/* Copyright 2017-2023 Arm Limited and/or its affiliates
 * <open-source-office@arm.com>
 * SPDX-License-Identifier: Apache-2.0
 */

#include <stdio.h>
#include <string.h>
#include "device_cfg.h"
#include "Driver_USART.h"
#include "bsp_serial.h"

extern ARM_DRIVER_USART Driver_USART0;

void bsp_serial_init(void)
{
    Driver_USART0.Initialize(NULL);
    Driver_USART0.Control(ARM_USART_MODE_ASYNCHRONOUS, DEFAULT_UART_BAUDRATE);
}

void bsp_serial_print(char *str)
{
    (void)Driver_USART0.Send(str, strlen(str));
}

#if defined(__ARMCOMPILER_VERSION)

/* Retarget armclang, which requires all IO system calls to be overridden together. */

#include <rt_sys.h>

#define STDIN_FILENO  0
#define STDOUT_FILENO 1
#define STDERR_FILENO 2

FILEHANDLE _sys_open(const char *name, int openmode)
{
    if (name == NULL) {
        return -1;
    }

    // By default, the Arm Compiler uses the special file path ":tt" for stdin,
    // stdout and stderr and distinguishes between them using openmode. For details,
    // see https://github.com/ARM-software/abi-aa/blob/2022Q1/semihosting/semihosting.rst#sys-open-0x01
    if (strcmp(name, ":tt") == 0) {
        if (openmode & OPEN_W) {
            return STDOUT_FILENO;
        }
        if (openmode & OPEN_A) {
            return STDERR_FILENO;
        }
        return STDIN_FILENO;
    }

    return -1;
}

int _sys_close(FILEHANDLE fh)
{
    /* Not implemented */
    (void)fh;
    return -1;
}

int _sys_write(FILEHANDLE fd, const unsigned char *str, unsigned int len, int mode)
{
    /* From <rt_sys.h>: `mode' exists for historical reasons and must be ignored. */
    (void)mode;

    if (fd != STDOUT_FILENO && fd != STDERR_FILENO) {
        return -1;
    }

    if (Driver_USART0.Send(str, len) != ARM_DRIVER_OK) {
        return -1;
    }

    return 0;
}

int _sys_read(FILEHANDLE fd, unsigned char *str, unsigned int len, int mode)
{
    // From <rt_sys.h>: `mode' exists for historical reasons and must be ignored.
    (void)mode;

    /* Not implemented */
    (void)str;
    (void)len;
    return -1;
}

int _sys_istty(FILEHANDLE fh)
{
    /* Not implemented */
    (void)fh;
    return 0;
}

long _sys_flen(FILEHANDLE fh)
{
    /* Not implemented */
    (void)fh;
    return -1;
}

int _sys_seek(FILEHANDLE fh, long offset)
{
    /* Not implemented */
    (void)fh;
    (void)offset;
    return -1;
}

#else /* !defined(__ARMCOMPILER_VERSION) */

/* Redirects gcc printf to UART0 */
int _write(int fd, char *str, int len)
{
    if (Driver_USART0.Send(str, len) == ARM_DRIVER_OK) {
        return len;
    }
    return 0;
}

#endif