tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
[MIPS] add DECstation I/O ASIC clocksource
Add DECstation I/O ASIC clocksource
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
authored by
Yoichi Yuasa
and committed by
Ralf Baechle
4247417d
05a96fae
+73
-1
+4
arch/mips/Kconfig
+4
arch/mips/Kconfig
···
82
82
bool "DECstations"
83
83
select BOOT_ELF32
84
84
select CEVT_R4K
85
+
select CSRC_IOASIC
85
86
select CSRC_R4K
86
87
select CPU_DADDI_WORKAROUNDS if 64BIT
87
88
select CPU_R4000_WORKAROUNDS if 64BIT
···
783
782
bool
784
783
785
784
config CSRC_BCM1480
785
+
bool
786
+
787
+
config CSRC_IOASIC
786
788
bool
787
789
788
790
config CSRC_R4K
+1
-1
arch/mips/dec/time.c
+1
-1
arch/mips/dec/time.c
···
165
165
166
166
if (!cpu_has_counter && IOASIC)
167
167
/* For pre-R4k systems we use the I/O ASIC's counter. */
168
-
clocksource_mips.read = dec_ioasic_hpt_read;
168
+
dec_ioasic_clocksource_init();
169
169
170
170
/* Set up the rate of periodic DS1287 interrupts. */
171
171
CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - __ffs(HZ)), RTC_REG_A);
+1
arch/mips/kernel/Makefile
+1
arch/mips/kernel/Makefile
···
14
14
obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
15
15
obj-$(CONFIG_CEVT_TXX9) += cevt-txx9.o
16
16
obj-$(CONFIG_CSRC_BCM1480) += csrc-bcm1480.o
17
+
obj-$(CONFIG_CSRC_IOASIC) += csrc-ioasic.o
17
18
obj-$(CONFIG_CSRC_R4K) += csrc-r4k.o
18
19
obj-$(CONFIG_CSRC_SB1250) += csrc-sb1250.o
19
20
obj-$(CONFIG_SYNC_R4K) += sync-r4k.o
+65
arch/mips/kernel/csrc-ioasic.c
+65
arch/mips/kernel/csrc-ioasic.c
···
1
+
/*
2
+
* DEC I/O ASIC's counter clocksource
3
+
*
4
+
* Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
5
+
*
6
+
* This program is free software; you can redistribute it and/or modify
7
+
* it under the terms of the GNU General Public License as published by
8
+
* the Free Software Foundation; either version 2 of the License, or
9
+
* (at your option) any later version.
10
+
*
11
+
* This program is distributed in the hope that it will be useful,
12
+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
13
+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14
+
* GNU General Public License for more details.
15
+
*
16
+
* You should have received a copy of the GNU General Public License
17
+
* along with this program; if not, write to the Free Software
18
+
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19
+
*/
20
+
#include <linux/clocksource.h>
21
+
#include <linux/init.h>
22
+
23
+
#include <asm/ds1287.h>
24
+
#include <asm/time.h>
25
+
#include <asm/dec/ioasic.h>
26
+
#include <asm/dec/ioasic_addrs.h>
27
+
28
+
static cycle_t dec_ioasic_hpt_read(void)
29
+
{
30
+
return ioasic_read(IO_REG_FCTR);
31
+
}
32
+
33
+
static struct clocksource clocksource_dec = {
34
+
.name = "dec-ioasic",
35
+
.read = dec_ioasic_hpt_read,
36
+
.mask = CLOCKSOURCE_MASK(32),
37
+
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
38
+
};
39
+
40
+
void __init dec_ioasic_clocksource_init(void)
41
+
{
42
+
unsigned int freq;
43
+
u32 start, end;
44
+
int i = HZ / 10;
45
+
46
+
47
+
while (!ds1287_timer_state())
48
+
;
49
+
50
+
start = dec_ioasic_hpt_read();
51
+
52
+
while (i--)
53
+
while (!ds1287_timer_state())
54
+
;
55
+
56
+
end = dec_ioasic_hpt_read();
57
+
58
+
freq = (end - start) * 10;
59
+
printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
60
+
61
+
clocksource_dec.rating = 200 + freq / 10000000;
62
+
clocksource_set_clock(&clocksource_dec, freq);
63
+
64
+
clocksource_register(&clocksource_dec);
65
+
}