backlight control on Luna: switch PWL instead of LEDB This change is preliminary toward upcoming rework of backlight control logic in our UI firmware. LEDB does not exist on Tango-based platforms (it is not brought out on Tango modules), thus turning it on and off produces absolutely no effect beyond making L1 disable deep sleep when LEDB is turned on. However, both iWOW DSK and our upcoming FC Caramel2 boards have a PWL LED, so let's switch that LED on and off to indicate the state of the UI firmware's backlight control. Note that we are NOT switching the actual Luna LCD backlight here, even though it is trivially controlled with a GPIO. The reason for this seemingly strange choice is that we don't want to turn this development board LCD backlight off until we bring the higher-level backlight control logic up to par, including new logic to "swallow" the first keypress that turns on the darkened LCD.

/************* Revision Controle System Header *************
 *                  GSM Layer 1 software 
 * L1GTT_MSGTY.H
 *
 *        Filename l1gtt_msgty.h
 *  Copyright 2003 (C) Texas Instruments  
 *
 ************* Revision Controle System Header *************/

#if (L1_GTT == 1)

typedef struct
{
  UWORD8 loop_type;  // Type of loop to be closed
}
T_TST_CLOSE_GTT_LOOP_REQ;

typedef struct
{
  UWORD8  scen_type;  // 1 = input on CTM Tx, 2 = input on Baudot encoder
                      // SIMULATION ONLY: 3 = input on CTM Rx, 4 = input on Baudot decoder
  UWORD16 rate;       // Number of frames (4.615 ms) between each new character arrival
                      // for scen_type 3 and 4: GTT input file number
}
T_TST_START_GTT_TEST_REQ;

#endif // L1_GTT