initial_commit

1 files changed, 474 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
new file mode 100644
index 00000000..e1969ce9
--- /dev/null
+++ b/arch/arm/mach-davinci/time.c
@@ -0,0 +1,474 @@
+/*
+ * DaVinci timer subsystem
+ *
+ * Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
+ *
+ * 2007 (c) MontaVista Software, Inc. This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+
+#include <mach/hardware.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+#include <mach/cputype.h>
+#include <mach/time.h>
+#include "clock.h"
+
+static struct clock_event_device clockevent_davinci;
+static unsigned int davinci_clock_tick_rate;
+
+/*
+ * This driver configures the 2 64-bit count-up timers as 4 independent
+ * 32-bit count-up timers used as follows:
+ */
+
+enum {
+	TID_CLOCKEVENT,
+	TID_CLOCKSOURCE,
+};
+
+/* Timer register offsets */
+#define PID12			0x0
+#define TIM12			0x10
+#define TIM34			0x14
+#define PRD12			0x18
+#define PRD34			0x1c
+#define TCR			0x20
+#define TGCR			0x24
+#define WDTCR			0x28
+
+/* Offsets of the 8 compare registers */
+#define	CMP12_0			0x60
+#define	CMP12_1			0x64
+#define	CMP12_2			0x68
+#define	CMP12_3			0x6c
+#define	CMP12_4			0x70
+#define	CMP12_5			0x74
+#define	CMP12_6			0x78
+#define	CMP12_7			0x7c
+
+/* Timer register bitfields */
+#define TCR_ENAMODE_DISABLE          0x0
+#define TCR_ENAMODE_ONESHOT          0x1
+#define TCR_ENAMODE_PERIODIC         0x2
+#define TCR_ENAMODE_MASK             0x3
+
+#define TGCR_TIMMODE_SHIFT           2
+#define TGCR_TIMMODE_64BIT_GP        0x0
+#define TGCR_TIMMODE_32BIT_UNCHAINED 0x1
+#define TGCR_TIMMODE_64BIT_WDOG      0x2
+#define TGCR_TIMMODE_32BIT_CHAINED   0x3
+
+#define TGCR_TIM12RS_SHIFT           0
+#define TGCR_TIM34RS_SHIFT           1
+#define TGCR_RESET                   0x0
+#define TGCR_UNRESET                 0x1
+#define TGCR_RESET_MASK              0x3
+
+#define WDTCR_WDEN_SHIFT             14
+#define WDTCR_WDEN_DISABLE           0x0
+#define WDTCR_WDEN_ENABLE            0x1
+#define WDTCR_WDKEY_SHIFT            16
+#define WDTCR_WDKEY_SEQ0             0xa5c6
+#define WDTCR_WDKEY_SEQ1             0xda7e
+
+struct timer_s {
+	char *name;
+	unsigned int id;
+	unsigned long period;
+	unsigned long opts;
+	unsigned long flags;
+	void __iomem *base;
+	unsigned long tim_off;
+	unsigned long prd_off;
+	unsigned long enamode_shift;
+	struct irqaction irqaction;
+};
+static struct timer_s timers[];
+
+/* values for 'opts' field of struct timer_s */
+#define TIMER_OPTS_DISABLED		0x01
+#define TIMER_OPTS_ONESHOT		0x02
+#define TIMER_OPTS_PERIODIC		0x04
+#define TIMER_OPTS_STATE_MASK		0x07
+
+#define TIMER_OPTS_USE_COMPARE		0x80000000
+#define USING_COMPARE(t)		((t)->opts & TIMER_OPTS_USE_COMPARE)
+
+static char *id_to_name[] = {
+	[T0_BOT]	= "timer0_0",
+	[T0_TOP]	= "timer0_1",
+	[T1_BOT]	= "timer1_0",
+	[T1_TOP]	= "timer1_1",
+};
+
+static int timer32_config(struct timer_s *t)
+{
+	u32 tcr;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+
+	if (USING_COMPARE(t)) {
+		struct davinci_timer_instance *dtip =
+				soc_info->timer_info->timers;
+		int event_timer = ID_TO_TIMER(timers[TID_CLOCKEVENT].id);
+
+		/*
+		 * Next interrupt should be the current time reg value plus
+		 * the new period (using 32-bit unsigned addition/wrapping
+		 * to 0 on overflow).  This assumes that the clocksource
+		 * is setup to count to 2^32-1 before wrapping around to 0.
+		 */
+		__raw_writel(__raw_readl(t->base + t->tim_off) + t->period,
+			t->base + dtip[event_timer].cmp_off);
+	} else {
+		tcr = __raw_readl(t->base + TCR);
+
+		/* disable timer */
+		tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
+		__raw_writel(tcr, t->base + TCR);
+
+		/* reset counter to zero, set new period */
+		__raw_writel(0, t->base + t->tim_off);
+		__raw_writel(t->period, t->base + t->prd_off);
+
+		/* Set enable mode */
+		if (t->opts & TIMER_OPTS_ONESHOT)
+			tcr |= TCR_ENAMODE_ONESHOT << t->enamode_shift;
+		else if (t->opts & TIMER_OPTS_PERIODIC)
+			tcr |= TCR_ENAMODE_PERIODIC << t->enamode_shift;
+
+		__raw_writel(tcr, t->base + TCR);
+	}
+	return 0;
+}
+
+static inline u32 timer32_read(struct timer_s *t)
+{
+	return __raw_readl(t->base + t->tim_off);
+}
+
+static irqreturn_t timer_interrupt(int irq, void *dev_id)
+{
+	struct clock_event_device *evt = &clockevent_davinci;
+
+	evt->event_handler(evt);
+	return IRQ_HANDLED;
+}
+
+/* called when 32-bit counter wraps */
+static irqreturn_t freerun_interrupt(int irq, void *dev_id)
+{
+	return IRQ_HANDLED;
+}
+
+static struct timer_s timers[] = {
+	[TID_CLOCKEVENT] = {
+		.name      = "clockevent",
+		.opts      = TIMER_OPTS_DISABLED,
+		.irqaction = {
+			.flags   = IRQF_DISABLED | IRQF_TIMER,
+			.handler = timer_interrupt,
+		}
+	},
+	[TID_CLOCKSOURCE] = {
+		.name       = "free-run counter",
+		.period     = ~0,
+		.opts       = TIMER_OPTS_PERIODIC,
+		.irqaction = {
+			.flags   = IRQF_DISABLED | IRQF_TIMER,
+			.handler = freerun_interrupt,
+		}
+	},
+};
+
+static void __init timer_init(void)
+{
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+	struct davinci_timer_instance *dtip = soc_info->timer_info->timers;
+	void __iomem *base[2];
+	int i;
+
+	/* Global init of each 64-bit timer as a whole */
+	for(i=0; i<2; i++) {
+		u32 tgcr;
+
+		base[i] = ioremap(dtip[i].base, SZ_4K);
+		if (WARN_ON(!base[i]))
+			continue;
+
+		/* Disabled, Internal clock source */
+		__raw_writel(0, base[i] + TCR);
+
+		/* reset both timers, no pre-scaler for timer34 */
+		tgcr = 0;
+		__raw_writel(tgcr, base[i] + TGCR);
+
+		/* Set both timers to unchained 32-bit */
+		tgcr = TGCR_TIMMODE_32BIT_UNCHAINED << TGCR_TIMMODE_SHIFT;
+		__raw_writel(tgcr, base[i] + TGCR);
+
+		/* Unreset timers */
+		tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
+			(TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
+		__raw_writel(tgcr, base[i] + TGCR);
+
+		/* Init both counters to zero */
+		__raw_writel(0, base[i] + TIM12);
+		__raw_writel(0, base[i] + TIM34);
+	}
+
+	/* Init of each timer as a 32-bit timer */
+	for (i=0; i< ARRAY_SIZE(timers); i++) {
+		struct timer_s *t = &timers[i];
+		int timer = ID_TO_TIMER(t->id);
+		u32 irq;
+
+		t->base = base[timer];
+		if (!t->base)
+			continue;
+
+		if (IS_TIMER_BOT(t->id)) {
+			t->enamode_shift = 6;
+			t->tim_off = TIM12;
+			t->prd_off = PRD12;
+			irq = dtip[timer].bottom_irq;
+		} else {
+			t->enamode_shift = 22;
+			t->tim_off = TIM34;
+			t->prd_off = PRD34;
+			irq = dtip[timer].top_irq;
+		}
+
+		/* Register interrupt */
+		t->irqaction.name = t->name;
+		t->irqaction.dev_id = (void *)t;
+
+		if (t->irqaction.handler != NULL) {
+			irq = USING_COMPARE(t) ? dtip[i].cmp_irq : irq;
+			setup_irq(irq, &t->irqaction);
+		}
+	}
+}
+
+/*
+ * clocksource
+ */
+static cycle_t read_cycles(struct clocksource *cs)
+{
+	struct timer_s *t = &timers[TID_CLOCKSOURCE];
+
+	return (cycles_t)timer32_read(t);
+}
+
+/*
+ * Kernel assumes that sched_clock can be called early but may not have
+ * things ready yet.
+ */
+static cycle_t read_dummy(struct clocksource *cs)
+{
+	return 0;
+}
+
+
+static struct clocksource clocksource_davinci = {
+	.rating		= 300,
+	.read		= read_dummy,
+	.mask		= CLOCKSOURCE_MASK(32),
+	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * Overwrite weak default sched_clock with something more precise
+ */
+unsigned long long notrace sched_clock(void)
+{
+	const cycle_t cyc = clocksource_davinci.read(&clocksource_davinci);
+
+	return clocksource_cyc2ns(cyc, clocksource_davinci.mult,
+				clocksource_davinci.shift);
+}
+
+/*
+ * clockevent
+ */
+static int davinci_set_next_event(unsigned long cycles,
+				  struct clock_event_device *evt)
+{
+	struct timer_s *t = &timers[TID_CLOCKEVENT];
+
+	t->period = cycles;
+	timer32_config(t);
+	return 0;
+}
+
+static void davinci_set_mode(enum clock_event_mode mode,
+			     struct clock_event_device *evt)
+{
+	struct timer_s *t = &timers[TID_CLOCKEVENT];
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		t->period = davinci_clock_tick_rate / (HZ);
+		t->opts &= ~TIMER_OPTS_STATE_MASK;
+		t->opts |= TIMER_OPTS_PERIODIC;
+		timer32_config(t);
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+		t->opts &= ~TIMER_OPTS_STATE_MASK;
+		t->opts |= TIMER_OPTS_ONESHOT;
+		break;
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		t->opts &= ~TIMER_OPTS_STATE_MASK;
+		t->opts |= TIMER_OPTS_DISABLED;
+		break;
+	case CLOCK_EVT_MODE_RESUME:
+		break;
+	}
+}
+
+static struct clock_event_device clockevent_davinci = {
+	.features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+	.shift		= 32,
+	.set_next_event	= davinci_set_next_event,
+	.set_mode	= davinci_set_mode,
+};
+
+
+static void __init davinci_timer_init(void)
+{
+	struct clk *timer_clk;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+	unsigned int clockevent_id;
+	unsigned int clocksource_id;
+	static char err[] __initdata = KERN_ERR
+		"%s: can't register clocksource!\n";
+	int i;
+
+	clockevent_id = soc_info->timer_info->clockevent_id;
+	clocksource_id = soc_info->timer_info->clocksource_id;
+
+	timers[TID_CLOCKEVENT].id = clockevent_id;
+	timers[TID_CLOCKSOURCE].id = clocksource_id;
+
+	/*
+	 * If using same timer for both clock events & clocksource,
+	 * a compare register must be used to generate an event interrupt.
+	 * This is equivalent to a oneshot timer only (not periodic).
+	 */
+	if (clockevent_id == clocksource_id) {
+		struct davinci_timer_instance *dtip =
+				soc_info->timer_info->timers;
+		int event_timer = ID_TO_TIMER(clockevent_id);
+
+		/* Only bottom timers can use compare regs */
+		if (IS_TIMER_TOP(clockevent_id))
+			pr_warning("davinci_timer_init: Invalid use"
+				" of system timers.  Results unpredictable.\n");
+		else if ((dtip[event_timer].cmp_off == 0)
+				|| (dtip[event_timer].cmp_irq == 0))
+			pr_warning("davinci_timer_init:  Invalid timer instance"
+				" setup.  Results unpredictable.\n");
+		else {
+			timers[TID_CLOCKEVENT].opts |= TIMER_OPTS_USE_COMPARE;
+			clockevent_davinci.features = CLOCK_EVT_FEAT_ONESHOT;
+		}
+	}
+
+	timer_clk = clk_get(NULL, "timer0");
+	BUG_ON(IS_ERR(timer_clk));
+	clk_enable(timer_clk);
+
+	/* init timer hw */
+	timer_init();
+
+	davinci_clock_tick_rate = clk_get_rate(timer_clk);
+
+	/* setup clocksource */
+	clocksource_davinci.read = read_cycles;
+	clocksource_davinci.name = id_to_name[clocksource_id];
+	if (clocksource_register_hz(&clocksource_davinci,
+				    davinci_clock_tick_rate))
+		printk(err, clocksource_davinci.name);
+
+	/* setup clockevent */
+	clockevent_davinci.name = id_to_name[timers[TID_CLOCKEVENT].id];
+	clockevent_davinci.mult = div_sc(davinci_clock_tick_rate, NSEC_PER_SEC,
+					 clockevent_davinci.shift);
+	clockevent_davinci.max_delta_ns =
+		clockevent_delta2ns(0xfffffffe, &clockevent_davinci);
+	clockevent_davinci.min_delta_ns = 50000; /* 50 usec */
+
+	clockevent_davinci.cpumask = cpumask_of(0);
+	clockevents_register_device(&clockevent_davinci);
+
+	for (i=0; i< ARRAY_SIZE(timers); i++)
+		timer32_config(&timers[i]);
+}
+
+struct sys_timer davinci_timer = {
+	.init   = davinci_timer_init,
+};
+
+
+/* reset board using watchdog timer */
+void davinci_watchdog_reset(struct platform_device *pdev)
+{
+	u32 tgcr, wdtcr;
+	void __iomem *base;
+	struct clk *wd_clk;
+
+	base = ioremap(pdev->resource[0].start, SZ_4K);
+	if (WARN_ON(!base))
+		return;
+
+	wd_clk = clk_get(&pdev->dev, NULL);
+	if (WARN_ON(IS_ERR(wd_clk)))
+		return;
+	clk_enable(wd_clk);
+
+	/* disable, internal clock source */
+	__raw_writel(0, base + TCR);
+
+	/* reset timer, set mode to 64-bit watchdog, and unreset */
+	tgcr = 0;
+	__raw_writel(tgcr, base + TGCR);
+	tgcr = TGCR_TIMMODE_64BIT_WDOG << TGCR_TIMMODE_SHIFT;
+	tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
+		(TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
+	__raw_writel(tgcr, base + TGCR);
+
+	/* clear counter and period regs */
+	__raw_writel(0, base + TIM12);
+	__raw_writel(0, base + TIM34);
+	__raw_writel(0, base + PRD12);
+	__raw_writel(0, base + PRD34);
+
+	/* put watchdog in pre-active state */
+	wdtcr = __raw_readl(base + WDTCR);
+	wdtcr = (WDTCR_WDKEY_SEQ0 << WDTCR_WDKEY_SHIFT) |
+		(WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
+	__raw_writel(wdtcr, base + WDTCR);
+
+	/* put watchdog in active state */
+	wdtcr = (WDTCR_WDKEY_SEQ1 << WDTCR_WDKEY_SHIFT) |
+		(WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
+	__raw_writel(wdtcr, base + WDTCR);
+
+	/* write an invalid value to the WDKEY field to trigger
+	 * a watchdog reset */
+	wdtcr = 0x00004000;
+	__raw_writel(wdtcr, base + WDTCR);
+}