/* $NetBSD: clock.c,v 1.2 2010/03/02 21:52:32 matt Exp $ */
/*
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <lib/libsa/stand.h>
#include <dev/isa/isareg.h>
#include <dev/ic/i8253reg.h>
#include <powerpc/spr.h>
#include <powerpc/oea/spr.h>
#include "boot.h"
u_long ns_per_tick = NS_PER_TICK;
static inline u_quad_t mftb(void);
static inline void mfrtc(u_long *, u_long *);
static inline u_quad_t
mftb(void)
{
u_long scratch;
u_quad_t tb;
__asm volatile ("1: mftbu %0; mftb %0+1; mftbu %1; cmpw %0,%1; bne 1b"
: "=r"(tb), "=r"(scratch));
return (tb);
}
static inline void
mfrtc(u_long *up, u_long *lp)
{
u_long scratch;
__asm volatile ("1: mfspr %0,%3; mfspr %1,%4; mfspr %2,%3;"
"cmpw %0,%2; bne 1b"
: "=r"(*up), "=r"(*lp), "=r"(scratch)
: "n"(SPR_RTCU_R), "n"(SPR_RTCL_R));
}
/*
* Wait for about n microseconds (at least!).
*/
void
delay(u_int n)
{
u_quad_t tb;
u_long tbh, tbl, scratch;
unsigned int cpuvers;
__asm volatile ("mfpvr %0" : "=r"(cpuvers));
cpuvers >>= 16;
/*cpuvers = MPC601; for now */
if (cpuvers == MPC601) {
mfrtc(&tbh, &tbl);
while (n >= 1000000) {
tbh++;
n -= 1000000;
}
tbl += n * 1000;
if (tbl >= 1000000000) {
tbh++;
tbl -= 1000000000;
}
__asm volatile ("1: mfspr %0,%3; cmplw %0,%1; blt 1b; bgt 2f;"
"mfspr %0,%4; cmplw %0,%2; blt 1b; 2:"
: "=&r"(scratch)
: "r"(tbh), "r"(tbl), "n"(SPR_RTCU_R), "n"(SPR_RTCL_R));
} else {
tb = mftb();
tb += (n * 1000 + ns_per_tick - 1) / ns_per_tick;
tbh = tb >> 32;
tbl = tb;
__asm volatile ("1: mftbu %0; cmpw %0,%1; blt 1b; bgt 2f;"
"mftb %0; cmpw %0,%2; blt 1b; 2:"
: "=&r"(scratch)
: "r"(tbh), "r"(tbl));
}
}
