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/irq.h>
  15 #include <linux/time.h>
  16
  17 #include <asm/hardware.h>
  18 #include <asm/io.h>
  19 #include <asm/irq.h>
  20 #include <asm/leds.h>
  21
  22 #include <asm/mach/time.h>
  23 #include "common.h"
  24
  25 #if HZ < 100
  26 # define TIMER_CONTROL  TIMER_CONTROL2
  27 # define TIMER_LOAD     TIMER_LOAD2
  28 # define TIMER_CONSTANT (508469/HZ)
  29 # define TIMER_MODE     (TIMER_C_ENABLE | TIMER_C_PERIODIC | TIMER_C_508KHZ)
  30 # define TIMER_EOI      TIMER_EOI2
  31 # define TIMER_IRQ      IRQ_T2UI
  32 #else
  33 # define TIMER_CONTROL  TIMER_CONTROL3
  34 # define TIMER_LOAD     TIMER_LOAD3
  35 # define TIMER_CONSTANT (3686400/HZ)
  36 # define TIMER_MODE     (TIMER_C_ENABLE | TIMER_C_PERIODIC)
  37 # define TIMER_EOI      TIMER_EOI3
  38 # define TIMER_IRQ      IRQ_T3UI
  39 #endif
  40
  41 static irqreturn_t
  42 lh7a40x_timer_interrupt(int irq, void *dev_id)
  43 {
  44         write_seqlock(&xtime_lock);
  45
  46         TIMER_EOI = 0;
  47         timer_tick();
  48
  49         write_sequnlock(&xtime_lock);
  50
  51         return IRQ_HANDLED;
  52 }
  53
  54 static struct irqaction lh7a40x_timer_irq = {
  55         .name           = "LHA740x Timer Tick",
  56         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
  57         .handler        = lh7a40x_timer_interrupt,
  58 };
  59
  60 static void __init lh7a40x_timer_init (void)
  61 {
  62                                 /* Stop/disable all timers */
  63         TIMER_CONTROL1 = 0;
  64         TIMER_CONTROL2 = 0;
  65         TIMER_CONTROL3 = 0;
  66
  67         setup_irq (TIMER_IRQ, &lh7a40x_timer_irq);
  68
  69         TIMER_LOAD = TIMER_CONSTANT;
  70         TIMER_CONTROL = TIMER_MODE;
  71 }
  72
  73 struct sys_timer lh7a40x_timer = {
  74         .init           = &lh7a40x_timer_init,
  75 };