/* * arch/arm/plat-orion/time.c * * Marvell Orion SoC timer handling. * * 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. */ #include <linux/kernel.h> #include <linux/timer.h> #include <linux/clockchips.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <asm/sched_clock.h> /* * MBus bridge block registers. */ #define BRIDGE_CAUSE_OFF 0x0110 #define BRIDGE_MASK_OFF 0x0114 #define BRIDGE_INT_TIMER0 0x0002 #define BRIDGE_INT_TIMER1 0x0004 /* * Timer block registers. */ #define TIMER_CTRL_OFF 0x0000 #define TIMER0_EN 0x0001 #define TIMER0_RELOAD_EN 0x0002 #define TIMER1_EN 0x0004 #define TIMER1_RELOAD_EN 0x0008 #define TIMER0_RELOAD_OFF 0x0010 #define TIMER0_VAL_OFF 0x0014 #define TIMER1_RELOAD_OFF 0x0018 #define TIMER1_VAL_OFF 0x001c /* * SoC-specific data. */ static void __iomem *bridge_base; static u32 bridge_timer1_clr_mask; static void __iomem *timer_base; /* * Number of timer ticks per jiffy. */ static u32 ticks_per_jiffy; /* * Orion's sched_clock implementation. It has a resolution of * at least 7.5ns (133MHz TCLK). */ static u32 notrace orion_read_sched_clock(void) { return ~readl(timer_base + TIMER0_VAL_OFF); } /* * Clockevent handling. */ static int orion_clkevt_next_event(unsigned long delta, struct clock_event_device *dev) { unsigned long flags; u32 u; if (delta == 0) return -ETIME; local_irq_save(flags); /* * Clear and enable clockevent timer interrupt. */ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF); u = readl(bridge_base + BRIDGE_MASK_OFF); u |= BRIDGE_INT_TIMER1; writel(u, bridge_base + BRIDGE_MASK_OFF); /* * Setup new clockevent timer value. */ writel(delta, timer_base + TIMER1_VAL_OFF); /* * Enable the timer. */ u = readl(timer_base + TIMER_CTRL_OFF); u = (u & ~TIMER1_RELOAD_EN) | TIMER1_EN; writel(u, timer_base + TIMER_CTRL_OFF); local_irq_restore(flags); return 0; } static void orion_clkevt_mode(enum clock_event_mode mode, struct clock_event_device *dev) { unsigned long flags; u32 u; local_irq_save(flags); if (mode == CLOCK_EVT_MODE_PERIODIC) { /* * Setup timer to fire at 1/HZ intervals. */ writel(ticks_per_jiffy - 1, timer_base + TIMER1_RELOAD_OFF); writel(ticks_per_jiffy - 1, timer_base + TIMER1_VAL_OFF); /* * Enable timer interrupt. */ u = readl(bridge_base + BRIDGE_MASK_OFF); writel(u | BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF); /* * Enable timer. */ u = readl(timer_base + TIMER_CTRL_OFF); writel(u | TIMER1_EN | TIMER1_RELOAD_EN, timer_base + TIMER_CTRL_OFF); } else { /* * Disable timer. */ u = readl(timer_base + TIMER_CTRL_OFF); writel(u & ~TIMER1_EN, timer_base + TIMER_CTRL_OFF); /* * Disable timer interrupt. */ u = readl(bridge_base + BRIDGE_MASK_OFF); writel(u & ~BRIDGE_INT_TIMER1, bridge_base + BRIDGE_MASK_OFF); /* * ACK pending timer interrupt. */ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF); } local_irq_restore(flags); } static struct clock_event_device orion_clkevt = { .name = "orion_tick", .features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_PERIODIC, .shift = 32, .rating = 300, .set_next_event = orion_clkevt_next_event, .set_mode = orion_clkevt_mode, }; static irqreturn_t orion_timer_interrupt(int irq, void *dev_id) { /* * ACK timer interrupt and call event handler. */ writel(bridge_timer1_clr_mask, bridge_base + BRIDGE_CAUSE_OFF); orion_clkevt.event_handler(&orion_clkevt); return IRQ_HANDLED; } static struct irqaction orion_timer_irq = { .name = "orion_tick", .flags = IRQF_DISABLED | IRQF_TIMER, .handler = orion_timer_interrupt }; void __init orion_time_set_base(void __iomem *_timer_base) { timer_base = _timer_base; } void __init orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask, unsigned int irq, unsigned int tclk) { u32 u; /* * Set SoC-specific data. */ bridge_base = _bridge_base; bridge_timer1_clr_mask = _bridge_timer1_clr_mask; ticks_per_jiffy = (tclk + HZ/2) / HZ; /* * Set scale and timer for sched_clock. */ setup_sched_clock(orion_read_sched_clock, 32, tclk); /* * Setup free-running clocksource timer (interrupts * disabled). */ writel(0xffffffff, timer_base + TIMER0_VAL_OFF); writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF); u = readl(bridge_base + BRIDGE_MASK_OFF); writel(u & ~BRIDGE_INT_TIMER0, bridge_base + BRIDGE_MASK_OFF); u = readl(timer_base + TIMER_CTRL_OFF); writel(u | TIMER0_EN | TIMER0_RELOAD_EN, timer_base + TIMER_CTRL_OFF); clocksource_mmio_init(timer_base + TIMER0_VAL_OFF, "orion_clocksource", tclk, 300, 32, clocksource_mmio_readl_down); /* * Setup clockevent timer (interrupt-driven). */ setup_irq(irq, &orion_timer_irq); orion_clkevt.mult = div_sc(tclk, NSEC_PER_SEC, orion_clkevt.shift); orion_clkevt.max_delta_ns = clockevent_delta2ns(0xfffffffe, &orion_clkevt); orion_clkevt.min_delta_ns = clockevent_delta2ns(1, &orion_clkevt); orion_clkevt.cpumask = cpumask_of(0); clockevents_register_device(&orion_clkevt); }