1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * PDC early console support - use PDC firmware to dump text via boot console 4 * 5 * Copyright (C) 2001-2022 Helge Deller <deller@gmx.de> 6 */ 7 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 */ 14 pdc_console_write(struct console * co,const char * s,unsigned count)15 static void pdc_console_write(struct console *co, const char *s, unsigned count) 16 { 17 int i = 0; 18 19 do { 20 i += pdc_iodc_print(s + i, count - i); 21 } while (i < count); 22 } 23 24 #ifdef CONFIG_KGDB kgdb_pdc_read_char(void)25 static int kgdb_pdc_read_char(void) 26 { 27 int c = pdc_iodc_getc(); 28 29 return (c <= 0) ? NO_POLL_CHAR : c; 30 } 31 kgdb_pdc_write_char(u8 chr)32 static void kgdb_pdc_write_char(u8 chr) 33 { 34 /* no need to print char as it's shown on standard console */ 35 /* pdc_iodc_print(&chr, 1); */ 36 } 37 38 static struct kgdb_io kgdb_pdc_io_ops = { 39 .name = "kgdb_pdc", 40 .read_char = kgdb_pdc_read_char, 41 .write_char = kgdb_pdc_write_char, 42 }; 43 #endif 44 pdc_earlycon_setup(struct earlycon_device * device,const char * opt)45 static int __init pdc_earlycon_setup(struct earlycon_device *device, 46 const char *opt) 47 { 48 struct console *earlycon_console; 49 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)); 53 54 earlycon_console = device->con; 55 earlycon_console->write = pdc_console_write; 56 device->port.iotype = UPIO_MEM32BE; 57 58 #ifdef CONFIG_KGDB 59 kgdb_register_io_module(&kgdb_pdc_io_ops); 60 #endif 61 62 return 0; 63 } 64 65 EARLYCON_DECLARE(pdc, pdc_earlycon_setup); 66