1 files changed, 121 insertions, 0 deletions
diff --git a/arch/mips/kernel/cevt-ds1287.c b/arch/mips/kernel/cevt-ds1287.c
new file mode 100644
index 000000000..9a47fbcd4
--- /dev/null
+++ b/arch/mips/kernel/cevt-ds1287.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  DS1287 clockevent driver
+ *
+ *  Copyright (C) 2008	Yoichi Yuasa <yuasa@linux-mips.org>
+ */
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/mc146818rtc.h>
+#include <linux/irq.h>
+
+#include <asm/time.h>
+
+int ds1287_timer_state(void)
+{
+	return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
+}
+
+int ds1287_set_base_clock(unsigned int hz)
+{
+	u8 rate;
+
+	switch (hz) {
+	case 128:
+		rate = 0x9;
+		break;
+	case 256:
+		rate = 0x8;
+		break;
+	case 1024:
+		rate = 0x6;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	CMOS_WRITE(RTC_REF_CLCK_32KHZ | rate, RTC_REG_A);
+
+	return 0;
+}
+
+static int ds1287_set_next_event(unsigned long delta,
+				 struct clock_event_device *evt)
+{
+	return -EINVAL;
+}
+
+static int ds1287_shutdown(struct clock_event_device *evt)
+{
+	u8 val;
+
+	spin_lock(&rtc_lock);
+
+	val = CMOS_READ(RTC_REG_B);
+	val &= ~RTC_PIE;
+	CMOS_WRITE(val, RTC_REG_B);
+
+	spin_unlock(&rtc_lock);
+	return 0;
+}
+
+static int ds1287_set_periodic(struct clock_event_device *evt)
+{
+	u8 val;
+
+	spin_lock(&rtc_lock);
+
+	val = CMOS_READ(RTC_REG_B);
+	val |= RTC_PIE;
+	CMOS_WRITE(val, RTC_REG_B);
+
+	spin_unlock(&rtc_lock);
+	return 0;
+}
+
+static void ds1287_event_handler(struct clock_event_device *dev)
+{
+}
+
+static struct clock_event_device ds1287_clockevent = {
+	.name			= "ds1287",
+	.features		= CLOCK_EVT_FEAT_PERIODIC,
+	.set_next_event		= ds1287_set_next_event,
+	.set_state_shutdown	= ds1287_shutdown,
+	.set_state_periodic	= ds1287_set_periodic,
+	.tick_resume		= ds1287_shutdown,
+	.event_handler		= ds1287_event_handler,
+};
+
+static irqreturn_t ds1287_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *cd = &ds1287_clockevent;
+
+	/* Ack the RTC interrupt. */
+	CMOS_READ(RTC_REG_C);
+
+	cd->event_handler(cd);
+
+	return IRQ_HANDLED;
+}
+
+int __init ds1287_clockevent_init(int irq)
+{
+	unsigned long flags = IRQF_PERCPU | IRQF_TIMER;
+	struct clock_event_device *cd;
+
+	cd = &ds1287_clockevent;
+	cd->rating = 100;
+	cd->irq = irq;
+	clockevent_set_clock(cd, 32768);
+	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(&ds1287_clockevent);
+
+	return request_irq(irq, ds1287_interrupt, flags, "ds1287", NULL);
+}