arch/arm/mach-w90x900/time.c

   1 /*
   2  * linux/arch/arm/mach-w90x900/time.c
   3  *
   4  * Based on linux/arch/arm/plat-s3c24xx/time.c by Ben Dooks
   5  *
   6  * Copyright (c) 2008 Nuvoton technology corporation
   7  * All rights reserved.
   8  *
   9  * Wan ZongShun <mcuos.com@gmail.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/init.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/err.h>
  23 #include <linux/clk.h>
  24 #include <linux/io.h>
  25 #include <linux/leds.h>
  26
  27 #include <asm/mach-types.h>
  28 #include <asm/mach/irq.h>
  29 #include <asm/mach/time.h>
  30
  31 #include <mach/map.h>
  32 #include <mach/regs-timer.h>
  33
  34 static unsigned long w90x900_gettimeoffset(void)
  35 {
  36         return 0;
  37 }
  38
  39 /*IRQ handler for the timer*/
  40
  41 static irqreturn_t
  42 w90x900_timer_interrupt(int irq, void *dev_id)
  43 {
  44         timer_tick();
  45         __raw_writel(0x01, REG_TISR); /* clear TIF0 */
  46         return IRQ_HANDLED;
  47 }
  48
  49 static struct irqaction w90x900_timer_irq = {
  50         .name           = "w90x900 Timer Tick",
  51         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
  52         .handler        = w90x900_timer_interrupt,
  53 };
  54
  55 /*Set up timer reg.*/
  56
  57 static void w90x900_timer_setup(void)
  58 {
  59         __raw_writel(0, REG_TCSR0);
  60         __raw_writel(0, REG_TCSR1);
  61         __raw_writel(0, REG_TCSR2);
  62         __raw_writel(0, REG_TCSR3);
  63         __raw_writel(0, REG_TCSR4);
  64         __raw_writel(0x1F, REG_TISR);
  65         __raw_writel(15000000/(100 * 100), REG_TICR0);
  66         __raw_writel(0x68000063, REG_TCSR0);
  67 }
  68
  69 static void __init w90x900_timer_init(void)
  70 {
  71         w90x900_timer_setup();
  72         setup_irq(IRQ_TIMER0, &w90x900_timer_irq);
  73 }
  74
  75 struct sys_timer w90x900_timer = {
  76         .init           = w90x900_timer_init,
  77         .offset         = w90x900_gettimeoffset,
  78         .resume         = w90x900_timer_setup
  79 };