xref: /qemu/hw/core/qdev-clock.c (revision 513823e7521a09ed7ad1e32e6454bac3b2cbf52d)
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 alias, 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->alias = alias;
42     ncl->output = output;
43     ncl->clock = clk;
44 
45     QLIST_INSERT_HEAD(&dev->clocks, ncl, node);
46     return ncl;
47 }
48 
49 void qdev_finalize_clocklist(DeviceState *dev)
50 {
51     /* called by @dev's device_finalize() */
52     NamedClockList *ncl, *ncl_next;
53 
54     QLIST_FOREACH_SAFE(ncl, &dev->clocks, node, ncl_next) {
55         QLIST_REMOVE(ncl, node);
56         if (!ncl->alias) {
57             /*
58              * We kept a reference on the input clock to ensure it lives up to
59              * this point; it is used by the monitor to show the frequency.
60              */
61             object_unref(OBJECT(ncl->clock));
62         }
63         g_free(ncl->name);
64         g_free(ncl);
65     }
66 }
67 
68 Clock *qdev_init_clock_out(DeviceState *dev, const char *name)
69 {
70     Clock *clk = CLOCK(object_new(TYPE_CLOCK));
71     object_property_add_child(OBJECT(dev), name, OBJECT(clk));
72 
73     qdev_init_clocklist(dev, name, false, true, clk);
74     return clk;
75 }
76 
77 Clock *qdev_init_clock_in(DeviceState *dev, const char *name,
78                           ClockCallback *callback, void *opaque,
79                           unsigned int events)
80 {
81     Clock *clk = CLOCK(object_new(TYPE_CLOCK));
82     object_property_add_child(OBJECT(dev), name, OBJECT(clk));
83 
84     qdev_init_clocklist(dev, name, false, false, clk);
85     if (callback) {
86         clock_set_callback(clk, callback, opaque, events);
87     }
88     return clk;
89 }
90 
91 void qdev_init_clocks(DeviceState *dev, const ClockPortInitArray clocks)
92 {
93     const struct ClockPortInitElem *elem;
94 
95     for (elem = &clocks[0]; elem->name != NULL; elem++) {
96         Clock **clkp;
97         /* offset cannot be inside the DeviceState part */
98         assert(elem->offset > sizeof(DeviceState));
99         clkp = ((void *)dev) + elem->offset;
100         if (elem->is_output) {
101             *clkp = qdev_init_clock_out(dev, elem->name);
102         } else {
103             *clkp = qdev_init_clock_in(dev, elem->name, elem->callback, dev,
104                                        elem->callback_events);
105         }
106     }
107 }
108 
109 static NamedClockList *qdev_get_clocklist(DeviceState *dev, const char *name)
110 {
111     NamedClockList *ncl;
112 
113     QLIST_FOREACH(ncl, &dev->clocks, node) {
114         if (strcmp(name, ncl->name) == 0) {
115             return ncl;
116         }
117     }
118 
119     return NULL;
120 }
121 
122 Clock *qdev_get_clock_in(DeviceState *dev, const char *name)
123 {
124     NamedClockList *ncl;
125 
126     assert(name);
127 
128     ncl = qdev_get_clocklist(dev, name);
129     if (!ncl) {
130         error_report("Can not find clock-in '%s' for device type '%s'",
131                      name, object_get_typename(OBJECT(dev)));
132         abort();
133     }
134     assert(!ncl->output);
135 
136     return ncl->clock;
137 }
138 
139 Clock *qdev_get_clock_out(DeviceState *dev, const char *name)
140 {
141     NamedClockList *ncl;
142 
143     assert(name);
144 
145     ncl = qdev_get_clocklist(dev, name);
146     if (!ncl) {
147         error_report("Can not find clock-out '%s' for device type '%s'",
148                      name, object_get_typename(OBJECT(dev)));
149         abort();
150     }
151     assert(ncl->output);
152 
153     return ncl->clock;
154 }
155 
156 Clock *qdev_alias_clock(DeviceState *dev, const char *name,
157                         DeviceState *alias_dev, const char *alias_name)
158 {
159     NamedClockList *ncl = qdev_get_clocklist(dev, name);
160     Clock *clk = ncl->clock;
161 
162     ncl = qdev_init_clocklist(alias_dev, alias_name, true, ncl->output, clk);
163 
164     object_property_add_link(OBJECT(alias_dev), alias_name,
165                              TYPE_CLOCK,
166                              (Object **) &ncl->clock,
167                              NULL, OBJ_PROP_LINK_STRONG);
168     /*
169      * Since the link property has the OBJ_PROP_LINK_STRONG flag, the clk
170      * object reference count gets decremented on property deletion.
171      * However object_property_add_link does not increment it since it
172      * doesn't know the linked object. Increment it here to ensure the
173      * aliased clock stays alive during this device life-time.
174      */
175     object_ref(OBJECT(clk));
176 
177     return clk;
178 }
179 
180 void qdev_connect_clock_in(DeviceState *dev, const char *name, Clock *source)
181 {
182     assert(!dev->realized);
183     clock_set_source(qdev_get_clock_in(dev, name), source);
184 }
185