linux/drivers/usb/common/Makefile
Michal Sojka 0cfbd328d6 usb: Add LED triggers for USB activity
With this patch, USB activity can be signaled by blinking a LED. There
are two triggers, one for activity on USB host and one for USB gadget.

Both triggers should work with all host/device controllers. Tested only
with musb.

Performace: I measured performance overheads on ARM Cortex-A8 (TI
AM335x) running on 600 MHz.

Duration of usb_led_activity():
- with no LED attached to the trigger:        2 ± 1 µs
- with one GPIO LED attached to the trigger:  2 ± 1 µs or 8 ± 2 µs (two peaks in histogram)

Duration of functions calling usb_led_activity() (with this patch
applied and no LED attached to the trigger):
- __usb_hcd_giveback_urb():    10 - 25 µs
- usb_gadget_giveback_request(): 2 - 6 µs

Signed-off-by: Michal Sojka <sojka@merica.cz>
Acked-by: Felipe Balbi <balbi@ti.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-25 17:05:12 +02:00

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Makefile

#
# Makefile for the usb common parts.
#
obj-$(CONFIG_USB_COMMON) += usb-common.o
usb-common-y += common.o
usb-common-$(CONFIG_USB_LED_TRIG) += led.o
obj-$(CONFIG_USB_OTG_FSM) += usb-otg-fsm.o