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-rw-r--r--arch/arm/mach-davinci/time.c372
1 files changed, 372 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
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index 00000000000..4d8425de692
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+++ b/arch/arm/mach-davinci/time.c
@@ -0,0 +1,372 @@
+/*
+ * 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/spinlock.h>
+
+#include <asm/io.h>
+#include <asm/hardware.h>
+#include <asm/system.h>
+#include <asm/irq.h>
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+#include <asm/errno.h>
+#include <asm/arch/io.h>
+
+static struct clock_event_device clockevent_davinci;
+
+#define DAVINCI_TIMER0_BASE (IO_PHYS + 0x21400)
+#define DAVINCI_TIMER1_BASE (IO_PHYS + 0x21800)
+#define DAVINCI_WDOG_BASE (IO_PHYS + 0x21C00)
+
+enum {
+ T0_BOT = 0, T0_TOP, T1_BOT, T1_TOP, NUM_TIMERS,
+};
+
+#define IS_TIMER1(id) (id & 0x2)
+#define IS_TIMER0(id) (!IS_TIMER1(id))
+#define IS_TIMER_TOP(id) ((id & 0x1))
+#define IS_TIMER_BOT(id) (!IS_TIMER_TOP(id))
+
+static int timer_irqs[NUM_TIMERS] = {
+ IRQ_TINT0_TINT12,
+ IRQ_TINT0_TINT34,
+ IRQ_TINT1_TINT12,
+ IRQ_TINT1_TINT34,
+};
+
+/*
+ * This driver configures the 2 64-bit count-up timers as 4 independent
+ * 32-bit count-up timers used as follows:
+ *
+ * T0_BOT: Timer 0, bottom: clockevent source for hrtimers
+ * T0_TOP: Timer 0, top : clocksource for generic timekeeping
+ * T1_BOT: Timer 1, bottom: (used by DSP in TI DSPLink code)
+ * T1_TOP: Timer 1, top : <unused>
+ */
+#define TID_CLOCKEVENT T0_BOT
+#define TID_CLOCKSOURCE T0_TOP
+
+/* 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
+
+/* 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 reg_base;
+ unsigned long tim_reg;
+ unsigned long prd_reg;
+ unsigned long enamode_shift;
+ struct irqaction irqaction;
+};
+static struct timer_s timers[];
+
+/* values for 'opts' field of struct timer_s */
+#define TIMER_OPTS_DISABLED 0x00
+#define TIMER_OPTS_ONESHOT 0x01
+#define TIMER_OPTS_PERIODIC 0x02
+
+static int timer32_config(struct timer_s *t)
+{
+ u32 tcr = davinci_readl(t->reg_base + TCR);
+
+ /* disable timer */
+ tcr &= ~(TCR_ENAMODE_MASK << t->enamode_shift);
+ davinci_writel(tcr, t->reg_base + TCR);
+
+ /* reset counter to zero, set new period */
+ davinci_writel(0, t->tim_reg);
+ davinci_writel(t->period, t->prd_reg);
+
+ /* 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;
+ }
+
+ davinci_writel(tcr, t->reg_base + TCR);
+ return 0;
+}
+
+static inline u32 timer32_read(struct timer_s *t)
+{
+ return davinci_readl(t->tim_reg);
+}
+
+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)
+{
+ u32 bases[] = {DAVINCI_TIMER0_BASE, DAVINCI_TIMER1_BASE};
+ int i;
+
+ /* Global init of each 64-bit timer as a whole */
+ for(i=0; i<2; i++) {
+ u32 tgcr, base = bases[i];
+
+ /* Disabled, Internal clock source */
+ davinci_writel(0, base + TCR);
+
+ /* reset both timers, no pre-scaler for timer34 */
+ tgcr = 0;
+ davinci_writel(tgcr, base + TGCR);
+
+ /* Set both timers to unchained 32-bit */
+ tgcr = TGCR_TIMMODE_32BIT_UNCHAINED << TGCR_TIMMODE_SHIFT;
+ davinci_writel(tgcr, base + TGCR);
+
+ /* Unreset timers */
+ tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
+ (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
+ davinci_writel(tgcr, base + TGCR);
+
+ /* Init both counters to zero */
+ davinci_writel(0, base + TIM12);
+ davinci_writel(0, base + TIM34);
+ }
+
+ /* Init of each timer as a 32-bit timer */
+ for (i=0; i< ARRAY_SIZE(timers); i++) {
+ struct timer_s *t = &timers[i];
+
+ if (t->name) {
+ t->id = i;
+ t->reg_base = (IS_TIMER1(t->id) ?
+ DAVINCI_TIMER1_BASE : DAVINCI_TIMER0_BASE);
+
+ if (IS_TIMER_BOT(t->id)) {
+ t->enamode_shift = 6;
+ t->tim_reg = t->reg_base + TIM12;
+ t->prd_reg = t->reg_base + PRD12;
+ } else {
+ t->enamode_shift = 22;
+ t->tim_reg = t->reg_base + TIM34;
+ t->prd_reg = t->reg_base + PRD34;
+ }
+
+ /* Register interrupt */
+ t->irqaction.name = t->name;
+ t->irqaction.dev_id = (void *)t;
+ if (t->irqaction.handler != NULL) {
+ setup_irq(timer_irqs[t->id], &t->irqaction);
+ }
+
+ timer32_config(&timers[i]);
+ }
+ }
+}
+
+/*
+ * clocksource
+ */
+static cycle_t read_cycles(void)
+{
+ struct timer_s *t = &timers[TID_CLOCKSOURCE];
+
+ return (cycles_t)timer32_read(t);
+}
+
+static struct clocksource clocksource_davinci = {
+ .name = "timer0_1",
+ .rating = 300,
+ .read = read_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .shift = 24,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * 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 = CLOCK_TICK_RATE / (HZ);
+ t->opts = TIMER_OPTS_PERIODIC;
+ timer32_config(t);
+ break;
+ case CLOCK_EVT_MODE_ONESHOT:
+ t->opts = TIMER_OPTS_ONESHOT;
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ t->opts = TIMER_OPTS_DISABLED;
+ break;
+ }
+}
+
+static struct clock_event_device clockevent_davinci = {
+ .name = "timer0_0",
+ .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)
+{
+ static char err[] __initdata = KERN_ERR
+ "%s: can't register clocksource!\n";
+
+ /* init timer hw */
+ timer_init();
+
+ /* setup clocksource */
+ clocksource_davinci.mult =
+ clocksource_khz2mult(CLOCK_TICK_RATE/1000,
+ clocksource_davinci.shift);
+ if (clocksource_register(&clocksource_davinci))
+ printk(err, clocksource_davinci.name);
+
+ /* setup clockevent */
+ clockevent_davinci.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC,
+ clockevent_davinci.shift);
+ clockevent_davinci.max_delta_ns =
+ clockevent_delta2ns(0xfffffffe, &clockevent_davinci);
+ clockevent_davinci.min_delta_ns =
+ clockevent_delta2ns(1, &clockevent_davinci);
+
+ clockevent_davinci.cpumask = cpumask_of_cpu(0);
+ clockevents_register_device(&clockevent_davinci);
+}
+
+struct sys_timer davinci_timer = {
+ .init = davinci_timer_init,
+};
+
+
+/* reset board using watchdog timer */
+void davinci_watchdog_reset(void) {
+ u32 tgcr, wdtcr, base = DAVINCI_WDOG_BASE;
+
+ /* disable, internal clock source */
+ davinci_writel(0, base + TCR);
+
+ /* reset timer, set mode to 64-bit watchdog, and unreset */
+ tgcr = 0;
+ davinci_writel(tgcr, base + TCR);
+ tgcr = TGCR_TIMMODE_64BIT_WDOG << TGCR_TIMMODE_SHIFT;
+ tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) |
+ (TGCR_UNRESET << TGCR_TIM34RS_SHIFT);
+ davinci_writel(tgcr, base + TCR);
+
+ /* clear counter and period regs */
+ davinci_writel(0, base + TIM12);
+ davinci_writel(0, base + TIM34);
+ davinci_writel(0, base + PRD12);
+ davinci_writel(0, base + PRD34);
+
+ /* enable */
+ wdtcr = davinci_readl(base + WDTCR);
+ wdtcr |= WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT;
+ davinci_writel(wdtcr, base + WDTCR);
+
+ /* put watchdog in pre-active state */
+ wdtcr = (WDTCR_WDKEY_SEQ0 << WDTCR_WDKEY_SHIFT) |
+ (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
+ davinci_writel(wdtcr, base + WDTCR);
+
+ /* put watchdog in active state */
+ wdtcr = (WDTCR_WDKEY_SEQ1 << WDTCR_WDKEY_SHIFT) |
+ (WDTCR_WDEN_ENABLE << WDTCR_WDEN_SHIFT);
+ davinci_writel(wdtcr, base + WDTCR);
+
+ /* write an invalid value to the WDKEY field to trigger
+ * a watchdog reset */
+ wdtcr = 0x00004000;
+ davinci_writel(wdtcr, base + WDTCR);
+}