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 <linux/compiler.h>
#include <serial.h>
typedef volatile struct {
unsigned rxdata; /* Rx data reg */
unsigned txdata; /* Tx data reg */
unsigned status; /* Status reg */
unsigned control; /* Control reg */
unsigned divisor; /* Baud rate divisor reg */
unsigned endofpacket; /* End-of-packet reg */
} nios_uart_t;
/* status register */
#define NIOS_UART_PE (1 << 0) /* parity error */
#define NIOS_UART_FE (1 << 1) /* frame error */
#define NIOS_UART_BRK (1 << 2) /* break detect */
#define NIOS_UART_ROE (1 << 3) /* rx overrun */
#define NIOS_UART_TOE (1 << 4) /* tx overrun */
#define NIOS_UART_TMT (1 << 5) /* tx empty */
#define NIOS_UART_TRDY (1 << 6) /* tx ready */
#define NIOS_UART_RRDY (1 << 7) /* rx ready */
#define NIOS_UART_E (1 << 8) /* exception */
#define NIOS_UART_DCTS (1 << 10) /* cts change */
#define NIOS_UART_CTS (1 << 11) /* cts */
#define NIOS_UART_EOP (1 << 12) /* eop detected */
/* control register */
#define NIOS_UART_IPE (1 << 0) /* parity error int ena*/
#define NIOS_UART_IFE (1 << 1) /* frame error int ena */
#define NIOS_UART_IBRK (1 << 2) /* break detect int ena */
#define NIOS_UART_IROE (1 << 3) /* rx overrun int ena */
#define NIOS_UART_ITOE (1 << 4) /* tx overrun int ena */
#define NIOS_UART_ITMT (1 << 5) /* tx empty int ena */
#define NIOS_UART_ITRDY (1 << 6) /* tx ready int ena */
#define NIOS_UART_IRRDY (1 << 7) /* rx ready int ena */
#define NIOS_UART_IE (1 << 8) /* exception int ena */
#define NIOS_UART_TBRK (1 << 9) /* transmit break */
#define NIOS_UART_IDCTS (1 << 10) /* cts change int ena */
#define NIOS_UART_RTS (1 << 11) /* rts */
#define NIOS_UART_IEOP (1 << 12) /* eop detected int ena */
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;
}