ABB semaphore protection overhaul The ABB semaphone protection logic that came with TCS211 from TI was broken in several ways: * Some semaphore-protected functions were called from Application_Initialize() context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with NU_INVALID_SUSPEND in this context, but the return value wasn't checked, and NU_Release_Semaphore() would be called unconditionally at the end. The latter call would increment the semaphore count past 1, making the semaphore no longer binary and thus no longer effective for resource protection. The fix is to check the return value from NU_Obtain_Semaphore() and skip the NU_Release_Semaphore() call if the semaphore wasn't properly obtained. * Some SPI hardware manipulation was being done before entering the semaphore- protected critical section. The fix is to reorder the code: first obtain the semaphore, then do everything else. * In the corner case of L1/DSP recovery, l1_abb_power_on() would call some non-semaphore-protected ABB & SPI init functions. The fix is to skip those calls in the case of recovery. * A few additional corner cases existed, all of which are fixed by making ABB semaphore protection 100% consistent for all ABB functions and code paths. There is still one remaining problem of priority inversion: suppose a low- priority task calls an ABB function, and some medium-priority task just happens to preempt right in the middle of that semaphore-protected ABB operation. Then the high-priority SPI task is locked out for a non-deterministic time until that medium-priority task finishes its work and goes back to sleep. This priority inversion problem remains outstanding for now.

/**
 * @file   lls_api.h
 *
 * API Definition for LLS (Low Level Servies) Service.
 *
 * This file gathers all the constants, structure and functions declaration
 * useful for a LLS service user.
 *
 * @author   Laurent Sollier (l-sollier@ti.com)
 * @version 0.1
 */

/*
 * History:
 *
 *   Date          Author       Modification
 *  ----------------------------------------
 *  03/12/2002     L Sollier    Create
 *
 *
 * (C) Copyright 2002 by Texas Instruments Incorporated, All Rights Reserved
 */

#ifndef _LLS_API_H_
#define _LLS_API_H_


#include "rv/rv_general.h"

/**
 * @name External types
 *
 * Types used in API.
 *
 */
/*@{*/

/** Definition of available equipment, ... for D-Sample
 */
#define LLS_LED_A         0x01
#define LLS_BACKLIGHT     0x02
#define LLS_PRECHARGE_LED 0x03

/*@}*/

typedef UINT8 T_LLS_EQUIPMENT;

/**
 * @name API functions
 *
 * API functions declarations.
 */
/*@{*/

/**
 * function: lls_switch_on
 *
 * This function switch on an equipment.
 *
 * @param   equipment_sort    equipment sort.
 * @return
 *    - RV_OK if operation is successful,
 *    - RV_INVALID_PARAMETER if one parameter is incorrect,
 *    - RV_NOT_SUPPORTED 
 *
 */
T_RV_RET lls_switch_on(T_LLS_EQUIPMENT equipment_sort);


/**
 * function: lls_switch_off
 *
 * This function switch off an equipment.
 *
 * @param   equipment_sort    equipment sort.
 * @return
 *    - RV_OK if operation is successful,
 *    - RV_INVALID_PARAMETER if one parameter is incorrect,
 *    - RV_NOT_SUPPORTED 
 *
 */
T_RV_RET lls_switch_off(T_LLS_EQUIPMENT equipment_sort);


/*@}*/




#endif /* #ifndef _LLS_API_H_ */