hw/core/clock.c

   1 /*
   2  * Hardware Clocks
   3  *
   4  * Copyright GreenSocs 2016-2020
   5  *
   6  * Authors:
   7  *  Frederic Konrad
   8  *  Damien Hedde
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "hw/clock.h"
  16 #include "trace.h"
  17
  18 #define CLOCK_PATH(_clk) (_clk->canonical_path)
  19
  20 void clock_setup_canonical_path(Clock *clk)
  21 {
  22     g_free(clk->canonical_path);
  23     clk->canonical_path = object_get_canonical_path(OBJECT(clk));
  24 }
  25
  26 void clock_set_callback(Clock *clk, ClockCallback *cb, void *opaque)
  27 {
  28     clk->callback = cb;
  29     clk->callback_opaque = opaque;
  30 }
  31
  32 void clock_clear_callback(Clock *clk)
  33 {
  34     clock_set_callback(clk, NULL, NULL);
  35 }
  36
  37 bool clock_set(Clock *clk, uint64_t period)
  38 {
  39     if (clk->period == period) {
  40         return false;
  41     }
  42     trace_clock_set(CLOCK_PATH(clk), CLOCK_PERIOD_TO_NS(clk->period),
  43                     CLOCK_PERIOD_TO_NS(period));
  44     clk->period = period;
  45
  46     return true;
  47 }
  48
  49 static void clock_propagate_period(Clock *clk, bool call_callbacks)
  50 {
  51     Clock *child;
  52
  53     QLIST_FOREACH(child, &clk->children, sibling) {
  54         if (child->period != clk->period) {
  55             child->period = clk->period;
  56             trace_clock_update(CLOCK_PATH(child), CLOCK_PATH(clk),
  57                                CLOCK_PERIOD_TO_NS(clk->period),
  58                                call_callbacks);
  59             if (call_callbacks && child->callback) {
  60                 child->callback(child->callback_opaque);
  61             }
  62             clock_propagate_period(child, call_callbacks);
  63         }
  64     }
  65 }
  66
  67 void clock_propagate(Clock *clk)
  68 {
  69     assert(clk->source == NULL);
  70     trace_clock_propagate(CLOCK_PATH(clk));
  71     clock_propagate_period(clk, true);
  72 }
  73
  74 void clock_set_source(Clock *clk, Clock *src)
  75 {
  76     /* changing clock source is not supported */
  77     assert(!clk->source);
  78
  79     trace_clock_set_source(CLOCK_PATH(clk), CLOCK_PATH(src));
  80
  81     clk->period = src->period;
  82     QLIST_INSERT_HEAD(&src->children, clk, sibling);
  83     clk->source = src;
  84     clock_propagate_period(clk, false);
  85 }
  86
  87 static void clock_disconnect(Clock *clk)
  88 {
  89     if (clk->source == NULL) {
  90         return;
  91     }
  92
  93     trace_clock_disconnect(CLOCK_PATH(clk));
  94
  95     clk->source = NULL;
  96     QLIST_REMOVE(clk, sibling);
  97 }
  98
  99 static void clock_initfn(Object *obj)
 100 {
 101     Clock *clk = CLOCK(obj);
 102
 103     QLIST_INIT(&clk->children);
 104 }
 105
 106 static void clock_finalizefn(Object *obj)
 107 {
 108     Clock *clk = CLOCK(obj);
 109     Clock *child, *next;
 110
 111     /* clear our list of children */
 112     QLIST_FOREACH_SAFE(child, &clk->children, sibling, next) {
 113         clock_disconnect(child);
 114     }
 115
 116     /* remove us from source's children list */
 117     clock_disconnect(clk);
 118
 119     g_free(clk->canonical_path);
 120 }
 121
 122 static const TypeInfo clock_info = {
 123     .name              = TYPE_CLOCK,
 124     .parent            = TYPE_OBJECT,
 125     .instance_size     = sizeof(Clock),
 126     .instance_init     = clock_initfn,
 127     .instance_finalize = clock_finalizefn,
 128 };
 129
 130 static void clock_register_types(void)
 131 {
 132     type_register_static(&clock_info);
 133 }
 134
 135 type_init(clock_register_types)