release/src-rt-6.x.4708/linux/linux-2.6.36/arch/mips/jz4740/timer.c

   1 /*
   2  *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
   3  *  JZ4740 platform timer support
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15
  16 #include <linux/io.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19
  20 #include "timer.h"
  21
  22 #include <asm/mach-jz4740/base.h>
  23
  24 void __iomem *jz4740_timer_base;
  25
  26 void jz4740_timer_enable_watchdog(void)
  27 {
  28         writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_CLEAR);
  29 }
  30 EXPORT_SYMBOL_GPL(jz4740_timer_enable_watchdog);
  31
  32 void jz4740_timer_disable_watchdog(void)
  33 {
  34         writel(BIT(16), jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
  35 }
  36 EXPORT_SYMBOL_GPL(jz4740_timer_disable_watchdog);
  37
  38 void __init jz4740_timer_init(void)
  39 {
  40         jz4740_timer_base = ioremap(JZ4740_TCU_BASE_ADDR, 0x100);
  41
  42         if (!jz4740_timer_base)
  43                 panic("Failed to ioremap timer registers");
  44
  45         /* Disable all timer clocks except for those used as system timers */
  46         writel(0x000100fc, jz4740_timer_base + JZ_REG_TIMER_STOP_SET);
  47
  48         /* Timer irqs are unmasked by default, mask them */
  49         writel(0x00ff00ff, jz4740_timer_base + JZ_REG_TIMER_MASK_SET);
  50 }