linuxdebug/arch/parisc/kernel/pdc_cons.c

66 lines
1.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PDC early console support - use PDC firmware to dump text via boot console
*
* Copyright (C) 2001-2022 Helge Deller <deller@gmx.de>
*/
#include <linux/console.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/kgdb.h>
#include <asm/page.h> /* for PAGE0 */
#include <asm/pdc.h> /* for iodc_call() proto and friends */
static void pdc_console_write(struct console *co, const char *s, unsigned count)
{
int i = 0;
do {
i += pdc_iodc_print(s + i, count - i);
} while (i < count);
}
#ifdef CONFIG_KGDB
static int kgdb_pdc_read_char(void)
{
int c = pdc_iodc_getc();
return (c <= 0) ? NO_POLL_CHAR : c;
}
static void kgdb_pdc_write_char(u8 chr)
{
/* no need to print char as it's shown on standard console */
/* pdc_iodc_print(&chr, 1); */
}
static struct kgdb_io kgdb_pdc_io_ops = {
.name = "kgdb_pdc",
.read_char = kgdb_pdc_read_char,
.write_char = kgdb_pdc_write_char,
};
#endif
static int __init pdc_earlycon_setup(struct earlycon_device *device,
const char *opt)
{
struct console *earlycon_console;
/* If the console is duplex then copy the COUT parameters to CIN. */
if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
earlycon_console = device->con;
earlycon_console->write = pdc_console_write;
device->port.iotype = UPIO_MEM32BE;
#ifdef CONFIG_KGDB
kgdb_register_io_module(&kgdb_pdc_io_ops);
#endif
return 0;
}
EARLYCON_DECLARE(pdc, pdc_earlycon_setup);