/* * Marvell Armada 370/XP SoC timer handling. * * Copyright (C) 2012 Marvell * * Lior Amsalem * Gregory CLEMENT * Thomas Petazzoni * * 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. * * Timer 0 is used as free-running clocksource, while timer 1 is * used as clock_event_device. * * --- * Clocksource driver for Armada 370 and Armada XP SoC. * This driver implements one compatible string for each SoC, given * each has its own characteristics: * * * Armada 370 has no 25 MHz fixed timer. * * * Armada XP cannot work properly without such 25 MHz fixed timer as * doing otherwise leads to using a clocksource whose frequency varies * when doing cpufreq frequency changes. * * See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * Timer block registers. */ #define TIMER_CTRL_OFF 0x0000 #define TIMER0_EN BIT(0) #define TIMER0_RELOAD_EN BIT(1) #define TIMER0_25MHZ BIT(11) #define TIMER0_DIV(div) ((div) << 19) #define TIMER1_EN BIT(2) #define TIMER1_RELOAD_EN BIT(3) #define TIMER1_25MHZ BIT(12) #define TIMER1_DIV(div) ((div) << 22) #define TIMER_EVENTS_STATUS 0x0004 #define TIMER0_CLR_MASK (~0x1) #define TIMER1_CLR_MASK (~0x100) #define TIMER0_RELOAD_OFF 0x0010 #define TIMER0_VAL_OFF 0x0014 #define TIMER1_RELOAD_OFF 0x0018 #define TIMER1_VAL_OFF 0x001c #define LCL_TIMER_EVENTS_STATUS 0x0028 /* Global timers are connected to the coherency fabric clock, and the below divider reduces their incrementing frequency. */ #define TIMER_DIVIDER_SHIFT 5 #define TIMER_DIVIDER (1 << TIMER_DIVIDER_SHIFT) /* * SoC-specific data. */ static void __iomem *timer_base, *local_base; static unsigned int timer_clk; static bool timer25Mhz = true; static u32 enable_mask; /* * Number of timer ticks per jiffy. */ static u32 ticks_per_jiffy; static struct clock_event_device __percpu *armada_370_xp_evt; static void local_timer_ctrl_clrset(u32 clr, u32 set) { writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set, local_base + TIMER_CTRL_OFF); } static u64 notrace armada_370_xp_read_sched_clock(void) { return ~readl(timer_base + TIMER0_VAL_OFF); } /* * Clockevent handling. */ static int armada_370_xp_clkevt_next_event(unsigned long delta, struct clock_event_device *dev) { /* * Clear clockevent timer interrupt. */ writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); /* * Setup new clockevent timer value. */ writel(delta, local_base + TIMER0_VAL_OFF); /* * Enable the timer. */ local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask); return 0; } static int armada_370_xp_clkevt_shutdown(struct clock_event_device *evt) { /* * Disable timer. */ local_timer_ctrl_clrset(TIMER0_EN, 0); /* * ACK pending timer interrupt. */ writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); return 0; } static int armada_370_xp_clkevt_set_periodic(struct clock_event_device *evt) { /* * Setup timer to fire at 1/HZ intervals. */ writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF); writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF); /* * Enable timer. */ local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask); return 0; } static int armada_370_xp_clkevt_irq; static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id) { /* * ACK timer interrupt and call event handler. */ struct clock_event_device *evt = dev_id; writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS); evt->event_handler(evt); return IRQ_HANDLED; } /* * Setup the local clock events for a CPU. */ static int armada_370_xp_timer_setup(struct clock_event_device *evt) { u32 clr = 0, set = 0; int cpu = smp_processor_id(); if (timer25Mhz) set = TIMER0_25MHZ; else clr = TIMER0_25MHZ; local_timer_ctrl_clrset(clr, set); evt->name = "armada_370_xp_per_cpu_tick", evt->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC; evt->shift = 32, evt->rating = 300, evt->set_next_event = armada_370_xp_clkevt_next_event, evt->set_state_shutdown = armada_370_xp_clkevt_shutdown; evt->set_state_periodic = armada_370_xp_clkevt_set_periodic; evt->set_state_oneshot = armada_370_xp_clkevt_shutdown; evt->tick_resume = armada_370_xp_clkevt_shutdown; evt->irq = armada_370_xp_clkevt_irq; evt->cpumask = cpumask_of(cpu); clockevents_config_and_register(evt, timer_clk, 1, 0xfffffffe); enable_percpu_irq(evt->irq, 0); return 0; } static void armada_370_xp_timer_stop(struct clock_event_device *evt) { evt->set_state_shutdown(evt); disable_percpu_irq(evt->irq); } static int armada_370_xp_timer_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: armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt)); break; case CPU_DYING: armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt)); break; } return NOTIFY_OK; } static struct notifier_block armada_370_xp_timer_cpu_nb = { .notifier_call = armada_370_xp_timer_cpu_notify, }; static u32 timer0_ctrl_reg, timer0_local_ctrl_reg; static int armada_370_xp_timer_suspend(void) { timer0_ctrl_reg = readl(timer_base + TIMER_CTRL_OFF); timer0_local_ctrl_reg = readl(local_base + TIMER_CTRL_OFF); return 0; } static void armada_370_xp_timer_resume(void) { writel(0xffffffff, timer_base + TIMER0_VAL_OFF); writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); writel(timer0_ctrl_reg, timer_base + TIMER_CTRL_OFF); writel(timer0_local_ctrl_reg, local_base + TIMER_CTRL_OFF); } struct syscore_ops armada_370_xp_timer_syscore_ops = { .suspend = armada_370_xp_timer_suspend, .resume = armada_370_xp_timer_resume, }; static unsigned long armada_370_delay_timer_read(void) { return ~readl(timer_base + TIMER0_VAL_OFF); } static struct delay_timer armada_370_delay_timer = { .read_current_timer = armada_370_delay_timer_read, }; static void __init armada_370_xp_timer_common_init(struct device_node *np) { u32 clr = 0, set = 0; int res; timer_base = of_iomap(np, 0); WARN_ON(!timer_base); local_base = of_iomap(np, 1); if (timer25Mhz) { set = TIMER0_25MHZ; enable_mask = TIMER0_EN; } else { clr = TIMER0_25MHZ; enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT); } atomic_io_modify(timer_base + TIMER_CTRL_OFF, clr | set, set); local_timer_ctrl_clrset(clr, set); /* * We use timer 0 as clocksource, and private(local) timer 0 * for clockevents */ armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4); ticks_per_jiffy = (timer_clk + HZ / 2) / HZ; /* * Setup free-running clocksource timer (interrupts * disabled). */ writel(0xffffffff, timer_base + TIMER0_VAL_OFF); writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); atomic_io_modify(timer_base + TIMER_CTRL_OFF, TIMER0_RELOAD_EN | enable_mask, TIMER0_RELOAD_EN | enable_mask); armada_370_delay_timer.freq = timer_clk; register_current_timer_delay(&armada_370_delay_timer); /* * Set scale and timer for sched_clock. */ sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk); clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "armada_370_xp_clocksource", timer_clk, 300, 32, clocksource_mmio_readl_down); register_cpu_notifier(&armada_370_xp_timer_cpu_nb); armada_370_xp_evt = alloc_percpu(struct clock_event_device); /* * Setup clockevent timer (interrupt-driven). */ res = request_percpu_irq(armada_370_xp_clkevt_irq, armada_370_xp_timer_interrupt, "armada_370_xp_per_cpu_tick", armada_370_xp_evt); /* Immediately configure the timer on the boot CPU */ if (!res) armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt)); register_syscore_ops(&armada_370_xp_timer_syscore_ops); } static void __init armada_xp_timer_init(struct device_node *np) { struct clk *clk = of_clk_get_by_name(np, "fixed"); /* The 25Mhz fixed clock is mandatory, and must always be available */ BUG_ON(IS_ERR(clk)); clk_prepare_enable(clk); timer_clk = clk_get_rate(clk); armada_370_xp_timer_common_init(np); } CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer", armada_xp_timer_init); static void __init armada_375_timer_init(struct device_node *np) { struct clk *clk; clk = of_clk_get_by_name(np, "fixed"); if (!IS_ERR(clk)) { clk_prepare_enable(clk); timer_clk = clk_get_rate(clk); } else { /* * This fallback is required in order to retain proper * devicetree backwards compatibility. */ clk = of_clk_get(np, 0); /* Must have at least a clock */ BUG_ON(IS_ERR(clk)); clk_prepare_enable(clk); timer_clk = clk_get_rate(clk) / TIMER_DIVIDER; timer25Mhz = false; } armada_370_xp_timer_common_init(np); } CLOCKSOURCE_OF_DECLARE(armada_375, "marvell,armada-375-timer", armada_375_timer_init); static void __init armada_370_timer_init(struct device_node *np) { struct clk *clk = of_clk_get(np, 0); BUG_ON(IS_ERR(clk)); clk_prepare_enable(clk); timer_clk = clk_get_rate(clk) / TIMER_DIVIDER; timer25Mhz = false; armada_370_xp_timer_common_init(np); } CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer", armada_370_timer_init);