include/asm-sh/fast_timer.h

   1 #ifndef __ASM_SH_FAST_TIMER_H
   2 #define __ASM_SH_FAST_TIMER_H
   3
   4 #include <linux/sched.h>
   5 #include <linux/interrupt.h>
   6 #include <asm/io.h>
   7 #include <asm/clock.h>
   8
   9 #define FAST_POLL_INTR
  10
  11 #define FASTTIMER_IRQ   17
  12 #define FASTTIMER_IPR_ADDR  INTC_IPRA
  13 #define FASTTIMER_IPR_POS    2
  14 #define FASTTIMER_PRIORITY   3
  15
  16 #ifdef FAST_POLL_INTR
  17 #define TMU1_TCR_INIT   0x0020
  18 #else
  19 #define TMU1_TCR_INIT   0
  20 #endif
  21 #define TMU_TSTR_INIT   1
  22 #define TMU1_TCR_CALIB  0x0000
  23 #define TMU_TOCR        0xffd80000      /* Byte access */
  24 #define TMU_TSTR        0xffd80004      /* Byte access */
  25 #define TMU1_TCOR       0xffd80014      /* Long access */
  26 #define TMU1_TCNT       0xffd80018      /* Long access */
  27 #define TMU1_TCR        0xffd8001c      /* Word access */
  28
  29 static irqreturn_t
  30 fast_timer_interrupt(int irq, void *dev_id)
  31 {
  32         unsigned long timer_status;
  33
  34         timer_status = ctrl_inw(TMU1_TCR);
  35         timer_status &= ~0x100;
  36         ctrl_outw(timer_status, TMU1_TCR);
  37
  38         do_fast_timer();
  39         return IRQ_HANDLED;
  40 }
  41
  42 static void fast_timer_set(void)
  43 {
  44         unsigned long interval;
  45         struct clk *clk = clk_get("module_clk");
  46
  47 #ifdef FAST_POLL_INTR
  48         if (clk) {
  49                 interval = (clk_get_rate(clk)/4 + fast_timer_rate/2) / fast_timer_rate;
  50         } else
  51 #endif
  52         interval = 0xffffffff;
  53
  54         ctrl_outb(ctrl_inb(TMU_TSTR) & ~0x2, TMU_TSTR); /* disable timer 1 */
  55         ctrl_outw(TMU1_TCR_INIT, TMU1_TCR);
  56         ctrl_outl(interval, TMU1_TCOR);
  57         ctrl_outl(interval, TMU1_TCNT);
  58         ctrl_outb(ctrl_inb(TMU_TSTR) | 0x2, TMU_TSTR); /* enable timer 1 */
  59 }
  60
  61 static int __init fast_timer_setup(void)
  62 {
  63 #ifdef FAST_POLL_INTR
  64         static struct ipr_data fast_timer_ipr_map[] = {
  65                 { FASTTIMER_IRQ, FASTTIMER_IPR_ADDR, FASTTIMER_IPR_POS, FASTTIMER_PRIORITY},
  66         };
  67
  68         make_ipr_irq(fast_timer_ipr_map, ARRAY_SIZE(fast_timer_ipr_map));
  69
  70         if (request_irq(FASTTIMER_IRQ, fast_timer_interrupt, SA_INTERRUPT,
  71                         "fast timer", NULL))
  72                 return -EBUSY;
  73 #endif
  74
  75         fast_timer_rate = cpu_data->type == CPU_SH7751R ? 2000 : 1000;
  76         fast_timer_set();
  77
  78 #ifdef FAST_POLL_INTR
  79         printk("fast timer: %d Hz, IRQ %d\n", fast_timer_rate,
  80                         FASTTIMER_IRQ);
  81 #else
  82         printk("fast timer: %d Hz\n", fast_timer_rate);
  83 #endif
  84         return 0;
  85 }
  86
  87 static void __exit fast_timer_cleanup(void)
  88 {
  89         ctrl_outb(ctrl_inb(TMU_TSTR) & ~0x2, TMU_TSTR); /* disable timer 1 */
  90         free_irq(FASTTIMER_IRQ, NULL);
  91 }
  92
  93 #if 0
  94 /*
  95  * return the current ticks on the fast timer
  96  */
  97
  98 unsigned long fast_timer_count(void)
  99 {
 100         return(ctrl_inl(TMU1_TCNT));
 101 }
 102 #endif
 103
 104 #endif