|  | /* | 
|  | * 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> | 
|  |  | 
|  | #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 unsigned long atlas7_timer_rate; | 
|  |  | 
|  | 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) | 0x3, | 
|  | 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 (clockevent_state_oneshot(ce)) | 
|  | sirfsoc_timer_count_disable(cpu); | 
|  |  | 
|  | ce->event_handler(ce); | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | /* read 64-bit timer counter */ | 
|  | static u64 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(); | 
|  |  | 
|  | /* disable timer first, then modify the related registers */ | 
|  | sirfsoc_timer_count_disable(cpu); | 
|  |  | 
|  | 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; | 
|  | } | 
|  |  | 
|  | /* Oneshot is enabled in set_next_event */ | 
|  | static int sirfsoc_timer_shutdown(struct clock_event_device *evt) | 
|  | { | 
|  | sirfsoc_timer_count_disable(smp_processor_id()); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | 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 sirfsoc_local_timer_starting_cpu(unsigned int cpu) | 
|  | { | 
|  | struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu); | 
|  | 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_state_shutdown = sirfsoc_timer_shutdown; | 
|  | ce->set_state_oneshot = sirfsoc_timer_shutdown; | 
|  | ce->tick_resume = sirfsoc_timer_shutdown; | 
|  | ce->set_next_event = sirfsoc_timer_set_next_event; | 
|  | clockevents_calc_mult_shift(ce, atlas7_timer_rate, 60); | 
|  | ce->max_delta_ns = clockevent_delta2ns(-2, ce); | 
|  | ce->max_delta_ticks = (unsigned long)-2; | 
|  | ce->min_delta_ns = clockevent_delta2ns(2, ce); | 
|  | ce->min_delta_ticks = 2; | 
|  | ce->cpumask = cpumask_of(cpu); | 
|  |  | 
|  | action->dev_id = ce; | 
|  | BUG_ON(setup_irq(ce->irq, action)); | 
|  | irq_force_affinity(action->irq, cpumask_of(cpu)); | 
|  |  | 
|  | clockevents_register_device(ce); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int sirfsoc_local_timer_dying_cpu(unsigned int cpu) | 
|  | { | 
|  | 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); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int __init sirfsoc_clockevent_init(void) | 
|  | { | 
|  | sirfsoc_clockevent = alloc_percpu(struct clock_event_device); | 
|  | BUG_ON(!sirfsoc_clockevent); | 
|  |  | 
|  | /* Install and invoke hotplug callbacks */ | 
|  | return cpuhp_setup_state(CPUHP_AP_MARCO_TIMER_STARTING, | 
|  | "clockevents/marco:starting", | 
|  | sirfsoc_local_timer_starting_cpu, | 
|  | sirfsoc_local_timer_dying_cpu); | 
|  | } | 
|  |  | 
|  | /* initialize the kernel jiffy timer source */ | 
|  | static int __init sirfsoc_atlas7_timer_init(struct device_node *np) | 
|  | { | 
|  | struct clk *clk; | 
|  |  | 
|  | clk = of_clk_get(np, 0); | 
|  | BUG_ON(IS_ERR(clk)); | 
|  |  | 
|  | BUG_ON(clk_prepare_enable(clk)); | 
|  |  | 
|  | atlas7_timer_rate = clk_get_rate(clk); | 
|  |  | 
|  | /* timer dividers: 0, not divided */ | 
|  | writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL); | 
|  | writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL); | 
|  | writel_relaxed(0, 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, atlas7_timer_rate)); | 
|  |  | 
|  | return sirfsoc_clockevent_init(); | 
|  | } | 
|  |  | 
|  | static int __init sirfsoc_of_timer_init(struct device_node *np) | 
|  | { | 
|  | sirfsoc_timer_base = of_iomap(np, 0); | 
|  | if (!sirfsoc_timer_base) { | 
|  | pr_err("unable to map timer cpu registers\n"); | 
|  | return -ENXIO; | 
|  | } | 
|  |  | 
|  | sirfsoc_timer_irq.irq = irq_of_parse_and_map(np, 0); | 
|  | if (!sirfsoc_timer_irq.irq) { | 
|  | pr_err("No irq passed for timer0 via DT\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1); | 
|  | if (!sirfsoc_timer1_irq.irq) { | 
|  | pr_err("No irq passed for timer1 via DT\n"); | 
|  | return -EINVAL; | 
|  | } | 
|  |  | 
|  | return sirfsoc_atlas7_timer_init(np); | 
|  | } | 
|  | TIMER_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init); |