alistair23-linux/arch/arm/mach-shmobile/timer.c
Magnus Damm 0f2c9f20e4 ARM: mach-shmobile: Introduce shmobile_setup_delay()
Add the function shmobile_setup_delay() to let platforms
configure their maximum loops per jiffy delay. With this
jiffies calculation done the dependency on early timer
is removed.

In the future this allows us to assign timers
using the regular driver model via the device tree.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-04-11 12:11:48 +02:00

78 lines
2.3 KiB
C

/*
* SH-Mobile Timer
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2002 - 2009 Paul Mundt
*
* 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; version 2 of the License.
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <asm/mach/time.h>
#include <asm/smp_twd.h>
void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
unsigned int mult, unsigned int div)
{
/* calculate a worst-case loops-per-jiffy value
* based on maximum cpu core mhz setting and the
* __delay() implementation in arch/arm/lib/delay.S
*
* this will result in a longer delay than expected
* when the cpu core runs on lower frequencies.
*/
unsigned int value = (1000000 * mult) / (HZ * div);
lpj_fine = max_cpu_core_mhz * value;
}
static void __init shmobile_late_time_init(void)
{
/*
* Make sure all compiled-in early timers register themselves.
*
* Run probe() for two "earlytimer" devices, these will be the
* clockevents and clocksource devices respectively. In the event
* that only a clockevents device is available, we -ENODEV on the
* clocksource and the jiffies clocksource is used transparently
* instead. No error handling is necessary here.
*/
early_platform_driver_register_all("earlytimer");
early_platform_driver_probe("earlytimer", 2, 0);
}
void __init shmobile_earlytimer_init(void)
{
late_time_init = shmobile_late_time_init;
}
static void __init shmobile_timer_init(void)
{
}
void __init shmobile_twd_init(struct twd_local_timer *twd_local_timer)
{
#ifdef CONFIG_HAVE_ARM_TWD
int err = twd_local_timer_register(twd_local_timer);
if (err)
pr_err("twd_local_timer_register failed %d\n", err);
#endif
}
struct sys_timer shmobile_timer = {
.init = shmobile_timer_init,
};