1 /*
2 * Common time prototypes and such for all ppc machines.
3 *
4 * Written by Cort Dougan (cort@fsmlabs.com) to merge
5 * Paul Mackerras' version and mine for PReP and Pmac.
6 */
7
8 #ifdef __KERNEL__
9 #ifndef __ASM_TIME_H__
10 #define __ASM_TIME_H__
11
12 #include <linux/config.h>
13 #include <linux/mc146818rtc.h>
14 #include <linux/threads.h>
15 #include <linux/compiler.h>
16
17 #include <asm/processor.h>
18
19 /* time.c */
20 extern unsigned tb_ticks_per_jiffy;
21 extern unsigned tb_to_us;
22 extern unsigned tb_last_stamp;
23 extern unsigned long disarm_decr[NR_CPUS];
24
25 extern void to_tm(int tim, struct rtc_time * tm);
26 extern time_t last_rtc_update;
27
28 extern void set_dec_cpu6(unsigned int val);
29
30 int via_calibrate_decr(void);
31
32 /* Accessor functions for the decrementer register.
33 * The 40x doesn't even have a decrementer. I tried to use the
34 * generic timer interrupt code, which seems OK, with the 40x PIT
35 * in auto-reload mode. The problem is PIT stops counting when it
36 * hits zero. If it would wrap, we could use it just like a decrementer.
37 */
get_dec(void)38 static __inline__ unsigned int get_dec(void)
39 {
40 #if defined(CONFIG_40x)
41 return (mfspr(SPRN_PIT));
42 #else
43 return (mfspr(SPRN_DEC));
44 #endif
45 }
46
set_dec(unsigned int val)47 static __inline__ void set_dec(unsigned int val)
48 {
49 #if defined(CONFIG_40x)
50 return; /* Have to let it auto-reload */
51 #elif defined(CONFIG_8xx_CPU6)
52 set_dec_cpu6(val);
53 #else
54 mtspr(SPRN_DEC, val);
55 #endif
56 }
57
58 /* Accessor functions for the timebase (RTC on 601) registers. */
59 /* If one day CONFIG_POWER is added just define __USE_RTC as 1 */
60 #ifdef CONFIG_6xx
__USE_RTC(void)61 extern __inline__ int __attribute_const__ __USE_RTC(void) {
62 return (mfspr(SPRN_PVR)>>16) == 1;
63 }
64 #else
65 #define __USE_RTC() 0
66 #endif
67
get_tbl(void)68 extern __inline__ unsigned long get_tbl(void) {
69 unsigned long tbl;
70 asm volatile("mftb %0" : "=r" (tbl));
71 return tbl;
72 }
73
get_tbu(void)74 extern __inline__ unsigned long get_tbu(void) {
75 unsigned long tbl;
76 asm volatile("mftbu %0" : "=r" (tbl));
77 return tbl;
78 }
79
set_tb(unsigned int upper,unsigned int lower)80 extern __inline__ void set_tb(unsigned int upper, unsigned int lower)
81 {
82 mtspr(SPRN_TBWL, 0);
83 mtspr(SPRN_TBWU, upper);
84 mtspr(SPRN_TBWL, lower);
85 }
86
get_rtcl(void)87 extern __inline__ unsigned long get_rtcl(void) {
88 unsigned long rtcl;
89 asm volatile("mfrtcl %0" : "=r" (rtcl));
90 return rtcl;
91 }
92
get_native_tbl(void)93 extern __inline__ unsigned get_native_tbl(void) {
94 if (__USE_RTC())
95 return get_rtcl();
96 else
97 return get_tbl();
98 }
99
100 /* On machines with RTC, this function can only be used safely
101 * after the timestamp and for 1 second. It is only used by gettimeofday
102 * however so it should not matter.
103 */
tb_ticks_since(unsigned tstamp)104 extern __inline__ unsigned tb_ticks_since(unsigned tstamp) {
105 if (__USE_RTC()) {
106 int delta = get_rtcl() - tstamp;
107 return delta<0 ? delta + 1000000000 : delta;
108 } else {
109 return get_tbl() - tstamp;
110 }
111 }
112
113 #if 0
114 extern __inline__ unsigned long get_bin_rtcl(void) {
115 unsigned long rtcl, rtcu1, rtcu2;
116 asm volatile("\
117 1: mfrtcu %0\n\
118 mfrtcl %1\n\
119 mfrtcu %2\n\
120 cmpw %0,%2\n\
121 bne- 1b\n"
122 : "=r" (rtcu1), "=r" (rtcl), "=r" (rtcu2)
123 : : "cr0");
124 return rtcu2*1000000000+rtcl;
125 }
126
127 extern __inline__ unsigned binary_tbl(void) {
128 if (__USE_RTC())
129 return get_bin_rtcl();
130 else
131 return get_tbl();
132 }
133 #endif
134
135 /* Use mulhwu to scale processor timebase to timeval */
136 #define mulhwu(x,y) \
137 ({unsigned z; asm ("mulhwu %0,%1,%2" : "=r" (z) : "r" (x), "r" (y)); z;})
138
139 unsigned mulhwu_scale_factor(unsigned, unsigned);
140 #endif /* __ASM_TIME_H__ */
141 #endif /* __KERNEL__ */
142