u-boot/drivers/serial/altera_uart.c

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/*
* (C) Copyright 2004, Psyent Corporation <www.psyent.com>
* Scott McNutt <smcnutt@psyent.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <watchdog.h>
#include <asm/io.h>
#include <nios2-io.h>
#include <linux/compiler.h>
#include <serial.h>
DECLARE_GLOBAL_DATA_PTR;
/*------------------------------------------------------------------
* UART the serial port
*-----------------------------------------------------------------*/
static nios_uart_t *uart = (nios_uart_t *) CONFIG_SYS_NIOS_CONSOLE;
#if defined(CONFIG_SYS_NIOS_FIXEDBAUD)
/*
* Everything's already setup for fixed-baud PTF
* assignment
*/
static void altera_serial_setbrg(void)
{
}
static int altera_serial_init(void)
{
return 0;
}
#else
static void altera_serial_setbrg(void)
{
unsigned div;
div = (CONFIG_SYS_CLK_FREQ/gd->baudrate)-1;
writel (div, &uart->divisor);
}
static int altera_serial_init(void)
{
serial_setbrg();
return 0;
}
#endif /* CONFIG_SYS_NIOS_FIXEDBAUD */
/*-----------------------------------------------------------------------
* UART CONSOLE
*---------------------------------------------------------------------*/
static void altera_serial_putc(char c)
{
if (c == '\n')
serial_putc ('\r');
while ((readl (&uart->status) & NIOS_UART_TRDY) == 0)
WATCHDOG_RESET ();
writel ((unsigned char)c, &uart->txdata);
}
static int altera_serial_tstc(void)
{
return (readl (&uart->status) & NIOS_UART_RRDY);
}
static int altera_serial_getc(void)
{
while (serial_tstc () == 0)
WATCHDOG_RESET ();
return (readl (&uart->rxdata) & 0x00ff );
}
static struct serial_device altera_serial_drv = {
.name = "altera_serial",
.start = altera_serial_init,
.stop = NULL,
.setbrg = altera_serial_setbrg,
.putc = altera_serial_putc,
.puts = default_serial_puts,
.getc = altera_serial_getc,
.tstc = altera_serial_tstc,
};
void altera_serial_initialize(void)
{
serial_register(&altera_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &altera_serial_drv;
}