/*
* File : board.c
* This file is part of RT-Thread RTOS
* COPYRIGHT (C) 2009 RT-Thread Develop 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
* 2010-03-08 Bernard The first version for LPC17xx
* 2010-05-02 Aozima update CMSIS to 130
*/
#include <rthw.h>
#include <rtthread.h>
#include "LPC17xx.h"
#define IER_RBR 0x01
#define IER_THRE 0x02
#define IER_RLS 0x04
#define IIR_PEND 0x01
#define IIR_RLS 0x03
#define IIR_RDA 0x02
#define IIR_CTI 0x06
#define IIR_THRE 0x01
#define LSR_RDR 0x01
#define LSR_OE 0x02
#define LSR_PE 0x04
#define LSR_FE 0x08
#define LSR_BI 0x10
#define LSR_THRE 0x20
#define LSR_TEMT 0x40
#define LSR_RXFE 0x80
/**
* @addtogroup LPC176x
*/
/*@{*/
#if defined(RT_USING_UART0) && defined(RT_USING_DEVICE)
#define UART_BAUDRATE 115200
#define LPC_UART LPC_UART0
#define UART_IRQn UART0_IRQn
struct rt_uart_lpc
{
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, iir;
struct rt_uart_lpc *uart = &uart_device;
/* enter interrupt */
rt_interrupt_enter();
/* read IIR and clear it */
iir = LPC_UART->IIR;
iir >>= 1; /* skip pending bit in IIR */
iir &= 0x07; /* check bit 1~3, interrupt identification */
if (iir == IIR_RDA) /* Receive Data Available */
{
/* Receive Data Available */
uart->rx_buffer[uart->save_index] = LPC_UART->RBR;
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);
}
}
else if (iir == IIR_RLS)
{
iir = LPC_UART->LSR; //oe pe fe oe read for clear interrupt
}
/* leave interrupt */
rt_interrupt_leave();
return;
}
static rt_err_t rt_uart_init(rt_device_t dev)
{
rt_uint32_t Fdiv;
rt_uint32_t pclkdiv, pclk;
/* Init UART Hardware */
if (LPC_UART == LPC_UART0)
{
LPC_PINCON->PINSEL0 &= ~0x000000F0;
LPC_PINCON->PINSEL0 |= 0x00000050; /* RxD0 is P0.3 and TxD0 is P0.2 */
/* By default, the PCLKSELx value is zero, thus, the PCLK for
all the peripherals is 1/4 of the SystemFrequency. */
/* Bit 6~7 is for UART0 */
pclkdiv = (LPC_SC->PCLKSEL0 >> 6) & 0x03;
switch (pclkdiv)
{
case 0x00:
default:
pclk = SystemCoreClock / 4;
break;
case 0x01:
pclk = SystemCoreClock;
break;
case 0x02:
pclk = SystemCoreClock / 2;
break;
case 0x03:
pclk = SystemCoreClock / 8;
break;
}
LPC_UART0->LCR = 0x83; /* 8 bits, no Parity, 1 Stop bit */
Fdiv = (pclk / 16) / UART_BAUDRATE; /*baud rate */
LPC_UART0->DLM = Fdiv / 256;
LPC_UART0->DLL = Fdiv % 256;
LPC_UART0->LCR = 0x03; /* DLAB = 0 */
LPC_UART0->FCR = 0x07; /* Enable and reset TX and RX FIFO. */
}
else if ((LPC_UART1_TypeDef *)LPC_UART == LPC_UART1)
{
LPC_PINCON->PINSEL4 &= ~0x0000000F;
LPC_PINCON->PINSEL4 |= 0x0000000A; /* Enable RxD1 P2.1, TxD1 P2.0 */
/* By default, the PCLKSELx value is zero, thus, the PCLK for
all the peripherals is 1/4 of the SystemFrequency. */
/* Bit 8,9 are for UART1 */
pclkdiv = (LPC_SC->PCLKSEL0 >> 8) & 0x03;
switch (pclkdiv)
{
case 0x00:
default:
pclk = SystemCoreClock / 4;
break;
case 0x01:
pclk = SystemCoreClock;
break;
case 0x02:
pclk = SystemCoreClock / 2;
break;
case 0x03:
pclk = SystemCoreClock / 8;
break;
}
LPC_UART1->LCR = 0x83; /* 8 bits, no Parity, 1 Stop bit */
Fdiv = (pclk / 16) / UART_BAUDRATE ; /*baud rate */
LPC_UART1->DLM = Fdiv / 256;
LPC_UART1->DLL = Fdiv % 256;
LPC_UART1->LCR = 0x03; /* DLAB = 0 */
LPC_UART1->FCR = 0x07; /* Enable and reset TX and RX FIFO. */
}
/* Ensure a clean start, no data in either TX or RX FIFO. */
while ((LPC_UART->LSR & (LSR_THRE | LSR_TEMT)) != (LSR_THRE | LSR_TEMT));
while (LPC_UART->LSR & LSR_RDR)
{
Fdiv = LPC_UART->RBR; /* Dump data from RX FIFO */
}
LPC_UART->IER = IER_RBR | IER_THRE | IER_RLS; /* Enable UART interrupt */
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)
{
/* Enable the UART Interrupt */
NVIC_EnableIRQ(UART_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(UART_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_lpc *uart = (struct rt_uart_lpc *)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')
{
/* THRE status, contain valid data */
while (!(LPC_UART->LSR & LSR_THRE));
/* write data */
LPC_UART->THR = '\r';
}
/* THRE status, contain valid data */
while (!(LPC_UART->LSR & LSR_THRE));
/* write data */
LPC_UART->THR = *ptr;
ptr ++;
size --;
}
}
else
{
while (size != 0)
{
/* THRE status, contain valid data */
while (!(LPC_UART->LSR & LSR_THRE));
/* write data */
LPC_UART->THR = *ptr;
ptr++;
size--;
}
}
return (rt_size_t) ptr - (rt_size_t) buffer;
}
void rt_hw_uart_init(void)
{
struct rt_uart_lpc *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.user_data = RT_NULL;
rt_device_register(&uart->parent,
"uart0", RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_INT_RX);
}
#endif /* end of UART */
/*@}*/