From 996a953de02ffb852c9ac736f4e892008ed68884 Mon Sep 17 00:00:00 2001 From: Fabio Baltieri Date: Tue, 18 Dec 2012 18:50:55 +0100 Subject: [PATCH] can: add tx/rx LED trigger support This patch implements the functions to add two LED triggers, named -tx and -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 Cc: Marc Kleine-Budde Signed-off-by: Fabio Baltieri Acked-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- drivers/net/can/Kconfig | 11 +++++ drivers/net/can/Makefile | 2 + drivers/net/can/led.c | 86 ++++++++++++++++++++++++++++++++++++++++ include/linux/can/dev.h | 8 ++++ include/linux/can/led.h | 42 ++++++++++++++++++++ 5 files changed, 149 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 0c5a65682d01..1cca19f1c490 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -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 diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index 7de59862bbe9..c7440392adbb 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 000000000000..c50a0d741c57 --- /dev/null +++ b/drivers/net/can/led.c @@ -0,0 +1,86 @@ +/* + * Copyright 2012, Fabio Baltieri + * + * 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 +#include +#include +#include +#include +#include + +#include + +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 2b2fc345afca..7747d9bcdc84 100644 --- a/include/linux/can/dev.h +++ b/include/linux/can/dev.h @@ -16,6 +16,7 @@ #include #include #include +#include /* * 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 000000000000..12d5549abb95 --- /dev/null +++ b/include/linux/can/led.h @@ -0,0 +1,42 @@ +/* + * Copyright 2012, Fabio Baltieri + * + * 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 +#include + +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 -- 2.30.2