xref: /openbmc/linux/arch/sparc/include/asm/timer_32.h (revision 384740dc)
1 /*
2  * timer.h:  Definitions for the timer chips on the Sparc.
3  *
4  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5  */
6 
7 
8 #ifndef _SPARC_TIMER_H
9 #define _SPARC_TIMER_H
10 
11 #include <asm/system.h>  /* For SUN4M_NCPUS */
12 #include <asm/sun4paddr.h>
13 #include <asm/btfixup.h>
14 
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 ;(
21  */
22 
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.
28  */
29 
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;
35 };
36 
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
43 
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.
48  */
49 
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.
53  */
54 
55 #define SUN4M_PRM_CNT_L       0x80000000
56 #define SUN4M_PRM_CNT_LVALUE  0x7FFFFC00
57 
58 struct sun4m_timer_percpu_info {
59   __volatile__ unsigned int l14_timer_limit;    /* Initial value is 0x009c4000 */
60   __volatile__ unsigned int l14_cur_count;
61 
62   /* This register appears to be write only and/or inaccessible
63    * on Uni-Processor sun4m machines.
64    */
65   __volatile__ unsigned int l14_limit_noclear;  /* Data access error is here */
66 
67   __volatile__ unsigned int cntrl;            /* =1 after POST on Aurora */
68   __volatile__ unsigned char space[PAGE_SIZE - 16];
69 };
70 
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;
75 
76 	/* Again, this appears to be write only and/or inaccessible
77 	 * on uni-processor sun4m machines.
78 	 */
79 	volatile unsigned int l10_limit_noclear;
80 
81 	/* This register too, it must be magic. */
82 	volatile unsigned int foobar;
83 
84 	volatile unsigned int cfg;     /* equals zero at boot time... */
85 };
86 
87 #define SUN4D_PRM_CNT_L       0x80000000
88 #define SUN4D_PRM_CNT_LVALUE  0x7FFFFC00
89 
90 struct sun4d_timer_regs {
91 	volatile unsigned int l10_timer_limit;
92 	volatile unsigned int l10_cur_countx;
93 	volatile unsigned int l10_limit_noclear;
94 	volatile unsigned int ctrl;
95 	volatile unsigned int l10_cur_count;
96 };
97 
98 extern struct sun4d_timer_regs *sun4d_timers;
99 
100 extern __volatile__ unsigned int *master_l10_counter;
101 extern __volatile__ unsigned int *master_l10_limit;
102 
103 /* FIXME: Make do_[gs]ettimeofday btfixup calls */
104 BTFIXUPDEF_CALL(int, bus_do_settimeofday, struct timespec *tv)
105 #define bus_do_settimeofday(tv) BTFIXUP_CALL(bus_do_settimeofday)(tv)
106 
107 #endif /* !(_SPARC_TIMER_H) */
108