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-rw-r--r--arch/arm/mach-davinci/time.c414
1 files changed, 414 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
new file mode 100644
index 000000000..5a6de5368
--- /dev/null
+++ b/arch/arm/mach-davinci/time.c
@@ -0,0 +1,414 @@
+/*
+ * 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/of.h>
+#include <linux/platform_device.h>
+#include <linux/sched_clock.h>
+
+#include <asm/mach/irq.h>
+#include <asm/mach/time.h>
+
+#include <mach/cputype.h>
+#include <mach/hardware.h>
+#include <mach/time.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
+
+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_TIMER,
+ .handler = timer_interrupt,
+ }
+ },
+ [TID_CLOCKSOURCE] = {
+ .name = "free-run counter",
+ .period = ~0,
+ .opts = TIMER_OPTS_PERIODIC,
+ .irqaction = {
+ .flags = 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 u64 read_cycles(struct clocksource *cs)
+{
+ struct timer_s *t = &timers[TID_CLOCKSOURCE];
+
+ return (cycles_t)timer32_read(t);
+}
+
+static struct clocksource clocksource_davinci = {
+ .rating = 300,
+ .read = read_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+/*
+ * Overwrite weak default sched_clock with something more precise
+ */
+static u64 notrace davinci_read_sched_clock(void)
+{
+ return timer32_read(&timers[TID_CLOCKSOURCE]);
+}
+
+/*
+ * 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 int davinci_shutdown(struct clock_event_device *evt)
+{
+ struct timer_s *t = &timers[TID_CLOCKEVENT];
+
+ t->opts &= ~TIMER_OPTS_STATE_MASK;
+ t->opts |= TIMER_OPTS_DISABLED;
+ return 0;
+}
+
+static int davinci_set_oneshot(struct clock_event_device *evt)
+{
+ struct timer_s *t = &timers[TID_CLOCKEVENT];
+
+ t->opts &= ~TIMER_OPTS_STATE_MASK;
+ t->opts |= TIMER_OPTS_ONESHOT;
+ return 0;
+}
+
+static int davinci_set_periodic(struct clock_event_device *evt)
+{
+ struct timer_s *t = &timers[TID_CLOCKEVENT];
+
+ t->period = davinci_clock_tick_rate / (HZ);
+ t->opts &= ~TIMER_OPTS_STATE_MASK;
+ t->opts |= TIMER_OPTS_PERIODIC;
+ timer32_config(t);
+ return 0;
+}
+
+static struct clock_event_device clockevent_davinci = {
+ .features = CLOCK_EVT_FEAT_PERIODIC |
+ CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = davinci_set_next_event,
+ .set_state_shutdown = davinci_shutdown,
+ .set_state_periodic = davinci_set_periodic,
+ .set_state_oneshot = davinci_set_oneshot,
+};
+
+void __init davinci_timer_init(struct clk *timer_clk)
+{
+ struct davinci_soc_info *soc_info = &davinci_soc_info;
+ unsigned int clockevent_id;
+ unsigned int clocksource_id;
+ 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_warn("%s: Invalid use of system timers. Results unpredictable.\n",
+ __func__);
+ else if ((dtip[event_timer].cmp_off == 0)
+ || (dtip[event_timer].cmp_irq == 0))
+ pr_warn("%s: Invalid timer instance setup. Results unpredictable.\n",
+ __func__);
+ else {
+ timers[TID_CLOCKEVENT].opts |= TIMER_OPTS_USE_COMPARE;
+ clockevent_davinci.features = CLOCK_EVT_FEAT_ONESHOT;
+ }
+ }
+
+ BUG_ON(IS_ERR(timer_clk));
+ clk_prepare_enable(timer_clk);
+
+ /* init timer hw */
+ timer_init();
+
+ davinci_clock_tick_rate = clk_get_rate(timer_clk);
+
+ /* setup clocksource */
+ clocksource_davinci.name = id_to_name[clocksource_id];
+ if (clocksource_register_hz(&clocksource_davinci,
+ davinci_clock_tick_rate))
+ pr_err("%s: can't register clocksource!\n",
+ clocksource_davinci.name);
+
+ sched_clock_register(davinci_read_sched_clock, 32,
+ davinci_clock_tick_rate);
+
+ /* setup clockevent */
+ clockevent_davinci.name = id_to_name[timers[TID_CLOCKEVENT].id];
+
+ clockevent_davinci.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&clockevent_davinci,
+ davinci_clock_tick_rate, 1, 0xfffffffe);
+
+ for (i=0; i< ARRAY_SIZE(timers); i++)
+ timer32_config(&timers[i]);
+}
+
+static int __init of_davinci_timer_init(struct device_node *np)
+{
+ struct clk *clk;
+
+ clk = of_clk_get(np, 0);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ davinci_timer_init(clk);
+
+ return 0;
+}
+TIMER_OF_DECLARE(davinci_timer, "ti,da830-timer", of_davinci_timer_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-30 05:52:36 +0000