lunaix-os/hal/timer/timer_device.c

   1 #include <lunaix/spike.h>
   2 #include <lunaix/time.h>
   3
   4 #include <hal/hwtimer.h>
   5
   6 const struct hwtimer_pot* systimer = NULL;
   7
   8 static struct device_alias* timer_alias;
   9 static DEFINE_LLIST(timer_devices);
  10
  11 ticks_t
  12 hwtimer_current_systicks()
  13 {
  14     assert(systimer);
  15     return systimer->systick_raw;
  16 }
  17
  18 ticks_t
  19 hwtimer_to_ticks(u32_t value, int unit)
  20 {
  21     assert(systimer);
  22
  23     // in case system frequency is less than 1000Hz
  24     if (unit != TIME_MS) {
  25         return systimer->running_freq * unit * value;
  26     }
  27
  28     ticks_t freq_ms = systimer->running_freq / 1000;
  29
  30     return freq_ms * value;
  31 }
  32
  33 static struct hwtimer_pot*
  34 __select_timer()
  35 {
  36     struct hwtimer_pot *pos, *n, *sel = NULL;
  37
  38     llist_for_each(pos, n, &timer_devices, timers)
  39     {
  40         if (unlikely(!sel)) {
  41             sel = pos;
  42             continue;
  43         }
  44
  45         if (sel->precedence < pos->precedence) {
  46             sel = pos;
  47         }
  48     }
  49
  50     return sel;
  51 }
  52
  53 void
  54 hwtimer_init(u32_t hertz, void* tick_callback)
  55 {
  56     struct hwtimer_pot* selected;
  57     struct device* time_dev;
  58
  59     selected = __select_timer();
  60
  61     assert(selected);
  62     systimer = selected;
  63
  64     selected->callback = tick_callback;
  65     selected->running_freq = hertz;
  66
  67     selected->ops->calibrate(selected, hertz);
  68
  69     time_dev = potens_dev(selected);
  70     timer_alias = device_addalias(NULL, dev_meta(time_dev), "timer");
  71 }
  72
  73
  74 struct hwtimer_pot*
  75 hwtimer_attach_potens(struct device* dev, int precedence,
  76                       struct hwtimer_pot_ops* ops)
  77 {
  78     struct hwtimer_pot* hwpot;
  79     struct potens_meta* pot;
  80
  81     if (!potens_check_unique(dev, potens(HWTIMER)))
  82     {
  83         return NULL;
  84     }
  85
  86     hwpot = new_potens(potens(HWTIMER), struct hwtimer_pot);
  87     hwpot->ops = ops;
  88     hwpot->precedence = precedence;
  89
  90     device_grant_potens(dev, potens_meta(hwpot));
  91
  92     llist_append(&timer_devices, &hwpot->timers);
  93
  94     return hwpot;
  95 }