rt-thread-official/components/drivers/serial/serial.c

365 lines
8.0 KiB
C

/*
* File : serial.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rt-thread.org/license/LICENSE
*
* Change Logs:
* Date Author Notes
* 2006-03-13 bernard first version
* 2012-05-15 lgnq modified according bernard's implementation.
* 2012-05-28 bernard code cleanup
*/
#include <rthw.h>
#include <rtthread.h>
#include <rtdevice.h>
rt_inline void serial_ringbuffer_init(struct serial_ringbuffer *rbuffer)
{
rt_memset(rbuffer->buffer, 0, sizeof(rbuffer->buffer));
rbuffer->put_index = 0;
rbuffer->get_index = 0;
}
rt_inline void serial_ringbuffer_putc(struct serial_ringbuffer *rbuffer, char ch)
{
rt_base_t level;
/* disable interrupt */
level = rt_hw_interrupt_disable();
rbuffer->buffer[rbuffer->put_index] = ch;
rbuffer->put_index = (rbuffer->put_index + 1) & (SERIAL_RBUFFER_SIZE - 1);
/* if the next position is read index, discard this 'read char' */
if (rbuffer->put_index == rbuffer->get_index)
{
rbuffer->get_index = (rbuffer->get_index + 1) & (SERIAL_RBUFFER_SIZE - 1);
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
}
rt_inline int serial_ringbuffer_putchar(struct serial_ringbuffer *rbuffer, char ch)
{
rt_base_t level;
rt_uint16_t next_index;
/* disable interrupt */
level = rt_hw_interrupt_disable();
next_index = (rbuffer->put_index + 1) & (SERIAL_RBUFFER_SIZE - 1);
if (next_index != rbuffer->get_index)
{
rbuffer->buffer[rbuffer->put_index] = ch;
rbuffer->put_index = next_index;
}
else
{
/* enable interrupt */
rt_hw_interrupt_enable(level);
return -1;
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
return 1;
}
rt_inline int serial_ringbuffer_getc(struct serial_ringbuffer *rbuffer)
{
int ch;
rt_base_t level;
ch = -1;
/* disable interrupt */
level = rt_hw_interrupt_disable();
if (rbuffer->get_index != rbuffer->put_index)
{
ch = rbuffer->buffer[rbuffer->get_index];
rbuffer->get_index = (rbuffer->get_index + 1) & (SERIAL_RBUFFER_SIZE - 1);
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
return ch;
}
rt_inline rt_uint32_t serial_ringbuffer_size(struct serial_ringbuffer *rbuffer)
{
rt_uint32_t size;
rt_base_t level;
level = rt_hw_interrupt_disable();
size = (rbuffer->put_index - rbuffer->get_index) & (SERIAL_RBUFFER_SIZE - 1);
rt_hw_interrupt_enable(level);
return size;
}
/* RT-Thread Device Interface */
/*
* This function initializes serial
*/
static rt_err_t rt_serial_init(struct rt_device *dev)
{
rt_err_t result = RT_EOK;
struct rt_serial_device *serial;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
if (!(dev->flag & RT_DEVICE_FLAG_ACTIVATED))
{
/* apply configuration */
if (serial->ops->configure)
result = serial->ops->configure(serial, &serial->config);
if (result != RT_EOK)
return result;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
serial_ringbuffer_init(serial->int_rx);
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
serial_ringbuffer_init(serial->int_tx);
/* set activated */
dev->flag |= RT_DEVICE_FLAG_ACTIVATED;
}
return result;
}
static rt_err_t rt_serial_open(struct rt_device *dev, rt_uint16_t oflag)
{
struct rt_serial_device *serial;
rt_uint32_t int_flags = 0;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
int_flags = RT_SERIAL_RX_INT;
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
int_flags |= RT_SERIAL_TX_INT;
if (int_flags)
{
serial->ops->control(serial, RT_DEVICE_CTRL_SET_INT, (void *)int_flags);
}
return RT_EOK;
}
static rt_err_t rt_serial_close(struct rt_device *dev)
{
struct rt_serial_device *serial;
rt_uint32_t int_flags = 0;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
int_flags = RT_SERIAL_RX_INT;
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
int_flags |= RT_SERIAL_TX_INT;
if (int_flags)
{
serial->ops->control(serial, RT_DEVICE_CTRL_CLR_INT, (void *)int_flags);
}
return RT_EOK;
}
static rt_size_t rt_serial_read(struct rt_device *dev, rt_off_t pos, void *buffer, rt_size_t size)
{
rt_uint8_t *ptr;
rt_uint32_t read_nbytes;
struct rt_serial_device *serial;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
ptr = (rt_uint8_t *)buffer;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
/* interrupt mode Rx */
while (size)
{
int ch;
ch = serial_ringbuffer_getc(serial->int_rx);
if (ch == -1)
break;
*ptr = ch & 0xff;
ptr ++;
size --;
}
}
else
{
/* polling mode */
while ((rt_uint32_t)ptr - (rt_uint32_t)buffer < size)
{
*ptr = serial->ops->getc(serial);
ptr ++;
}
}
read_nbytes = (rt_uint32_t)ptr - (rt_uint32_t)buffer;
/* set error code */
if (read_nbytes == 0)
{
rt_set_errno(-RT_EEMPTY);
}
return read_nbytes;
}
static rt_size_t rt_serial_write(struct rt_device *dev, rt_off_t pos,
const void *buffer, rt_size_t size)
{
rt_uint8_t *ptr;
rt_size_t write_nbytes = 0;
struct rt_serial_device *serial;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
ptr = (rt_uint8_t*)buffer;
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
{
/* warning: data will be discarded if buffer is full */
while (size)
{
if (serial_ringbuffer_putchar(serial->int_tx, *ptr) != -1)
{
ptr ++;
size --;
}
else
break;
}
}
else
{
/* polling mode */
while (size)
{
/*
* to be polite with serial console add a line feed
* to the carriage return character
*/
if (*ptr == '\n' && (dev->flag & RT_DEVICE_FLAG_STREAM))
{
serial->ops->putc(serial, '\r');
}
serial->ops->putc(serial, *ptr);
++ptr;
--size;
}
}
write_nbytes = (rt_uint32_t)ptr - (rt_uint32_t)buffer;
if (write_nbytes == 0)
{
rt_set_errno(-RT_EFULL);
}
return write_nbytes;
}
static rt_err_t rt_serial_control(struct rt_device *dev, rt_uint8_t cmd, void *args)
{
struct rt_serial_device *serial;
RT_ASSERT(dev != RT_NULL);
serial = (struct rt_serial_device *)dev;
switch (cmd)
{
case RT_DEVICE_CTRL_SUSPEND:
/* suspend device */
dev->flag |= RT_DEVICE_FLAG_SUSPENDED;
break;
case RT_DEVICE_CTRL_RESUME:
/* resume device */
dev->flag &= ~RT_DEVICE_FLAG_SUSPENDED;
break;
case RT_DEVICE_CTRL_CONFIG:
/* configure device */
serial->ops->configure(serial, (struct serial_configure *)args);
break;
}
return RT_EOK;
}
/*
* serial register
*/
rt_err_t rt_hw_serial_register(struct rt_serial_device *serial, const char *name, rt_uint32_t flag, void *data)
{
struct rt_device *device;
RT_ASSERT(serial != RT_NULL);
device = &(serial->parent);
device->type = RT_Device_Class_Char;
device->rx_indicate = RT_NULL;
device->tx_complete = RT_NULL;
device->init = rt_serial_init;
device->open = rt_serial_open;
device->close = rt_serial_close;
device->read = rt_serial_read;
device->write = rt_serial_write;
device->control = rt_serial_control;
device->user_data = data;
/* register a character device */
return rt_device_register(device, name, flag);
}
/* ISR for serial interrupt */
void rt_hw_serial_isr(struct rt_serial_device *serial)
{
int ch = -1;
/* interrupt mode receive */
RT_ASSERT(serial->parent.flag & RT_DEVICE_FLAG_INT_RX);
while (1)
{
ch = serial->ops->getc(serial);
if (ch == -1)
break;
serial_ringbuffer_putc(serial->int_rx, ch);
}
/* invoke callback */
if (serial->parent.rx_indicate != RT_NULL)
{
rt_size_t rx_length;
/* get rx length */
rx_length = serial_ringbuffer_size(serial->int_rx);
serial->parent.rx_indicate(&serial->parent, rx_length);
}
}