[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 <linux/reboot.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();

	/*
	 * This starts up the shadow buffer, incase anything crashes before
	 * setup arch
	 */
	mark_shadow_error();
	early_shadow_puts(linux_banner);
	early_shadow_stamp();

	if (CPUID != bfin_cpuid()) {
		early_shadow_puts("Running on wrong machine type, expected");
		early_shadow_reg(CPUID, 16);
		early_shadow_puts(", but running on");
		early_shadow_reg(bfin_cpuid(), 16);
		early_shadow_puts("\n");
	}

	/* 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));

}

__attribute__((__noreturn__))
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);

	if (!shadow_console_enabled()) {
		/* crap - we crashed before setup_arch() */
		early_shadow_puts("panic before setup_arch\n");
		early_shadow_puts("IPEND:");
		early_shadow_reg(fp->ipend, 16);
		if (fp->seqstat & SEQSTAT_EXCAUSE) {
			early_shadow_puts("\nEXCAUSE:");
			early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
		}
		if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
			early_shadow_puts("\nHWERRCAUSE:");
			early_shadow_reg(
				(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
		}
		early_shadow_puts("\nErr @");
		if (fp->ipend & EVT_EVX)
			early_shadow_reg(fp->retx, 32);
		else
			early_shadow_reg(fp->pc, 32);
#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
		early_shadow_puts("\nTrace:");
		if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
			while (bfin_read_TBUFSTAT() & TBUFCNT) {
				early_shadow_puts("\nT  :");
				early_shadow_reg(bfin_read_TBUF(), 32);
				early_shadow_puts("\n S :");
				early_shadow_reg(bfin_read_TBUF(), 32);
			}
		}
#endif
		early_shadow_puts("\nUse bfin-elf-addr2line to determine "
			"function names\n");
		/*
		 * We should panic(), but we can't - since panic calls printk,
		 * and printk uses memcpy.
		 * we want to reboot, but if the machine type is different,
		 * can't due to machine specific reboot sequences
		 */
		if (CPUID == bfin_cpuid()) {
			early_shadow_puts("Trying to restart\n");
			machine_restart("");
		}

		early_shadow_puts("Halting, since it is not safe to restart\n");
		while (1)
			asm volatile ("EMUEXCPT; IDLE;\n");

	} else {
		printk(KERN_EMERG "Early panic\n");
		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>
837ec2d5	30	#include <linux/reboot.h>
0ae53640 RG	31	#include <asm/blackfin.h>
	32	#include <asm/irq_handler.h>
	33	#include <asm/early_printk.h>
	34
	35	#ifdef CONFIG_SERIAL_BFIN
	36	extern struct console *bfin_earlyserial_init(unsigned int port,
	37	unsigned int cflag);
	38	#endif
a88c71e4 MF	39	#ifdef CONFIG_BFIN_JTAG_COMM
	40	extern struct console *bfin_jc_early_init(void);
	41	#endif
0ae53640 RG	42
	43	static struct console *early_console;
	44
337d390b	45	/* Default console */
0ae53640 RG	46	#define DEFAULT_PORT 0
	47	#define DEFAULT_CFLAG CS8\|B57600
	48
337d390b RG	49	/* Default console for early crashes */
	50	#define DEFAULT_EARLY_PORT "serial,uart0,57600"
	51
0ae53640 RG	52	#ifdef CONFIG_SERIAL_CORE
	53	/* What should get here is "0,57600" */
	54	static struct console * __init earlyserial_init(char *buf)
	55	{
	56	int baud, bit;
	57	char parity;
	58	unsigned int serial_port = DEFAULT_PORT;
	59	unsigned int cflag = DEFAULT_CFLAG;
	60
	61	serial_port = simple_strtoul(buf, &buf, 10);
	62	buf++;
	63
	64	cflag = 0;
	65	baud = simple_strtoul(buf, &buf, 10);
	66	switch (baud) {
	67	case 1200:
	68	cflag \|= B1200;
	69	break;
	70	case 2400:
	71	cflag \|= B2400;
	72	break;
	73	case 4800:
	74	cflag \|= B4800;
	75	break;
	76	case 9600:
	77	cflag \|= B9600;
	78	break;
	79	case 19200:
	80	cflag \|= B19200;
	81	break;
	82	case 38400:
	83	cflag \|= B38400;
	84	break;
	85	case 115200:
	86	cflag \|= B115200;
	87	break;
	88	default:
	89	cflag \|= B57600;
	90	}
	91
	92	parity = buf[0];
	93	buf++;
	94	switch (parity) {
	95	case 'e':
	96	cflag \|= PARENB;
	97	break;
	98	case 'o':
	99	cflag \|= PARODD;
	100	break;
	101	}
	102
	103	bit = simple_strtoul(buf, &buf, 10);
	104	switch (bit) {
	105	case 5:
	106	cflag \|= CS5;
	107	break;
	108	case 6:
09b7f4ad	109	cflag \|= CS6;
0ae53640 RG	110	break;
0ae53640 RG	111	case 7:
09b7f4ad	112	cflag \|= CS7;
0ae53640 RG	113	break;
	114	default:
	115	cflag \|= CS8;
	116	}
	117
	118	#ifdef CONFIG_SERIAL_BFIN
	119	return bfin_earlyserial_init(serial_port, cflag);
	120	#else
	121	return NULL;
	122	#endif
	123
	124	}
	125	#endif
	126
	127	int __init setup_early_printk(char *buf)
	128	{
	129
	130	/* Crashing in here would be really bad, so check both the var
	131	and the pointer before we start using it
	132	*/
	133	if (!buf)
	134	return 0;
	135
	136	if (!*buf)
	137	return 0;
	138
	139	if (early_console != NULL)
	140	return 0;
	141
	142	#ifdef CONFIG_SERIAL_BFIN
	143	/* Check for Blackfin Serial */
	144	if (!strncmp(buf, "serial,uart", 11)) {
	145	buf += 11;
	146	early_console = earlyserial_init(buf);
	147	}
	148	#endif
a88c71e4 MF	149
	150	#ifdef CONFIG_BFIN_JTAG_COMM
	151	/* Check for Blackfin JTAG */
	152	if (!strncmp(buf, "jtag", 4)) {
	153	buf += 4;
	154	early_console = bfin_jc_early_init();
	155	}
	156	#endif
	157
0ae53640 RG	158	#ifdef CONFIG_FB
	159	/* TODO: add framebuffer console support */
	160	#endif
	161
	162	if (likely(early_console)) {
	163	early_console->flags \|= CON_BOOT;
	164
	165	register_console(early_console);
	166	printk(KERN_INFO "early printk enabled on %s%d\n",
	167	early_console->name,
	168	early_console->index);
	169	}
	170
	171	return 0;
	172	}
	173
337d390b RG	174	/*
	175	* Set up a temporary Event Vector Table, so if something bad happens before
	176	* the kernel is fully started, it doesn't vector off into somewhere we don't
	177	* know
	178	*/
	179
	180	asmlinkage void __init init_early_exception_vectors(void)
	181	{
685a694f	182	u32 evt;
337d390b RG	183	SSYNC();
337d390b RG	184
837ec2d5 RG	185	/*
	186	* This starts up the shadow buffer, incase anything crashes before
	187	* setup arch
	188	*/
	189	mark_shadow_error();
	190	early_shadow_puts(linux_banner);
	191	early_shadow_stamp();
	192
	193	if (CPUID != bfin_cpuid()) {
	194	early_shadow_puts("Running on wrong machine type, expected");
	195	early_shadow_reg(CPUID, 16);
	196	early_shadow_puts(", but running on");
	197	early_shadow_reg(bfin_cpuid(), 16);
	198	early_shadow_puts("\n");
	199	}
	200
337d390b RG	201	/* cannot program in software:
	202	* evt0 - emulation (jtag)
	203	* evt1 - reset
	204	*/
685a694f MF	205	for (evt = EVT2; evt <= EVT15; evt += 4)
685a694f MF	206	bfin_write32(evt, early_trap);
337d390b RG	207	CSYNC();
337d390b RG	208
79f1ec86	209	/* Set all the return from interrupt, exception, NMI to a known place
337d390b RG	210	* so if we do a RETI, RETX or RETN by mistake - we go somewhere known
	211	* Note - don't change RETS - we are in a subroutine, or
	212	* RETE - since it might screw up if emulator is attached
	213	*/
	214	asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
	215	: : "p"(early_trap));
	216
	217	}
	218
837ec2d5	219	__attribute__((__noreturn__))
337d390b RG	220	asmlinkage void __init early_trap_c(struct pt_regs fp, void retaddr)
	221	{
	222	/* This can happen before the uart is initialized, so initialize
54ebae71 RG	223	* the UART now (but only if we are running on the processor we think
	224	* we are compiled for - otherwise we write to MMRs that don't exist,
	225	* and cause other problems. Nothing comes out the UART, but it does
	226	* end up in the __buf_log.
337d390b	227	*/
54ebae71	228	if (likely(early_console == NULL) && CPUID == bfin_cpuid())
337d390b RG	229	setup_early_printk(DEFAULT_EARLY_PORT);
337d390b RG	230
837ec2d5 RG	231	if (!shadow_console_enabled()) {
	232	/* crap - we crashed before setup_arch() */
	233	early_shadow_puts("panic before setup_arch\n");
	234	early_shadow_puts("IPEND:");
	235	early_shadow_reg(fp->ipend, 16);
	236	if (fp->seqstat & SEQSTAT_EXCAUSE) {
	237	early_shadow_puts("\nEXCAUSE:");
	238	early_shadow_reg(fp->seqstat & SEQSTAT_EXCAUSE, 8);
	239	}
	240	if (fp->seqstat & SEQSTAT_HWERRCAUSE) {
	241	early_shadow_puts("\nHWERRCAUSE:");
	242	early_shadow_reg(
	243	(fp->seqstat & SEQSTAT_HWERRCAUSE) >> 14, 8);
	244	}
	245	early_shadow_puts("\nErr @");
	246	if (fp->ipend & EVT_EVX)
	247	early_shadow_reg(fp->retx, 32);
	248	else
	249	early_shadow_reg(fp->pc, 32);
	250	#ifdef CONFIG_DEBUG_BFIN_HWTRACE_ON
	251	early_shadow_puts("\nTrace:");
	252	if (likely(bfin_read_TBUFSTAT() & TBUFCNT)) {
	253	while (bfin_read_TBUFSTAT() & TBUFCNT) {
	254	early_shadow_puts("\nT :");
	255	early_shadow_reg(bfin_read_TBUF(), 32);
	256	early_shadow_puts("\n S :");
	257	early_shadow_reg(bfin_read_TBUF(), 32);
	258	}
	259	}
	260	#endif
	261	early_shadow_puts("\nUse bfin-elf-addr2line to determine "
	262	"function names\n");
	263	/*
	264	* We should panic(), but we can't - since panic calls printk,
	265	* and printk uses memcpy.
	266	* we want to reboot, but if the machine type is different,
	267	* can't due to machine specific reboot sequences
	268	*/
	269	if (CPUID == bfin_cpuid()) {
	270	early_shadow_puts("Trying to restart\n");
	271	machine_restart("");
	272	}
	273
	274	early_shadow_puts("Halting, since it is not safe to restart\n");
	275	while (1)
	276	asm volatile ("EMUEXCPT; IDLE;\n");
	277
	278	} else {
	279	printk(KERN_EMERG "Early panic\n");
	280	show_regs(fp);
	281	dump_bfin_trace_buffer();
	282	}
337d390b RG	283
	284	panic("Died early");
	285	}
	286
0ae53640	287	early_param("earlyprintk", setup_early_printk);