rt-thread/components/drivers/hwtimer/hwtimer.c

356 lines
8.1 KiB
C

/*
* File : hwtimer.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Change Logs:
* Date Author Notes
* 2015-08-31 heyuanjie87 first version
*/
#include <rtthread.h>
#include <rtdevice.h>
rt_inline rt_uint32_t timeout_calc(rt_hwtimer_t *timer, rt_hwtimerval_t *tv)
{
float overflow;
float timeout;
rt_uint32_t counter;
int i, index;
float tv_sec;
float devi_min = 1;
float devi;
/* 把定时器溢出时间和定时时间换算成秒 */
overflow = timer->info->maxcnt/(float)timer->freq;
tv_sec = tv->sec + tv->usec/(float)1000000;
if (tv_sec < (1/(float)timer->freq))
{
/* 定时时间小于计数周期 */
i = 0;
timeout = 1/(float)timer->freq;
}
else
{
for (i = 1; i > 0; i ++)
{
timeout = tv_sec/i;
if (timeout <= overflow)
{
counter = timeout*timer->freq;
devi = tv_sec - (counter/(float)timer->freq)*i;
/* 计算最小误差 */
if (devi > devi_min)
{
i = index;
timeout = tv_sec/i;
break;
}
else if (devi == 0)
{
break;
}
else if (devi < devi_min)
{
devi_min = devi;
index = i;
}
}
}
}
timer->cycles = i;
timer->reload = i;
timer->period_sec = timeout;
counter = timeout*timer->freq;
return counter;
}
static rt_err_t rt_hwtimer_init(struct rt_device *dev)
{
rt_err_t result = RT_EOK;
rt_hwtimer_t *timer;
timer = (rt_hwtimer_t *)dev;
/* 尝试将默认计数频率设为1Mhz */
if ((1000000 <= timer->info->maxfreq) && (1000000 >= timer->info->minfreq))
{
timer->freq = 1000000;
}
else
{
timer->freq = timer->info->minfreq;
}
timer->mode = HWTIMER_MODE_ONESHOT;
timer->cycles = 0;
timer->overflow = 0;
if (timer->ops->init)
{
timer->ops->init(timer, 1);
}
else
{
result = -RT_ENOSYS;
}
return result;
}
static rt_err_t rt_hwtimer_open(struct rt_device *dev, rt_uint16_t oflag)
{
rt_err_t result = RT_EOK;
rt_hwtimer_t *timer;
timer = (rt_hwtimer_t *)dev;
if (timer->ops->control != RT_NULL)
{
timer->ops->control(timer, HWTIMER_CTRL_FREQ_SET, &timer->freq);
}
else
{
result = -RT_ENOSYS;
}
return result;
}
static rt_err_t rt_hwtimer_close(struct rt_device *dev)
{
rt_err_t result = RT_EOK;
rt_hwtimer_t *timer;
timer = (rt_hwtimer_t*)dev;
if (timer->ops->init != RT_NULL)
{
timer->ops->init(timer, 0);
}
else
{
result = -RT_ENOSYS;
}
dev->flag &= ~RT_DEVICE_FLAG_ACTIVATED;
dev->rx_indicate = RT_NULL;
return result;
}
static rt_size_t rt_hwtimer_read(struct rt_device *dev, rt_off_t pos, void *buffer, rt_size_t size)
{
rt_hwtimer_t *timer;
rt_hwtimerval_t tv;
rt_uint32_t cnt;
float t;
timer = (rt_hwtimer_t *)dev;
if (timer->ops->count_get == RT_NULL)
return 0;
cnt = timer->ops->count_get(timer);
if (timer->info->cntmode == HWTIMER_CNTMODE_DW)
{
cnt = timer->info->maxcnt - cnt;
}
t = timer->overflow * timer->period_sec + cnt/(float)timer->freq;
tv.sec = t;
tv.usec = (t - tv.sec) * 1000000;
size = size > sizeof(tv)? sizeof(tv) : size;
rt_memcpy(buffer, &tv, size);
return size;
}
static rt_size_t rt_hwtimer_write(struct rt_device *dev, rt_off_t pos, const void *buffer, rt_size_t size)
{
rt_uint32_t t;
rt_hwtimer_mode_t opm = HWTIMER_MODE_PERIOD;
rt_hwtimer_t *timer;
timer = (rt_hwtimer_t *)dev;
if ((timer->ops->start == RT_NULL) || (timer->ops->stop == RT_NULL))
return 0;
if (size != sizeof(rt_hwtimerval_t))
return 0;
if ((timer->cycles <= 1) && (timer->mode == HWTIMER_MODE_ONESHOT))
{
opm = HWTIMER_MODE_ONESHOT;
}
timer->ops->stop(timer);
timer->overflow = 0;
t = timeout_calc(timer, (rt_hwtimerval_t*)buffer);
if (timer->ops->start(timer, t, opm) != RT_EOK)
size = 0;
return size;
}
static rt_err_t rt_hwtimer_control(struct rt_device *dev, rt_uint8_t cmd, void *args)
{
rt_err_t result = RT_EOK;
rt_hwtimer_t *timer;
timer = (rt_hwtimer_t *)dev;
switch (cmd)
{
case HWTIMER_CTRL_STOP:
{
if (timer->ops->stop != RT_NULL)
{
timer->ops->stop(timer);
}
else
{
result = -RT_ENOSYS;
}
}
break;
case HWTIMER_CTRL_FREQ_SET:
{
rt_uint32_t *f;
if (args == RT_NULL)
{
result = -RT_EEMPTY;
break;
}
f = (rt_uint32_t*)args;
if ((*f > timer->info->maxfreq) || (*f < timer->info->minfreq))
{
result = -RT_ERROR;
break;
}
if (timer->ops->control != RT_NULL)
{
result = timer->ops->control(timer, cmd, args);
if (result == RT_EOK)
{
timer->freq = *f;
}
}
else
{
result = -RT_ENOSYS;
}
}
break;
case HWTIMER_CTRL_INFO_GET:
{
if (args == RT_NULL)
{
result = -RT_EEMPTY;
break;
}
*((struct rt_hwtimer_info*)args) = *timer->info;
}
case HWTIMER_CTRL_MODE_SET:
{
rt_hwtimer_mode_t *m;
if (args == RT_NULL)
{
result = -RT_EEMPTY;
break;
}
m = (rt_hwtimer_mode_t*)args;
if ((*m != HWTIMER_MODE_ONESHOT) && (*m != HWTIMER_MODE_PERIOD))
{
result = -RT_ERROR;
break;
}
timer->mode = *m;
}
break;
default:
{
result = -RT_ENOSYS;
}
break;
}
return result;
}
void rt_device_hwtimer_isr(rt_hwtimer_t *timer)
{
RT_ASSERT(timer != RT_NULL);
timer->overflow ++;
if (timer->cycles != 0)
{
timer->cycles --;
}
if (timer->cycles == 0)
{
timer->cycles = timer->reload;
if (timer->mode == HWTIMER_MODE_ONESHOT)
{
if (timer->ops->stop != RT_NULL)
{
timer->ops->stop(timer);
}
}
if (timer->parent.rx_indicate != RT_NULL)
{
timer->parent.rx_indicate(&timer->parent, sizeof(struct rt_hwtimerval));
}
}
}
rt_err_t rt_device_hwtimer_register(rt_hwtimer_t *timer, const char *name, void *user_data)
{
struct rt_device *device;
RT_ASSERT(timer != RT_NULL);
RT_ASSERT(timer->ops != RT_NULL);
RT_ASSERT(timer->info != RT_NULL);
device = &(timer->parent);
device->type = RT_Device_Class_Timer;
device->rx_indicate = RT_NULL;
device->tx_complete = RT_NULL;
device->init = rt_hwtimer_init;
device->open = rt_hwtimer_open;
device->close = rt_hwtimer_close;
device->read = rt_hwtimer_read;
device->write = rt_hwtimer_write;
device->control = rt_hwtimer_control;
device->user_data = user_data;
return rt_device_register(device, name, RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STANDALONE);
}