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/*
* Copyright (c) 2018 Western Digital Corporation or its affiliates.
*
* Authors:
* Anup Patel <anup.patel@wdc.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <sbi/riscv_io.h>
#include <plat/serial/sifive-uart.h>
#define UART_REG_TXFIFO 0
#define UART_REG_RXFIFO 1
#define UART_REG_TXCTRL 2
#define UART_REG_RXCTRL 3
#define UART_REG_IE 4
#define UART_REG_IP 5
#define UART_REG_DIV 6
#define UART_TXFIFO_FULL 0x80000000
#define UART_RXFIFO_EMPTY 0x80000000
#define UART_RXFIFO_DATA 0x000000ff
#define UART_TXCTRL_TXEN 0x1
#define UART_RXCTRL_RXEN 0x1
static volatile void *uart_base;
static u32 uart_in_freq;
static u32 uart_baudrate;
static u32 get_reg(u32 num)
{
return readl(uart_base + (num * 0x4));
}
static void set_reg(u32 num, u32 val)
{
writel(val, uart_base + (num * 0x4));
}
void sifive_uart_putc(char ch)
{
while (get_reg(UART_REG_TXFIFO) & UART_TXFIFO_FULL);
set_reg(UART_REG_TXFIFO, ch);
}
char sifive_uart_getc(void)
{
u32 ret = get_reg(UART_REG_RXFIFO);
if (!(ret & UART_RXFIFO_EMPTY))
return ret & UART_RXFIFO_DATA;
return 0;
}
int sifive_uart_init(unsigned long base,
u32 in_freq, u32 baudrate)
{
uart_base = (volatile void *)base;
uart_in_freq = in_freq;
uart_baudrate = baudrate;
/* Configure baudrate */
set_reg(UART_REG_DIV, (in_freq / baudrate) - 1);
/* Disable interrupts */
set_reg(UART_REG_IE, 0);
/* Enable TX */
set_reg(UART_REG_TXCTRL, UART_TXCTRL_TXEN);
/* Enable Rx */
set_reg(UART_REG_RXCTRL, UART_RXCTRL_RXEN);
return 0;
}
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