1 /* $NetBSD: clock.c,v 1.2 2010/03/02 21:52:32 matt Exp $ */ 2 3 /* 4 * Copyright (C) 1995, 1996 Wolfgang Solfrank. 5 * Copyright (C) 1995, 1996 TooLs GmbH. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by TooLs GmbH. 19 * 4. The name of TooLs GmbH may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 27 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 28 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 30 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF 31 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 #include <lib/libsa/stand.h> 35 #include <dev/isa/isareg.h> 36 #include <dev/ic/i8253reg.h> 37 #include <powerpc/spr.h> 38 #include <powerpc/oea/spr.h> 39 40 #include "boot.h" 41 42 u_long ns_per_tick = NS_PER_TICK; 43 44 static inline u_quad_t mftb(void); 45 static inline void mfrtc(u_long *, u_long *); 46 47 static inline u_quad_t 48 mftb(void) 49 { 50 u_long scratch; 51 u_quad_t tb; 52 53 __asm volatile ("1: mftbu %0; mftb %0+1; mftbu %1; cmpw %0,%1; bne 1b" 54 : "=r"(tb), "=r"(scratch)); 55 return (tb); 56 } 57 58 static inline void 59 mfrtc(u_long *up, u_long *lp) 60 { 61 u_long scratch; 62 63 __asm volatile ("1: mfspr %0,%3; mfspr %1,%4; mfspr %2,%3;" 64 "cmpw %0,%2; bne 1b" 65 : "=r"(*up), "=r"(*lp), "=r"(scratch) 66 : "n"(SPR_RTCU_R), "n"(SPR_RTCL_R)); 67 } 68 69 /* 70 * Wait for about n microseconds (at least!). 71 */ 72 void 73 delay(u_int n) 74 { 75 u_quad_t tb; 76 u_long tbh, tbl, scratch; 77 unsigned int cpuvers; 78 79 __asm volatile ("mfpvr %0" : "=r"(cpuvers)); 80 cpuvers >>= 16; 81 /*cpuvers = MPC601; for now */ 82 83 if (cpuvers == MPC601) { 84 mfrtc(&tbh, &tbl); 85 while (n >= 1000000) { 86 tbh++; 87 n -= 1000000; 88 } 89 tbl += n * 1000; 90 if (tbl >= 1000000000) { 91 tbh++; 92 tbl -= 1000000000; 93 } 94 __asm volatile ("1: mfspr %0,%3; cmplw %0,%1; blt 1b; bgt 2f;" 95 "mfspr %0,%4; cmplw %0,%2; blt 1b; 2:" 96 : "=&r"(scratch) 97 : "r"(tbh), "r"(tbl), "n"(SPR_RTCU_R), "n"(SPR_RTCL_R)); 98 } else { 99 tb = mftb(); 100 tb += (n * 1000 + ns_per_tick - 1) / ns_per_tick; 101 tbh = tb >> 32; 102 tbl = tb; 103 __asm volatile ("1: mftbu %0; cmpw %0,%1; blt 1b; bgt 2f;" 104 "mftb %0; cmpw %0,%2; blt 1b; 2:" 105 : "=&r"(scratch) 106 : "r"(tbh), "r"(tbl)); 107 } 108 } 109