1 /*
2 * $Id: time.h,v 1.12 1999/08/27 04:21:23 cort Exp $
3 * Common time prototypes and such for all ppc machines.
4 *
5 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
6 * Paul Mackerras' version and mine for PReP and Pmac.
7 */
8
9 #ifdef __KERNEL__
10 #include <linux/config.h>
11 #include <linux/mc146818rtc.h>
12
13 #include <asm/processor.h>
14
15 /* time.c */
16 extern unsigned tb_ticks_per_jiffy;
17 extern unsigned tb_to_us;
18 extern unsigned tb_last_stamp;
19
20 extern void to_tm(int tim, struct rtc_time * tm);
21 extern time_t last_rtc_update;
22
23 int via_calibrate_decr(void);
24
25 /* Accessor functions for the decrementer register. */
26 static __inline__ unsigned int get_dec(void)
27 {
28 #if defined(CONFIG_4xx)
29 return (mfspr(SPRN_PIT));
30 #else
31 return (mfspr(SPRN_DEC));
32 #endif
33 }
34
35 static __inline__ void set_dec(unsigned int val)
36 {
37 #if defined(CONFIG_4xx)
38 mtspr(SPRN_PIT, val);
39 #else
40 #ifdef CONFIG_8xx_CPU6
41 set_dec_cpu6(val);
42 #else
43 mtspr(SPRN_DEC, val);
44 #endif
45 #endif
46 }
47
48 /* Accessor functions for the timebase (RTC on 601) registers. */
49 /* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
50 #ifdef CONFIG_6xx
51 extern __inline__ int const __USE_RTC(void) {
52 return (mfspr(SPRN_PVR)>>16) == 1;
53 }
54 #else
55 #define __USE_RTC() 0
56 #endif
57
58 extern __inline__ unsigned long get_tbl(void) {
59 unsigned long tbl;
60 asm volatile("mftb %0" : "=r" (tbl));
61 return tbl;
62 }
63
64 extern __inline__ unsigned long get_rtcl(void) {
65 unsigned long rtcl;
66 asm volatile("mfrtcl %0" : "=r" (rtcl));
67 return rtcl;
68 }
69
70 extern __inline__ unsigned get_native_tbl(void) {
71 if (__USE_RTC())
72 return get_rtcl();
73 else
74 return get_tbl();
75 }
76
77 /* On machines with RTC, this function can only be used safely
78 * after the timestamp and for 1 second. It is only used by gettimeofday
79 * however so it should not matter.
80 */
81 extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
82 if (__USE_RTC()) {
83 int delta = get_rtcl() - tstamp;
84 return delta<0 ? delta + 1000000000 : delta;
85 } else {
86 return get_tbl() - tstamp;
87 }
88 }
89
90 #if 0
91 extern __inline__ unsigned long get_bin_rtcl(void) {
92 unsigned long rtcl, rtcu1, rtcu2;
93 asm volatile("\
94 1: mfrtcu %0\n\
95 mfrtcl %1\n\
96 mfrtcu %2\n\
97 cmpw %0,%2\n\
98 bne- 1b\n"
99 : "=r" (rtcu1), "=r" (rtcl), "=r" (rtcu2)
100 : : "cr0");
101 return rtcu2*1000000000+rtcl;
102 }
103
104 extern __inline__ unsigned binary_tbl(void) {
105 if (__USE_RTC())
106 return get_bin_rtcl();
107 else
108 return get_tbl();
109 }
110 #endif
111
112 /* Use mulhwu to scale processor timebase to timeval */
113 #define mulhwu(x,y) \
114 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
115
116 unsigned mulhwu_scale_factor(unsigned, unsigned);
117 #endif /* __KERNEL__ */
118
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