1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * PDC early console support - use PDC firmware to dump text via boot console
5 * Copyright (C) 2001-2022 Helge Deller <deller@gmx.de>
8 #include <linux/console.h>
9 #include <linux/init.h>
10 #include <linux/serial_core.h>
11 #include <linux/kgdb.h>
12 #include <asm/page.h> /* for PAGE0 */
13 #include <asm/pdc.h> /* for iodc_call() proto and friends */
15 static void pdc_console_write(struct console *co, const char *s, unsigned count)
20 i += pdc_iodc_print(s + i, count - i);
25 static int kgdb_pdc_read_char(void)
27 int c = pdc_iodc_getc();
29 return (c <= 0) ? NO_POLL_CHAR : c;
32 static void kgdb_pdc_write_char(u8 chr)
34 /* no need to print char as it's shown on standard console */
35 /* pdc_iodc_print(&chr, 1); */
38 static struct kgdb_io kgdb_pdc_io_ops = {
40 .read_char = kgdb_pdc_read_char,
41 .write_char = kgdb_pdc_write_char,
45 static int __init pdc_earlycon_setup(struct earlycon_device *device,
48 struct console *earlycon_console;
50 /* If the console is duplex then copy the COUT parameters to CIN. */
51 if (PAGE0->mem_cons.cl_class == CL_DUPLEX)
52 memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons));
54 earlycon_console = device->con;
55 earlycon_console->write = pdc_console_write;
56 device->port.iotype = UPIO_MEM32BE;
59 kgdb_register_io_module(&kgdb_pdc_io_ops);
65 EARLYCON_DECLARE(pdc, pdc_earlycon_setup);