e4db9253d6
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>
140 lines
3.0 KiB
C
140 lines
3.0 KiB
C
/*
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* DS1287 clockevent driver
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*
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* Copyright (C) 2008 Yoichi Yuasa <yuasa@linux-mips.org>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <linux/clockchips.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/mc146818rtc.h>
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#include <linux/irq.h>
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#include <asm/time.h>
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int ds1287_timer_state(void)
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{
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return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
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}
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int ds1287_set_base_clock(unsigned int hz)
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{
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u8 rate;
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switch (hz) {
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case 128:
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rate = 0x9;
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break;
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case 256:
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rate = 0x8;
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break;
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case 1024:
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rate = 0x6;
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break;
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default:
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return -EINVAL;
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}
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CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
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return 0;
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}
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static int ds1287_set_next_event(unsigned long delta,
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struct clock_event_device *evt)
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{
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return -EINVAL;
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}
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static int ds1287_shutdown(struct clock_event_device *evt)
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{
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u8 val;
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spin_lock(&rtc_lock);
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val = CMOS_READ(RTC_REG_B);
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val &= ~RTC_PIE;
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CMOS_WRITE(val, RTC_REG_B);
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spin_unlock(&rtc_lock);
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return 0;
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}
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static int ds1287_set_periodic(struct clock_event_device *evt)
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{
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u8 val;
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spin_lock(&rtc_lock);
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val = CMOS_READ(RTC_REG_B);
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val |= RTC_PIE;
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CMOS_WRITE(val, RTC_REG_B);
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spin_unlock(&rtc_lock);
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return 0;
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}
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static void ds1287_event_handler(struct clock_event_device *dev)
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{
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}
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static struct clock_event_device ds1287_clockevent = {
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.name = "ds1287",
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.features = CLOCK_EVT_FEAT_PERIODIC,
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.set_next_event = ds1287_set_next_event,
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.set_state_shutdown = ds1287_shutdown,
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.set_state_periodic = ds1287_set_periodic,
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.tick_resume = ds1287_shutdown,
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.event_handler = ds1287_event_handler,
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};
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static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *cd = &ds1287_clockevent;
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/* Ack the RTC interrupt. */
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CMOS_READ(RTC_REG_C);
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cd->event_handler(cd);
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return IRQ_HANDLED;
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}
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static struct irqaction ds1287_irqaction = {
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.handler = ds1287_interrupt,
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.flags = IRQF_PERCPU | IRQF_TIMER,
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.name = "ds1287",
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};
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int __init ds1287_clockevent_init(int irq)
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{
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struct clock_event_device *cd;
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cd = &ds1287_clockevent;
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cd->rating = 100;
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cd->irq = irq;
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clockevent_set_clock(cd, 32768);
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cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
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cd->max_delta_ticks = 0x7fffffff;
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cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
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cd->min_delta_ticks = 0x300;
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cd->cpumask = cpumask_of(0);
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clockevents_register_device(&ds1287_clockevent);
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return setup_irq(irq, &ds1287_irqaction);
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}
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