rt-thread-official/bsp/nuc140/uart.c

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#include <rthw.h>
#include <rtthread.h>
#include "CMSIS/CM0/NUC1xx.h"
/**
* @addtogroup NUC1xx
*/
/*@{*/
#if defined(RT_USING_UART) && defined(RT_USING_DEVICE)
#define UART_BAUDRATE 115200
struct rt_uart_nuc
{
struct rt_device parent;
/* buffer for reception */
rt_uint8_t read_index, save_index;
rt_uint8_t rx_buffer[RT_UART_RX_BUFFER_SIZE];
}uart_device;
void UART0_IRQHandler(void)
{
rt_ubase_t level;
struct rt_uart_nuc* uart = &uart_device;
if (UART0->ISR.RDA_INT == 1) /* Receive Data Available */
{
while (UART0->ISR.RDA_IF == 1)
{
/* Receive Data Available */
uart->rx_buffer[uart->save_index] = UART0->DATA;
level = rt_hw_interrupt_disable();
uart->save_index ++;
if (uart->save_index >= RT_UART_RX_BUFFER_SIZE)
uart->save_index = 0;
rt_hw_interrupt_enable(level);
}
/* invoke callback */
if(uart->parent.rx_indicate != RT_NULL)
{
rt_size_t length;
if (uart->read_index > uart->save_index)
length = RT_UART_RX_BUFFER_SIZE - uart->read_index + uart->save_index;
else
length = uart->save_index - uart->read_index;
uart->parent.rx_indicate(&uart->parent, length);
}
}
return;
}
static rt_err_t rt_uart_init (rt_device_t dev)
{
/* Multi-Function Pin: Enable UART0:Tx Rx */
SYS->GPBMFP.UART0_RX = 1;
SYS->GPBMFP.UART0_TX = 1;
/* Configure GCR to reset UART0 */
SYS->IPRSTC2.UART0_RST = 1;
SYS->IPRSTC2.UART0_RST = 0;
/* Enable UART clock */
SYSCLK->APBCLK.UART0_EN = 1;
/* Select UART clock source */
SYSCLK->CLKSEL1.UART_S = 0;
/* Data format */
UART0->LCR.WLS = 3;
/* Configure the baud rate */
*((__IO uint32_t *)&UART0->BAUD) = 0x3F000066; /* This setting is for 115200bsp with 12Mhz clock source */
return RT_EOK;
}
static rt_err_t rt_uart_open(rt_device_t dev, rt_uint16_t oflag)
{
RT_ASSERT(dev != RT_NULL);
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
/* open receive data available interrupt */
UART0->IER.RDA_IEN = 1;
/* Enable the UART Interrupt */
NVIC_EnableIRQ(UART0_IRQn);
}
return RT_EOK;
}
static rt_err_t rt_uart_close(rt_device_t dev)
{
RT_ASSERT(dev != RT_NULL);
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
/* Disable the UART Interrupt */
NVIC_DisableIRQ(UART0_IRQn);
}
return RT_EOK;
}
static rt_size_t rt_uart_read(rt_device_t dev, rt_off_t pos, void* buffer, rt_size_t size)
{
rt_uint8_t* ptr;
struct rt_uart_nuc *uart = (struct rt_uart_nuc*)dev;
RT_ASSERT(uart != RT_NULL);
/* point to buffer */
ptr = (rt_uint8_t*) buffer;
if (dev->flag & RT_DEVICE_FLAG_INT_RX)
{
while (size)
{
/* interrupt receive */
rt_base_t level;
/* disable interrupt */
level = rt_hw_interrupt_disable();
if (uart->read_index != uart->save_index)
{
*ptr = uart->rx_buffer[uart->read_index];
uart->read_index ++;
if (uart->read_index >= RT_UART_RX_BUFFER_SIZE)
uart->read_index = 0;
}
else
{
/* no data in rx buffer */
/* enable interrupt */
rt_hw_interrupt_enable(level);
break;
}
/* enable interrupt */
rt_hw_interrupt_enable(level);
ptr ++;
size --;
}
return (rt_uint32_t)ptr - (rt_uint32_t)buffer;
}
return 0;
}
static rt_size_t rt_uart_write(rt_device_t dev, rt_off_t pos, const void* buffer, rt_size_t size)
{
char *ptr;
ptr = (char*)buffer;
if (dev->flag & RT_DEVICE_FLAG_STREAM)
{
/* stream mode */
while (size)
{
if (*ptr == '\n')
{
/* check whether UART is empty */
while (UART0->FSR.TX_EMPTY !=1);
/* write data */
UART0->DATA = '\r';
}
/* check whether UART is empty */
while (UART0->FSR.TX_EMPTY !=1);
/* write data */
UART0->DATA = *ptr;
ptr ++;
size --;
}
}
else
{
while ( size != 0 )
{
/* check whether UART is empty */
while (UART0->FSR.TX_EMPTY !=1);
/* write data */
UART0->DATA = *ptr;
ptr++;
size--;
}
}
return (rt_size_t) ptr - (rt_size_t) buffer;
}
void rt_hw_uart_init(void)
{
struct rt_uart_nuc* uart;
/* get uart device */
uart = &uart_device;
/* device initialization */
uart->parent.type = RT_Device_Class_Char;
rt_memset(uart->rx_buffer, 0, sizeof(uart->rx_buffer));
uart->read_index = uart->save_index = 0;
/* device interface */
uart->parent.init = rt_uart_init;
uart->parent.open = rt_uart_open;
uart->parent.close = rt_uart_close;
uart->parent.read = rt_uart_read;
uart->parent.write = rt_uart_write;
uart->parent.control = RT_NULL;
uart->parent.private = RT_NULL;
rt_device_register(&uart->parent,
"uart1", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_INT_RX);
}
#endif /* end of UART */
/*@}*/