| /* |
| * System timer for CSR SiRFprimaII |
| * |
| * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company. |
| * |
| * Licensed under GPLv2 or later. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/interrupt.h> |
| #include <linux/clockchips.h> |
| #include <linux/clocksource.h> |
| #include <linux/cpu.h> |
| #include <linux/bitops.h> |
| #include <linux/irq.h> |
| #include <linux/clk.h> |
| #include <linux/slab.h> |
| #include <linux/of.h> |
| #include <linux/of_irq.h> |
| #include <linux/of_address.h> |
| #include <linux/sched_clock.h> |
| #include <asm/mach/time.h> |
| |
| #define SIRFSOC_TIMER_32COUNTER_0_CTRL 0x0000 |
| #define SIRFSOC_TIMER_32COUNTER_1_CTRL 0x0004 |
| #define SIRFSOC_TIMER_MATCH_0 0x0018 |
| #define SIRFSOC_TIMER_MATCH_1 0x001c |
| #define SIRFSOC_TIMER_COUNTER_0 0x0048 |
| #define SIRFSOC_TIMER_COUNTER_1 0x004c |
| #define SIRFSOC_TIMER_INTR_STATUS 0x0060 |
| #define SIRFSOC_TIMER_WATCHDOG_EN 0x0064 |
| #define SIRFSOC_TIMER_64COUNTER_CTRL 0x0068 |
| #define SIRFSOC_TIMER_64COUNTER_LO 0x006c |
| #define SIRFSOC_TIMER_64COUNTER_HI 0x0070 |
| #define SIRFSOC_TIMER_64COUNTER_LOAD_LO 0x0074 |
| #define SIRFSOC_TIMER_64COUNTER_LOAD_HI 0x0078 |
| #define SIRFSOC_TIMER_64COUNTER_RLATCHED_LO 0x007c |
| #define SIRFSOC_TIMER_64COUNTER_RLATCHED_HI 0x0080 |
| |
| #define SIRFSOC_TIMER_REG_CNT 6 |
| |
| static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = { |
| SIRFSOC_TIMER_WATCHDOG_EN, |
| SIRFSOC_TIMER_32COUNTER_0_CTRL, |
| SIRFSOC_TIMER_32COUNTER_1_CTRL, |
| SIRFSOC_TIMER_64COUNTER_CTRL, |
| SIRFSOC_TIMER_64COUNTER_RLATCHED_LO, |
| SIRFSOC_TIMER_64COUNTER_RLATCHED_HI, |
| }; |
| |
| static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT]; |
| |
| static void __iomem *sirfsoc_timer_base; |
| |
| /* disable count and interrupt */ |
| static inline void sirfsoc_timer_count_disable(int idx) |
| { |
| writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) & ~0x7, |
| sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx); |
| } |
| |
| /* enable count and interrupt */ |
| static inline void sirfsoc_timer_count_enable(int idx) |
| { |
| writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) | 0x7, |
| sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx); |
| } |
| |
| /* timer interrupt handler */ |
| static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id) |
| { |
| struct clock_event_device *ce = dev_id; |
| int cpu = smp_processor_id(); |
| |
| /* clear timer interrupt */ |
| writel_relaxed(BIT(cpu), sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS); |
| |
| if (ce->mode == CLOCK_EVT_MODE_ONESHOT) |
| sirfsoc_timer_count_disable(cpu); |
| |
| ce->event_handler(ce); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* read 64-bit timer counter */ |
| static cycle_t sirfsoc_timer_read(struct clocksource *cs) |
| { |
| u64 cycles; |
| |
| writel_relaxed((readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) | |
| BIT(0)) & ~BIT(1), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL); |
| |
| cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_HI); |
| cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_LO); |
| |
| return cycles; |
| } |
| |
| static int sirfsoc_timer_set_next_event(unsigned long delta, |
| struct clock_event_device *ce) |
| { |
| int cpu = smp_processor_id(); |
| |
| writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0 + |
| 4 * cpu); |
| writel_relaxed(delta, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0 + |
| 4 * cpu); |
| |
| /* enable the tick */ |
| sirfsoc_timer_count_enable(cpu); |
| |
| return 0; |
| } |
| |
| static void sirfsoc_timer_set_mode(enum clock_event_mode mode, |
| struct clock_event_device *ce) |
| { |
| switch (mode) { |
| case CLOCK_EVT_MODE_ONESHOT: |
| /* enable in set_next_event */ |
| break; |
| default: |
| break; |
| } |
| |
| sirfsoc_timer_count_disable(smp_processor_id()); |
| } |
| |
| static void sirfsoc_clocksource_suspend(struct clocksource *cs) |
| { |
| int i; |
| |
| for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++) |
| sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]); |
| } |
| |
| static void sirfsoc_clocksource_resume(struct clocksource *cs) |
| { |
| int i; |
| |
| for (i = 0; i < SIRFSOC_TIMER_REG_CNT - 2; i++) |
| writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]); |
| |
| writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 2], |
| sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO); |
| writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 1], |
| sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI); |
| |
| writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) | |
| BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL); |
| } |
| |
| static struct clock_event_device __percpu *sirfsoc_clockevent; |
| |
| static struct clocksource sirfsoc_clocksource = { |
| .name = "sirfsoc_clocksource", |
| .rating = 200, |
| .mask = CLOCKSOURCE_MASK(64), |
| .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
| .read = sirfsoc_timer_read, |
| .suspend = sirfsoc_clocksource_suspend, |
| .resume = sirfsoc_clocksource_resume, |
| }; |
| |
| static struct irqaction sirfsoc_timer_irq = { |
| .name = "sirfsoc_timer0", |
| .flags = IRQF_TIMER | IRQF_NOBALANCING, |
| .handler = sirfsoc_timer_interrupt, |
| }; |
| |
| static struct irqaction sirfsoc_timer1_irq = { |
| .name = "sirfsoc_timer1", |
| .flags = IRQF_TIMER | IRQF_NOBALANCING, |
| .handler = sirfsoc_timer_interrupt, |
| }; |
| |
| static int __cpuinit sirfsoc_local_timer_setup(struct clock_event_device *ce) |
| { |
| int cpu = smp_processor_id(); |
| struct irqaction *action; |
| |
| if (cpu == 0) |
| action = &sirfsoc_timer_irq; |
| else |
| action = &sirfsoc_timer1_irq; |
| |
| ce->irq = action->irq; |
| ce->name = "local_timer"; |
| ce->features = CLOCK_EVT_FEAT_ONESHOT; |
| ce->rating = 200; |
| ce->set_mode = sirfsoc_timer_set_mode; |
| ce->set_next_event = sirfsoc_timer_set_next_event; |
| clockevents_calc_mult_shift(ce, CLOCK_TICK_RATE, 60); |
| ce->max_delta_ns = clockevent_delta2ns(-2, ce); |
| ce->min_delta_ns = clockevent_delta2ns(2, ce); |
| ce->cpumask = cpumask_of(cpu); |
| |
| action->dev_id = ce; |
| BUG_ON(setup_irq(ce->irq, action)); |
| irq_set_affinity(action->irq, cpumask_of(cpu)); |
| |
| clockevents_register_device(ce); |
| return 0; |
| } |
| |
| static void __cpuinit sirfsoc_local_timer_stop(struct clock_event_device *ce) |
| { |
| int cpu = smp_processor_id(); |
| |
| sirfsoc_timer_count_disable(1); |
| |
| if (cpu == 0) |
| remove_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq); |
| else |
| remove_irq(sirfsoc_timer1_irq.irq, &sirfsoc_timer1_irq); |
| } |
| |
| static int __cpuinit sirfsoc_cpu_notify(struct notifier_block *self, |
| unsigned long action, void *hcpu) |
| { |
| /* |
| * Grab cpu pointer in each case to avoid spurious |
| * preemptible warnings |
| */ |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_STARTING: |
| sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent)); |
| break; |
| case CPU_DYING: |
| sirfsoc_local_timer_stop(this_cpu_ptr(sirfsoc_clockevent)); |
| break; |
| } |
| |
| return NOTIFY_OK; |
| } |
| |
| static struct notifier_block sirfsoc_cpu_nb __cpuinitdata = { |
| .notifier_call = sirfsoc_cpu_notify, |
| }; |
| |
| static void __init sirfsoc_clockevent_init(void) |
| { |
| sirfsoc_clockevent = alloc_percpu(struct clock_event_device); |
| BUG_ON(!sirfsoc_clockevent); |
| |
| BUG_ON(register_cpu_notifier(&sirfsoc_cpu_nb)); |
| |
| /* Immediately configure the timer on the boot CPU */ |
| sirfsoc_local_timer_setup(this_cpu_ptr(sirfsoc_clockevent)); |
| } |
| |
| /* initialize the kernel jiffy timer source */ |
| static void __init sirfsoc_marco_timer_init(void) |
| { |
| unsigned long rate; |
| u32 timer_div; |
| struct clk *clk; |
| |
| /* timer's input clock is io clock */ |
| clk = clk_get_sys("io", NULL); |
| |
| BUG_ON(IS_ERR(clk)); |
| rate = clk_get_rate(clk); |
| |
| BUG_ON(rate < CLOCK_TICK_RATE); |
| BUG_ON(rate % CLOCK_TICK_RATE); |
| |
| /* Initialize the timer dividers */ |
| timer_div = rate / CLOCK_TICK_RATE - 1; |
| writel_relaxed(timer_div << 16, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL); |
| writel_relaxed(timer_div << 16, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL); |
| writel_relaxed(timer_div << 16, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_1_CTRL); |
| |
| /* Initialize timer counters to 0 */ |
| writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO); |
| writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI); |
| writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) | |
| BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL); |
| writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0); |
| writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_1); |
| |
| /* Clear all interrupts */ |
| writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS); |
| |
| BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, CLOCK_TICK_RATE)); |
| |
| sirfsoc_clockevent_init(); |
| } |
| |
| static void __init sirfsoc_of_timer_init(struct device_node *np) |
| { |
| sirfsoc_timer_base = of_iomap(np, 0); |
| if (!sirfsoc_timer_base) |
| panic("unable to map timer cpu registers\n"); |
| |
| sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0); |
| if (!sirfsoc_timer_irq.irq) |
| panic("No irq passed for timer0 via DT\n"); |
| |
| sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1); |
| if (!sirfsoc_timer1_irq.irq) |
| panic("No irq passed for timer1 via DT\n"); |
| |
| sirfsoc_marco_timer_init(); |
| } |
| CLOCKSOURCE_OF_DECLARE(sirfsoc_marco_timer, "sirf,marco-tick", sirfsoc_of_timer_init ); |