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author | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
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committer | root <root@artemis.panaceas.org> | 2015-12-25 04:40:36 +0000 |
commit | 849369d6c66d3054688672f97d31fceb8e8230fb (patch) | |
tree | 6135abc790ca67dedbe07c39806591e70eda81ce /arch/arm/mach-footbridge/isa-timer.c | |
download | linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.gz linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.tar.bz2 linux-3.0.35-kobo-849369d6c66d3054688672f97d31fceb8e8230fb.zip |
initial_commit
Diffstat (limited to 'arch/arm/mach-footbridge/isa-timer.c')
-rw-r--r-- | arch/arm/mach-footbridge/isa-timer.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/arch/arm/mach-footbridge/isa-timer.c b/arch/arm/mach-footbridge/isa-timer.c new file mode 100644 index 00000000..7020f1a3 --- /dev/null +++ b/arch/arm/mach-footbridge/isa-timer.c @@ -0,0 +1,95 @@ +/* + * linux/arch/arm/mach-footbridge/isa-timer.c + * + * Copyright (C) 1998 Russell King. + * Copyright (C) 1998 Phil Blundell + */ +#include <linux/clockchips.h> +#include <linux/clocksource.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <linux/timex.h> + +#include <asm/irq.h> +#include <asm/i8253.h> +#include <asm/mach/time.h> + +#include "common.h" + +DEFINE_RAW_SPINLOCK(i8253_lock); + +static void pit_set_mode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + unsigned long flags; + + raw_local_irq_save(flags); + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + outb_p(0x34, PIT_MODE); + outb_p(PIT_LATCH & 0xff, PIT_CH0); + outb_p(PIT_LATCH >> 8, PIT_CH0); + break; + + case CLOCK_EVT_MODE_SHUTDOWN: + case CLOCK_EVT_MODE_UNUSED: + outb_p(0x30, PIT_MODE); + outb_p(0, PIT_CH0); + outb_p(0, PIT_CH0); + break; + + case CLOCK_EVT_MODE_ONESHOT: + case CLOCK_EVT_MODE_RESUME: + break; + } + local_irq_restore(flags); +} + +static int pit_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + return 0; +} + +static struct clock_event_device pit_ce = { + .name = "pit", + .features = CLOCK_EVT_FEAT_PERIODIC, + .set_mode = pit_set_mode, + .set_next_event = pit_set_next_event, + .shift = 32, +}; + +static irqreturn_t pit_timer_interrupt(int irq, void *dev_id) +{ + struct clock_event_device *ce = dev_id; + ce->event_handler(ce); + return IRQ_HANDLED; +} + +static struct irqaction pit_timer_irq = { + .name = "pit", + .handler = pit_timer_interrupt, + .flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL, + .dev_id = &pit_ce, +}; + +static void __init isa_timer_init(void) +{ + pit_ce.cpumask = cpumask_of(smp_processor_id()); + pit_ce.mult = div_sc(PIT_TICK_RATE, NSEC_PER_SEC, pit_ce.shift); + pit_ce.max_delta_ns = clockevent_delta2ns(0x7fff, &pit_ce); + pit_ce.min_delta_ns = clockevent_delta2ns(0x000f, &pit_ce); + + clocksource_i8253_init(); + + setup_irq(pit_ce.irq, &pit_timer_irq); + clockevents_register_device(&pit_ce); +} + +struct sys_timer isa_timer = { + .init = isa_timer_init, +}; |