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

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
......@@ -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
......
......@@ -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/
......
/*
* 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);
......@@ -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
};
/*
......
/*
* 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
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