Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=eca8c2424171b6b6b2dcb0faa92dfddd1e3297d9
Commit:     eca8c2424171b6b6b2dcb0faa92dfddd1e3297d9
Parent:     486cab2ba25b469f7a8822e84fd43960a472e3d9
Author:     Ben Dooks <[EMAIL PROTECTED]>
AuthorDate: Mon May 28 18:19:16 2007 +0100
Committer:  Russell King <[EMAIL PROTECTED]>
CommitDate: Wed May 30 13:15:23 2007 +0100

    [ARM] 4412/1: S3C2412: reset errata fix
    
    The S3C2412 has an reset-errata where the clock
    may cause a glitch switching back to EXTCLK. We
    force a switch to EXTCLK before writing the
    reset register to force use of the CLKCON sync
    logic to properly switch.
    
    Fix problem reported by Matthieu Castet.
    
    Signed-off-by: Ben Dooks <[EMAIL PROTECTED]>
    Signed-off-by: Russell King <[EMAIL PROTECTED]>
---
 arch/arm/mach-s3c2412/s3c2412.c             |   24 ++++++++++++++++++++++++
 include/asm-arm/arch-s3c2410/regs-s3c2412.h |   21 +++++++++++++++++++++
 2 files changed, 45 insertions(+), 0 deletions(-)

diff --git a/arch/arm/mach-s3c2412/s3c2412.c b/arch/arm/mach-s3c2412/s3c2412.c
index c602aa3..782b581 100644
--- a/arch/arm/mach-s3c2412/s3c2412.c
+++ b/arch/arm/mach-s3c2412/s3c2412.c
@@ -16,6 +16,7 @@
 #include <linux/list.h>
 #include <linux/timer.h>
 #include <linux/init.h>
+#include <linux/delay.h>
 #include <linux/sysdev.h>
 #include <linux/serial_core.h>
 #include <linux/platform_device.h>
@@ -29,6 +30,7 @@
 #include <asm/io.h>
 #include <asm/irq.h>
 
+#include <asm/arch/reset.h>
 #include <asm/arch/idle.h>
 
 #include <asm/arch/regs-clock.h>
@@ -38,6 +40,7 @@
 #include <asm/arch/regs-gpioj.h>
 #include <asm/arch/regs-dsc.h>
 #include <asm/arch/regs-spi.h>
+#include <asm/arch/regs-s3c2412.h>
 
 #include <asm/plat-s3c24xx/s3c2412.h>
 #include <asm/plat-s3c24xx/cpu.h>
@@ -106,6 +109,23 @@ static void s3c2412_idle(void)
        cpu_do_idle();
 }
 
+static void s3c2412_hard_reset(void)
+{
+       /* errata "Watch-dog/Software Reset Problem" specifies that
+        * this reset must be done with the SYSCLK sourced from
+        * EXTCLK instead of FOUT to avoid a glitch in the reset
+        * mechanism.
+        *
+        * See the watchdog section of the S3C2412 manual for more
+        * information on this fix.
+        */
+
+       __raw_writel(0x00, S3C2412_CLKSRC);
+       __raw_writel(S3C2412_SWRST_RESET, S3C2412_SWRST);
+
+       mdelay(1);
+}
+
 /* s3c2412_map_io
  *
  * register the standard cpu IO areas, and any passed in from the
@@ -122,6 +142,10 @@ void __init s3c2412_map_io(struct map_desc *mach_desc, int 
mach_size)
 
        s3c24xx_idle = s3c2412_idle;
 
+       /* set custom reset hook */
+
+       s3c24xx_reset_hook = s3c2412_hard_reset;
+
        /* register our io-tables */
 
        iotable_init(s3c2412_iodesc, ARRAY_SIZE(s3c2412_iodesc));
diff --git a/include/asm-arm/arch-s3c2410/regs-s3c2412.h 
b/include/asm-arm/arch-s3c2410/regs-s3c2412.h
new file mode 100644
index 0000000..8ca6a3b
--- /dev/null
+++ b/include/asm-arm/arch-s3c2410/regs-s3c2412.h
@@ -0,0 +1,21 @@
+/* linux/include/asm-arm/arch-s3c2410/regs-s3c2412.h
+ *
+ * Copyright 2007 Simtec Electronics
+ *     http://armlinux.simtec.co.uk/
+ *     Ben Dooks <[EMAIL PROTECTED]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * S3C2412 specific register definitions
+*/
+
+#ifndef __ASM_ARCH_REGS_S3C2412_H
+#define __ASM_ARCH_REGS_S3C2412_H "s3c2412"
+
+#define S3C2412_SWRST          (S3C24XX_VA_CLKPWR + 0x30)
+#define S3C2412_SWRST_RESET    (0x533C2412)
+
+#endif /* __ASM_ARCH_REGS_S3C2412_H */
+
-
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