arch/arm/mach-epxa10db/time.c

   1 /*
   2  *  linux/arch/arm/mach-epxa10db/time.c
   3  *
   4  *  Copyright (C) 2000 Deep Blue Solutions
   5  *  Copyright (C) 2001 Altera Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/sched.h>
  15
  16 #include <asm/hardware.h>
  17 #include <asm/system.h>
  18 #include <asm/leds.h>
  19
  20 #include <asm/mach/time.h>
  21
  22 #define TIMER00_TYPE (volatile unsigned int*)
  23 #include <asm/arch/timer00.h>
  24
  25 static int epxa10db_set_rtc(void)
  26 {
  27         return 1;
  28 }
  29
  30 static int epxa10db_rtc_init(void)
  31 {
  32         set_rtc = epxa10db_set_rtc;
  33
  34         return 0;
  35 }
  36
  37 __initcall(epxa10db_rtc_init);
  38
  39
  40 /*
  41  * IRQ handler for the timer
  42  */
  43 static irqreturn_t
  44 epxa10db_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  45 {
  46         write_seqlock(&xtime_lock);
  47
  48         // ...clear the interrupt
  49         *TIMER0_CR(IO_ADDRESS(EXC_TIMER00_BASE))|=TIMER0_CR_CI_MSK;
  50
  51         timer_tick(regs);
  52         write_sequnlock(&xtime_lock);
  53
  54         return IRQ_HANDLED;
  55 }
  56
  57 static struct irqaction epxa10db_timer_irq = {
  58         .name           = "Excalibur Timer Tick",
  59         .flags          = SA_INTERRUPT | SA_TIMER,
  60         .handler        = epxa10db_timer_interrupt,
  61 };
  62
  63 /*
  64  * Set up timer interrupt, and return the current time in seconds.
  65  */
  66 static void __init epxa10db_timer_init(void)
  67 {
  68         /* Start the timer */
  69         *TIMER0_LIMIT(IO_ADDRESS(EXC_TIMER00_BASE))=(unsigned int)(EXC_AHB2_CLK_FREQUENCY/200);
  70         *TIMER0_PRESCALE(IO_ADDRESS(EXC_TIMER00_BASE))=1;
  71         *TIMER0_CR(IO_ADDRESS(EXC_TIMER00_BASE))=TIMER0_CR_IE_MSK | TIMER0_CR_S_MSK;
  72
  73         setup_irq(IRQ_TIMER0, &epxa10db_timer_irq);
  74 }
  75
  76 struct sys_timer epxa10db_timer = {
  77         .init           = epxa10db_timer_init,
  78 };