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
|
/*
* 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/i8253.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/irqchip/mips-gic.h>
#include <linux/timex.h>
#include <linux/mc146818rtc.h>
#include <asm/cpu.h>
#include <asm/mipsregs.h>
#include <asm/mipsmtregs.h>
#include <asm/hardirq.h>
#include <asm/irq.h>
#include <asm/div64.h>
#include <asm/setup.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/maltaint.h>
static int mips_cpu_timer_irq;
static int mips_cpu_perf_irq;
extern int cp0_perfcount_irq;
static unsigned int gic_frequency;
static void mips_timer_dispatch(void)
{
do_IRQ(mips_cpu_timer_irq);
}
static void mips_perf_dispatch(void)
{
do_IRQ(mips_cpu_perf_irq);
}
static unsigned int freqround(unsigned int freq, unsigned int amount)
{
freq += amount;
freq -= freq % (amount*2);
return freq;
}
/*
* Estimate CPU and GIC frequencies.
*/
static void __init estimate_frequencies(void)
{
unsigned long flags;
unsigned int count, start;
cycle_t giccount = 0, gicstart = 0;
#if defined(CONFIG_KVM_GUEST) && CONFIG_KVM_GUEST_TIMER_FREQ
mips_hpt_frequency = CONFIG_KVM_GUEST_TIMER_FREQ * 1000000;
return;
#endif
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));
/* Initialize counters. */
start = read_c0_count();
if (gic_present)
gicstart = gic_read_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();
if (gic_present)
giccount = gic_read_count();
local_irq_restore(flags);
count -= start;
mips_hpt_frequency = count;
if (gic_present) {
giccount -= gicstart;
gic_frequency = giccount;
}
}
void read_persistent_clock(struct timespec *ts)
{
ts->tv_sec = mc146818_get_cmos_time();
ts->tv_nsec = 0;
}
int get_c0_perfcount_int(void)
{
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_PERFCTR, mips_perf_dispatch);
mips_cpu_perf_irq = MSC01E_INT_BASE + MSC01E_INT_PERFCTR;
} else if (gic_present) {
mips_cpu_perf_irq = gic_get_c0_perfcount_int();
} else if (cp0_perfcount_irq >= 0) {
mips_cpu_perf_irq = MIPS_CPU_IRQ_BASE + cp0_perfcount_irq;
} else {
mips_cpu_perf_irq = -1;
}
return mips_cpu_perf_irq;
}
unsigned int get_c0_compare_int(void)
{
if (cpu_has_veic) {
set_vi_handler(MSC01E_INT_CPUCTR, mips_timer_dispatch);
mips_cpu_timer_irq = MSC01E_INT_BASE + MSC01E_INT_CPUCTR;
} else if (gic_present) {
mips_cpu_timer_irq = gic_get_c0_compare_int();
} else {
mips_cpu_timer_irq = MIPS_CPU_IRQ_BASE + cp0_compare_irq;
}
return mips_cpu_timer_irq;
}
static void __init init_rtc(void)
{
/* stop the clock whilst setting it up */
CMOS_WRITE(RTC_SET | RTC_24H, RTC_CONTROL);
/* 32KHz time base */
CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_FREQ_SELECT);
/* start the clock */
CMOS_WRITE(RTC_24H, RTC_CONTROL);
}
void __init plat_time_init(void)
{
unsigned int prid = read_c0_prid() & (PRID_COMP_MASK | PRID_IMP_MASK);
unsigned int freq;
init_rtc();
estimate_frequencies();
freq = mips_hpt_frequency;
if ((prid != (PRID_COMP_MIPS | PRID_IMP_20KC)) &&
(prid != (PRID_COMP_MIPS | PRID_IMP_25KF)))
freq *= 2;
freq = freqround(freq, 5000);
printk("CPU frequency %d.%02d MHz\n", freq/1000000,
(freq%1000000)*100/1000000);
mips_scroll_message();
#ifdef CONFIG_I8253
/* Only Malta has a PIT. */
setup_pit_timer();
#endif
#ifdef CONFIG_MIPS_GIC
if (gic_present) {
freq = freqround(gic_frequency, 5000);
printk("GIC frequency %d.%02d MHz\n", freq/1000000,
(freq%1000000)*100/1000000);
#ifdef CONFIG_CLKSRC_MIPS_GIC
gic_clocksource_init(gic_frequency);
#endif
}
#endif
}
|
