Initial import

1 files changed, 170 insertions, 0 deletions

diff --git a/arch/arm/mach-gemini/time.c b/arch/arm/mach-gemini/time.c
new file mode 100644
index 000000000..0a63c4d25
--- /dev/null
+++ b/arch/arm/mach-gemini/time.c
@@ -0,0 +1,170 @@
+/*
+ *  Copyright (C) 2001-2006 Storlink, Corp.
+ *  Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
+ *
+ * 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/interrupt.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+#include <mach/hardware.h>
+#include <mach/global_reg.h>
+#include <asm/mach/time.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+
+/*
+ * Register definitions for the timers
+ */
+#define TIMER_COUNT(BASE_ADDR)		(BASE_ADDR  + 0x00)
+#define TIMER_LOAD(BASE_ADDR)		(BASE_ADDR  + 0x04)
+#define TIMER_MATCH1(BASE_ADDR)		(BASE_ADDR  + 0x08)
+#define TIMER_MATCH2(BASE_ADDR)		(BASE_ADDR  + 0x0C)
+#define TIMER_CR(BASE_ADDR)		(BASE_ADDR  + 0x30)
+
+#define TIMER_1_CR_ENABLE		(1 << 0)
+#define TIMER_1_CR_CLOCK		(1 << 1)
+#define TIMER_1_CR_INT			(1 << 2)
+#define TIMER_2_CR_ENABLE		(1 << 3)
+#define TIMER_2_CR_CLOCK		(1 << 4)
+#define TIMER_2_CR_INT			(1 << 5)
+#define TIMER_3_CR_ENABLE		(1 << 6)
+#define TIMER_3_CR_CLOCK		(1 << 7)
+#define TIMER_3_CR_INT			(1 << 8)
+
+static unsigned int tick_rate;
+
+static int gemini_timer_set_next_event(unsigned long cycles,
+				       struct clock_event_device *evt)
+{
+	u32 cr;
+
+	cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+
+	/* This may be overdoing it, feel free to test without this */
+	cr &= ~TIMER_2_CR_ENABLE;
+	cr &= ~TIMER_2_CR_INT;
+	writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+
+	/* Set next event */
+	writel(cycles, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
+	writel(cycles, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
+	cr |= TIMER_2_CR_ENABLE;
+	cr |= TIMER_2_CR_INT;
+	writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+
+	return 0;
+}
+
+static void gemini_timer_set_mode(enum clock_event_mode mode,
+				  struct clock_event_device *evt)
+{
+	u32 period = DIV_ROUND_CLOSEST(tick_rate, HZ);
+	u32 cr;
+
+	switch (mode) {
+        case CLOCK_EVT_MODE_PERIODIC:
+		/* Start the timer */
+		writel(period,
+		       TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER2_BASE)));
+		writel(period,
+		       TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER2_BASE)));
+		cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+		cr |= TIMER_2_CR_ENABLE;
+		cr |= TIMER_2_CR_INT;
+		writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_UNUSED:
+        case CLOCK_EVT_MODE_SHUTDOWN:
+	case CLOCK_EVT_MODE_RESUME:
+		/*
+		 * Disable also for oneshot: the set_next() call will
+		 * arm the timer instead.
+		 */
+		cr = readl(TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+		cr &= ~TIMER_2_CR_ENABLE;
+		cr &= ~TIMER_2_CR_INT;
+		writel(cr, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+		break;
+	default:
+                break;
+	}
+}
+
+/* Use TIMER2 as clock event */
+static struct clock_event_device gemini_clockevent = {
+	.name		= "TIMER2",
+	.rating		= 300, /* Reasonably fast and accurate clock event */
+	.features	= CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.set_next_event	= gemini_timer_set_next_event,
+	.set_mode	= gemini_timer_set_mode,
+};
+
+/*
+ * IRQ handler for the timer
+ */
+static irqreturn_t gemini_timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &gemini_clockevent;
+
+	evt->event_handler(evt);
+	return IRQ_HANDLED;
+}
+
+static struct irqaction gemini_timer_irq = {
+	.name		= "Gemini Timer Tick",
+	.flags		= IRQF_TIMER,
+	.handler	= gemini_timer_interrupt,
+};
+
+/*
+ * Set up timer interrupt, and return the current time in seconds.
+ */
+void __init gemini_timer_init(void)
+{
+	u32 reg_v;
+
+	reg_v = readl(IO_ADDRESS(GEMINI_GLOBAL_BASE + GLOBAL_STATUS));
+	tick_rate = REG_TO_AHB_SPEED(reg_v) * 1000000;
+
+	printk(KERN_INFO "Bus: %dMHz", tick_rate / 1000000);
+
+	tick_rate /= 6;		/* APB bus run AHB*(1/6) */
+
+	switch(reg_v & CPU_AHB_RATIO_MASK) {
+	case CPU_AHB_1_1:
+		printk(KERN_CONT "(1/1)\n");
+		break;
+	case CPU_AHB_3_2:
+		printk(KERN_CONT "(3/2)\n");
+		break;
+	case CPU_AHB_24_13:
+		printk(KERN_CONT "(24/13)\n");
+		break;
+	case CPU_AHB_2_1:
+		printk(KERN_CONT "(2/1)\n");
+		break;
+	}
+
+	/*
+	 * Make irqs happen for the system timer
+	 */
+	setup_irq(IRQ_TIMER2, &gemini_timer_irq);
+
+	/* Enable and use TIMER1 as clock source */
+	writel(0xffffffff, TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE)));
+	writel(0xffffffff, TIMER_LOAD(IO_ADDRESS(GEMINI_TIMER1_BASE)));
+	writel(TIMER_1_CR_ENABLE, TIMER_CR(IO_ADDRESS(GEMINI_TIMER_BASE)));
+	if (clocksource_mmio_init(TIMER_COUNT(IO_ADDRESS(GEMINI_TIMER1_BASE)),
+				  "TIMER1", tick_rate, 300, 32,
+				  clocksource_mmio_readl_up))
+		pr_err("timer: failed to initialize gemini clock source\n");
+
+	/* Configure and register the clockevent */
+	clockevents_config_and_register(&gemini_clockevent, tick_rate,
+					1, 0xffffffff);
+}