[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>
This commit is contained in:
Yoichi Yuasa 2008-04-24 09:48:40 +09:00 committed by Ralf Baechle
parent 05a96fae43
commit 4247417d84
5 changed files with 73 additions and 1 deletions

View File

@ -82,6 +82,7 @@ config MACH_DECSTATION
bool "DECstations"
select BOOT_ELF32
select CEVT_R4K
select CSRC_IOASIC
select CSRC_R4K
select CPU_DADDI_WORKAROUNDS if 64BIT
select CPU_R4000_WORKAROUNDS if 64BIT
@ -784,6 +785,9 @@ config CEVT_TXX9
config CSRC_BCM1480
bool
config CSRC_IOASIC
bool
config CSRC_R4K
bool

View File

@ -165,7 +165,7 @@ void __init plat_time_init(void)
if (!cpu_has_counter && IOASIC)
/* For pre-R4k systems we use the I/O ASIC's counter. */
clocksource_mips.read = dec_ioasic_hpt_read;
dec_ioasic_clocksource_init();
/* Set up the rate of periodic DS1287 interrupts. */
CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - __ffs(HZ)), RTC_REG_A);

View File

@ -14,6 +14,7 @@ obj-$(CONFIG_CEVT_GT641XX) += cevt-gt641xx.o
obj-$(CONFIG_CEVT_SB1250) += cevt-sb1250.o
obj-$(CONFIG_CEVT_TXX9) += cevt-txx9.o
obj-$(CONFIG_CSRC_BCM1480) += csrc-bcm1480.o
obj-$(CONFIG_CSRC_IOASIC) += csrc-ioasic.o
obj-$(CONFIG_CSRC_R4K) += csrc-r4k.o
obj-$(CONFIG_CSRC_SB1250) += csrc-sb1250.o
obj-$(CONFIG_SYNC_R4K) += sync-r4k.o

View File

@ -0,0 +1,65 @@
/*
* DEC I/O ASIC's counter clocksource
*
* Copyright (C) 2008 Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <linux/clocksource.h>
#include <linux/init.h>
#include <asm/ds1287.h>
#include <asm/time.h>
#include <asm/dec/ioasic.h>
#include <asm/dec/ioasic_addrs.h>
static cycle_t dec_ioasic_hpt_read(void)
{
return ioasic_read(IO_REG_FCTR);
}
static struct clocksource clocksource_dec = {
.name = "dec-ioasic",
.read = dec_ioasic_hpt_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
void __init dec_ioasic_clocksource_init(void)
{
unsigned int freq;
u32 start, end;
int i = HZ / 10;
while (!ds1287_timer_state())
;
start = dec_ioasic_hpt_read();
while (i--)
while (!ds1287_timer_state())
;
end = dec_ioasic_hpt_read();
freq = (end - start) * 10;
printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);
clocksource_dec.rating = 200 + freq / 10000000;
clocksource_set_clock(&clocksource_dec, freq);
clocksource_register(&clocksource_dec);
}

View File

@ -33,4 +33,6 @@ static inline u32 ioasic_read(unsigned int reg)
extern void init_ioasic_irqs(int base);
extern void dec_ioasic_clocksource_init(void);
#endif /* __ASM_DEC_IOASIC_H */