[deliverable/linux.git] / arch / mips / bcm47xx / time.c

/*
 *  Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
 *
 *  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  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  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.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */


#include <linux/init.h>
#include <linux/ssb/ssb.h>
#include <asm/time.h>
#include <bcm47xx.h>

void __init plat_time_init(void)
{
	unsigned long hz;

	/*
	 * Use deterministic values for initial counter interrupt
	 * so that calibrate delay avoids encountering a counter wrap.
	 */
	write_c0_count(0);
	write_c0_compare(0xffff);

	hz = ssb_cpu_clock(&ssb_bcm47xx.mipscore) / 2;
	if (!hz)
		hz = 100000000;

	/* Set MIPS counter frequency for fixed_rate_gettimeoffset() */
	mips_hpt_frequency = hz;
}
Commit	Line	Data
1c0c13eb AJ	1	/*
	2	* Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the
	6	* Free Software Foundation; either version 2 of the License, or (at your
	7	* option) any later version.
	8	*
	9	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	10	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	11	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
	12	* NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
	13	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
	14	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
	15	* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
	16	* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	17	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	18	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	19	*
	20	* You should have received a copy of the GNU General Public License along
	21	* with this program; if not, write to the Free Software Foundation, Inc.,
	22	* 675 Mass Ave, Cambridge, MA 02139, USA.
	23	*/
	24
	25
	26	#include <linux/init.h>
	27	#include <linux/ssb/ssb.h>
	28	#include <asm/time.h>
	29	#include <bcm47xx.h>
	30
4b550488	31	void __init plat_time_init(void)
1c0c13eb AJ	32	{
	33	unsigned long hz;
	34
	35	/*
	36	* Use deterministic values for initial counter interrupt
	37	* so that calibrate delay avoids encountering a counter wrap.
	38	*/
	39	write_c0_count(0);
	40	write_c0_compare(0xffff);
	41
	42	hz = ssb_cpu_clock(&ssb_bcm47xx.mipscore) / 2;
	43	if (!hz)
	44	hz = 100000000;
	45
	46	/* Set MIPS counter frequency for fixed_rate_gettimeoffset() */
	47	mips_hpt_frequency = hz;
	48	}