[linux.git] / arch / mips / kernel / csrc-ioasic.c

/*
 *  DEC I/O ASIC's counter clocksource
 *
 *  Copyright (C) 2008	Yoichi Yuasa <[email protected]>
 *
 *  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(struct clocksource *cs)
{
	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(&clocksource_dec);

	while (i--)
		while (!ds1287_timer_state())
			;

	end = dec_ioasic_hpt_read(&clocksource_dec);

	freq = (end - start) * 10;
	printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);

	clocksource_dec.rating = 200 + freq / 10000000;
	clocksource_register_hz(&clocksource_dec, freq);
}
Commit	Line	Data
4247417d YY	1	/*
	2	* DEC I/O ASIC's counter clocksource
	3	*
70342287	4	* Copyright (C) 2008 Yoichi Yuasa <[email protected]>
4247417d YY	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
8e19608e	28	static cycle_t dec_ioasic_hpt_read(struct clocksource *cs)
4247417d YY	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
8e19608e	50	start = dec_ioasic_hpt_read(&clocksource_dec);
4247417d YY	51
	52	while (i--)
	53	while (!ds1287_timer_state())
	54	;
	55
8e19608e	56	end = dec_ioasic_hpt_read(&clocksource_dec);
4247417d YY	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;
75c4fd8c	62	clocksource_register_hz(&clocksource_dec, freq);
4247417d	63	}