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linux-next/arch/mips/kernel/csrc-bcm1480.c
Deng-Cheng Zhu 27acdea8fe MIPS: csrc-bcm1480: Implement read_sched_clock
Use the ZBbus cycle counter for sched_clock source. This implementation
will give high resolution cputime accounting.

Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: macro@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9480/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-04-01 17:21:27 +02:00

58 lines
1.6 KiB
C

/*
* Copyright (C) 2000,2001,2004 Broadcom Corporation
*
* 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.
*/
#include <linux/clocksource.h>
#include <linux/sched_clock.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/time.h>
#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_scd.h>
#include <asm/sibyte/sb1250.h>
static cycle_t bcm1480_hpt_read(struct clocksource *cs)
{
return (cycle_t) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
}
struct clocksource bcm1480_clocksource = {
.name = "zbbus-cycles",
.rating = 200,
.read = bcm1480_hpt_read,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static u64 notrace sb1480_read_sched_clock(void)
{
return __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
}
void __init sb1480_clocksource_init(void)
{
struct clocksource *cs = &bcm1480_clocksource;
unsigned int plldiv;
unsigned long zbbus;
plldiv = G_BCM1480_SYS_PLL_DIV(__raw_readq(IOADDR(A_SCD_SYSTEM_CFG)));
zbbus = ((plldiv >> 1) * 50000000) + ((plldiv & 1) * 25000000);
clocksource_register_hz(cs, zbbus);
sched_clock_register(sb1480_read_sched_clock, 64, zbbus);
}