2 * linux/arch/arm/mach-footbridge/dc21285-timer.c
4 * Copyright (C) 1998 Russell King.
5 * Copyright (C) 1998 Phil Blundell
7 #include <linux/init.h>
8 #include <linux/interrupt.h>
13 #include <asm/hardware/dec21285.h>
14 #include <asm/mach/time.h>
19 * Footbridge timer 1 support.
21 static unsigned long timer1_latch
;
23 static unsigned long timer1_gettimeoffset (void)
25 unsigned long value
= timer1_latch
- *CSR_TIMER1_VALUE
;
27 return ((tick_nsec
/ 1000) * value
) / timer1_latch
;
31 timer1_interrupt(int irq
, void *dev_id
, struct pt_regs
*regs
)
33 write_seqlock(&xtime_lock
);
39 write_sequnlock(&xtime_lock
);
44 static struct irqaction footbridge_timer_irq
= {
45 .name
= "Timer1 timer tick",
46 .handler
= timer1_interrupt
,
47 .flags
= IRQF_DISABLED
| IRQF_TIMER
,
51 * Set up timer interrupt.
53 static void __init
footbridge_timer_init(void)
55 timer1_latch
= (mem_fclk_21285
+ 8 * HZ
) / (16 * HZ
);
58 *CSR_TIMER1_LOAD
= timer1_latch
;
59 *CSR_TIMER1_CNTL
= TIMER_CNTL_ENABLE
| TIMER_CNTL_AUTORELOAD
| TIMER_CNTL_DIV16
;
61 setup_irq(IRQ_TIMER1
, &footbridge_timer_irq
);
66 struct sys_timer footbridge_timer
= {
67 .init
= footbridge_timer_init
,
68 .offset
= timer1_gettimeoffset
,