include/asm-arm/arch-l7200/time.h

   1 /*
   2  * linux/include/asm-arm/arch-l7200/time.h
   3  *
   4  * Copyright (C) 2000 Rob Scott (rscott@mtrob.fdns.net)
   5  *                    Steve Hill (sjhill@cotw.com)
   6  *
   7  * Changelog:
   8  *   01-02-2000 RS      Created l7200 version, derived from rpc code
   9  *   05-03-2000 SJH     Complete rewrite
  10  */
  11 #ifndef _ASM_ARCH_TIME_H
  12 #define _ASM_ARCH_TIME_H
  13
  14 #include <asm/arch/irqs.h>
  15
  16 /*
  17  * RTC base register address
  18  */
  19 #define RTC_BASE        (IO_BASE_2 + 0x2000)
  20
  21 /*
  22  * RTC registers
  23  */
  24 #define RTC_RTCDR       (*(volatile unsigned char *) (RTC_BASE + 0x000))
  25 #define RTC_RTCMR       (*(volatile unsigned char *) (RTC_BASE + 0x004))
  26 #define RTC_RTCS        (*(volatile unsigned char *) (RTC_BASE + 0x008))
  27 #define RTC_RTCC        (*(volatile unsigned char *) (RTC_BASE + 0x008))
  28 #define RTC_RTCDV       (*(volatile unsigned char *) (RTC_BASE + 0x00c))
  29 #define RTC_RTCCR       (*(volatile unsigned char *) (RTC_BASE + 0x010))
  30
  31 /*
  32  * RTCCR register values
  33  */
  34 #define RTC_RATE_32     0x00      /* 32 Hz tick */
  35 #define RTC_RATE_64     0x10      /* 64 Hz tick */
  36 #define RTC_RATE_128    0x20      /* 128 Hz tick */
  37 #define RTC_RATE_256    0x30      /* 256 Hz tick */
  38 #define RTC_EN_ALARM    0x01      /* Enable alarm */
  39 #define RTC_EN_TIC      0x04      /* Enable counter */
  40 #define RTC_EN_STWDOG   0x08      /* Enable watchdog */
  41
  42 /*
  43  * Handler for RTC timer interrupt
  44  */
  45 static irqreturn_t
  46 timer_interrupt(int irq, void *dev_id)
  47 {
  48         struct pt_regs *regs = get_irq_regs();
  49         do_timer(1);
  50 #ifndef CONFIG_SMP
  51         update_process_times(user_mode(regs));
  52 #endif
  53         do_profile(regs);
  54         RTC_RTCC = 0;                           /* Clear interrupt */
  55
  56         return IRQ_HANDLED;
  57 }
  58
  59 /*
  60  * Set up RTC timer interrupt, and return the current time in seconds.
  61  */
  62 void __init time_init(void)
  63 {
  64         RTC_RTCC = 0;                           /* Clear interrupt */
  65
  66         timer_irq.handler = timer_interrupt;
  67
  68         setup_irq(IRQ_RTC_TICK, &timer_irq);
  69
  70         RTC_RTCCR = RTC_RATE_128 | RTC_EN_TIC;  /* Set rate and enable timer */
  71 }
  72
  73 #endif