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/arch/sh/kernel/early_printk.c

https://bitbucket.org/evzijst/gittest
C | 137 lines | 85 code | 25 blank | 27 comment | 5 complexity | d2ad168bd629e1c9134b468e6a0de21f MD5 | raw file
  1/*
  2 * arch/sh/kernel/early_printk.c
  3 *
  4 *  Copyright (C) 1999, 2000  Niibe Yutaka
  5 *  Copyright (C) 2002  M. R. Brown
  6 *  Copyright (C) 2004  Paul Mundt
  7 *
  8 * This file is subject to the terms and conditions of the GNU General Public
  9 * License.  See the file "COPYING" in the main directory of this archive
 10 * for more details.
 11 */
 12#include <linux/console.h>
 13#include <linux/tty.h>
 14#include <linux/init.h>
 15#include <asm/io.h>
 16
 17#ifdef CONFIG_SH_STANDARD_BIOS
 18#include <asm/sh_bios.h>
 19
 20/*
 21 *	Print a string through the BIOS
 22 */
 23static void sh_console_write(struct console *co, const char *s,
 24				 unsigned count)
 25{
 26	sh_bios_console_write(s, count);
 27}
 28
 29/*
 30 *	Setup initial baud/bits/parity. We do two things here:
 31 *	- construct a cflag setting for the first rs_open()
 32 *	- initialize the serial port
 33 *	Return non-zero if we didn't find a serial port.
 34 */
 35static int __init sh_console_setup(struct console *co, char *options)
 36{
 37	int	cflag = CREAD | HUPCL | CLOCAL;
 38
 39	/*
 40	 *	Now construct a cflag setting.
 41	 *	TODO: this is a totally bogus cflag, as we have
 42	 *	no idea what serial settings the BIOS is using, or
 43	 *	even if its using the serial port at all.
 44	 */
 45	cflag |= B115200 | CS8 | /*no parity*/0;
 46
 47	co->cflag = cflag;
 48
 49	return 0;
 50}
 51
 52static struct console early_console = {
 53	.name		= "bios",
 54	.write		= sh_console_write,
 55	.setup		= sh_console_setup,
 56	.flags		= CON_PRINTBUFFER,
 57	.index		= -1,
 58};
 59#endif
 60
 61#ifdef CONFIG_EARLY_SCIF_CONSOLE
 62#define SCIF_REG	0xffe80000
 63
 64static void scif_sercon_putc(int c)
 65{
 66	while (!(ctrl_inw(SCIF_REG + 0x10) & 0x20)) ;
 67
 68	ctrl_outb(c, SCIF_REG + 12);
 69	ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0x9f), SCIF_REG + 0x10);
 70
 71	if (c == '\n')
 72		scif_sercon_putc('\r');
 73}
 74
 75static void scif_sercon_flush(void)
 76{
 77	ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
 78
 79	while (!(ctrl_inw(SCIF_REG + 0x10) & 0x40)) ;
 80
 81	ctrl_outw((ctrl_inw(SCIF_REG + 0x10) & 0xbf), SCIF_REG + 0x10);
 82}
 83
 84static void scif_sercon_write(struct console *con, const char *s, unsigned count)
 85{
 86	while (count-- > 0)
 87		scif_sercon_putc(*s++);
 88
 89	scif_sercon_flush();
 90}
 91
 92static int __init scif_sercon_setup(struct console *con, char *options)
 93{
 94	con->cflag = CREAD | HUPCL | CLOCAL | B115200 | CS8;
 95
 96	return 0;
 97}
 98
 99static struct console early_console = {
100	.name		= "sercon",
101	.write		= scif_sercon_write,
102	.setup		= scif_sercon_setup,
103	.flags		= CON_PRINTBUFFER,
104	.index		= -1,
105};
106
107void scif_sercon_init(int baud)
108{
109	ctrl_outw(0, SCIF_REG + 8);
110	ctrl_outw(0, SCIF_REG);
111
112	/* Set baud rate */
113	ctrl_outb((CONFIG_SH_PCLK_FREQ + 16 * baud) /
114		  (32 * baud) - 1, SCIF_REG + 4);
115
116	ctrl_outw(12, SCIF_REG + 24);
117	ctrl_outw(8, SCIF_REG + 24);
118	ctrl_outw(0, SCIF_REG + 32);
119	ctrl_outw(0x60, SCIF_REG + 16);
120	ctrl_outw(0, SCIF_REG + 36);
121	ctrl_outw(0x30, SCIF_REG + 8);
122}
123#endif
124
125void __init enable_early_printk(void)
126{
127#ifdef CONFIG_EARLY_SCIF_CONSOLE
128	scif_sercon_init(115200);
129#endif
130	register_console(&early_console);
131}
132
133void disable_early_printk(void)
134{
135	unregister_console(&early_console);
136}
137