[deliverable/linux.git] / arch / blackfin / kernel / early_printk.c

/*
 * File:         arch/blackfin/kernel/early_printk.c
 * Based on:     arch/x86_64/kernel/early_printk.c
 * Author:       Robin Getz <rgetz@blackfin.uclinux.org
 *
 * Created:      14Aug2007
 * Description:  allow a console to be used for early printk
 *
 * Modified:
 *               Copyright 2004-2007 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/serial_core.h>
#include <linux/console.h>
#include <linux/string.h>
#include <asm/blackfin.h>
#include <asm/irq_handler.h>
#include <asm/early_printk.h>

#ifdef CONFIG_SERIAL_BFIN
extern struct console *bfin_earlyserial_init(unsigned int port,
						unsigned int cflag);
#endif
#ifdef CONFIG_BFIN_JTAG_COMM
extern struct console *bfin_jc_early_init(void);
#endif

static struct console *early_console;

/* Default console */
#define DEFAULT_PORT 0
#define DEFAULT_CFLAG CS8|B57600

/* Default console for early crashes */
#define DEFAULT_EARLY_PORT "serial,uart0,57600"

#ifdef CONFIG_SERIAL_CORE
/* What should get here is "0,57600" */
static struct console * __init earlyserial_init(char *buf)
{
	int baud, bit;
	char parity;
	unsigned int serial_port = DEFAULT_PORT;
	unsigned int cflag = DEFAULT_CFLAG;

	serial_port = simple_strtoul(buf, &buf, 10);
	buf++;

	cflag = 0;
	baud = simple_strtoul(buf, &buf, 10);
	switch (baud) {
	case 1200:
		cflag |= B1200;
		break;
	case 2400:
		cflag |= B2400;
		break;
	case 4800:
		cflag |= B4800;
		break;
	case 9600:
		cflag |= B9600;
		break;
	case 19200:
		cflag |= B19200;
		break;
	case 38400:
		cflag |= B38400;
		break;
	case 115200:
		cflag |= B115200;
		break;
	default:
		cflag |= B57600;
	}

	parity = buf[0];
	buf++;
	switch (parity) {
	case 'e':
		cflag |= PARENB;
		break;
	case 'o':
		cflag |= PARODD;
		break;
	}

	bit = simple_strtoul(buf, &buf, 10);
	switch (bit) {
	case 5:
		cflag |= CS5;
		break;
	case 6:
		cflag |= CS6;
		break;
	case 7:
		cflag |= CS7;
		break;
	default:
		cflag |= CS8;
	}

#ifdef CONFIG_SERIAL_BFIN
	return bfin_earlyserial_init(serial_port, cflag);
#else
	return NULL;
#endif

}
#endif

int __init setup_early_printk(char *buf)
{

	/* Crashing in here would be really bad, so check both the var
	   and the pointer before we start using it
	 */
	if (!buf)
		return 0;

	if (!*buf)
		return 0;

	if (early_console != NULL)
		return 0;

#ifdef CONFIG_SERIAL_BFIN
	/* Check for Blackfin Serial */
	if (!strncmp(buf, "serial,uart", 11)) {
		buf += 11;
		early_console = earlyserial_init(buf);
	}
#endif

#ifdef CONFIG_BFIN_JTAG_COMM
	/* Check for Blackfin JTAG */
	if (!strncmp(buf, "jtag", 4)) {
		buf += 4;
		early_console = bfin_jc_early_init();
	}
#endif

#ifdef CONFIG_FB
		/* TODO: add framebuffer console support */
#endif

	if (likely(early_console)) {
		early_console->flags |= CON_BOOT;

		register_console(early_console);
		printk(KERN_INFO "early printk enabled on %s%d\n",
			early_console->name,
			early_console->index);
	}

	return 0;
}

/*
 * Set up a temporary Event Vector Table, so if something bad happens before
 * the kernel is fully started, it doesn't vector off into somewhere we don't
 * know
 */

asmlinkage void __init init_early_exception_vectors(void)
{
	u32 evt;
	SSYNC();

	/* cannot program in software:
	 * evt0 - emulation (jtag)
	 * evt1 - reset
	 */
	for (evt = EVT2; evt <= EVT15; evt += 4)
		bfin_write32(evt, early_trap);
	CSYNC();

	/* Set all the return from interrupt, exception, NMI to a known place
	 * so if we do a RETI, RETX or RETN by mistake - we go somewhere known
	 * Note - don't change RETS - we are in a subroutine, or
	 * RETE - since it might screw up if emulator is attached
	 */
	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
		: : "p"(early_trap));

}

asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
{
	/* This can happen before the uart is initialized, so initialize
	 * the UART now (but only if we are running on the processor we think
	 * we are compiled for - otherwise we write to MMRs that don't exist,
	 * and cause other problems. Nothing comes out the UART, but it does
	 * end up in the __buf_log.
	 */
	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
		setup_early_printk(DEFAULT_EARLY_PORT);

	printk(KERN_EMERG "Early panic\n");
	dump_bfin_mem(fp);
	show_regs(fp);
	dump_bfin_trace_buffer();

	panic("Died early");
}

early_param("earlyprintk", setup_early_printk);
Commit	Line	Data
0ae53640 RG	1	/*
	2	* File: arch/blackfin/kernel/early_printk.c
	3	* Based on: arch/x86_64/kernel/early_printk.c
	4	* Author: Robin Getz <rgetz@blackfin.uclinux.org
	5	*
	6	* Created: 14Aug2007
	7	* Description: allow a console to be used for early printk
	8	*
	9	* Modified:
	10	* Copyright 2004-2007 Analog Devices Inc.
	11	*
	12	* Bugs: Enter bugs at http://blackfin.uclinux.org/
	13	*
	14	* This program is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU General Public License as published by
	16	* the Free Software Foundation; either version 2 of the License, or
	17	* (at your option) any later version.
	18	*
	19	* This program is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*/
	24
	25	#include <linux/kernel.h>
	26	#include <linux/init.h>
	27	#include <linux/serial_core.h>
	28	#include <linux/console.h>
	29	#include <linux/string.h>
	30	#include <asm/blackfin.h>
	31	#include <asm/irq_handler.h>
	32	#include <asm/early_printk.h>
	33
	34	#ifdef CONFIG_SERIAL_BFIN
	35	extern struct console *bfin_earlyserial_init(unsigned int port,
	36	unsigned int cflag);
	37	#endif
a88c71e4 MF	38	#ifdef CONFIG_BFIN_JTAG_COMM
	39	extern struct console *bfin_jc_early_init(void);
	40	#endif
0ae53640 RG	41
	42	static struct console *early_console;
	43
337d390b	44	/* Default console */
0ae53640 RG	45	#define DEFAULT_PORT 0
	46	#define DEFAULT_CFLAG CS8\|B57600
	47
337d390b RG	48	/* Default console for early crashes */
	49	#define DEFAULT_EARLY_PORT "serial,uart0,57600"
	50
0ae53640 RG	51	#ifdef CONFIG_SERIAL_CORE
	52	/* What should get here is "0,57600" */
	53	static struct console * __init earlyserial_init(char *buf)
	54	{
	55	int baud, bit;
	56	char parity;
	57	unsigned int serial_port = DEFAULT_PORT;
	58	unsigned int cflag = DEFAULT_CFLAG;
	59
	60	serial_port = simple_strtoul(buf, &buf, 10);
	61	buf++;
	62
	63	cflag = 0;
	64	baud = simple_strtoul(buf, &buf, 10);
	65	switch (baud) {
	66	case 1200:
	67	cflag \|= B1200;
	68	break;
	69	case 2400:
	70	cflag \|= B2400;
	71	break;
	72	case 4800:
	73	cflag \|= B4800;
	74	break;
	75	case 9600:
	76	cflag \|= B9600;
	77	break;
	78	case 19200:
	79	cflag \|= B19200;
	80	break;
	81	case 38400:
	82	cflag \|= B38400;
	83	break;
	84	case 115200:
	85	cflag \|= B115200;
	86	break;
	87	default:
	88	cflag \|= B57600;
	89	}
	90
	91	parity = buf[0];
	92	buf++;
	93	switch (parity) {
	94	case 'e':
	95	cflag \|= PARENB;
	96	break;
	97	case 'o':
	98	cflag \|= PARODD;
	99	break;
	100	}
	101
	102	bit = simple_strtoul(buf, &buf, 10);
	103	switch (bit) {
	104	case 5:
	105	cflag \|= CS5;
	106	break;
	107	case 6:
09b7f4ad	108	cflag \|= CS6;
0ae53640 RG	109	break;
0ae53640 RG	110	case 7:
09b7f4ad	111	cflag \|= CS7;
0ae53640 RG	112	break;
	113	default:
	114	cflag \|= CS8;
	115	}
	116
	117	#ifdef CONFIG_SERIAL_BFIN
	118	return bfin_earlyserial_init(serial_port, cflag);
	119	#else
	120	return NULL;
	121	#endif
	122
	123	}
	124	#endif
	125
	126	int __init setup_early_printk(char *buf)
	127	{
	128
	129	/* Crashing in here would be really bad, so check both the var
	130	and the pointer before we start using it
	131	*/
	132	if (!buf)
	133	return 0;
	134
	135	if (!*buf)
	136	return 0;
	137
	138	if (early_console != NULL)
	139	return 0;
	140
	141	#ifdef CONFIG_SERIAL_BFIN
	142	/* Check for Blackfin Serial */
	143	if (!strncmp(buf, "serial,uart", 11)) {
	144	buf += 11;
	145	early_console = earlyserial_init(buf);
	146	}
	147	#endif
a88c71e4 MF	148
	149	#ifdef CONFIG_BFIN_JTAG_COMM
	150	/* Check for Blackfin JTAG */
	151	if (!strncmp(buf, "jtag", 4)) {
	152	buf += 4;
	153	early_console = bfin_jc_early_init();
	154	}
	155	#endif
	156
0ae53640 RG	157	#ifdef CONFIG_FB
	158	/* TODO: add framebuffer console support */
	159	#endif
	160
	161	if (likely(early_console)) {
	162	early_console->flags \|= CON_BOOT;
	163
	164	register_console(early_console);
	165	printk(KERN_INFO "early printk enabled on %s%d\n",
	166	early_console->name,
	167	early_console->index);
	168	}
	169
	170	return 0;
	171	}
	172
337d390b RG	173	/*
	174	* Set up a temporary Event Vector Table, so if something bad happens before
	175	* the kernel is fully started, it doesn't vector off into somewhere we don't
	176	* know
	177	*/
	178
	179	asmlinkage void __init init_early_exception_vectors(void)
	180	{
685a694f	181	u32 evt;
337d390b RG	182	SSYNC();
	183
	184	/* cannot program in software:
	185	* evt0 - emulation (jtag)
	186	* evt1 - reset
	187	*/
685a694f MF	188	for (evt = EVT2; evt <= EVT15; evt += 4)
685a694f MF	189	bfin_write32(evt, early_trap);
337d390b RG	190	CSYNC();
337d390b RG	191
79f1ec86	192	/* Set all the return from interrupt, exception, NMI to a known place
337d390b RG	193	* so if we do a RETI, RETX or RETN by mistake - we go somewhere known
	194	* Note - don't change RETS - we are in a subroutine, or
	195	* RETE - since it might screw up if emulator is attached
	196	*/
	197	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
	198	: : "p"(early_trap));
	199
	200	}
	201
	202	asmlinkage void __init early_trap_c(struct pt_regs fp, void retaddr)
	203	{
	204	/* This can happen before the uart is initialized, so initialize
54ebae71 RG	205	* the UART now (but only if we are running on the processor we think
	206	* we are compiled for - otherwise we write to MMRs that don't exist,
	207	* and cause other problems. Nothing comes out the UART, but it does
	208	* end up in the __buf_log.
337d390b	209	*/
54ebae71	210	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
337d390b RG	211	setup_early_printk(DEFAULT_EARLY_PORT);
337d390b RG	212
54ebae71	213	printk(KERN_EMERG "Early panic\n");
b03b08ba	214	dump_bfin_mem(fp);
49dce912	215	show_regs(fp);
337d390b RG	216	dump_bfin_trace_buffer();
	217
	218	panic("Died early");
	219	}
	220
0ae53640	221	early_param("earlyprintk", setup_early_printk);