blob: 9a81402ffb256e9eb505143373a49f47cc22e216 [file] [log] [blame] [edit]
/*
* (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 data; /* Data register */
unsigned control; /* Control register */
} nios_jtag_t;
/* data register */
#define NIOS_JTAG_RVALID (1<<15) /* Read valid */
#define NIOS_JTAG_DATA(d) ((d)&0x0ff) /* Read data */
#define NIOS_JTAG_RAVAIL(d) ((d)>>16) /* Read space avail */
/* control register */
#define NIOS_JTAG_RE (1 << 0) /* read intr enable */
#define NIOS_JTAG_WE (1 << 1) /* write intr enable */
#define NIOS_JTAG_RI (1 << 8) /* read intr pending */
#define NIOS_JTAG_WI (1 << 9) /* write intr pending*/
#define NIOS_JTAG_AC (1 << 10) /* activity indicator */
#define NIOS_JTAG_RRDY (1 << 12) /* read available */
#define NIOS_JTAG_WSPACE(d) ((d)>>16) /* Write space avail */
DECLARE_GLOBAL_DATA_PTR;
/*------------------------------------------------------------------
* JTAG acts as the serial port
*-----------------------------------------------------------------*/
static nios_jtag_t *jtag = (nios_jtag_t *)CONFIG_SYS_NIOS_CONSOLE;
static void altera_jtag_serial_setbrg(void)
{
}
static int altera_jtag_serial_init(void)
{
return 0;
}
static void altera_jtag_serial_putc(char c)
{
while (1) {
unsigned st = readl(&jtag->control);
if (NIOS_JTAG_WSPACE(st))
break;
#ifdef CONFIG_ALTERA_JTAG_UART_BYPASS
if (!(st & NIOS_JTAG_AC)) /* no connection */
return;
#endif
WATCHDOG_RESET();
}
writel ((unsigned char)c, &jtag->data);
}
static int altera_jtag_serial_tstc(void)
{
return ( readl (&jtag->control) & NIOS_JTAG_RRDY);
}
static int altera_jtag_serial_getc(void)
{
int c;
unsigned val;
while (1) {
WATCHDOG_RESET ();
val = readl (&jtag->data);
if (val & NIOS_JTAG_RVALID)
break;
}
c = val & 0x0ff;
return (c);
}
static struct serial_device altera_jtag_serial_drv = {
.name = "altera_jtag_uart",
.start = altera_jtag_serial_init,
.stop = NULL,
.setbrg = altera_jtag_serial_setbrg,
.putc = altera_jtag_serial_putc,
.puts = default_serial_puts,
.getc = altera_jtag_serial_getc,
.tstc = altera_jtag_serial_tstc,
};
void altera_jtag_serial_initialize(void)
{
serial_register(&altera_jtag_serial_drv);
}
__weak struct serial_device *default_serial_console(void)
{
return &altera_jtag_serial_drv;
}