Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759677AbYFZNUz (ORCPT ); Thu, 26 Jun 2008 09:20:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752553AbYFZNUn (ORCPT ); Thu, 26 Jun 2008 09:20:43 -0400 Received: from 238.225.broadband7.iol.cz ([88.102.225.238]:24042 "EHLO monstr.eu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752195AbYFZNUm (ORCPT ); Thu, 26 Jun 2008 09:20:42 -0400 From: monstr@seznam.cz To: linux-kernel@vger.kernel.org Cc: arnd@arndb.de, linux-arch@vger.kernel.org, stephen.neuendorffer@xilinx.com, John.Linn@xilinx.com, john.williams@petalogix.com, matthew@wil.cx, will.newton@gmail.com, drepper@redhat.com, microblaze-uclinux@itee.uq.edu.au, grant.likely@secretlab.ca, linuxppc-dev@ozlabs.org, vapier.adi@gmail.com, alan@lxorguk.ukuu.org.uk, hpa@zytor.com, Michal Simek Subject: [PATCH 20/60] microblaze_v4: early_printk support Date: Thu, 26 Jun 2008 14:29:49 +0200 Message-Id: <1214483429-32360-21-git-send-email-monstr@seznam.cz> X-Mailer: git-send-email 1.5.4.GIT In-Reply-To: <1214483429-32360-20-git-send-email-monstr@seznam.cz> References: <1214483429-32360-1-git-send-email-monstr@seznam.cz> <1214483429-32360-2-git-send-email-monstr@seznam.cz> <1214483429-32360-3-git-send-email-monstr@seznam.cz> <1214483429-32360-4-git-send-email-monstr@seznam.cz> <1214483429-32360-5-git-send-email-monstr@seznam.cz> <1214483429-32360-6-git-send-email-monstr@seznam.cz> <1214483429-32360-7-git-send-email-monstr@seznam.cz> <1214483429-32360-8-git-send-email-monstr@seznam.cz> <1214483429-32360-9-git-send-email-monstr@seznam.cz> <1214483429-32360-10-git-send-email-monstr@seznam.cz> <1214483429-32360-11-git-send-email-monstr@seznam.cz> <1214483429-32360-12-git-send-email-monstr@seznam.cz> <1214483429-32360-13-git-send-email-monstr@seznam.cz> <1214483429-32360-14-git-send-email-monstr@seznam.cz> <1214483429-32360-15-git-send-email-monstr@seznam.cz> <1214483429-32360-16-git-send-email-monstr@seznam.cz> <1214483429-32360-17-git-send-email-monstr@seznam.cz> <1214483429-32360-18-git-send-email-monstr@seznam.cz> <1214483429-32360-19-git-send-email-monstr@seznam.cz> <1214483429-32360-20-git-send-email-monstr@seznam.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3881 Lines: 153 From: Michal Simek Signed-off-by: Michal Simek --- arch/microblaze/kernel/early_printk.c | 130 +++++++++++++++++++++++++++++++++ 1 files changed, 130 insertions(+), 0 deletions(-) create mode 100644 arch/microblaze/kernel/early_printk.c diff --git a/arch/microblaze/kernel/early_printk.c b/arch/microblaze/kernel/early_printk.c new file mode 100644 index 0000000..6da0fd9 --- /dev/null +++ b/arch/microblaze/kernel/early_printk.c @@ -0,0 +1,130 @@ +/* + * Early printk support for Microblaze. + * + * Copyright (C) 2007-2008 Michal Simek + * Copyright (C) 2003-2006 Yasushi SHOJI + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +/* FIXME Once we got some system without uart light, we need to refactor */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_EARLY_PRINTK +#define BASE_ADDR ((unsigned char *)CONFIG_EARLY_PRINTK_UARTLITE_ADDRESS) + +#define RX_FIFO BASE_ADDR +#define TX_FIFO ((unsigned long *)(BASE_ADDR + 4)) +#define STATUS ((unsigned long *)(BASE_ADDR + 8)) +#define CONTROL ((unsigned long *)(BASE_ADDR + 12)) + +static void early_printk_putc(char c) +{ + /* + * Limit how many times we'll spin waiting for TX FIFO status. + * This will prevent lockups if the base address is incorrectly + * set, or any other issue on the UARTLITE. + * This limit is pretty arbitrary, unless we are at about 10 baud + * we'll never timeout on a working UART. + */ + + unsigned retries = 10000; + while (retries-- && (ioread32(STATUS) & (1<<3))) + ; + + /* Only attempt the iowrite if we didn't timeout */ + if (retries) + iowrite32((c & 0xff), TX_FIFO); +} + +static void early_printk_write(struct console *unused, + const char *s, unsigned n) +{ + while (*s && n-- > 0) { + early_printk_putc(*s); + if (*s == '\n') + early_printk_putc('\r'); + s++; + } +} + +static struct console early_serial_console = { + .name = "earlyser", + .write = early_printk_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/* Direct interface for emergencies */ +static struct console *early_console = &early_serial_console; +static int early_console_initialized; + +void early_printk(const char *fmt, ...) +{ + char buf[512]; + int n; + va_list ap; + + if (early_console_initialized) { + va_start(ap, fmt); + n = vscnprintf(buf, 512, fmt, ap); + early_console->write(early_console, buf, n); + va_end(ap); + } +} + +static int __initdata keep_early; + +int __init setup_early_printk(char *opt) +{ + char *space; + char buf[256]; + + if (early_console_initialized) + return 1; + + strlcpy(buf, opt, sizeof(buf)); + space = strchr(buf, ' '); + if (space) + *space = 0; + + if (strstr(buf, "keep")) + keep_early = 1; + + early_console = &early_serial_console; + early_console_initialized = 1; + register_console(early_console); + return 0; +} +#if 0 +static void __init disable_early_printk(void) +{ + if (!early_console_initialized || !early_console) + return; + if (!keep_early) { + printk(KERN_INFO "disabling early console\n"); + unregister_console(early_console); + early_console_initialized = 0; + } else + printk(KERN_INFO "keeping early console\n"); +} +#endif + +__setup("earlyprintk=", setup_early_printk); + +#else +void early_printk(const char *fmt, ...) +{ +} +#endif -- 1.5.4.GIT -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/