Commit 996a953d authored by Fabio Baltieri's avatar Fabio Baltieri Committed by Marc Kleine-Budde
Browse files

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: default avatarFabio Baltieri <fabio.baltieri@gmail.com>
Acked-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 0024d8ad

drivers/net/can/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -51,6 +51,17 @@ 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 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

drivers/net/can/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -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/

drivers/net/can/led.c

0 → 100644
+86 −0
Original line number Diff line number Diff line 
/*

 * 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);

include/linux/can/dev.h

+8 −0
Original line number Diff line number Diff line
@@ -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

};



/*

include/linux/can/led.h

0 → 100644
+42 −0
Original line number Diff line number Diff line 
/*

 * 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.

 */



#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

CRA Git | Maintained and supported by SUSTech CRA and CCSE