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/*
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2020 Vijai Kumar K <vijai@behindbytes.com>
*/
#include <sbi/riscv_io.h>
#include <sbi/sbi_console.h>
#include <sbi_utils/serial/shakti-uart.h>
#define REG_BAUD 0x00
#define REG_TX 0x04
#define REG_RX 0x08
#define REG_STATUS 0x0C
#define REG_DELAY 0x10
#define REG_CONTROL 0x14
#define REG_INT_EN 0x18
#define REG_IQ_CYCLES 0x1C
#define REG_RX_THRES 0x20
#define UART_TX_FULL 0x2
#define UART_RX_NOT_EMPTY 0x4
#define UART_RX_FULL 0x8
static volatile char *uart_base;
static void shakti_uart_putc(char ch)
{
while ((readb(uart_base + REG_STATUS) & UART_TX_FULL))
;
writeb(ch, uart_base + REG_TX);
}
static int shakti_uart_getc(void)
{
if (readb(uart_base + REG_STATUS) & UART_RX_NOT_EMPTY)
return readb(uart_base + REG_RX);
return -1;
}
static struct sbi_console_device shakti_console = {
.name = "shakti_uart",
.console_putc = shakti_uart_putc,
.console_getc = shakti_uart_getc
};
int shakti_uart_init(unsigned long base, u32 in_freq, u32 baudrate)
{
uart_base = (volatile char *)base;
u16 baud;
if (baudrate) {
baud = (u16)(in_freq / (16 * baudrate));
writew(baud, uart_base + REG_BAUD);
}
sbi_console_set_device(&shakti_console);
return 0;
}
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