[POWERPC] Add non-OF serial console support
Add serial console support for non-OF systems. There is a generic serial
console layer which calls a serial console driver. Included is the serial
console driver for the ns16550 class of uarts. Necessary support routines
are added as well.
Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/boot/util.S b/arch/powerpc/boot/util.S
new file mode 100644
index 0000000..427ddfc
--- /dev/null
+++ b/arch/powerpc/boot/util.S
@@ -0,0 +1,88 @@
+/*
+ * Copied from <file:arch/powerpc/kernel/misc_32.S>
+ *
+ * This file contains miscellaneous low-level functions.
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ *
+ * kexec bits:
+ * Copyright (C) 2002-2003 Eric Biederman <ebiederm@xmission.com>
+ * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
+ *
+ * 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.
+ *
+ */
+#include "ppc_asm.h"
+
+#define SPRN_PVR 0x11F /* Processor Version Register */
+
+ .text
+
+/* udelay (on non-601 processors) needs to know the period of the
+ * timebase in nanoseconds. This used to be hardcoded to be 60ns
+ * (period of 66MHz/4). Now a variable is used that is initialized to
+ * 60 for backward compatibility, but it can be overridden as necessary
+ * with code something like this:
+ * extern unsigned long timebase_period_ns;
+ * timebase_period_ns = 1000000000 / bd->bi_tbfreq;
+ */
+ .data
+ .globl timebase_period_ns
+timebase_period_ns:
+ .long 60
+
+ .text
+/*
+ * Delay for a number of microseconds
+ */
+ .globl udelay
+udelay:
+ mfspr r4,SPRN_PVR
+ srwi r4,r4,16
+ cmpwi 0,r4,1 /* 601 ? */
+ bne .udelay_not_601
+00: li r0,86 /* Instructions / microsecond? */
+ mtctr r0
+10: addi r0,r0,0 /* NOP */
+ bdnz 10b
+ subic. r3,r3,1
+ bne 00b
+ blr
+
+.udelay_not_601:
+ mulli r4,r3,1000 /* nanoseconds */
+ /* Change r4 to be the number of ticks using:
+ * (nanoseconds + (timebase_period_ns - 1 )) / timebase_period_ns
+ * timebase_period_ns defaults to 60 (16.6MHz) */
+ mflr r5
+ bl 0f
+0: mflr r6
+ mtlr r5
+ lis r5,0b@ha
+ addi r5,r5,0b@l
+ subf r5,r5,r6 /* In case we're relocated */
+ addis r5,r5,timebase_period_ns@ha
+ lwz r5,timebase_period_ns@l(r5)
+ add r4,r4,r5
+ addi r4,r4,-1
+ divw r4,r4,r5 /* BUS ticks */
+1: mftbu r5
+ mftb r6
+ mftbu r7
+ cmpw 0,r5,r7
+ bne 1b /* Get [synced] base time */
+ addc r9,r6,r4 /* Compute end time */
+ addze r8,r5
+2: mftbu r5
+ cmpw 0,r5,r8
+ blt 2b
+ bgt 3f
+ mftb r6
+ cmpw 0,r6,r9
+ blt 2b
+3: blr