1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
|
/*
* Carsten Langgaard, carstenl@mips.com
* Copyright (C) 1999,2000 MIPS Technologies, Inc. All rights reserved.
*
* This program is free software; you can distribute it and/or modify it
* under the terms of the GNU General Public License (Version 2) as
* published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
*
* Setting up the clock on the MIPS boards.
*/
#include <linux/types.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/mc146818rtc.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/hardirq.h>
#include <asm/i8253.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/cpu.h>
#include <asm/time.h>
#include <asm/mc146818-time.h>
#include <asm/msc01_ic.h>
#include <asm/mips-boards/generic.h>
#include <asm/mips-boards/prom.h>
#ifdef CONFIG_MIPS_ATLAS
#include <asm/mips-boards/atlasint.h>
#endif
#ifdef CONFIG_MIPS_MALTA
#include <asm/mips-boards/maltaint.h>
#endif
#ifdef CONFIG_MIPS_SEAD
#include <asm/mips-boards/seadint.h>
#endif
unsigned long cpu_khz;
static int mips_cpu_timer_irq;
static int mips_cpu_perf_irq;
extern int cp0_perfcount_irq;
DEFINE_PER_CPU(unsigned int, tickcount);
#define tickcount_this_cpu __get_cpu_var(tickcount)
static unsigned long ledbitmask;
static void mips_timer_dispatch(void)
{
#if defined(CONFIG_MIPS_MALTA) || defined(CONFIG_MIPS_ATLAS)
/*
* Yes, this is very tacky, won't work as expected with SMTC and
* dyntick will break it,
* but it gives me a nice warm feeling during debug
*/
#define LEDBAR 0xbf000408
if (tickcount_this_cpu++ >= HZ) {
tickcount_this_cpu = 0;
change_bit(smp_processor_id(), &ledbitmask);
smp_wmb(); /* Make sure every one else sees the change */
/* This will pick up any recent changes made by other CPU's */
*(unsigned int *)LEDBAR = ledbitmask;
}
#endif
do_IRQ(mips_cpu_timer_irq);
}
static void mips_perf_dispatch(void)
{
do_IRQ(mips_cpu_perf_irq);
}
/*
* Estimate CPU frequency. Sets mips_hpt_frequency as a side-effect
*/
static unsigned int __init estimate_cpu_frequency(void)
{
unsigned int prid = read_c0_prid() & 0xffff00;
unsigned int count;
#if defined(CONFIG_MIPS_SEAD) || defined(CONFIG_MIPS_SIM)
/*
* The SEAD board doesn't have a real time clock, so we can't
* really calculate the timer frequency
* For now we hardwire the SEAD board frequency to 12MHz.
*/
if ((prid == (PRID_COMP_MIPS | PRID_IMP_20KC)) ||
(prid == (PRID_COMP_MIPS | PRID_IMP_25KF)))
count = 12000000;
else
count = 6000000;
#endif
#if defined(CONFIG_MIPS_ATLAS) || defined(CONFIG_MIPS_MALTA)
unsigned long flags;
unsigned int start;
local_irq_save(flags);
/* Start counter exactly on falling edge of update flag */
while (CMOS_READ(RTC_REG_A) & RTC_UIP);
while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
/* Start r4k counter. */
start = read_c0_count();
/* Read counter exactly on falling edge of update flag */
while (CMOS_READ(RTC_REG_A) & RTC_UIP);
while (!(CMOS_READ(RTC_REG_A) & RTC_UIP));
count = read_c0_count() - start;
/* restore interrupts */
local_irq_restore(flags);
#endif
mips_hpt_frequency = count;
if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
(prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
count *= 2;
count += 5000; /* round */
count -= count%10000;
return count;
}
unsigned long read_persistent_clock(void)
{
return mc146818_get_cmos_time();
}
void __init plat_perf_setup(void)
{
#ifdef MSC01E_INT_BASE
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch);
mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR;
} else
#endif
if (cp0_perfcount_irq >= 0) {
if (cpu_has_vint)
set_vi_handler(cp0_perfcount_irq, mips_perf_dispatch);
mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
#ifdef CONFIG_SMP
set_irq_handler(mips_cpu_perf_irq, handle_percpu_irq);
#endif
}
}
unsigned int __cpuinit get_c0_compare_int(void)
{
#ifdef MSC01E_INT_BASE
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch);
mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
} else
#endif
{
if (cpu_has_vint)
set_vi_handler(cp0_compare_irq, mips_timer_dispatch);
mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
}
return mips_cpu_timer_irq;
}
void __init plat_time_init(void)
{
unsigned int est_freq;
/* Set Data mode - binary. */
CMOS_WRITE(CMOS_READ(RTC_CONTROL) | RTC_DM_BINARY, RTC_CONTROL);
est_freq = estimate_cpu_frequency();
printk("CPU frequency %d.%02d MHz\n", est_freq/1000000,
(est_freq%1000000)*100/1000000);
cpu_khz = est_freq / 1000;
mips_scroll_message();
#ifdef CONFIG_I8253 /* Only Malta has a PIT */
setup_pit_timer();
#endif
plat_perf_setup();
}
|
