Re: [PATCH v4] leds: trigger: Introduce a NETDEV trigger

This commit introduces a NETDEV trigger for named device
activity. Available triggers are link, rx, and tx.

Signed-off-by: Ben Whitten <redacted>

---
Changes in v4:
Adopt SPDX licence header
Changes in v3:
Cancel the software blink prior to a oneshot re-queue
Changes in v2:
Sort includes and redate documentation
Correct licence
Remove macro and replace with generic function using enums
Convert blink logic in stats work to use led_blink_oneshot
Uses configured brightness instead of FULL
---
 .../ABI/testing/sysfs-class-led-trigger-netdev     |  45 ++
 drivers/leds/trigger/Kconfig                       |   7 +
 drivers/leds/trigger/Makefile                      |   1 +
 drivers/leds/trigger/ledtrig-netdev.c              | 498 +++++++++++++++++++++
 4 files changed, 551 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-led-trigger-netdev
 create mode 100644 drivers/leds/trigger/ledtrig-netdev.c

diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-netdev b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev
new file mode 100644
index 0000000..451af6d
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-trigger-netdev

@@ -0,0 +1,45 @@
+What:		/sys/class/leds/<led>/device_name
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Specifies the network device name to monitor.
+
+What:		/sys/class/leds/<led>/interval
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Specifies the duration of the LED blink in milliseconds.
+		Defaults to 50 ms.
+
+What:		/sys/class/leds/<led>/link
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal the link state of the named network device.
+		If set to 0 (default), the LED's normal state is off.
+		If set to 1, the LED's normal state reflects the link state
+		of the named network device.
+		Setting this value also immediately changes the LED state.
+
+What:		/sys/class/leds/<led>/tx
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal transmission of data on the named network device.
+		If set to 0 (default), the LED will not blink on transmission.
+		If set to 1, the LED will blink for the milliseconds specified
+		in interval to signal transmission.
+
+What:		/sys/class/leds/<led>/rx
+Date:		Dec 2017
+KernelVersion:	4.16
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Signal reception of data on the named network device.
+		If set to 0 (default), the LED will not blink on reception.
+		If set to 1, the LED will blink for the milliseconds specified
+		in interval to signal reception.

diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index 3f9ddb9..4ec1853 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig

@@ -126,4 +126,11 @@ config LEDS_TRIGGER_PANIC
 	  a different trigger.
 	  If unsure, say Y.
 
+config LEDS_TRIGGER_NETDEV
+	tristate "LED Netdev Trigger"
+	depends on NET && LEDS_TRIGGERS
+	help
+	  This allows LEDs to be controlled by network device activity.
+	  If unsure, say Y.
+
 endif # LEDS_TRIGGERS

diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
index 9f2e868..59e163d 100644
--- a/drivers/leds/trigger/Makefile
+++ b/drivers/leds/trigger/Makefile

@@ -11,3 +11,4 @@ obj-$(CONFIG_LEDS_TRIGGER_DEFAULT_ON)	+= ledtrig-default-on.o
 obj-$(CONFIG_LEDS_TRIGGER_TRANSIENT)	+= ledtrig-transient.o
 obj-$(CONFIG_LEDS_TRIGGER_CAMERA)	+= ledtrig-camera.o
 obj-$(CONFIG_LEDS_TRIGGER_PANIC)	+= ledtrig-panic.o
+obj-$(CONFIG_LEDS_TRIGGER_NETDEV)	+= ledtrig-netdev.o

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
new file mode 100644
index 0000000..3d24573
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-netdev.c

@@ -0,0 +1,498 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright 2017 Ben Whitten <ben.whitten@gmail.com>
+// Copyright 2007 Oliver Jowett <oliver@opencloud.com>
+/*
+ * LED Kernel Netdev Trigger
+ *
+ * Toggles the LED to reflect the link and traffic state of a named net device
+ *
+ * Derived from ledtrig-timer.c which is:
+ *  Copyright 2005-2006 Openedhand Ltd.
+ *  Author: Richard Purdie <rpurdie@openedhand.com>
+ *
+ */