rt-thread-official/bsp/qemu-riscv-virt64/driver/drv_uart.c

152 lines
3.3 KiB
C

/*
* Copyright (c) 2006-2021, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2021-05-20 bigmagic first version
*/
#include <rthw.h>
#include <rtdevice.h>
#include "board.h"
#include "drv_uart.h"
#include <stdio.h>
#include "sbi.h"
#include "interrupt.h"
struct device_uart
{
rt_ubase_t hw_base;
rt_uint32_t irqno;
};
static rt_err_t rt_uart_configure(struct rt_serial_device *serial, struct serial_configure *cfg);
static rt_err_t uart_control(struct rt_serial_device *serial, int cmd, void *arg);
static int drv_uart_putc(struct rt_serial_device *serial, char c);
static int drv_uart_getc(struct rt_serial_device *serial);
void virt_uart_init(void)
{
//http://byterunner.com/16550.html
uart_write_reg(IER, 0x00);
uint8_t lcr = uart_read_reg(LCR);
uart_write_reg(LCR, lcr | (1 << 7));
uart_write_reg(DLL, 0x03);
uart_write_reg(DLM, 0x00);
lcr = 0;
uart_write_reg(LCR, lcr | (3 << 0));
/*
* enable receive interrupts.
*/
uint8_t ier = uart_read_reg(IER);
uart_write_reg(IER, ier | (1 << 0));
}
/*
* UART interface
*/
static rt_err_t rt_uart_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
{
struct device_uart *uart;
RT_ASSERT(serial != RT_NULL);
serial->config = *cfg;
return (RT_EOK);
}
static rt_err_t uart_control(struct rt_serial_device *serial, int cmd, void *arg)
{
struct device_uart *uart;
uart = serial->parent.user_data;
rt_uint32_t channel = 1;
RT_ASSERT(uart != RT_NULL);
RT_ASSERT(channel != 3);
switch (cmd)
{
case RT_DEVICE_CTRL_CLR_INT:
break;
case RT_DEVICE_CTRL_SET_INT:
break;
}
return (RT_EOK);
}
static int drv_uart_putc(struct rt_serial_device *serial, char c)
{
while ((uart_read_reg(LSR) & LSR_TX_IDLE) == 0);
return uart_write_reg(THR, c);
}
static int drv_uart_getc(struct rt_serial_device *serial)
{
if (uart_read_reg(LSR) & LSR_RX_READY){
return uart_read_reg(RHR);
} else {
return -1;
}
//return sbi_console_getchar();
}
static void rt_hw_uart_isr(int irqno, void *param)
{
struct rt_serial_device *serial = (struct rt_serial_device*)param;
rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
}
struct rt_serial_device serial1;
struct device_uart uart1;
const struct rt_uart_ops _uart_ops =
{
rt_uart_configure,
uart_control,
drv_uart_putc,
drv_uart_getc,
RT_NULL
};
/*
* UART Initiation
*/
int rt_hw_uart_init(void)
{
struct rt_serial_device *serial;
struct device_uart *uart;
struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
{
serial = &serial1;
uart = &uart1;
serial->ops = &_uart_ops;
serial->config = config;
serial->config.baud_rate = UART_DEFAULT_BAUDRATE;
uart->hw_base = UART_BASE;
uart->irqno = UART0_IRQ;
virt_uart_init();
rt_hw_serial_register(serial,
"uart",
RT_DEVICE_FLAG_STREAM | RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
uart);
rt_hw_interrupt_install(uart->irqno, rt_hw_uart_isr, serial, "uart");
rt_hw_interrupt_umask(uart->irqno);
}
return 0;
}