From 996a953de02ffb852c9ac736f4e892008ed68884 Mon Sep 17 00:00:00 2001 From: Fabio Baltieri Date: Tue, 18 Dec 2012 18:50:55 +0100 Subject: 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/led.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 86 insertions(+) create mode 100644 drivers/net/can/led.c (limited to 'drivers/net/can/led.c') 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); -- cgit v1.2.3 From a1ef7bd9fce8aba8e4701e60208148fb3bc9bdd4 Mon Sep 17 00:00:00 2001 From: Kurt Van Dijck Date: Tue, 18 Dec 2012 18:50:57 +0100 Subject: can: rename LED trigger name on netdev renames The LED trigger name for CAN devices is based on the initial CAN device name, but does never change. The LED trigger name is not guaranteed to be unique in case of hotplugging CAN devices. This patch tries to address this problem by modifying the LED trigger name according to the CAN device name when the latter changes. v1 - Kurt Van Dijck v2 - Fabio Baltieri - remove rename blocking if trigger is bound - use led-subsystem function for the actual rename (still WiP) - call init/exit functions from dev.c v3 - Kurt Van Dijck - safe operation for non-candev based devices (vcan, slcan) based on earlier patch v4 - Kurt Van Dijck - trivial patch mistakes fixed Signed-off-by: Kurt Van Dijck Signed-off-by: Fabio Baltieri Signed-off-by: Marc Kleine-Budde --- drivers/net/can/dev.c | 5 +++++ drivers/net/can/led.c | 38 ++++++++++++++++++++++++++++++++++++++ include/linux/can/led.h | 9 +++++++++ 3 files changed, 52 insertions(+) (limited to 'drivers/net/can/led.c') diff --git a/drivers/net/can/dev.c b/drivers/net/can/dev.c index 13e738098fbe..6abc6e59778e 100644 --- a/drivers/net/can/dev.c +++ b/drivers/net/can/dev.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #define MOD_DESC "CAN device driver interface" @@ -811,6 +812,8 @@ static __init int can_dev_init(void) { int err; + can_led_notifier_init(); + err = rtnl_link_register(&can_link_ops); if (!err) printk(KERN_INFO MOD_DESC "\n"); @@ -822,6 +825,8 @@ module_init(can_dev_init); static __exit void can_dev_exit(void) { rtnl_link_unregister(&can_link_ops); + + can_led_notifier_exit(); } module_exit(can_dev_exit); diff --git a/drivers/net/can/led.c b/drivers/net/can/led.c index c50a0d741c57..f27fca65dc4a 100644 --- a/drivers/net/can/led.c +++ b/drivers/net/can/led.c @@ -1,5 +1,6 @@ /* * Copyright 2012, Fabio Baltieri + * Copyright 2012, Kurt Van Dijck * * 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 @@ -84,3 +85,40 @@ void devm_can_led_init(struct net_device *netdev) devres_add(&netdev->dev, res); } EXPORT_SYMBOL_GPL(devm_can_led_init); + +/* NETDEV rename notifier to rename the associated led triggers too */ +static int can_led_notifier(struct notifier_block *nb, unsigned long msg, + void *data) +{ + struct net_device *netdev = data; + struct can_priv *priv = safe_candev_priv(netdev); + char name[CAN_LED_NAME_SZ]; + + if (!priv) + return NOTIFY_DONE; + + if (msg == NETDEV_CHANGENAME) { + snprintf(name, sizeof(name), "%s-tx", netdev->name); + led_trigger_rename_static(name, priv->tx_led_trig); + + snprintf(name, sizeof(name), "%s-rx", netdev->name); + led_trigger_rename_static(name, priv->rx_led_trig); + } + + return NOTIFY_DONE; +} + +/* notifier block for netdevice event */ +static struct notifier_block can_netdev_notifier __read_mostly = { + .notifier_call = can_led_notifier, +}; + +int __init can_led_notifier_init(void) +{ + return register_netdevice_notifier(&can_netdev_notifier); +} + +void __exit can_led_notifier_exit(void) +{ + unregister_netdevice_notifier(&can_netdev_notifier); +} diff --git a/include/linux/can/led.h b/include/linux/can/led.h index 12d5549abb95..9c1167baf273 100644 --- a/include/linux/can/led.h +++ b/include/linux/can/led.h @@ -26,6 +26,8 @@ enum can_led_event { void can_led_event(struct net_device *netdev, enum can_led_event event); void devm_can_led_init(struct net_device *netdev); +int __init can_led_notifier_init(void); +void __exit can_led_notifier_exit(void); #else @@ -36,6 +38,13 @@ static inline void can_led_event(struct net_device *netdev, static inline void devm_can_led_init(struct net_device *netdev) { } +static inline int can_led_notifier_init(void) +{ + return 0; +} +static inline void can_led_notifier_exit(void) +{ +} #endif -- cgit v1.2.3