arch/arm/mach-lh7a40x/time.c

   1 /*
   2  *  arch/arm/mach-lh7a40x/time.c
   3  *
   4  *  Copyright (C) 2004 Logic Product Development
   5  *
   6  *  This program is free software; you can redistribute it and/or
   7  *  modify it under the terms of the GNU General Public License
   8  *  version 2 as published by the Free Software Foundation.
   9  *
  10  */
  11 #include <linux/module.h>
  12 #include <linux/kernel.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/time.h>
  15
  16 #include <asm/hardware.h>
  17 #include <asm/io.h>
  18 #include <asm/irq.h>
  19 #include <asm/leds.h>
  20
  21 #include <asm/mach/time.h>
  22 #include "common.h"
  23
  24 #if HZ < 100
  25 # define TIMER_CONTROL  TIMER_CONTROL2
  26 # define TIMER_LOAD     TIMER_LOAD2
  27 # define TIMER_CONSTANT (508469/HZ)
  28 # define TIMER_MODE     (TIMER_C_ENABLE | TIMER_C_PERIODIC | TIMER_C_508KHZ)
  29 # define TIMER_EOI      TIMER_EOI2
  30 # define TIMER_IRQ      IRQ_T2UI
  31 #else
  32 # define TIMER_CONTROL  TIMER_CONTROL3
  33 # define TIMER_LOAD     TIMER_LOAD3
  34 # define TIMER_CONSTANT (3686400/HZ)
  35 # define TIMER_MODE     (TIMER_C_ENABLE | TIMER_C_PERIODIC)
  36 # define TIMER_EOI      TIMER_EOI3
  37 # define TIMER_IRQ      IRQ_T3UI
  38 #endif
  39
  40 static irqreturn_t
  41 lh7a40x_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
  42 {
  43         write_seqlock(&xtime_lock);
  44
  45         TIMER_EOI = 0;
  46         timer_tick(regs);
  47
  48         write_sequnlock(&xtime_lock);
  49
  50         return IRQ_HANDLED;
  51 }
  52
  53 static struct irqaction lh7a40x_timer_irq = {
  54         .name           = "LHA740x Timer Tick",
  55         .flags          = SA_INTERRUPT | SA_TIMER,
  56         .handler        = lh7a40x_timer_interrupt,
  57 };
  58
  59 static void __init lh7a40x_timer_init (void)
  60 {
  61                                 /* Stop/disable all timers */
  62         TIMER_CONTROL1 = 0;
  63         TIMER_CONTROL2 = 0;
  64         TIMER_CONTROL3 = 0;
  65
  66         setup_irq (TIMER_IRQ, &lh7a40x_timer_irq);
  67
  68         TIMER_LOAD = TIMER_CONSTANT;
  69         TIMER_CONTROL = TIMER_MODE;
  70 }
  71
  72 struct sys_timer lh7a40x_timer = {
  73         .init           = &lh7a40x_timer_init,
  74 };