arch/h8300/kernel/timer/timer16.c

   1 /*
   2  *  linux/arch/h8300/kernel/timer/timer16.c
   3  *
   4  *  Yoshinori Sato <ysato@users.sourcefoge.jp>
   5  *
   6  *  16bit Timer Handler
   7  *
   8  */
   9
  10 #include <linux/errno.h>
  11 #include <linux/sched.h>
  12 #include <linux/kernel.h>
  13 #include <linux/param.h>
  14 #include <linux/string.h>
  15 #include <linux/mm.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/init.h>
  18 #include <linux/timex.h>
  19
  20 #include <asm/segment.h>
  21 #include <asm/io.h>
  22 #include <asm/irq.h>
  23 #include <asm/regs306x.h>
  24
  25 /* 16bit timer */
  26 #if CONFIG_H8300_TIMER16_CH == 0
  27 #define _16BASE 0xffff78
  28 #define _16IRQ  24
  29 #elif CONFIG_H8300_TIMER16_CH == 1
  30 #define _16BASE 0xffff80
  31 #define _16IRQ  28
  32 #elif CONFIG_H8300_TIMER16_CH == 2
  33 #define _16BASE 0xffff88
  34 #define _16IRQ  32
  35 #else
  36 #error Unknown timer channel.
  37 #endif
  38
  39 #define TCR     0
  40 #define TIOR    1
  41 #define TCNT    2
  42 #define GRA     4
  43 #define GRB     6
  44
  45 #define H8300_TIMER_FREQ CONFIG_CPU_CLOCK*10000 /* Timer input freq. */
  46
  47 static irqreturn_t timer_interrupt(int irq, void *dev_id)
  48 {
  49         h8300_timer_tick();
  50         ctrl_bclr(CONFIG_H8300_TIMER16_CH, TISRA);
  51         return IRQ_HANDLED;
  52 }
  53
  54 static struct irqaction timer16_irq = {
  55         .name           = "timer-16",
  56         .handler        = timer_interrupt,
  57         .flags          = IRQF_DISABLED | IRQF_TIMER,
  58 };
  59
  60 static const int __initdata divide_rate[] = {1, 2, 4, 8};
  61
  62 void __init h8300_timer_setup(void)
  63 {
  64         unsigned int div;
  65         unsigned int cnt;
  66
  67         calc_param(cnt, div, divide_rate, 0x10000);
  68
  69         setup_irq(_16IRQ, &timer16_irq);
  70
  71         /* initialize timer */
  72         ctrl_outb(0, TSTR);
  73         ctrl_outb(CCLR0 | div, _16BASE + TCR);
  74         ctrl_outw(cnt, _16BASE + GRA);
  75         ctrl_bset(4 + CONFIG_H8300_TIMER16_CH, TISRA);
  76         ctrl_bset(CONFIG_H8300_TIMER16_CH, TSTR);
  77 }