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rt-thread-official/libcpu/arm/stm32/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.
*/
#include "serial.h"
#include <stm32f10x_dma.h>
static void rt_serial_enable_dma(DMA_Channel_TypeDef* dma_channel,
rt_uint32_t address, rt_uint32_t size);
/**
* @addtogroup STM32
*/
/*@{*/
/**
* This function read a character from serial without interrupt enable mode
*
* @return the read char
*/
int rt_serial_getc(struct stm32_serial_device* uart)
{
rt_base_t level;
int ch = -1;
/* disable interrupt */
level = rt_hw_interrupt_disable();
if (uart->int_rx->read_index != uart->int_rx->save_index)
{
ch = uart->int_rx->rx_buffer[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);
return ch;
}
/* save a char to serial buffer */
void rt_serial_savechar(struct stm32_serial_device* uart, char ch)
{
rt_base_t level;
/* disable interrupt */
level = rt_hw_interrupt_disable();
uart->int_rx->rx_buffer[uart->int_rx->save_index] = ch;
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);
}
/**
* This function will write a character to serial without interrupt enable mode
*
* @param c the char to write
*/
void rt_serial_putc(rt_device_t device, const char c)
{
struct stm32_serial_device* uart = (struct stm32_serial_device*) device->private;
/*
* to be polite with serial console add a line feed
* to the carriage return character
*/
if (c=='\n' && (device->flag & RT_DEVICE_FLAG_STREAM))
rt_serial_putc(device, '\r');
while (!(uart->uart_device->SR & USART_FLAG_TXE));
uart->uart_device->DR = (c & 0x1FF);
}
/* 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->private;
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_RX)
{
RT_ASSERT(uart->dma_rx->dma_channel != RT_NULL);
uart->dma_rx->read_index = uart->dma_rx->read_descriptor = 0;
uart->dma_rx->is_full = RT_FALSE;
}
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
{
rt_memset(uart->int_tx->tx_buffer, 0,
sizeof(uart->int_tx->tx_buffer));
uart->int_tx->write_index = uart->int_tx->save_index = 0;
}
if (dev->flag & RT_DEVICE_FLAG_DMA_TX)
{
RT_ASSERT(uart->dma_rx->dma_channel != RT_NULL);
uart->dma_tx->list_head = uart->dma_tx->list_tail = RT_NULL;
}
/* 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)
{
struct stm32_serial_device* uart;
RT_ASSERT(dev != RT_NULL);
uart = (struct stm32_serial_device*)dev->private;
if (dev->flag & RT_DEVICE_FLAG_DMA_RX)
{
/* enable Rx DMA */
rt_serial_enable_dma(uart->dma_rx->dma_channel,
(rt_uint32_t)&(uart->dma_rx->rx_buffer[uart->dma_rx->save_descriptor][0]),
UART_DMA_RX_BUFFER_SIZE);
}
return RT_EOK;
}
static rt_err_t rt_serial_close(rt_device_t dev)
{
struct stm32_serial_device* uart;
RT_ASSERT(dev != RT_NULL);
uart = (struct stm32_serial_device*)dev->private;
if (dev->flag & RT_DEVICE_FLAG_DMA_RX)
{
/* disable DMA */
DMA_Cmd(uart->dma_rx->dma_channel, DISABLE);
}
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->private;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
rt_int32_t ch;
/* interrupt mode Rx */
while (size)
{
/* get a character */
ch = rt_serial_getc(uart);
if (ch < 0)
{
/* set error code */
err_code = -RT_EEMPTY;
break;
}
else
{
*ptr++ = ch;
size --;
}
}
}
else if (dev->flag & RT_DEVICE_FLAG_DMA_RX)
{
/* check queue empty */
if ((uart->dma_rx->read_descriptor == uart->dma_rx->save_descriptor))
{
/* set error code */
err_code = -RT_EEMPTY;
}
else
{
/* read data */
while ((rt_uint32_t)ptr - (rt_uint32_t)buffer < size)
{
/* read buffer */
*ptr ++ = uart->dma_rx->
rx_buffer[uart->dma_rx->read_descriptor][uart->dma_rx->read_index];
/* move to next position */
uart->dma_rx->read_index ++;
/* wrap read index */
if (uart->dma_rx->read_index >= UART_DMA_RX_BUFFER_SIZE)
{
/* wrap read index */
uart->dma_rx->read_index = 0;
/* move to next read descriptor */
uart->dma_rx->read_descriptor ++;
/* wrap read descriptor */
if (uart->dma_rx->read_descriptor >= UART_DMA_RX_DESCRIPTOR)
uart->dma_rx->read_descriptor = 0;
if (uart->dma_rx->is_full == RT_TRUE)
{
rt_uint32_t level;
level = rt_hw_interrupt_disable();
uart->dma_rx->save_descriptor ++;
if (uart->dma_rx->save_descriptor >= UART_DMA_RX_DESCRIPTOR)
uart->dma_rx->save_descriptor = 0;
rt_hw_interrupt_enable(level);
/* re-enable DMA to receive */
rt_serial_enable_dma(uart->dma_rx->dma_channel,
(rt_uint32_t)&(uart->dma_rx->rx_buffer[uart->dma_rx->save_descriptor][0]),
UART_DMA_RX_BUFFER_SIZE);
}
/* check queue empty */
if ((uart->dma_rx->read_descriptor == uart->dma_rx->save_descriptor))
{
/* set error code */
err_code = -RT_EEMPTY;
break;
}
}
}
}
}
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_Channel_TypeDef* dma_channel,
rt_uint32_t address, rt_uint32_t size)
{
RT_ASSERT(dma_channel != RT_NULL);
/* disable DMA */
DMA_Cmd(dma_channel, DISABLE);
/* set buffer address */
dma_channel->CMAR = address;
/* set size */
dma_channel->CNDTR = 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->private;
if (dev->flag & RT_DEVICE_FLAG_INT_TX)
{
/* interrupt mode Tx */
while (uart->int_tx->save_index != uart->int_tx->write_index)
{
/* save on tx buffer */
uart->int_tx->tx_buffer[uart->int_tx->save_index] = *ptr++;
-- size;
/* move to next position */
uart->int_tx->save_index ++;
/* wrap save index */
if (uart->int_tx->save_index >= UART_TX_BUFFER_SIZE)
uart->int_tx->save_index = 0;
}
/* set error code */
if (size > 0)
err_code = -RT_EFULL;
}
#ifdef RT_USING_HEAP
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_malloc (sizeof(struct stm32_serial_data_node));
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);
}
}
#endif
else
{
/* polling mode */
while (size)
{
rt_serial_putc(dev, *ptr);
++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, rt_uint8_t cmd, void *args)
{
struct stm32_serial_device* uart;
RT_ASSERT(dev != RT_NULL);
uart = (struct stm32_serial_device*)dev->private;
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);
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->private = 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->private;
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_serial_savechar(uart, uart->uart_device->DR & 0xff);
}
/* 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)
{
/* interrupt mode transmission */
RT_ASSERT(device->flag & RT_DEVICE_FLAG_INT_TX);
/* transmission completed */
uart->int_tx->write_index ++;
if (uart->int_tx->write_index >= UART_TX_BUFFER_SIZE)
uart->int_tx->write_index = 0;
/* clear interrupt */
USART_ClearITPendingBit(uart->uart_device, USART_IT_TC);
/* start next transmission */
if (uart->int_tx->write_index <
uart->int_tx->save_index)
{
uart->uart_device->DR = uart->int_tx
->tx_buffer[uart->int_tx->write_index];
}
}
}
/*
* ISR for DMA mode Rx
*/
void rt_hw_serial_dma_rx_isr(rt_device_t device)
{
rt_uint32_t next_descriptor;
struct stm32_serial_device* uart = (struct stm32_serial_device*) device->private;
/* DMA mode receive */
RT_ASSERT(device->flag & RT_DEVICE_FLAG_DMA_RX);
/* invoke callback */
if (device->rx_indicate != RT_NULL)
device->rx_indicate(device, UART_DMA_RX_BUFFER_SIZE);
next_descriptor = uart->dma_rx->save_descriptor;
/* move to next descriptor */
next_descriptor ++;
if (next_descriptor >= UART_DMA_RX_DESCRIPTOR)
next_descriptor = 0;
if (next_descriptor != uart->dma_rx->read_descriptor)
{
uart->dma_rx->save_descriptor = next_descriptor;
/* enable next DMA */
rt_serial_enable_dma(uart->dma_rx->dma_channel,
(rt_uint32_t)&(uart->dma_rx->rx_buffer[uart->dma_rx->save_descriptor][0]),
UART_DMA_RX_BUFFER_SIZE);
}
else
{
/* no descriptor yet, disable DMA */
DMA_Cmd(uart->dma_rx->dma_channel, DISABLE);
uart->dma_rx->is_full = RT_TRUE;
}
}
/*
* ISR for DMA mode Tx
*/
void rt_hw_serial_dma_tx_isr(rt_device_t device)
{
#ifdef RT_USING_HEAP
rt_uint32_t level;
struct stm32_serial_data_node* data_node;
struct stm32_serial_device* uart = (struct stm32_serial_device*) device->private;
/* 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 tail */
uart->dma_tx->list_tail = data_node->prev;
if (uart->dma_tx->list_tail == RT_NULL)
uart->dma_tx->list_head = RT_NULL;
/* enable interrupt */
rt_hw_interrupt_enable(level);
/* free data node memory(!!) */
rt_free(data_node);
if (uart->dma_tx->list_tail != RT_NULL)
{
/* transmit next data node */
rt_serial_enable_dma(uart->dma_tx->dma_channel,
(rt_uint32_t)uart->dma_tx->list_tail->data_ptr,
uart->dma_tx->list_tail->data_size);
}
else
{
/* no data to be transmitted, disable DMA */
DMA_Cmd(uart->dma_tx->dma_channel, DISABLE);
}
#endif
}
/*@}*/
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