_device *netdev,
+ enum can_led_event event)
+{
+}
+static inline void devm_can_led_init(struct net_device *netdev)
+{
+}
+
+#endif
+
+#endif
--
1.7.11.rc1.9.gf623ca1.dirty
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