sched: make early bootup sched_clock() use safer
[wrt350n-kernel.git] / include / asm-sparc / timer.h
blobcb1fa1d1f184dbc2c2880c93003c71ea87764f1e
1 /* $Id: timer.h,v 1.21 1999/04/20 13:22:51 anton Exp $
2 * timer.h: Definitions for the timer chips on the Sparc.
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 */
8 #ifndef _SPARC_TIMER_H
9 #define _SPARC_TIMER_H
11 #include <asm/system.h> /* For SUN4M_NCPUS */
12 #include <asm/sun4paddr.h>
13 #include <asm/btfixup.h>
15 /* Timer structures. The interrupt timer has two properties which
16 * are the counter (which is handled in do_timer in sched.c) and the limit.
17 * This limit is where the timer's counter 'wraps' around. Oddly enough,
18 * the sun4c timer when it hits the limit wraps back to 1 and not zero
19 * thus when calculating the value at which it will fire a microsecond you
20 * must adjust by one. Thanks SUN for designing such great hardware ;(
23 /* Note that I am only going to use the timer that interrupts at
24 * Sparc IRQ 10. There is another one available that can fire at
25 * IRQ 14. Currently it is left untouched, we keep the PROM's limit
26 * register value and let the prom take these interrupts. This allows
27 * L1-A to work.
30 struct sun4c_timer_info {
31 __volatile__ unsigned int cur_count10;
32 __volatile__ unsigned int timer_limit10;
33 __volatile__ unsigned int cur_count14;
34 __volatile__ unsigned int timer_limit14;
37 #define SUN4C_TIMER_PHYSADDR 0xf3000000
38 #ifdef CONFIG_SUN4
39 #define SUN_TIMER_PHYSADDR SUN4_300_TIMER_PHYSADDR
40 #else
41 #define SUN_TIMER_PHYSADDR SUN4C_TIMER_PHYSADDR
42 #endif
44 /* A sun4m has two blocks of registers which are probably of the same
45 * structure. LSI Logic's L64851 is told to _decrement_ from the limit
46 * value. Aurora behaves similarly but its limit value is compacted in
47 * other fashion (it's wider). Documented fields are defined here.
50 /* As with the interrupt register, we have two classes of timer registers
51 * which are per-cpu and master. Per-cpu timers only hit that cpu and are
52 * only level 14 ticks, master timer hits all cpus and is level 10.
55 #define SUN4M_PRM_CNT_L 0x80000000
56 #define SUN4M_PRM_CNT_LVALUE 0x7FFFFC00
58 struct sun4m_timer_percpu_info {
59 __volatile__ unsigned int l14_timer_limit; /* Initial value is 0x009c4000 */
60 __volatile__ unsigned int l14_cur_count;
62 /* This register appears to be write only and/or inaccessible
63 * on Uni-Processor sun4m machines.
65 __volatile__ unsigned int l14_limit_noclear; /* Data access error is here */
67 __volatile__ unsigned int cntrl; /* =1 after POST on Aurora */
68 __volatile__ unsigned char space[PAGE_SIZE - 16];
71 struct sun4m_timer_regs {
72 struct sun4m_timer_percpu_info cpu_timers[SUN4M_NCPUS];
73 volatile unsigned int l10_timer_limit;
74 volatile unsigned int l10_cur_count;
76 /* Again, this appears to be write only and/or inaccessible
77 * on uni-processor sun4m machines.
79 volatile unsigned int l10_limit_noclear;
81 /* This register too, it must be magic. */
82 volatile unsigned int foobar;
84 volatile unsigned int cfg; /* equals zero at boot time... */
87 extern struct sun4m_timer_regs *sun4m_timers;
89 #define SUN4D_PRM_CNT_L 0x80000000
90 #define SUN4D_PRM_CNT_LVALUE 0x7FFFFC00
92 struct sun4d_timer_regs {
93 volatile unsigned int l10_timer_limit;
94 volatile unsigned int l10_cur_countx;
95 volatile unsigned int l10_limit_noclear;
96 volatile unsigned int ctrl;
97 volatile unsigned int l10_cur_count;
100 extern struct sun4d_timer_regs *sun4d_timers;
102 extern __volatile__ unsigned int *master_l10_counter;
103 extern __volatile__ unsigned int *master_l10_limit;
105 /* FIXME: Make do_[gs]ettimeofday btfixup calls */
106 BTFIXUPDEF_CALL(int, bus_do_settimeofday, struct timespec *tv)
107 #define bus_do_settimeofday(tv) BTFIXUP_CALL(bus_do_settimeofday)(tv)
109 #endif /* !(_SPARC_TIMER_H) */