/* $Id: s3c2410_watchdog.c,v 1.5 2008/12/11 12:18:17 ecd Exp $
 */

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <errno.h>

#include <x49gp.h>
#include <s3c2410.h>
#include <s3c2410_intc.h>


typedef struct {
	uint32_t			wtcon;
	uint32_t			wtdat;
	uint32_t			wtcnt;

	unsigned int		nr_regs;
	s3c2410_offset_t	*regs;

	x49gp_t			*x49gp;

	unsigned long		interval;
	x49gp_timer_t		*timer;
} s3c2410_watchdog_t;

static int
s3c2410_watchdog_data_init(s3c2410_watchdog_t *watchdog)
{
	s3c2410_offset_t regs[] = {
		S3C2410_OFFSET(WATCHDOG, WTCON, 0x8021, watchdog->wtcon),
		S3C2410_OFFSET(WATCHDOG, WTDAT, 0x8000, watchdog->wtdat),
		S3C2410_OFFSET(WATCHDOG, WTCNT, 0x8000, watchdog->wtcnt)
	};

	memset(watchdog, 0, sizeof(s3c2410_watchdog_t));

	watchdog->regs = malloc(sizeof(regs));
	if (NULL == watchdog->regs) {
		fprintf(stderr, "%s:%u: Out of memory\n",
			__FUNCTION__, __LINE__);
		return -ENOMEM;
	}

	memcpy(watchdog->regs, regs, sizeof(regs));
	watchdog->nr_regs = sizeof(regs) / sizeof(regs[0]);

	return 0;
}

static void
s3c2410_watchdog_tick(void *data)
{
	s3c2410_watchdog_t *watchdog = data;
	x49gp_t *x49gp = watchdog->x49gp;

	if (watchdog->wtcnt > 0) {
		watchdog->wtcnt--;
	} else {
		watchdog->wtcnt = watchdog->wtdat;
	}

	if (watchdog->wtcnt > 0) {
//		watchdog->timer.expires += watchdog->interval;
		x49gp_mod_timer(watchdog->timer, x49gp_get_clock() + watchdog->interval);
		return;
	}

	if (watchdog->wtcon & 0x0004) {
#ifdef DEBUG_S3C2410_WATCHDOG
		printf("WATCHDOG: assert WDT interrupt\n");
#endif
//		g_mutex_lock(x49gp->memlock);

		s3c2410_intc_assert(x49gp, INT_WDT, 0);

//		g_mutex_unlock(x49gp->memlock);
	}

	if (watchdog->wtcon & 0x0001) {
#ifdef DEBUG_S3C2410_WATCHDOG
		printf("WATCHDOG: assert internal RESET\n");
#endif

		x49gp_modules_reset(x49gp, X49GP_RESET_WATCHDOG);
		cpu_reset(x49gp->env);

//		if (x49gp->arm->NresetSig != LOW) {
//			x49gp->arm->NresetSig = LOW;
//			x49gp->arm->Exception++;
//		}
		return;
	}

//	watchdog->timer.expires += watchdog->interval;
	x49gp_mod_timer(watchdog->timer, x49gp_get_clock() + watchdog->interval);
}

unsigned long
s3c2410_watchdog_next_interrupt(x49gp_t *x49gp)
{
	s3c2410_watchdog_t *watchdog = x49gp->s3c2410_watchdog;
	unsigned long irq;
	unsigned long ticks;

	ticks = x49gp_get_clock();

	if (!(watchdog->wtcon & 0x0020)) {
		return ~(0);
	}

	if (x49gp_timer_pending(watchdog->timer)) {
		irq = x49gp_timer_expires(watchdog->timer) - ticks;
	} else {
		irq = 0;
	}

	if (watchdog->wtcnt) {
		irq += (watchdog->wtcnt - 1) * watchdog->interval;
	} else {
		irq += watchdog->wtdat * watchdog->interval;
	}

#ifdef DEBUG_S3C2410_WATCHDOG
	printf("WATCHDOG: wtcnt %u, interval %lu, expires %llu, next irq %lu\n",
		watchdog->wtcnt, watchdog->interval, (unsigned long long) (x49gp_timer_pending(watchdog->timer) ? x49gp_timer_expires(watchdog->timer) : 0), irq);
#endif

	return irq;
}

static int
s3c2410_watchdog_update(s3c2410_watchdog_t *watchdog)
{
	uint32_t pre, mux;

	if (!(watchdog->wtcon & 0x0020)) {
		x49gp_del_timer(watchdog->timer);
#ifdef DEBUG_S3C2410_WATCHDOG
		printf("WATCHDOG: stop timer\n");
#endif
		return 0;
	}

	pre = (watchdog->wtcon >> 8) & 0xff;
	mux = (watchdog->wtcon >> 3) & 3;

	watchdog->interval = (pre + 1) * (16 << mux);

#ifdef DEBUG_S3C2410_WATCHDOG
	printf("WATCHDOG: start tick (%lu PCLKs)\n", watchdog->interval);
#endif
	x49gp_mod_timer(watchdog->timer, x49gp_get_clock() + watchdog->interval);
	return 0;
}

static uint32_t
s3c2410_watchdog_read(void *opaque, target_phys_addr_t offset)
{
	s3c2410_watchdog_t *watchdog = opaque;
	s3c2410_offset_t *reg;

	if (! S3C2410_OFFSET_OK(watchdog, offset)) {
		return ~(0);
	}

	reg = S3C2410_OFFSET_ENTRY(watchdog, offset);


#ifdef DEBUG_S3C2410_WATCHDOG
	printf("read  %s [%08x] %s [%08lx] data %08x\n",
		"s3c2410-watchdog", S3C2410_WATCHDOG_BASE,
		reg->name, (unsigned long) offset, *(reg->datap));
#endif

	return *(reg->datap);
}

static void
s3c2410_watchdog_write(void *opaque, target_phys_addr_t offset, uint32_t data)
{
	s3c2410_watchdog_t *watchdog = opaque;
	s3c2410_offset_t *reg;

	if (! S3C2410_OFFSET_OK(watchdog, offset)) {
		return;
	}

	reg = S3C2410_OFFSET_ENTRY(watchdog, offset);

#ifdef DEBUG_S3C2410_WATCHDOG
	printf("write %s [%08x] %s [%08lx] data %08x\n",
		"s3c2410-watchdog", S3C2410_WATCHDOG_BASE,
		reg->name, (unsigned long) offset, data);
#endif

	*(reg->datap) = data;

	switch (offset) {
	case S3C2410_WATCHDOG_WTCON:
	case S3C2410_WATCHDOG_WTCNT:
		s3c2410_watchdog_update(watchdog);
		break;
	default:
		break;
	}
}

static int
s3c2410_watchdog_load(x49gp_module_t *module, GKeyFile *key)
{
	s3c2410_watchdog_t *watchdog = module->user_data;
	s3c2410_offset_t *reg;
	int error = 0;
	int i;

#ifdef DEBUG_X49GP_MODULES
	printf("%s: %s:%u\n", module->name, __FUNCTION__, __LINE__);
#endif

	for (i = 0; i < watchdog->nr_regs; i++) {
		reg = &watchdog->regs[i];

		if (NULL == reg->name)
			continue;

		if (x49gp_module_get_u32(module, key, reg->name,
					 reg->reset, reg->datap))
			error = -EAGAIN;
	}

	s3c2410_watchdog_update(watchdog);

	return error;
}

static int
s3c2410_watchdog_save(x49gp_module_t *module, GKeyFile *key)
{
	s3c2410_watchdog_t *watchdog = module->user_data;
	s3c2410_offset_t *reg;
	int i;

#ifdef DEBUG_X49GP_MODULES
	printf("%s: %s:%u\n", module->name, __FUNCTION__, __LINE__);
#endif

	for (i = 0; i < watchdog->nr_regs; i++) {
		reg = &watchdog->regs[i];

		if (NULL == reg->name)
			continue;

		x49gp_module_set_u32(module, key, reg->name, *(reg->datap));
	}

	return 0;
}

static int
s3c2410_watchdog_reset(x49gp_module_t *module, x49gp_reset_t reset)
{
	s3c2410_watchdog_t *watchdog = module->user_data;
	s3c2410_offset_t *reg;
	int i;

#ifdef DEBUG_X49GP_MODULES
	printf("%s: %s:%u\n", module->name, __FUNCTION__, __LINE__);
#endif

	for (i = 0; i < watchdog->nr_regs; i++) {
		reg = &watchdog->regs[i];

		if (NULL == reg->name)
			continue;

		*(reg->datap) = reg->reset;
	}

	s3c2410_watchdog_update(watchdog);

	return 0;
}

static CPUReadMemoryFunc *s3c2410_watchdog_readfn[] =
{
	s3c2410_watchdog_read,
	s3c2410_watchdog_read,
	s3c2410_watchdog_read
};

static CPUWriteMemoryFunc *s3c2410_watchdog_writefn[] =
{
	s3c2410_watchdog_write,
	s3c2410_watchdog_write,
	s3c2410_watchdog_write
};

static int
s3c2410_watchdog_init(x49gp_module_t *module)
{
	s3c2410_watchdog_t *watchdog;
	int iotype;

#ifdef DEBUG_X49GP_MODULES
	printf("%s: %s:%u\n", module->name, __FUNCTION__, __LINE__);
#endif

	watchdog = malloc(sizeof(s3c2410_watchdog_t));
	if (NULL == watchdog) {
		fprintf(stderr, "%s: %s:%u: Out of memory\n",
			module->x49gp->progname, __FUNCTION__, __LINE__);
		return -ENOMEM;
	}
	if (s3c2410_watchdog_data_init(watchdog)) {
		free(watchdog);
		return -ENOMEM;
	}

	module->user_data = watchdog;

	watchdog->x49gp = module->x49gp;
	module->x49gp->s3c2410_watchdog = watchdog;

	watchdog->timer = x49gp_new_timer(X49GP_TIMER_VIRTUAL,
					  s3c2410_watchdog_tick, watchdog);

	iotype = cpu_register_io_memory(s3c2410_watchdog_readfn,
					s3c2410_watchdog_writefn, watchdog);
#ifdef DEBUG_S3C2410_WATCHDOG
	printf("%s: iotype %08x\n", __FUNCTION__, iotype);
#endif
	cpu_register_physical_memory(S3C2410_WATCHDOG_BASE, S3C2410_MAP_SIZE, iotype);
	return 0;
}

static int
s3c2410_watchdog_exit(x49gp_module_t *module)
{
	s3c2410_watchdog_t *watchdog;

#ifdef DEBUG_X49GP_MODULES
	printf("%s: %s:%u\n", module->name, __FUNCTION__, __LINE__);
#endif

	if (module->user_data) {
		watchdog = module->user_data;
		if (watchdog->regs)
			free(watchdog->regs);
		free(watchdog);
	}

	x49gp_module_unregister(module);
	free(module);

	return 0;
}

int
x49gp_s3c2410_watchdog_init(x49gp_t *x49gp)
{
	x49gp_module_t *module;

	if (x49gp_module_init(x49gp, "s3c2410-watchdog",
			      s3c2410_watchdog_init,
			      s3c2410_watchdog_exit,
			      s3c2410_watchdog_reset,
			      s3c2410_watchdog_load,
			      s3c2410_watchdog_save,
			      NULL, &module)) {
		return -1;
	}

	return x49gp_module_register(module);
}