| /* |
| * 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; |
| int i; |
| |
| /* Global init of each 64-bit timer as a whole */ |
| for(i=0; i<2; i++) { |
| u32 tgcr; |
| void __iomem *base = dtip[i].base; |
| |
| /* Disabled, Internal clock source */ |
| __raw_writel(0, base + TCR); |
| |
| /* reset both timers, no pre-scaler for timer34 */ |
| tgcr = 0; |
| __raw_writel(tgcr, base + TGCR); |
| |
| /* Set both timers to unchained 32-bit */ |
| tgcr = TGCR_TIMMODE_32BIT_UNCHAINED << TGCR_TIMMODE_SHIFT; |
| __raw_writel(tgcr, base + TGCR); |
| |
| /* Unreset timers */ |
| tgcr |= (TGCR_UNRESET << TGCR_TIM12RS_SHIFT) | |
| (TGCR_UNRESET << TGCR_TIM34RS_SHIFT); |
| __raw_writel(tgcr, base + TGCR); |
| |
| /* Init both counters to zero */ |
| __raw_writel(0, base + TIM12); |
| __raw_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]; |
| int timer = ID_TO_TIMER(t->id); |
| u32 irq; |
| |
| t->base = dtip[timer].base; |
| |
| 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); |
| } |
| |
| timer32_config(&timers[i]); |
| } |
| } |
| |
| /* |
| * clocksource |
| */ |
| static cycle_t 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), |
| .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 = 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"; |
| |
| 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; |
| } |
| } |
| |
| /* init timer hw */ |
| timer_init(); |
| |
| timer_clk = clk_get(NULL, "timer0"); |
| BUG_ON(IS_ERR(timer_clk)); |
| clk_enable(timer_clk); |
| |
| davinci_clock_tick_rate = clk_get_rate(timer_clk); |
| |
| /* setup clocksource */ |
| clocksource_davinci.name = id_to_name[clocksource_id]; |
| clocksource_davinci.mult = |
| clocksource_khz2mult(davinci_clock_tick_rate/1000, |
| clocksource_davinci.shift); |
| if (clocksource_register(&clocksource_davinci)) |
| 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); |
| } |
| |
| struct sys_timer davinci_timer = { |
| .init = davinci_timer_init, |
| }; |
| |
| |
| /* reset board using watchdog timer */ |
| void davinci_watchdog_reset(void) |
| { |
| u32 tgcr, wdtcr; |
| struct platform_device *pdev = &davinci_wdt_device; |
| void __iomem *base = IO_ADDRESS(pdev->resource[0].start); |
| struct clk *wd_clk; |
| |
| 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); |
| } |