hw/core/qdev-clock.c

   1 /*
   2  * Device's clock input and output
   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 "qemu/error-report.h"
  16 #include "hw/qdev-clock.h"
  17 #include "hw/qdev-core.h"
  18 #include "qapi/error.h"
  19
  20 /*
  21  * qdev_init_clocklist:
  22  * Add a new clock in a device
  23  */
  24 static NamedClockList *qdev_init_clocklist(DeviceState *dev, const char *name,
  25                                            bool output, Clock *clk)
  26 {
  27     NamedClockList *ncl;
  28
  29     /*
  30      * Clock must be added before realize() so that we can compute the
  31      * clock's canonical path during device_realize().
  32      */
  33     assert(!dev->realized);
  34
  35     /*
  36      * The ncl structure is freed by qdev_finalize_clocklist() which will
  37      * be called during @dev's device_finalize().
  38      */
  39     ncl = g_new0(NamedClockList, 1);
  40     ncl->name = g_strdup(name);
  41     ncl->output = output;
  42     ncl->alias = (clk != NULL);
  43
  44     /*
  45      * Trying to create a clock whose name clashes with some other
  46      * clock or property is a bug in the caller and we will abort().
  47      */
  48     if (clk == NULL) {
  49         clk = CLOCK(object_new(TYPE_CLOCK));
  50         object_property_add_child(OBJECT(dev), name, OBJECT(clk));
  51         if (output) {
  52             /*
  53              * Remove object_new()'s initial reference.
  54              * Note that for inputs, the reference created by object_new()
  55              * will be deleted in qdev_finalize_clocklist().
  56              */
  57             object_unref(OBJECT(clk));
  58         }
  59     } else {
  60         object_property_add_link(OBJECT(dev), name,
  61                                  object_get_typename(OBJECT(clk)),
  62                                  (Object **) &ncl->clock,
  63                                  NULL, OBJ_PROP_LINK_STRONG);
  64         /*
  65          * Since the link property has the OBJ_PROP_LINK_STRONG flag, the clk
  66          * object reference count gets decremented on property deletion.
  67          * However object_property_add_link does not increment it since it
  68          * doesn't know the linked object. Increment it here to ensure the
  69          * aliased clock stays alive during this device life-time.
  70          */
  71         object_ref(OBJECT(clk));
  72     }
  73
  74     ncl->clock = clk;
  75
  76     QLIST_INSERT_HEAD(&dev->clocks, ncl, node);
  77     return ncl;
  78 }
  79
  80 void qdev_finalize_clocklist(DeviceState *dev)
  81 {
  82     /* called by @dev's device_finalize() */
  83     NamedClockList *ncl, *ncl_next;
  84
  85     QLIST_FOREACH_SAFE(ncl, &dev->clocks, node, ncl_next) {
  86         QLIST_REMOVE(ncl, node);
  87         if (!ncl->output && !ncl->alias) {
  88             /*
  89              * We kept a reference on the input clock to ensure it lives up to
  90              * this point so we can safely remove the callback.
  91              * It avoids having a callback to a deleted object if ncl->clock
  92              * is still referenced somewhere else (eg: by a clock output).
  93              */
  94             clock_clear_callback(ncl->clock);
  95             object_unref(OBJECT(ncl->clock));
  96         }
  97         g_free(ncl->name);
  98         g_free(ncl);
  99     }
 100 }
 101
 102 Clock *qdev_init_clock_out(DeviceState *dev, const char *name)
 103 {
 104     NamedClockList *ncl;
 105
 106     assert(name);
 107
 108     ncl = qdev_init_clocklist(dev, name, true, NULL);
 109
 110     return ncl->clock;
 111 }
 112
 113 Clock *qdev_init_clock_in(DeviceState *dev, const char *name,
 114                           ClockCallback *callback, void *opaque,
 115                           unsigned int events)
 116 {
 117     NamedClockList *ncl;
 118
 119     assert(name);
 120
 121     ncl = qdev_init_clocklist(dev, name, false, NULL);
 122
 123     if (callback) {
 124         clock_set_callback(ncl->clock, callback, opaque, events);
 125     }
 126     return ncl->clock;
 127 }
 128
 129 void qdev_init_clocks(DeviceState *dev, const ClockPortInitArray clocks)
 130 {
 131     const struct ClockPortInitElem *elem;
 132
 133     for (elem = &clocks[0]; elem->name != NULL; elem++) {
 134         Clock **clkp;
 135         /* offset cannot be inside the DeviceState part */
 136         assert(elem->offset > sizeof(DeviceState));
 137         clkp = ((void *)dev) + elem->offset;
 138         if (elem->is_output) {
 139             *clkp = qdev_init_clock_out(dev, elem->name);
 140         } else {
 141             *clkp = qdev_init_clock_in(dev, elem->name, elem->callback, dev,
 142                                        elem->callback_events);
 143         }
 144     }
 145 }
 146
 147 static NamedClockList *qdev_get_clocklist(DeviceState *dev, const char *name)
 148 {
 149     NamedClockList *ncl;
 150
 151     QLIST_FOREACH(ncl, &dev->clocks, node) {
 152         if (strcmp(name, ncl->name) == 0) {
 153             return ncl;
 154         }
 155     }
 156
 157     return NULL;
 158 }
 159
 160 Clock *qdev_get_clock_in(DeviceState *dev, const char *name)
 161 {
 162     NamedClockList *ncl;
 163
 164     assert(name);
 165
 166     ncl = qdev_get_clocklist(dev, name);
 167     if (!ncl) {
 168         error_report("Can not find clock-in '%s' for device type '%s'",
 169                      name, object_get_typename(OBJECT(dev)));
 170         abort();
 171     }
 172     assert(!ncl->output);
 173
 174     return ncl->clock;
 175 }
 176
 177 Clock *qdev_get_clock_out(DeviceState *dev, const char *name)
 178 {
 179     NamedClockList *ncl;
 180
 181     assert(name);
 182
 183     ncl = qdev_get_clocklist(dev, name);
 184     if (!ncl) {
 185         error_report("Can not find clock-out '%s' for device type '%s'",
 186                      name, object_get_typename(OBJECT(dev)));
 187         abort();
 188     }
 189     assert(ncl->output);
 190
 191     return ncl->clock;
 192 }
 193
 194 Clock *qdev_alias_clock(DeviceState *dev, const char *name,
 195                         DeviceState *alias_dev, const char *alias_name)
 196 {
 197     NamedClockList *ncl;
 198
 199     assert(name && alias_name);
 200
 201     ncl = qdev_get_clocklist(dev, name);
 202
 203     qdev_init_clocklist(alias_dev, alias_name, ncl->output, ncl->clock);
 204
 205     return ncl->clock;
 206 }
 207
 208 void qdev_connect_clock_in(DeviceState *dev, const char *name, Clock *source)
 209 {
 210     assert(!dev->realized);
 211     clock_set_source(qdev_get_clock_in(dev, name), source);
 212 }