Initial commit for Planck PCB Rev 1.

- Backlight on PB7 controlled by Timer1 Fast PWM (no interrupts).
- Backlight commands connected temporarily to top left keys.
- Backlight init called from matrix.c, since there's no generic keyboard_init() override function.

keyboard/planck/Makefile

@@ -50,7 +50,8 @@ TARGET_DIR = .
 # project specific files
 SRC =	keymap_common.c \
 	matrix.c \
-	led.c
+	led.c \
+	backlight.c
 
 ifdef KEYMAP
     SRC := keymap_$(KEYMAP).c $(SRC)
@@ -118,9 +119,10 @@ MOUSEKEY_ENABLE = yes	# Mouse keys(+4700)
 EXTRAKEY_ENABLE = yes	# Audio control and System control(+450)
 CONSOLE_ENABLE = yes	# Console for debug(+400)
 COMMAND_ENABLE = yes    # Commands for debug and configuration
+# Do not enable SLEEP_LED_ENABLE. it uses the same timer as BACKLIGHT_ENABLE
 #SLEEP_LED_ENABLE = yes  # Breathing sleep LED during USB suspend
 NKRO_ENABLE = yes	# USB Nkey Rollover - not yet supported in LUFA
-
+BACKLIGHT_ENABLE = yes  # Enable keyboard backlight functionality
 
 # Optimize size but this may cause error "relocation truncated to fit"
 #EXTRALDFLAGS = -Wl,--relax