/*

 * QEMU ETRAX Timers

 *

 * Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdio.h>

#include <sys/time.h>

#include "hw.h"

#include "sysemu.h"

#include "qemu-timer.h"

#define D(x)

#define RW_TMR0_DIV   0x00

#define R_TMR0_DATA   0x04

#define RW_TMR0_CTRL  0x08

#define RW_TMR1_DIV   0x10

#define R_TMR1_DATA   0x14

#define RW_TMR1_CTRL  0x18

#define R_TIME        0x38

#define RW_WD_CTRL    0x40

#define R_WD_STAT     0x44

#define RW_INTR_MASK  0x48

#define RW_ACK_INTR   0x4c

#define R_INTR        0x50

#define R_MASKED_INTR 0x54

struct fs_timer_t {

	CPUState *env;

	qemu_irq *irq;

	qemu_irq *nmi;

	QEMUBH *bh_t0;

	QEMUBH *bh_t1;

	QEMUBH *bh_wd;

	ptimer_state *ptimer_t0;

	ptimer_state *ptimer_t1;

	ptimer_state *ptimer_wd;

	struct timeval last;

	int wd_hits;

	/* Control registers.  */

	uint32_t rw_tmr0_div;

	uint32_t r_tmr0_data;

	uint32_t rw_tmr0_ctrl;

	uint32_t rw_tmr1_div;

	uint32_t r_tmr1_data;

	uint32_t rw_tmr1_ctrl;

	uint32_t rw_wd_ctrl;

	uint32_t rw_intr_mask;

	uint32_t rw_ack_intr;

	uint32_t r_intr;

	uint32_t r_masked_intr;

};

static uint32_t timer_rinvalid (void *opaque, target_phys_addr_t addr)

{

	struct fs_timer_t *t = opaque;

	CPUState *env = t->env;

	cpu_abort(env, "Unsupported short access. reg=" TARGET_FMT_plx "\n",

		  addr);

	return 0;

}

static uint32_t timer_readl (void *opaque, target_phys_addr_t addr)

{

	struct fs_timer_t *t = opaque;

	uint32_t r = 0;

	switch (addr) {

	case R_TMR0_DATA:

		break;

	case R_TMR1_DATA:

		D(printf ("R_TMR1_DATA\n"));

		break;

	case R_TIME:

		r = qemu_get_clock(vm_clock) / 10;

		break;

	case RW_INTR_MASK:

		r = t->rw_intr_mask;

		break;

	case R_MASKED_INTR:

		r = t->r_intr & t->rw_intr_mask;

		break;

	default:

		D(printf ("%s %x\n", __func__, addr));

		break;

	}

	return r;

}

static void

timer_winvalid (void *opaque, target_phys_addr_t addr, uint32_t value)

{

	struct fs_timer_t *t = opaque;

	CPUState *env = t->env;

	cpu_abort(env, "Unsupported short access. reg=" TARGET_FMT_plx "\n",

		  addr);

}

#define TIMER_SLOWDOWN 1

static void update_ctrl(struct fs_timer_t *t, int tnum)

{

	unsigned int op;

	unsigned int freq;

	unsigned int freq_hz;

	unsigned int div;

	uint32_t ctrl;

	ptimer_state *timer;

	if (tnum == 0) {

		ctrl = t->rw_tmr0_ctrl;

		div = t->rw_tmr0_div;

		timer = t->ptimer_t0;

	} else {

		ctrl = t->rw_tmr1_ctrl;

		div = t->rw_tmr1_div;

		timer = t->ptimer_t1;

	}

	op = ctrl & 3;

	freq = ctrl >> 2;

	freq_hz = 32000000;

	switch (freq)

	{

	case 0:

	case 1:

		D(printf ("extern or disabled timer clock?\n"));

		break;

	case 4: freq_hz =  29493000; break;

	case 5: freq_hz =  32000000; break;

	case 6: freq_hz =  32768000; break;

	case 7: freq_hz = 100001000; break;

	default:

		abort();

		break;

	}

	D(printf ("freq_hz=%d div=%d\n", freq_hz, div));

	div = div * TIMER_SLOWDOWN;

	div >>= 10;

	freq_hz >>= 10;

	ptimer_set_freq(timer, freq_hz);

	ptimer_set_limit(timer, div, 0);

	switch (op)

	{

		case 0:

			/* Load.  */

			ptimer_set_limit(timer, div, 1);

			break;

		case 1:

			/* Hold.  */

			ptimer_stop(timer);

			break;

		case 2:

			/* Run.  */

			ptimer_run(timer, 0);

			break;

		default:

			abort();

			break;

	}

}

static void timer_update_irq(struct fs_timer_t *t)

{

	t->r_intr &= ~(t->rw_ack_intr);

	t->r_masked_intr = t->r_intr & t->rw_intr_mask;

	D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));

	if (t->r_masked_intr)

		qemu_irq_raise(t->irq[0]);

	else

		qemu_irq_lower(t->irq[0]);

}

static void timer0_hit(void *opaque)

{

	struct fs_timer_t *t = opaque;

	t->r_intr |= 1;

	timer_update_irq(t);

}

static void timer1_hit(void *opaque)

{

	struct fs_timer_t *t = opaque;

	t->r_intr |= 2;

	timer_update_irq(t);

}

static void watchdog_hit(void *opaque)

{

	struct fs_timer_t *t = opaque;

	if (t->wd_hits == 0) {

		/* real hw gives a single tick before reseting but we are

		   a bit friendlier to compensate for our slower execution.  */

		ptimer_set_count(t->ptimer_wd, 10);

		ptimer_run(t->ptimer_wd, 1);

		qemu_irq_raise(t->nmi[0]);

	}

	else

		qemu_system_reset_request();

	t->wd_hits++;

}

static inline void timer_watchdog_update(struct fs_timer_t *t, uint32_t value)

{

	unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);

	unsigned int wd_key = t->rw_wd_ctrl >> 9;

	unsigned int wd_cnt = t->rw_wd_ctrl & 511;

	unsigned int new_key = value >> 9 & ((1 << 7) - 1);

	unsigned int new_cmd = (value >> 8) & 1;

	/* If the watchdog is enabled, they written key must match the

	   complement of the previous.  */

	wd_key = ~wd_key & ((1 << 7) - 1);

	if (wd_en && wd_key != new_key)

		return;

	D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n", 

		 wd_en, new_key, wd_key, new_cmd, wd_cnt));

	if (t->wd_hits)

		qemu_irq_lower(t->nmi[0]);

	t->wd_hits = 0;

	ptimer_set_freq(t->ptimer_wd, 760);

	if (wd_cnt == 0)

		wd_cnt = 256;

	ptimer_set_count(t->ptimer_wd, wd_cnt);

	if (new_cmd)

		ptimer_run(t->ptimer_wd, 1);

	else

		ptimer_stop(t->ptimer_wd);

	t->rw_wd_ctrl = value;

}

static void

timer_writel (void *opaque, target_phys_addr_t addr, uint32_t value)

{

	struct fs_timer_t *t = opaque;

	switch (addr)

	{

		case RW_TMR0_DIV:

			t->rw_tmr0_div = value;

			break;

		case RW_TMR0_CTRL:

			D(printf ("RW_TMR0_CTRL=%x\n", value));

			t->rw_tmr0_ctrl = value;

			update_ctrl(t, 0);

			break;

		case RW_TMR1_DIV:

			t->rw_tmr1_div = value;

			break;

		case RW_TMR1_CTRL:

			D(printf ("RW_TMR1_CTRL=%x\n", value));

			t->rw_tmr1_ctrl = value;

			update_ctrl(t, 1);

			break;

		case RW_INTR_MASK:

			D(printf ("RW_INTR_MASK=%x\n", value));

			t->rw_intr_mask = value;

			timer_update_irq(t);

			break;

		case RW_WD_CTRL:

			timer_watchdog_update(t, value);

			break;

		case RW_ACK_INTR:

			t->rw_ack_intr = value;

			timer_update_irq(t);

			t->rw_ack_intr = 0;

			break;

		default:

			printf ("%s " TARGET_FMT_plx " %x\n",

				__func__, addr, value);

			break;

	}

}

static CPUReadMemoryFunc *timer_read[] = {

	&timer_rinvalid,

	&timer_rinvalid,

	&timer_readl,

};

static CPUWriteMemoryFunc *timer_write[] = {

	&timer_winvalid,

	&timer_winvalid,

	&timer_writel,

};

static void etraxfs_timer_reset(void *opaque)

{

	struct fs_timer_t *t = opaque;

	ptimer_stop(t->ptimer_t0);

	ptimer_stop(t->ptimer_t1);

	ptimer_stop(t->ptimer_wd);

	t->rw_wd_ctrl = 0;

	t->r_intr = 0;

	t->rw_intr_mask = 0;

	qemu_irq_lower(t->irq[0]);

}

void etraxfs_timer_init(CPUState *env, qemu_irq *irqs, qemu_irq *nmi,

			target_phys_addr_t base)

{

	static struct fs_timer_t *t;

	int timer_regs;

	t = qemu_mallocz(sizeof *t);

	if (!t)

		return;

	t->bh_t0 = qemu_bh_new(timer0_hit, t);

	t->bh_t1 = qemu_bh_new(timer1_hit, t);

	t->bh_wd = qemu_bh_new(watchdog_hit, t);

	t->ptimer_t0 = ptimer_init(t->bh_t0);

	t->ptimer_t1 = ptimer_init(t->bh_t1);

	t->ptimer_wd = ptimer_init(t->bh_wd);

	t->irq = irqs;

	t->nmi = nmi;

	t->env = env;

	timer_regs = cpu_register_io_memory(0, timer_read, timer_write, t);

	cpu_register_physical_memory (base, 0x5c, timer_regs);

	qemu_register_reset(etraxfs_timer_reset, t);

}