/*
 * File:        net_timer.c
 * Purpose:     Provide a timer use by the BaS network as a timeout
 *              indicator
 *
 * Notes:
 */
#include "net_timer.h"
#include <stdint.h>
#include <stdbool.h>
#include "MCF5475.h"
#include "interrupts.h"

#if defined(MACHINE_FIREBEE)
#include "firebee.h"
#elif defined(MACHINE_M5484LITE)
#include "m5484l.h"
#else
#error unknown machine!
#endif

static NET_TIMER net_timer[4] =
{
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0},
	{0, 0, 0, 0, 0, 0, 0}
};


int timer_default_isr(void *not_used, NET_TIMER *t)
{
	(void) not_used;

	/* 
	 * Clear the pending event 
	 */
	MCF_GPT_GMS(t->ch) = 0;

	/*
	 * Clear the reference - the desired seconds have expired
	 */
	t->reference = 0;

	return 1;
}

void timer_irq_enable(uint8_t ch)
{
	/*
	 * Setup the appropriate ICR
	 */
	MCF_INTC_ICR(TIMER_VECTOR(ch) - 64) =
		(uint8_t)(0
				| MCF_INTC_ICR_IP(net_timer[ch].pri)
				| MCF_INTC_ICR_IL(net_timer[ch].lvl));

	/*
	 * Unmask the FEC interrupt in the interrupt controller
	 */
	if (ch == 3)
		MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK59;
	else if (ch == 2)
		MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK60;
	else if (ch == 1)
		MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK61;
	else
		MCF_INTC_IMRH &= ~MCF_INTC_IMRH_INT_MASK62;
}

bool timer_set_secs(uint8_t ch, uint32_t secs)
{
	uint16_t timeout;

	/*
	 * Reset the timer
	 */
	MCF_GPT_GMS(ch) = 0;

	/* 
	 * Get the timeout in seconds 
	 */
	timeout = (uint16_t)(secs * net_timer[ch].cnt);

	/*
	 * Set the reference indicating that we have not yet reached the
	 * desired timeout
	 */
	net_timer[ch].reference = 1;

	/*
	 * Enable timer interrupt to the processor
	 */
	timer_irq_enable(ch);

	/*
	 * Enable the timer using the pre-calculated values
	 */
	MCF_GPT_GCIR(ch) = (0
			| MCF_GPT_GCIR_CNT(timeout)
			| MCF_GPT_GCIR_PRE(net_timer[ch].pre)
			);
	MCF_GPT_GMS(ch) = net_timer[ch].gms;

	return true;
}

uint32_t timer_get_reference(uint8_t ch)
{   
	return (uint32_t) net_timer[ch].reference;
}

bool timer_init(uint8_t ch, uint8_t lvl, uint8_t pri)
{
	/* 
	 * Initialize the timer to expire after one second
	 * 
	 * This routine should only be called by the project (board) specific
	 * initialization code.
	 */
	if (!((ch <= 3) && (lvl <= 7) && (lvl >= 1) && (pri <= 7)))
		return false;

	/*
	 * Reset the timer
	 */
	MCF_GPT_GMS(ch) = 0;

	/* 
	 * Save off the channel, and interrupt lvl/pri information
	 */
	net_timer[ch].ch = ch;
	net_timer[ch].lvl = lvl;
	net_timer[ch].pri = pri;

	/*
	 * Register the timer interrupt handler
	 */
	if (!isr_register_handler(ISR_DBUG_ISR, 
				TIMER_VECTOR(ch), 
				(int (*)(void *,void *)) timer_default_isr,
				NULL, 
				(void *) &net_timer[ch])
	   )
	{
		return false;
	}

	/*
	 * Calculate the require CNT value to get a 1 second timeout
	 *
	 * 1 sec = CNT * Clk Period * PRE
	 * CNT = 1 sec / (Clk Period * PRE)
	 * CNT = Clk Freq / PRE
	 *
	 * The system clock frequency is defined as SYSTEM_CLOCK and
	 * is given in MHz. We need to multiple it by 1000000 to get the 
	 * true value.  If we assume PRE to be the maximum of 0xFFFF, 
	 * then the CNT value needed to achieve a 1 second timeout is 
	 * given by:
	 *
	 * CNT = SYSTEM_CLOCK * (1000000/0xFFFF)
	 */
	net_timer[ch].pre = 0xFFFF;
	net_timer[ch].cnt = (uint16_t) (SYSCLK * (1000000 / 0xFFFF));

	/* 
	 * Save off the appropriate mode select register value 
	 */
	net_timer[ch].gms = (0 
			| MCF_GPT_GMS_TMS_GPIO
			| MCF_GPT_GMS_IEN
			| MCF_GPT_GMS_SC
			| MCF_GPT_GMS_CE
			);

	return true;
}