sys/src/9/ppc/saturntimer.c

   1 #include "u.h"
   2 #include "../port/lib.h"
   3 #include "mem.h"
   4 #include "dat.h"
   5 #include "fns.h"
   6 #include "io.h"
   7 #include "../port/error.h"
   8 #include "msaturn.h"
   9
  10 enum {
  11         Timer_ctrl = Saturn + 0x0106,
  12         Timer0_load = Saturn + 0x0200,
  13         Timer0_cnt = Saturn + 0x0204,
  14         Timer1_load = Saturn + 0x0300,
  15         Timer1_cnt = Saturn + 0x0304,
  16
  17         T0_event = RBIT(13, ushort),
  18         T0_ie = RBIT(14, ushort),
  19         T0_cen = RBIT(15, ushort),
  20         T1_event = RBIT(5, ushort),
  21         T1_ie = RBIT(6, ushort),
  22         T1_cen = RBIT(7, ushort),
  23 };
  24
  25 static ulong ticks;
  26 static Lock tlock;
  27 static ushort timer_ctl;
  28
  29 void
  30 saturntimerintr(Ureg *u, void*)
  31 {
  32         ushort ctl = *(ushort*)Timer_ctrl, v = 0;
  33
  34         if(ctl&T1_event){
  35                 v = T1_event;
  36                 ticks++;
  37         }
  38
  39         *(ushort*)Timer_ctrl = timer_ctl|T0_event|v;
  40         intack();
  41         timerintr(u, 0);
  42 }
  43
  44 void
  45 timerinit(void)
  46 {
  47         *(ushort*)Timer_ctrl = 0;
  48         *(ulong*)Timer0_load = m->bushz  / HZ;
  49         *(ulong*)Timer0_cnt = m->bushz / HZ;
  50         *(ulong*)Timer1_load = m->bushz;
  51         *(ulong*)Timer1_cnt = m->bushz;
  52
  53         intrenable(Vectimer0, saturntimerintr, nil, "timer");
  54
  55         timer_ctl = T0_cen|T0_ie|T1_cen;
  56         *(ushort*)Timer_ctrl = timer_ctl;
  57 }
  58
  59 uvlong
  60 fastticks(uvlong *hz)
  61 {
  62         assert(*(ushort*)Timer_ctrl&T1_cen);
  63         if(*(ushort*)Timer_ctrl&T1_event){
  64                 *(ushort*)Timer_ctrl = timer_ctl|T1_event;
  65                 ticks++;
  66         }
  67
  68         if (hz)
  69                 *hz = m->bushz;
  70
  71         return (uvlong)ticks*m->bushz+(uvlong)(m->bushz-*(ulong*)Timer1_cnt);
  72 }
  73
  74 void
  75 timerset(uvlong next)
  76 {
  77         ulong offset;
  78         uvlong now;
  79
  80         ilock(&tlock);
  81         *(ushort*)Timer_ctrl = T1_cen;
  82
  83         now = fastticks(nil);
  84         offset = next - now;
  85         if((long)offset < 10000)
  86                 offset = 10000;
  87         else if(offset > m->bushz)
  88                 offset = m->bushz;
  89
  90         *(ulong*)Timer0_cnt = offset;
  91         *(ushort*)Timer_ctrl = timer_ctl;
  92         assert(*(ushort*)Timer_ctrl & T1_cen);
  93         iunlock(&tlock);
  94 }
  95