/************************************************************************************
 * startHeartbeatTimer.c
 *
 *   synopsis: Initializes a timer channel and uses it to put a square wave onto the
 *            TOUT pin which is wired to an LED.
 *
 *  Damon Fasching, UW Madison (510)486-5230               fasching@wisconsin.cern.ch
 ************************************************************************************/
#include <csl.h>
#include <csl_timer.h>

#include "resources.h"
#include "registerIndices.h"
#include "memoryPartitions.h"
#include "peripheralMap.h"

#pragma CODE_SECTION(startHeartbeatTimer, "xcode");
#pragma CODE_SECTION(startUserTimer,      "xcode");

TIMER_Handle hHeartbeatTimerCh;

/************************************************************************************
 * startHeartbeatTimer
 *
 *  synopsis: Initializes the timer (timer 0) which drives the "heart-beat" LED.
 *
 * timerPeriod is the value to be loaded into the timer period register.
 *   For TIMER_CLK_INTERNAL, the timer counter counts at the cpuClk/4 = 40 MHz on ROD.
 *   When the counter value is reached:
 *     1) The value of TSTAT toggles           AND
 *     2) The Timer Counter Register is reset.    
 * So, at 40 MHz counting, the timer frequency is given by:
 *     f = 40 MHz/(2*timerPeriod)
 *
 *     timerPeriod    f (Hz)    P (s)
 *      0x10000000      .074   13.4
 *      0x01000000     1.2      0.84
 *      0x00100000    19.1      0.052 
 *
 *  modifications/bugs    
 *   - Both MDSP/SDSP timer 0 TOUT now drive the green LED directly.   01.09.02 dpsf
 *   - Timer handle is now global for access by other routines.        28.01.03 dpsf
 ************************************************************************************/
void startHeartbeatTimer(UINT32 period) {
	UINT32 timerCtl= 0x0, count= 0x0;
	
	hHeartbeatTimerCh = TIMER_open(HEARTBEAT_TIMER_CH, TIMER_OPEN_RESET);
	
	timerCtl= TIMER_CTL_RMK(TIMER_CTL_INVINP_NO, TIMER_CTL_CLKSRC_CPUOVR4,
	                        TIMER_CTL_CP_CLOCK, TIMER_CTL_HLD_NO, TIMER_CTL_GO_YES,
	                        TIMER_CTL_PWID_ONE, TIMER_CTL_DATOUT_0,
	                        TIMER_CTL_INVOUT_NO, TIMER_CTL_FUNC_TOUT);

	TIMER_configArgs(hHeartbeatTimerCh, timerCtl, period, count);
	return;
}

/************************************************************************************
 * startUserTimer
 *
 *  synopsis: If the user timer is available, starts it and returns the handle.
 *            If it is not available, returns INV.
 *
 *  modifications/bugs    
 *   - Timer was initialized in paused state, causing primitives which depend on
 *     it to loop endlessly (..._HLD_YES). Set to HLD_NO.              08.04.02 dpsf
 *   - This routine is now called once by the main loop, to set the timer running
 *     endlessly at the maximum period (0xffffffff). Timing is done by calling
 *     TIMER_getCount successively & subtracting (UINT32 will always give the
 *     correct value: dt= 2 -0xfffffffe = 4.                           15.01.03 dpsf
 ************************************************************************************/
TIMER_Handle startUserTimer(UINT32 period) {
	UINT32 timerCtl= 0x0, count= 0x0;
	TIMER_Handle hUserTimer;
	
	hUserTimer = TIMER_open(USER_TIMER_CH, TIMER_OPEN_RESET);
	if (hUserTimer != INV) {
		timerCtl= TIMER_CTL_RMK(TIMER_CTL_INVINP_NO, TIMER_CTL_CLKSRC_CPUOVR4,
		                        TIMER_CTL_CP_CLOCK,  TIMER_CTL_HLD_NO, TIMER_CTL_GO_YES,
		                        TIMER_CTL_PWID_ONE,  TIMER_CTL_DATOUT_0,
		                        TIMER_CTL_INVOUT_NO, TIMER_CTL_FUNC_GPIO);
		TIMER_configArgs(hUserTimer, timerCtl, period, count);
	}
	return hUserTimer;
}