rt-thread/bsp/stm32f20x/Drivers/serial.c

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/*
* File : serial.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2009, 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
* 2009-02-05 Bernard first version
* 2009-10-25 Bernard fix rt_serial_read bug when there is no data
* in the buffer.
* 2010-03-29 Bernard cleanup code.
*/
#include "serial.h"
#include <stm32f2xx_dma.h>
#include <stm32f2xx_usart.h>
static void rt_serial_enable_dma(DMA_Stream_TypeDef* dma_channel,
rt_uint32_t address, rt_uint32_t size);
/**
* @addtogroup STM32
*/
/*@{*/
/* RT-Thread Device Interface */
static rt_err_t rt_serial_init (rt_device_t dev)
{
struct stm32_serial_device* uart = (struct stm32_serial_device*) dev->user_data;
if (!(dev->flag & RT_DEVICE_FLAG_ACTIVATED))
{
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
rt_memset(uart->int_rx->rx_buffer, 0,
sizeof(uart->int_rx->rx_buffer));
uart->int_rx->read_index = 0;
uart->int_rx->save_index = 0;
}
if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
{
RT_ASSERT(uart->dma_tx->dma_channel != RT_NULL);
uart->dma_tx->list_head = uart->dma_tx->list_tail = RT_NULL;
/* init data node memory pool */
rt_mp_init(&(uart->dma_tx->data_node_mp), "dn",
uart->dma_tx->data_node_mem_pool,
sizeof(uart->dma_tx->data_node_mem_pool),
sizeof(struct stm32_serial_data_node));
}
/* Enable USART */
USART_Cmd(uart->uart_device, ENABLE);
dev->flag |= RT_DEVICE_FLAG_ACTIVATED;
}
return RT_EOK;
}
static rt_err_t rt_serial_open(rt_device_t dev, rt_uint16_t oflag)
{
return RT_EOK;
}
static rt_err_t rt_serial_close(rt_device_t dev)
{
return RT_EOK;
}
static rt_size_t rt_serial_read (rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
{
rt_uint8_t* ptr;
rt_err_t err_code;
struct stm32_serial_device* uart;
ptr = buffer;
err_code = RT_EOK;
uart = (struct stm32_serial_device*)dev->user_data;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
/* interrupt mode Rx */
while (size)
{
rt_base_t level;
/* disable interrupt */
level = rt_hw_interrupt_disable();
if (uart->int_rx->read_index != uart->int_rx->save_index)
{
/* read a character */
*ptr++ = uart->int_rx->rx_buffer[uart->int_rx->read_index];
size--;
/* move to next position */
uart->int_rx->read_index ++;
if (uart->int_rx->read_index >= UART_RX_BUFFER_SIZE)
uart->int_rx->read_index = 0;
}
else
{
/* set error code */
err_code = -RT_EEMPTY;
/* enable interrupt */
rt_hw_interrupt_enable(level);
break;
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
}
}
else
{
/* polling mode */
while ((rt_uint32_t)ptr - (rt_uint32_t)buffer < size)
{
while (uart->uart_device->SR & USART_FLAG_RXNE)
{
*ptr = uart->uart_device->DR & 0xff;
ptr ++;
}
}
}
/* set error code */
rt_set_errno(err_code);
return (rt_uint32_t)ptr - (rt_uint32_t)buffer;
}
static void rt_serial_enable_dma(DMA_Stream_TypeDef* dma_channel,
rt_uint32_t address, rt_uint32_t size)
{
RT_ASSERT(dma_channel != RT_NULL);
/* disable DMA */
DMA_Cmd(dma_channel, DISABLE);
2013-01-08 22:40:58 +08:00
/* set buffer address */
dma_channel->M0AR = address;
/* set size */
dma_channel->NDTR = size;
/* enable DMA */
DMA_Cmd(dma_channel, ENABLE);
}
static rt_size_t rt_serial_write (rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
{
rt_uint8_t* ptr;
rt_err_t err_code;
struct stm32_serial_device* uart;
err_code = RT_EOK;
ptr = (rt_uint8_t*)buffer;
uart = (struct stm32_serial_device*)dev->user_data;
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
{
/* interrupt mode Tx, does not support */
RT_ASSERT(0);
}
else if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
{
/* DMA mode Tx */
/* allocate a data node */
struct stm32_serial_data_node* data_node = (struct stm32_serial_data_node*)
rt_mp_alloc (&(uart->dma_tx->data_node_mp), RT_WAITING_FOREVER);
if (data_node == RT_NULL)
{
/* set error code */
err_code = -RT_ENOMEM;
}
else
{
rt_uint32_t level;
/* fill data node */
data_node->data_ptr = ptr;
data_node->data_size = size;
/* insert to data link */
data_node->next = RT_NULL;
/* disable interrupt */
level = rt_hw_interrupt_disable();
data_node->prev = uart->dma_tx->list_tail;
if (uart->dma_tx->list_tail != RT_NULL)
uart->dma_tx->list_tail->next = data_node;
uart->dma_tx->list_tail = data_node;
if (uart->dma_tx->list_head == RT_NULL)
{
/* start DMA to transmit data */
uart->dma_tx->list_head = data_node;
/* Enable DMA Channel */
rt_serial_enable_dma(uart->dma_tx->dma_channel,
(rt_uint32_t)uart->dma_tx->list_head->data_ptr,
uart->dma_tx->list_head->data_size);
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
}
}
else
{
/* polling mode */
if (dev->flag & RT_DEVICE_FLAG_STREAM)
{
/* stream mode */
while (size)
{
if (*ptr == '\n')
{
while (!(uart->uart_device->SR & USART_FLAG_TXE));
uart->uart_device->DR = '\r';
}
while (!(uart->uart_device->SR & USART_FLAG_TXE));
uart->uart_device->DR = (*ptr & 0x1FF);
++ptr; --size;
}
}
else
{
/* write data directly */
while (size)
{
while (!(uart->uart_device->SR & USART_FLAG_TXE));
uart->uart_device->DR = (*ptr & 0x1FF);
++ptr; --size;
}
}
}
/* set error code */
rt_set_errno(err_code);
return (rt_uint32_t)ptr - (rt_uint32_t)buffer;
}
static rt_err_t rt_serial_control (rt_device_t dev, int cmd, void *args)
{
struct stm32_serial_device* uart;
RT_ASSERT(dev != RT_NULL);
uart = (struct stm32_serial_device*)dev->user_data;
switch (cmd)
{
case RT_DEVICE_CTRL_SUSPEND:
/* suspend device */
dev->flag |= RT_DEVICE_FLAG_SUSPENDED;
USART_Cmd(uart->uart_device, DISABLE);
break;
case RT_DEVICE_CTRL_RESUME:
/* resume device */
dev->flag &= ~RT_DEVICE_FLAG_SUSPENDED;
USART_Cmd(uart->uart_device, ENABLE);
break;
}
return RT_EOK;
}
/*
* serial register for STM32
* support STM32F103VB and STM32F103ZE
*/
rt_err_t rt_hw_serial_register(rt_device_t device, const char* name, rt_uint32_t flag, struct stm32_serial_device *serial)
{
RT_ASSERT(device != RT_NULL);
if ((flag & RT_DEVICE_FLAG_DMA_RX) ||
(flag & RT_DEVICE_FLAG_INT_TX))
{
RT_ASSERT(0);
}
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 = serial;
/* register a character device */
return rt_device_register(device, name, RT_DEVICE_FLAG_RDWR | flag);
}
/* ISR for serial interrupt */
void rt_hw_serial_isr(rt_device_t device)
{
struct stm32_serial_device* uart = (struct stm32_serial_device*) device->user_data;
if(USART_GetITStatus(uart->uart_device, USART_IT_RXNE) != RESET)
{
/* interrupt mode receive */
RT_ASSERT(device->flag & RT_DEVICE_FLAG_INT_RX);
/* save on rx buffer */
while (uart->uart_device->SR & USART_FLAG_RXNE)
{
rt_base_t level;
/* disable interrupt */
level = rt_hw_interrupt_disable();
/* save character */
uart->int_rx->rx_buffer[uart->int_rx->save_index] = uart->uart_device->DR & 0xff;
uart->int_rx->save_index ++;
if (uart->int_rx->save_index >= UART_RX_BUFFER_SIZE)
uart->int_rx->save_index = 0;
/* if the next position is read index, discard this 'read char' */
if (uart->int_rx->save_index == uart->int_rx->read_index)
{
uart->int_rx->read_index ++;
if (uart->int_rx->read_index >= UART_RX_BUFFER_SIZE)
uart->int_rx->read_index = 0;
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
}
/* clear interrupt */
USART_ClearITPendingBit(uart->uart_device, USART_IT_RXNE);
/* invoke callback */
if (device->rx_indicate != RT_NULL)
{
rt_size_t rx_length;
/* get rx length */
rx_length = uart->int_rx->read_index > uart->int_rx->save_index ?
UART_RX_BUFFER_SIZE - uart->int_rx->read_index + uart->int_rx->save_index :
uart->int_rx->save_index - uart->int_rx->read_index;
device->rx_indicate(device, rx_length);
}
}
if (USART_GetITStatus(uart->uart_device, USART_IT_TC) != RESET)
{
/* clear interrupt */
USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
}
}
/*
* ISR for DMA mode Tx
*/
void rt_hw_serial_dma_tx_isr(rt_device_t device)
{
rt_uint32_t level;
struct stm32_serial_data_node* data_node;
struct stm32_serial_device* uart = (struct stm32_serial_device*) device->user_data;
/* DMA mode receive */
RT_ASSERT(device->flag & RT_DEVICE_FLAG_DMA_TX);
/* get the first data node */
data_node = uart->dma_tx->list_head;
RT_ASSERT(data_node != RT_NULL);
/* invoke call to notify tx complete */
if (device->tx_complete != RT_NULL)
device->tx_complete(device, data_node->data_ptr);
/* disable interrupt */
level = rt_hw_interrupt_disable();
/* remove list head */
uart->dma_tx->list_head = data_node->next;
if (uart->dma_tx->list_head == RT_NULL) /* data link empty */
uart->dma_tx->list_tail = RT_NULL;
/* enable interrupt */
rt_hw_interrupt_enable(level);
/* release data node memory */
rt_mp_free(data_node);
if (uart->dma_tx->list_head != RT_NULL)
{
/* transmit next data node */
rt_serial_enable_dma(uart->dma_tx->dma_channel,
(rt_uint32_t)uart->dma_tx->list_head->data_ptr,
uart->dma_tx->list_head->data_size);
}
else
{
/* no data to be transmitted, disable DMA */
DMA_Cmd(uart->dma_tx->dma_channel, DISABLE);
}
}
/*@}*/