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121 lines
2.3 KiB
121 lines
2.3 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* DS1287 clockevent driver |
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* |
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* Copyright (C) 2008 Yoichi Yuasa <[email protected]> |
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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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int __init ds1287_clockevent_init(int irq) |
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{ |
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unsigned long flags = IRQF_PERCPU | IRQF_TIMER; |
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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 request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL); |
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}
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