Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6
[linux-2.6] / arch / mips / mipssim / sim_time.c
1 #include <linux/types.h>
2 #include <linux/init.h>
3 #include <linux/kernel_stat.h>
4 #include <linux/sched.h>
5 #include <linux/spinlock.h>
6 #include <linux/interrupt.h>
7 #include <linux/mc146818rtc.h>
8 #include <linux/smp.h>
9 #include <linux/timex.h>
10
11 #include <asm/hardirq.h>
12 #include <asm/div64.h>
13 #include <asm/cpu.h>
14 #include <asm/time.h>
15 #include <asm/irq.h>
16 #include <asm/mc146818-time.h>
17 #include <asm/msc01_ic.h>
18
19 #include <asm/mips-boards/generic.h>
20 #include <asm/mips-boards/prom.h>
21 #include <asm/mips-boards/simint.h>
22
23
24 unsigned long cpu_khz;
25
26 /*
27  * Estimate CPU frequency.  Sets mips_hpt_frequency as a side-effect
28  */
29 static unsigned int __init estimate_cpu_frequency(void)
30 {
31         unsigned int prid = read_c0_prid() & 0xffff00;
32         unsigned int count;
33
34 #if 1
35         /*
36          * hardwire the board frequency to 12MHz.
37          */
38
39         if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) ||
40             (prid == (PRID_COMP_MIPS | PRID_IMP_25KF)))
41                 count = 12000000;
42         else
43                 count =  6000000;
44 #else
45         unsigned int flags;
46
47         local_irq_save(flags);
48
49         /* Start counter exactly on falling edge of update flag */
50         while (CMOS_READ(RTC_REG_A) & RTC_UIP);
51         while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
52
53         /* Start r4k counter. */
54         write_c0_count(0);
55
56         /* Read counter exactly on falling edge of update flag */
57         while (CMOS_READ(RTC_REG_A) & RTC_UIP);
58         while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
59
60         count = read_c0_count();
61
62         /* restore interrupts */
63         local_irq_restore(flags);
64 #endif
65
66         mips_hpt_frequency = count;
67
68         if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
69             (prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
70                 count *= 2;
71
72         count += 5000;    /* round */
73         count -= count%10000;
74
75         return count;
76 }
77
78 static int mips_cpu_timer_irq;
79
80 static void mips_timer_dispatch(void)
81 {
82         do_IRQ(mips_cpu_timer_irq);
83 }
84
85
86 unsigned __init get_c0_compare_int(void)
87 {
88 #ifdef MSC01E_INT_BASE
89         if (cpu_has_veic) {
90                 set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch);
91                 mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
92         } else {
93 #endif
94                 if (cpu_has_vint)
95                         set_vi_handler(cp0_compare_irq, mips_timer_dispatch);
96                 mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
97         }
98
99         return mips_cpu_timer_irq;
100 }
101
102 void __init plat_time_init(void)
103 {
104         unsigned int est_freq;
105
106         /* Set Data mode - binary. */
107         CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL);
108
109         est_freq = estimate_cpu_frequency();
110
111         printk(KERN_INFO "CPU frequency %d.%02d MHz\n", est_freq / 1000000,
112                (est_freq % 1000000) * 100 / 1000000);
113
114         cpu_khz = est_freq / 1000;
115 }