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54ebae7166
Before we configure the early UART, check to make sure we are running on the expected processor - otherwise, we cause problems by configuring pins that don't exist (and causing an infinite loop of faults). Signed-off-by: Robin Getz <robin.getz@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
222 lines
4.8 KiB
C
222 lines
4.8 KiB
C
/*
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* File: arch/blackfin/kernel/early_printk.c
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* Based on: arch/x86_64/kernel/early_printk.c
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* Author: Robin Getz <rgetz@blackfin.uclinux.org
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*
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* Created: 14Aug2007
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* Description: allow a console to be used for early printk
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*
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* Modified:
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* Copyright 2004-2007 Analog Devices Inc.
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*
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* Bugs: Enter bugs at http://blackfin.uclinux.org/
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/serial_core.h>
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#include <linux/console.h>
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#include <linux/string.h>
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#include <asm/blackfin.h>
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#include <asm/irq_handler.h>
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#include <asm/early_printk.h>
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#ifdef CONFIG_SERIAL_BFIN
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extern struct console *bfin_earlyserial_init(unsigned int port,
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unsigned int cflag);
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#endif
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#ifdef CONFIG_BFIN_JTAG_COMM
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extern struct console *bfin_jc_early_init(void);
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#endif
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static struct console *early_console;
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/* Default console */
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#define DEFAULT_PORT 0
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#define DEFAULT_CFLAG CS8|B57600
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/* Default console for early crashes */
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#define DEFAULT_EARLY_PORT "serial,uart0,57600"
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#ifdef CONFIG_SERIAL_CORE
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/* What should get here is "0,57600" */
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static struct console * __init earlyserial_init(char *buf)
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{
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int baud, bit;
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char parity;
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unsigned int serial_port = DEFAULT_PORT;
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unsigned int cflag = DEFAULT_CFLAG;
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serial_port = simple_strtoul(buf, &buf, 10);
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buf++;
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cflag = 0;
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baud = simple_strtoul(buf, &buf, 10);
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switch (baud) {
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case 1200:
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cflag |= B1200;
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break;
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case 2400:
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cflag |= B2400;
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break;
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case 4800:
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cflag |= B4800;
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break;
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case 9600:
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cflag |= B9600;
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break;
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case 19200:
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cflag |= B19200;
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break;
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case 38400:
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cflag |= B38400;
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break;
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case 115200:
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cflag |= B115200;
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break;
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default:
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cflag |= B57600;
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}
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parity = buf[0];
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buf++;
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switch (parity) {
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case 'e':
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cflag |= PARENB;
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break;
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case 'o':
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cflag |= PARODD;
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break;
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}
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bit = simple_strtoul(buf, &buf, 10);
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switch (bit) {
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case 5:
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cflag |= CS5;
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break;
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case 6:
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cflag |= CS6;
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break;
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case 7:
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cflag |= CS7;
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break;
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default:
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cflag |= CS8;
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}
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#ifdef CONFIG_SERIAL_BFIN
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return bfin_earlyserial_init(serial_port, cflag);
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#else
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return NULL;
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#endif
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}
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#endif
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int __init setup_early_printk(char *buf)
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{
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/* Crashing in here would be really bad, so check both the var
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and the pointer before we start using it
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*/
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if (!buf)
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return 0;
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if (!*buf)
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return 0;
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if (early_console != NULL)
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return 0;
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#ifdef CONFIG_SERIAL_BFIN
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/* Check for Blackfin Serial */
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if (!strncmp(buf, "serial,uart", 11)) {
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buf += 11;
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early_console = earlyserial_init(buf);
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}
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#endif
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#ifdef CONFIG_BFIN_JTAG_COMM
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/* Check for Blackfin JTAG */
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if (!strncmp(buf, "jtag", 4)) {
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buf += 4;
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early_console = bfin_jc_early_init();
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}
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#endif
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#ifdef CONFIG_FB
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/* TODO: add framebuffer console support */
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#endif
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if (likely(early_console)) {
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early_console->flags |= CON_BOOT;
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register_console(early_console);
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printk(KERN_INFO "early printk enabled on %s%d\n",
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early_console->name,
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early_console->index);
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}
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return 0;
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}
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/*
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* Set up a temporary Event Vector Table, so if something bad happens before
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* the kernel is fully started, it doesn't vector off into somewhere we don't
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* know
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*/
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asmlinkage void __init init_early_exception_vectors(void)
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{
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u32 evt;
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SSYNC();
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/* cannot program in software:
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* evt0 - emulation (jtag)
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* evt1 - reset
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*/
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for (evt = EVT2; evt <= EVT15; evt += 4)
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bfin_write32(evt, early_trap);
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CSYNC();
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/* Set all the return from interrupt, exception, NMI to a known place
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* so if we do a RETI, RETX or RETN by mistake - we go somewhere known
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* Note - don't change RETS - we are in a subroutine, or
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* RETE - since it might screw up if emulator is attached
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*/
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asm("\tRETI = %0; RETX = %0; RETN = %0;\n"
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: : "p"(early_trap));
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}
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asmlinkage void __init early_trap_c(struct pt_regs *fp, void *retaddr)
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{
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/* This can happen before the uart is initialized, so initialize
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* the UART now (but only if we are running on the processor we think
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* we are compiled for - otherwise we write to MMRs that don't exist,
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* and cause other problems. Nothing comes out the UART, but it does
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* end up in the __buf_log.
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*/
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if (likely(early_console == NULL) && CPUID == bfin_cpuid())
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setup_early_printk(DEFAULT_EARLY_PORT);
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printk(KERN_EMERG "Early panic\n");
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dump_bfin_mem(fp);
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show_regs(fp);
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dump_bfin_trace_buffer();
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panic("Died early");
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}
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early_param("earlyprintk", setup_early_printk);
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