With this patch, USB host activity can be signaled by blinking a LED.
This should work with all host controllers. Tested only with musb.
Signed-off-by: Michal Sojka <sojka@xxxxxxxxx>
---
drivers/usb/core/Kconfig | 9 +++++++++
drivers/usb/core/Makefile | 1 +
drivers/usb/core/hcd.c | 2 ++
drivers/usb/core/led.c | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/usb/hcd.h | 6 ++++++
5 files changed, 56 insertions(+)
create mode 100644 drivers/usb/core/led.c
diff --git a/drivers/usb/core/Kconfig b/drivers/usb/core/Kconfig
index 1060657..8295f65 100644
--- a/drivers/usb/core/Kconfig
+++ b/drivers/usb/core/Kconfig
@@ -90,3 +90,12 @@ config USB_OTG_FSM
Implements OTG Finite State Machine as specified in On-The-Go
and Embedded Host Supplement to the USB Revision 2.0 Specification.
+config USB_HOST_LED
+ bool "USB Host LED Trigger"
+ depends on LEDS_CLASS
+ select LEDS_TRIGGERS
+ help
+ This option adds a LED trigger for USB host controllers.
+
+ Say Y here if you are working on a system with led-class supported
+ LEDs and you want to use them as USB host activity indicators.
diff --git a/drivers/usb/core/Makefile b/drivers/usb/core/Makefile
index 2f6f932..324c8c9 100644
--- a/drivers/usb/core/Makefile
+++ b/drivers/usb/core/Makefile
@@ -9,5 +9,6 @@ usbcore-y += port.o
usbcore-$(CONFIG_PCI) += hcd-pci.o
usbcore-$(CONFIG_ACPI) += usb-acpi.o
+usbcore-$(CONFIG_USB_HOST_LED) += led.o
obj-$(CONFIG_USB) += usbcore.o
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 487abcf..46d9f3a 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -1664,6 +1664,8 @@ static void __usb_hcd_giveback_urb(struct urb *urb)
usbmon_urb_complete(&hcd->self, urb, status);
usb_anchor_suspend_wakeups(anchor);
usb_unanchor_urb(urb);
+ if (status == 0)
+ usb_hcd_led_activity();
/* pass ownership to the completion handler */
urb->status = status;
diff --git a/drivers/usb/core/led.c b/drivers/usb/core/led.c
new file mode 100644
index 0000000..49ff76c
--- /dev/null
+++ b/drivers/usb/core/led.c
@@ -0,0 +1,38 @@
+/*
+ * LED Trigger for USB Host Activity
+ *
+ * Copyright 2014 Michal Sojka <sojka@xxxxxxxxx>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/leds.h>
+#include <linux/usb/hcd.h>
+
+#define BLINK_DELAY 30
+
+DEFINE_LED_TRIGGER(ledtrig_usb_hcd);
+static unsigned long usb_hcd_blink_delay = BLINK_DELAY;
+
+void usb_hcd_led_activity(void)
+{
+ led_trigger_blink_oneshot(ledtrig_usb_hcd,
+ &usb_hcd_blink_delay, &usb_hcd_blink_delay, 0);
+}
+
+int __init ledtrig_usb_hcd_init(void)
+{
+ led_trigger_register_simple("usb-host", &ledtrig_usb_hcd);
+ return 0;
+}
+
+void __exit ledtrig_usb_hcd_exit(void)
+{
+ led_trigger_unregister_simple(ledtrig_usb_hcd);
+}
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index b43f0fe..eb5fa0f 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -700,6 +700,12 @@ extern struct rw_semaphore ehci_cf_port_reset_rwsem;
#define USB_EHCI_LOADED 2
extern unsigned long usb_hcds_loaded;
+#ifdef CONFIG_USB_HOST_LED
+extern void usb_hcd_led_activity(void);
+#else
+static inline void usb_hcd_led_activity(void) {}
+#endif
+
#endif /* __KERNEL__ */
#endif /* __USB_CORE_HCD_H */
--
2.1.0
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