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/*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2010 chysun2000@gmail.com
*
* This file is part of nios2sim-ng.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "nios2sim-ng.h"
#include "device.h"
#include "timer.h"
struct timer {
struct io_register regs[TIMER_REG_COUNT];
uint32_t set_period;
uint32_t curr_count;
};
static const uint32_t timer_valid_mask[TIMER_REG_COUNT] = {
0x3, 0xF, 0xFFFF, 0xFFFF, 0xFFFF, 0xFFFF
};
static const uint32_t timer_read_only_mask[TIMER_REG_COUNT] = {
0x2, 0, 0, 0, 0, 0
};
static int timer_init(struct device *dev)
{
unsigned int i;
struct timer *t = malloc(sizeof(struct timer));
struct io_register *regs;
if (unlikely(t == NULL))
return -1;
/* Initialite registers */
regs = t->regs;
for (i = 0; i < TIMER_REG_COUNT; i++) {
io_register_init(®s[i],
TIMER_BASE + REG_TO_OFF(i),
timer_valid_mask[i],
timer_read_only_mask[i],
0);
}
t->set_period = 0;
t->curr_count = 0;
dev->priv = t;
return 0;
}
static void update_period_reg(struct timer *t)
{
t->regs[TIMER_PERIODL_REG].value = t->curr_count & 0xFFFF;
t->regs[TIMER_PERIODH_REG].value = (t->curr_count & 0xFFFF0000) >> 16;
//copy_snapshot();
}
#if 0
static void copy_snapshot(struct timer *t)
{
t->regs[TIMER_SNAPL_REG].value = t->regs[TIMER_PERIODL_REG].value;
t->regs[TIMER_SNAPH_REG].value = t->regs[TIMER_PERIODH_REG].value;
}
static uint32_t timer_read(struct device *dev, uint32_t addr, uint32_t data_len)
{
struct timer *t = dev->priv;
uint32_t ret_val = 0;
uint32_t index = 0;
index = (addr - dev->base) / 4;
if (index >= TIMER_REG_COUNT)
return 0;
if (index == TIMER_SNAPL_REG || index == TIMER_SNAPH_REG)
copy_snapshot(t);
ret_val = io_register_read(&t->regs[index]);
ret_val = io_read_data(ret_val, data_len);
return ret_val;
}
static void timer_write(struct device *dev, uint32_t addr, uint32_t data, size_t count)
{
struct timer *t = dev->priv;
struct io_register *regs;
uint32_t index = 0;
uint32_t temp = 0;
uint32_t only_read_mask = 0;
uint32_t valid_mask = 0;
index = (addr - dev->base) / 4;
if (index >= TIMER_REG_COUNT)
return;
temp = regs[index].value;
valid_mask = regs[index].valid_mask;
only_read_mask = regs[index].readonly_mask;
regs[index].value = io_write_data_mask(temp, data, data_len, valid_mask, only_read_mask);
if (index == TIMER_PERIODL_REG){
t->set_period &= 0xFFFF0000;
t->set_period |= data & 0xFFFF;
t->curr_count = t->set_period;
update_period_reg(t);
} else if (index == TIMER_PERIODH_REG) {
hw.set_period = hw.set_period & 0xFFFF;
hw.set_period = hw.set_period | ((data & 0xFFFF) <<16);
hw.curr_count = hw.set_period;
update_period_reg(t);
} else if (index == TIMER_STATUS_REG) {
if ((regs[index].value & STATUS_TO_MASK) == 0)
clean_ipending(dev->irq_mask);
}
}
#endif
static bool timer_has_irq(struct device *dev)
{
struct timer *t = dev->priv;
uint32_t ctrl_val = io_register_read(&t->regs[TIMER_CTRL_REG]);
uint32_t status_val = io_register_read(&t->regs[TIMER_STATUS_REG]);
if ((ctrl_val & TIMER_CTRL_ITO_MASK) == TIMER_CTRL_ITO_MASK)
if ((status_val & TIMER_STATUS_TO_MASK) == TIMER_STATUS_TO_MASK)
return true;
return false;
}
static void decrease_counter(struct timer *t)
{
if (t->curr_count > 2)
t->curr_count -= 2;
else
t->curr_count = 0;
update_period_reg(t);
}
static bool timer_can_decrease(struct timer *t)
{
uint32_t ctrl_val = t->regs[TIMER_CTRL_REG].value;
/* Timer started? */
if ((ctrl_val & TIMER_CTRL_START_MASK) == 0)
return false;
/* Timer stopped? */
if ((ctrl_val & TIMER_CTRL_STOP_MASK) != 0)
return false;
/* If timer is not in continuous mode and counter has reached period */
if ((ctrl_val & TIMER_CTRL_CONT_MASK) == 0
&& t->set_period == t->curr_count)
return false;
return true;
}
static void update_status(struct timer *t)
{
if (t->curr_count <= 0) {
t->regs[TIMER_CTRL_REG].value |= TIMER_CTRL_ITO_MASK;
t->curr_count = t->set_period;
update_period_reg(t);
t->regs[TIMER_STATUS_REG].value |= TIMER_STATUS_TO_MASK;
}
}
static void timer_simulate(struct device *dev)
{
struct timer *t = dev->priv;
if (timer_can_decrease(t)) {
decrease_counter(t);
update_status(t);
}
}
struct device timer_core = {
.name = "Timer Core",
.base = TIMER_BASE,
.size = TIMER_SIZE,
.irq_mask = IRQ_TO_MASK(TIMER_IRQ),
.init = timer_init,
.is_dev_addr = NULL, /* use generic */
.has_irq = timer_has_irq,
.simulate = timer_simulate,
};
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