1 files changed, 76 insertions, 0 deletions
diff --git a/usb_keyboard.c b/usb_keyboard.c
new file mode 100644
index 0000000000..9d41e8bc59
--- /dev/null
+++ b/usb_keyboard.c
@@ -0,0 +1,76 @@
+#include <avr/interrupt.h>
+#include <avr/pgmspace.h>
+#include "usb_keyboard.h"
+
+
+// which modifier keys are currently pressed
+// 1=left ctrl,    2=left shift,   4=left alt,    8=left gui
+// 16=right ctrl, 32=right shift, 64=right alt, 128=right gui
+uint8_t keyboard_modifier_keys=0;
+
+// which keys are currently pressed, up to 6 keys may be down at once
+uint8_t keyboard_keys[6]={0,0,0,0,0,0};
+
+// protocol setting from the host.  We use exactly the same report
+// either way, so this variable only stores the setting since we
+// are required to be able to report which setting is in use.
+uint8_t keyboard_protocol=1;
+
+// the idle configuration, how often we send the report to the
+// host (ms * 4) even when it hasn't changed
+uint8_t keyboard_idle_config=125;
+
+// count until idle timeout
+uint8_t keyboard_idle_count=0;
+
+// 1=num lock, 2=caps lock, 4=scroll lock, 8=compose, 16=kana
+volatile uint8_t keyboard_leds=0;
+
+
+// perform a single keystroke
+int8_t usb_keyboard_press(uint8_t key, uint8_t modifier)
+{
+	int8_t r;
+
+	keyboard_modifier_keys = modifier;
+	keyboard_keys[0] = key;
+	r = usb_keyboard_send();
+	if (r) return r;
+	keyboard_modifier_keys = 0;
+	keyboard_keys[0] = 0;
+	return usb_keyboard_send();
+}
+
+// send the contents of keyboard_keys and keyboard_modifier_keys
+int8_t usb_keyboard_send(void)
+{
+	uint8_t i, intr_state, timeout;
+
+	if (!usb_configured()) return -1;
+	intr_state = SREG;
+	cli();
+	UENUM = KEYBOARD_ENDPOINT;
+	timeout = UDFNUML + 50;
+	while (1) {
+		// are we ready to transmit?
+		if (UEINTX & (1<<RWAL)) break;
+		SREG = intr_state;
+		// has the USB gone offline?
+		if (!usb_configured()) return -1;
+		// have we waited too long?
+		if (UDFNUML == timeout) return -1;
+		// get ready to try checking again
+		intr_state = SREG;
+		cli();
+		UENUM = KEYBOARD_ENDPOINT;
+	}
+	UEDATX = keyboard_modifier_keys;
+	UEDATX = 0;
+	for (i=0; i<6; i++) {
+		UEDATX = keyboard_keys[i];
+	}
+	UEINTX = 0x3A;
+	keyboard_idle_count = 0;
+	SREG = intr_state;
+	return 0;
+}