static int setup_led(void)
{
static int initialized = 0;
if(initialized)
return kIOReturnSuccess;
initialized = 1;
IOReturn ioReturnValue = kIOReturnError;
if (!(hidService = find_a_keyboard())) {
fprintf(stderr, "No keyboard found.\n");
return ioReturnValue;
}
hidDevice = (io_object_t)hidService;
create_hid_interface(hidDevice, &hidDeviceInterface);
find_led_cookies((IOHIDDeviceInterface122 **)hidDeviceInterface);
ioReturnValue = IOObjectRelease(hidDevice);
if (ioReturnValue != kIOReturnSuccess) {
goto out;
}
ioReturnValue = kIOReturnError;
if (hidDeviceInterface == NULL) {
fprintf(stderr, "Failed to create HID device interface.\n");
return ioReturnValue;
}
ioReturnValue = (*hidDeviceInterface)->open(hidDeviceInterface, 0);
if (ioReturnValue != kIOReturnSuccess) {
fprintf(stderr, "Failed to open HID device interface.\n");
goto out;
}
out:
if(ioReturnValue != kIOReturnSuccess)
(void)(*hidDeviceInterface)->Release(hidDeviceInterface);
return ioReturnValue;
}
int
manipulate_led(UInt32 whichLED, UInt32 value)
{
io_service_t hidService = (io_service_t)0;
io_object_t hidDevice = (io_object_t)0;
IOHIDDeviceInterface **hidDeviceInterface = NULL;
IOReturn ioReturnValue = kIOReturnError;
IOHIDElementCookie theCookie = (IOHIDElementCookie)0;
IOHIDEventStruct theEvent;
if (!(hidService = find_a_keyboard())) {
fprintf(stderr, "No keyboard found.\n");
return ioReturnValue;
}
hidDevice = (io_object_t)hidService;
create_hid_interface(hidDevice, &hidDeviceInterface);
find_led_cookies((IOHIDDeviceInterface122 **)hidDeviceInterface);
ioReturnValue = IOObjectRelease(hidDevice);
if (ioReturnValue != kIOReturnSuccess) {
goto out;
}
ioReturnValue = kIOReturnError;
if (hidDeviceInterface == NULL) {
fprintf(stderr, "Failed to create HID device interface.\n");
return ioReturnValue;
}
if (whichLED == kHIDUsage_LED_NumLock) {
theCookie = numlock_cookie;
} else if (whichLED == kHIDUsage_LED_CapsLock) {
theCookie = capslock_cookie;
}
if (theCookie == 0) {
fprintf(stderr, "Bad or missing LED cookie.\n");
goto out;
}
ioReturnValue = (*hidDeviceInterface)->open(hidDeviceInterface, 0);
if (ioReturnValue != kIOReturnSuccess) {
fprintf(stderr, "Failed to open HID device interface.\n");
goto out;
}
ioReturnValue = (*hidDeviceInterface)->getElementValue(hidDeviceInterface,
theCookie, &theEvent);
if (ioReturnValue != kIOReturnSuccess) {
(void)(*hidDeviceInterface)->close(hidDeviceInterface);
goto out;
}
fprintf(stdout, "%s\n", (theEvent.value) ? "on" : "off");
if (value != -1) {
if (theEvent.value != value) {
theEvent.value = value;
ioReturnValue = (*hidDeviceInterface)->setElementValue(
hidDeviceInterface, theCookie,
&theEvent, 0, 0, 0, 0);
if (ioReturnValue == kIOReturnSuccess) {
fprintf(stdout, "%s\n", (theEvent.value) ? "on" : "off");
}
}
}
ioReturnValue = (*hidDeviceInterface)->close(hidDeviceInterface);
out:
(void)(*hidDeviceInterface)->Release(hidDeviceInterface);
return ioReturnValue;
}