diff options
Diffstat (limited to 'arch/arm/common/timer-sp.c')
| -rw-r--r-- | arch/arm/common/timer-sp.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/arch/arm/common/timer-sp.c b/arch/arm/common/timer-sp.c new file mode 100644 index 000000000000..4740313daa5b --- /dev/null +++ b/arch/arm/common/timer-sp.c @@ -0,0 +1,154 @@ +/* + * linux/arch/arm/common/timer-sp.c + * + * Copyright (C) 1999 - 2003 ARM Limited + * Copyright (C) 2000 Deep Blue Solutions Ltd + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ +#include <linux/clocksource.h> +#include <linux/clockchips.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/io.h> + +#include <asm/hardware/arm_timer.h> + +/* + * These timers are currently always setup to be clocked at 1MHz. + */ +#define TIMER_FREQ_KHZ (1000) +#define TIMER_RELOAD (TIMER_FREQ_KHZ * 1000 / HZ) + +static void __iomem *clksrc_base; + +static cycle_t sp804_read(struct clocksource *cs) +{ + return ~readl(clksrc_base + TIMER_VALUE); +} + +static struct clocksource clocksource_sp804 = { + .name = "timer3", + .rating = 200, + .read = sp804_read, + .mask = CLOCKSOURCE_MASK(32), + .shift = 20, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; + +void __init sp804_clocksource_init(void __iomem *base) +{ + struct clocksource *cs = &clocksource_sp804; + + clksrc_base = base; + + /* setup timer 0 as free-running clocksource */ + writel(0, clksrc_base + TIMER_CTRL); + writel(0xffffffff, clksrc_base + TIMER_LOAD); + writel(0xffffffff, clksrc_base + TIMER_VALUE); + writel(TIMER_CTRL_32BIT | TIMER_CTRL_ENABLE | TIMER_CTRL_PERIODIC, + clksrc_base + TIMER_CTRL); + + cs->mult = clocksource_khz2mult(TIMER_FREQ_KHZ, cs->shift); + clocksource_register(cs); +} + + +static void __iomem *clkevt_base; + +/* + * IRQ handler for the timer + */ +static irqreturn_t sp804_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *evt = dev_id; + + /* clear the interrupt */ + writel(1, clkevt_base + TIMER_INTCLR); + + evt->event_handler(evt); + + return IRQ_HANDLED; +} + +static void sp804_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long ctrl = TIMER_CTRL_32BIT | TIMER_CTRL_IE; + + writel(ctrl, clkevt_base + TIMER_CTRL); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + writel(TIMER_RELOAD, clkevt_base + TIMER_LOAD); + ctrl |= TIMER_CTRL_PERIODIC | TIMER_CTRL_ENABLE; + break; + + case CLOCK_EVT_MODE_ONESHOT: + /* period set, and timer enabled in 'next_event' hook */ + ctrl |= TIMER_CTRL_ONESHOT; + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + default: + break; + } + + writel(ctrl, clkevt_base + TIMER_CTRL); +} + +static int sp804_set_next_event(unsigned long next, + struct clock_event_device *evt) +{ + unsigned long ctrl = readl(clkevt_base + TIMER_CTRL); + + writel(next, clkevt_base + TIMER_LOAD); + writel(ctrl | TIMER_CTRL_ENABLE, clkevt_base + TIMER_CTRL); + + return 0; +} + +static struct clock_event_device sp804_clockevent = { + .name = "timer0", + .shift = 32, + .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, + .set_mode = sp804_set_mode, + .set_next_event = sp804_set_next_event, + .rating = 300, + .cpumask = cpu_all_mask, +}; + +static struct irqaction sp804_timer_irq = { + .name = "timer", + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .handler = sp804_timer_interrupt, + .dev_id = &sp804_clockevent, +}; + +void __init sp804_clockevents_init(void __iomem *base, unsigned int timer_irq) +{ + struct clock_event_device *evt = &sp804_clockevent; + + clkevt_base = base; + + evt->irq = timer_irq; + evt->mult = div_sc(TIMER_FREQ_KHZ, NSEC_PER_MSEC, evt->shift); + evt->max_delta_ns = clockevent_delta2ns(0xffffffff, evt); + evt->min_delta_ns = clockevent_delta2ns(0xf, evt); + + setup_irq(timer_irq, &sp804_timer_irq); + clockevents_register_device(evt); +} |