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Diffstat (limited to 'arch/arm/mach-davinci/time.c')
| -rw-r--r-- | arch/arm/mach-davinci/time.c | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c new file mode 100644 index 000000000000..4d8425de6922 --- /dev/null +++ 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); +} |