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Diffstat (limited to 'arch/mips/pnx8550/common/time.c')
-rw-r--r--arch/mips/pnx8550/common/time.c151
1 files changed, 151 insertions, 0 deletions
diff --git a/arch/mips/pnx8550/common/time.c b/arch/mips/pnx8550/common/time.c
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+++ b/arch/mips/pnx8550/common/time.c
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+/*
+ * Copyright 2001, 2002, 2003 MontaVista Software Inc.
+ * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
+ * Copyright (C) 2007 Ralf Baechle (ralf@linux-mips.org)
+ *
+ * Common time service routines for MIPS machines. See
+ * Documents/MIPS/README.txt.
+ *
+ * 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.
+ */
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/param.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+#include <linux/smp.h>
+#include <linux/kernel_stat.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/time.h>
+#include <asm/hardirq.h>
+#include <asm/div64.h>
+#include <asm/debug.h>
+
+#include <int.h>
+#include <cm.h>
+
+static unsigned long cpj;
+
+static cycle_t hpt_read(struct clocksource *cs)
+{
+ return read_c0_count2();
+}
+
+static struct clocksource pnx_clocksource = {
+ .name = "pnx8xxx",
+ .rating = 200,
+ .read = hpt_read,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static irqreturn_t pnx8xxx_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *c = dev_id;
+
+ /* clear MATCH, signal the event */
+ c->event_handler(c);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction pnx8xxx_timer_irq = {
+ .handler = pnx8xxx_timer_interrupt,
+ .flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER,
+ .name = "pnx8xxx_timer",
+};
+
+static irqreturn_t monotonic_interrupt(int irq, void *dev_id)
+{
+ /* Timer 2 clear interrupt */
+ write_c0_compare2(-1);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction monotonic_irqaction = {
+ .handler = monotonic_interrupt,
+ .flags = IRQF_DISABLED | IRQF_TIMER,
+ .name = "Monotonic timer",
+};
+
+static int pnx8xxx_set_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ write_c0_compare(delta);
+ return 0;
+}
+
+static struct clock_event_device pnx8xxx_clockevent = {
+ .name = "pnx8xxx_clockevent",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = pnx8xxx_set_next_event,
+};
+
+static inline void timer_ack(void)
+{
+ write_c0_compare(cpj);
+}
+
+__init void plat_time_init(void)
+{
+ unsigned int configPR;
+ unsigned int n;
+ unsigned int m;
+ unsigned int p;
+ unsigned int pow2p;
+
+ pnx8xxx_clockevent.cpumask = cpu_none_mask;
+ clockevents_register_device(&pnx8xxx_clockevent);
+ clocksource_register(&pnx_clocksource);
+
+ /* Timer 1 start */
+ configPR = read_c0_config7();
+ configPR &= ~0x00000008;
+ write_c0_config7(configPR);
+
+ /* Timer 2 start */
+ configPR = read_c0_config7();
+ configPR &= ~0x00000010;
+ write_c0_config7(configPR);
+
+ /* Timer 3 stop */
+ configPR = read_c0_config7();
+ configPR |= 0x00000020;
+ write_c0_config7(configPR);
+
+
+ /* PLL0 sets MIPS clock (PLL1 <=> TM1, PLL6 <=> TM2, PLL5 <=> mem) */
+ /* (but only if CLK_MIPS_CTL select value [bits 3:1] is 1: FIXME) */
+
+ n = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_N_MASK) >> 16;
+ m = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_M_MASK) >> 8;
+ p = (PNX8550_CM_PLL0_CTL & PNX8550_CM_PLL_P_MASK) >> 2;
+ pow2p = (1 << p);
+
+ db_assert(m != 0 && pow2p != 0);
+
+ /*
+ * Compute the frequency as in the PNX8550 User Manual 1.0, p.186
+ * (a.k.a. 8-10). Divide by HZ for a timer offset that results in
+ * HZ timer interrupts per second.
+ */
+ mips_hpt_frequency = 27UL * ((1000000UL * n)/(m * pow2p));
+ cpj = DIV_ROUND_CLOSEST(mips_hpt_frequency, HZ);
+ write_c0_count(0);
+ timer_ack();
+
+ /* Setup Timer 2 */
+ write_c0_count2(0);
+ write_c0_compare2(0xffffffff);
+
+ setup_irq(PNX8550_INT_TIMER1, &pnx8xxx_timer_irq);
+ setup_irq(PNX8550_INT_TIMER2, &monotonic_irqaction);
+}