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-rw-r--r--arch/arm/mach-w90x900/time.c176
1 files changed, 176 insertions, 0 deletions
diff --git a/arch/arm/mach-w90x900/time.c b/arch/arm/mach-w90x900/time.c
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+++ b/arch/arm/mach-w90x900/time.c
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+/*
+ * linux/arch/arm/mach-w90x900/time.c
+ *
+ * Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks
+ *
+ * Copyright (c) 2009 Nuvoton technology corporation
+ * All rights reserved.
+ *
+ * Wan ZongShun <mcuos.com@gmail.com>
+ *
+ * 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/kernel.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/leds.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+
+#include <asm/mach-types.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+
+#include <mach/map.h>
+#include <mach/regs-timer.h>
+
+#define RESETINT 0x1f
+#define PERIOD (0x01 << 27)
+#define ONESHOT (0x00 << 27)
+#define COUNTEN (0x01 << 30)
+#define INTEN (0x01 << 29)
+
+#define TICKS_PER_SEC 100
+#define PRESCALE 0x63 /* Divider = prescale + 1 */
+
+#define TDR_SHIFT 24
+
+static unsigned int timer0_load;
+
+static void nuc900_clockevent_setmode(enum clock_event_mode mode,
+ struct clock_event_device *clk)
+{
+ unsigned int val;
+
+ val = __raw_readl(REG_TCSR0);
+ val &= ~(0x03 << 27);
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_PERIODIC:
+ __raw_writel(timer0_load, REG_TICR0);
+ val |= (PERIOD | COUNTEN | INTEN | PRESCALE);
+ break;
+
+ case CLOCK_EVT_MODE_ONESHOT:
+ val |= (ONESHOT | COUNTEN | INTEN | PRESCALE);
+ break;
+
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ }
+
+ __raw_writel(val, REG_TCSR0);
+}
+
+static int nuc900_clockevent_setnextevent(unsigned long evt,
+ struct clock_event_device *clk)
+{
+ unsigned int val;
+
+ __raw_writel(evt, REG_TICR0);
+
+ val = __raw_readl(REG_TCSR0);
+ val |= (COUNTEN | INTEN | PRESCALE);
+ __raw_writel(val, REG_TCSR0);
+
+ return 0;
+}
+
+static struct clock_event_device nuc900_clockevent_device = {
+ .name = "nuc900-timer0",
+ .shift = 32,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_mode = nuc900_clockevent_setmode,
+ .set_next_event = nuc900_clockevent_setnextevent,
+ .rating = 300,
+};
+
+/*IRQ handler for the timer*/
+
+static irqreturn_t nuc900_timer0_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &nuc900_clockevent_device;
+
+ __raw_writel(0x01, REG_TISR); /* clear TIF0 */
+
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction nuc900_timer0_irq = {
+ .name = "nuc900-timer0",
+ .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
+ .handler = nuc900_timer0_interrupt,
+};
+
+static void __init nuc900_clockevents_init(void)
+{
+ unsigned int rate;
+ struct clk *clk = clk_get(NULL, "timer0");
+
+ BUG_ON(IS_ERR(clk));
+
+ __raw_writel(0x00, REG_TCSR0);
+
+ clk_enable(clk);
+ rate = clk_get_rate(clk) / (PRESCALE + 1);
+
+ timer0_load = (rate / TICKS_PER_SEC);
+
+ __raw_writel(RESETINT, REG_TISR);
+ setup_irq(IRQ_TIMER0, &nuc900_timer0_irq);
+
+ nuc900_clockevent_device.mult = div_sc(rate, NSEC_PER_SEC,
+ nuc900_clockevent_device.shift);
+ nuc900_clockevent_device.max_delta_ns = clockevent_delta2ns(0xffffffff,
+ &nuc900_clockevent_device);
+ nuc900_clockevent_device.min_delta_ns = clockevent_delta2ns(0xf,
+ &nuc900_clockevent_device);
+ nuc900_clockevent_device.cpumask = cpumask_of(0);
+
+ clockevents_register_device(&nuc900_clockevent_device);
+}
+
+static void __init nuc900_clocksource_init(void)
+{
+ unsigned int val;
+ unsigned int rate;
+ struct clk *clk = clk_get(NULL, "timer1");
+
+ BUG_ON(IS_ERR(clk));
+
+ __raw_writel(0x00, REG_TCSR1);
+
+ clk_enable(clk);
+ rate = clk_get_rate(clk) / (PRESCALE + 1);
+
+ __raw_writel(0xffffffff, REG_TICR1);
+
+ val = __raw_readl(REG_TCSR1);
+ val |= (COUNTEN | PERIOD | PRESCALE);
+ __raw_writel(val, REG_TCSR1);
+
+ clocksource_mmio_init(REG_TDR1, "nuc900-timer1", rate, 200,
+ TDR_SHIFT, clocksource_mmio_readl_down);
+}
+
+static void __init nuc900_timer_init(void)
+{
+ nuc900_clocksource_init();
+ nuc900_clockevents_init();
+}
+
+struct sys_timer nuc900_timer = {
+ .init = nuc900_timer_init,
+};