arch/arm/mach-espd_4510b/time.c

   1 /*
   2  *  linux/arch/armnommu/mach-espd_4510b/time.c
   3  *
   4  *  Copyright (C) SAMSUNG ELECTRONICS
   5  *                      Hyok S. Choi <hyok.choi@samsung.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21 #include <linux/kernel.h>
  22 #include <linux/sched.h>
  23 #include <linux/init.h>
  24 #include <linux/interrupt.h>
  25 #include <asm/system.h>
  26 #include <asm/leds.h>
  27 #include <asm/mach-types.h>
  28
  29 #include <asm/io.h>
  30 #include <asm/irq.h>
  31 #include <asm/mach/time.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/hardware.h>
  34 #include <asm/arch/timex.h>
  35 #include <asm/mach/irq.h>
  36
  37 #define CLOCKS_PER_USEC (CONFIG_ARM_CLK/1000000)
  38
  39 static volatile unsigned long timer_cnt;
  40
  41 unsigned long s3c4510b_gettimeoffset (void)
  42 {
  43         unsigned long usec;
  44
  45         /* returns microseconds -- timer 1 is free running in countdown mode */
  46         usec = 0xFFFFFFFF - inl( REG_TCNT1);
  47         usec /= CLOCKS_PER_USEC;
  48
  49         return usec;
  50 }
  51
  52 static irqreturn_t
  53 s3c4510b_timer_interrupt(int irq, void *dev_id)
  54 {
  55
  56         timer_cnt++;
  57
  58 #ifdef CONFIG_ARCH_ESPD_4510B
  59         if ( ! (timer_cnt % (HZ/4))) {
  60                 LED_TOGGLE(0);
  61         }
  62 #endif
  63         timer_tick();
  64
  65         return IRQ_HANDLED;
  66 }
  67
  68 static struct irqaction s3c4510b_timer_irq = {
  69         .name           = "S3C4510b Timer Tick",
  70         .flags          = IRQF_DISABLED | IRQF_TIMER,
  71         .handler        = s3c4510b_timer_interrupt
  72 };
  73
  74
  75 /*
  76  * Set up timer interrupt
  77  */
  78
  79 void __init  s3c4510b_time_init (void)
  80 {
  81         u_int32_t period;
  82
  83         /*
  84          * disable and clear timers 0 and 1.  set both timers to
  85          * interval mode.
  86          */
  87         outl( 0x0, REG_TMOD);
  88         /* clear any pending interrupts */
  89         outl( 0x1FFFFF, REG_INTPEND);
  90
  91         timer_cnt = 0;
  92
  93         /* initialize the timer period */
  94         period = (CLOCK_TICK_RATE / HZ);
  95         outl( period, REG_TDATA0);
  96
  97         /* set timer1 to continually count down from FFFFFFFF */
  98         outl( 0xFFFFFFFF, REG_TDATA1);
  99
 100 //      printk(KERN_INFO "time_init():  TICK_RATE: %u, HZ: %u, period: %u\n", CLOCK_TICK_RATE, HZ, period);
 101
 102         s3c4510b_timer_irq.handler = s3c4510b_timer_interrupt;
 103
 104         /* set up the interrupt vevtor for timer 0 match */
 105         setup_irq( INT_TIMER0, &s3c4510b_timer_irq);
 106
 107         /* enable the timer IRQ */
 108         INT_ENABLE( INT_TIMER0);
 109
 110         /* let timer 0 run... */
 111         outl( TM0_RUN | TM1_RUN, REG_TMOD);
 112 }
 113
 114 struct sys_timer s3c4510b_timer = {
 115         .init           = s3c4510b_time_init,
 116         .offset         = s3c4510b_gettimeoffset,
 117 };
 118