remarkable-linux/arch/mips/kernel/cevt-gt641xx.c
Nicolai Stange e4db9253d6 MIPS: clockevent drivers: Set ->min_delta_ticks and ->max_delta_ticks
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.

Make the MIPS arch's clockevent drivers initialize these fields properly.

This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from these
drivers.

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Keguang Zhang <keguang.zhang@gmail.com>
Cc: John Crispin <john@phrozen.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2017-04-14 13:11:16 -07:00

165 lines
4.2 KiB
C

/*
* GT641xx clockevent routines.
*
* Copyright (C) 2007 Yoichi Yuasa <yuasa@linux-mips.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 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/clockchips.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/irq.h>
#include <asm/gt64120.h>
#include <asm/time.h>
static DEFINE_RAW_SPINLOCK(gt641xx_timer_lock);
static unsigned int gt641xx_base_clock;
void gt641xx_set_base_clock(unsigned int clock)
{
gt641xx_base_clock = clock;
}
int gt641xx_timer0_state(void)
{
if (GT_READ(GT_TC0_OFS))
return 0;
GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
GT_WRITE(GT_TC_CONTROL_OFS, GT_TC_CONTROL_ENTC0_MSK);
return 1;
}
static int gt641xx_timer0_set_next_event(unsigned long delta,
struct clock_event_device *evt)
{
u32 ctrl;
raw_spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
ctrl |= GT_TC_CONTROL_ENTC0_MSK;
GT_WRITE(GT_TC0_OFS, delta);
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
raw_spin_unlock(&gt641xx_timer_lock);
return 0;
}
static int gt641xx_timer0_shutdown(struct clock_event_device *evt)
{
u32 ctrl;
raw_spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl &= ~(GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK);
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
raw_spin_unlock(&gt641xx_timer_lock);
return 0;
}
static int gt641xx_timer0_set_oneshot(struct clock_event_device *evt)
{
u32 ctrl;
raw_spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl &= ~GT_TC_CONTROL_SELTC0_MSK;
ctrl |= GT_TC_CONTROL_ENTC0_MSK;
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
raw_spin_unlock(&gt641xx_timer_lock);
return 0;
}
static int gt641xx_timer0_set_periodic(struct clock_event_device *evt)
{
u32 ctrl;
raw_spin_lock(&gt641xx_timer_lock);
ctrl = GT_READ(GT_TC_CONTROL_OFS);
ctrl |= GT_TC_CONTROL_ENTC0_MSK | GT_TC_CONTROL_SELTC0_MSK;
GT_WRITE(GT_TC_CONTROL_OFS, ctrl);
raw_spin_unlock(&gt641xx_timer_lock);
return 0;
}
static void gt641xx_timer0_event_handler(struct clock_event_device *dev)
{
}
static struct clock_event_device gt641xx_timer0_clockevent = {
.name = "gt641xx-timer0",
.features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT,
.irq = GT641XX_TIMER0_IRQ,
.set_next_event = gt641xx_timer0_set_next_event,
.set_state_shutdown = gt641xx_timer0_shutdown,
.set_state_periodic = gt641xx_timer0_set_periodic,
.set_state_oneshot = gt641xx_timer0_set_oneshot,
.tick_resume = gt641xx_timer0_shutdown,
.event_handler = gt641xx_timer0_event_handler,
};
static irqreturn_t gt641xx_timer0_interrupt(int irq, void *dev_id)
{
struct clock_event_device *cd = &gt641xx_timer0_clockevent;
cd->event_handler(cd);
return IRQ_HANDLED;
}
static struct irqaction gt641xx_timer0_irqaction = {
.handler = gt641xx_timer0_interrupt,
.flags = IRQF_PERCPU | IRQF_TIMER,
.name = "gt641xx_timer0",
};
static int __init gt641xx_timer0_clockevent_init(void)
{
struct clock_event_device *cd;
if (!gt641xx_base_clock)
return 0;
GT_WRITE(GT_TC0_OFS, gt641xx_base_clock / HZ);
cd = &gt641xx_timer0_clockevent;
cd->rating = 200 + gt641xx_base_clock / 10000000;
clockevent_set_clock(cd, gt641xx_base_clock);
cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
cd->max_delta_ticks = 0x7fffffff;
cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
cd->min_delta_ticks = 0x300;
cd->cpumask = cpumask_of(0);
clockevents_register_device(&gt641xx_timer0_clockevent);
return setup_irq(GT641XX_TIMER0_IRQ, &gt641xx_timer0_irqaction);
}
arch_initcall(gt641xx_timer0_clockevent_init);