xref: /openbmc/qemu/include/hw/qdev-clock.h (revision dd205025)
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 #ifndef QDEV_CLOCK_H
15 #define QDEV_CLOCK_H
16 
17 #include "hw/clock.h"
18 
19 /**
20  * qdev_init_clock_in:
21  * @dev: the device to add an input clock to
22  * @name: the name of the clock (can't be NULL).
23  * @callback: optional callback to be called on update or NULL.
24  * @opaque: argument for the callback
25  * @returns: a pointer to the newly added clock
26  *
27  * Add an input clock to device @dev as a clock named @name.
28  * This adds a child<> property.
29  * The callback will be called with @opaque as opaque parameter.
30  */
31 Clock *qdev_init_clock_in(DeviceState *dev, const char *name,
32                           ClockCallback *callback, void *opaque);
33 
34 /**
35  * qdev_init_clock_out:
36  * @dev: the device to add an output clock to
37  * @name: the name of the clock (can't be NULL).
38  * @returns: a pointer to the newly added clock
39  *
40  * Add an output clock to device @dev as a clock named @name.
41  * This adds a child<> property.
42  */
43 Clock *qdev_init_clock_out(DeviceState *dev, const char *name);
44 
45 /**
46  * qdev_get_clock_in:
47  * @dev: the device which has the clock
48  * @name: the name of the clock (can't be NULL).
49  * @returns: a pointer to the clock
50  *
51  * Get the input clock @name from @dev or NULL if does not exist.
52  */
53 Clock *qdev_get_clock_in(DeviceState *dev, const char *name);
54 
55 /**
56  * qdev_get_clock_out:
57  * @dev: the device which has the clock
58  * @name: the name of the clock (can't be NULL).
59  * @returns: a pointer to the clock
60  *
61  * Get the output clock @name from @dev or NULL if does not exist.
62  */
63 Clock *qdev_get_clock_out(DeviceState *dev, const char *name);
64 
65 /**
66  * qdev_connect_clock_in:
67  * @dev: a device
68  * @name: the name of an input clock in @dev
69  * @source: the source clock (an output clock of another device for example)
70  *
71  * Set the source clock of input clock @name of device @dev to @source.
72  * @source period update will be propagated to @name clock.
73  *
74  * Must be called before @dev is realized.
75  */
76 void qdev_connect_clock_in(DeviceState *dev, const char *name, Clock *source);
77 
78 /**
79  * qdev_alias_clock:
80  * @dev: the device which has the clock
81  * @name: the name of the clock in @dev (can't be NULL)
82  * @alias_dev: the device to add the clock
83  * @alias_name: the name of the clock in @container
84  * @returns: a pointer to the clock
85  *
86  * Add a clock @alias_name in @alias_dev which is an alias of the clock @name
87  * in @dev. The direction _in_ or _out_ will the same as the original.
88  * An alias clock must not be modified or used by @alias_dev and should
89  * typically be only only for device composition purpose.
90  */
91 Clock *qdev_alias_clock(DeviceState *dev, const char *name,
92                         DeviceState *alias_dev, const char *alias_name);
93 
94 /**
95  * qdev_finalize_clocklist:
96  * @dev: the device being finalized
97  *
98  * Clear the clocklist from @dev. Only used internally in qdev.
99  */
100 void qdev_finalize_clocklist(DeviceState *dev);
101 
102 /**
103  * ClockPortInitElem:
104  * @name: name of the clock (can't be NULL)
105  * @output: indicates whether the clock is input or output
106  * @callback: for inputs, optional callback to be called on clock's update
107  * with device as opaque
108  * @offset: optional offset to store the ClockIn or ClockOut pointer in device
109  * state structure (0 means unused)
110  */
111 struct ClockPortInitElem {
112     const char *name;
113     bool is_output;
114     ClockCallback *callback;
115     size_t offset;
116 };
117 
118 #define clock_offset_value(devstate, field) \
119     (offsetof(devstate, field) + \
120      type_check(Clock *, typeof_field(devstate, field)))
121 
122 #define QDEV_CLOCK(out_not_in, devstate, field, cb) { \
123     .name = (stringify(field)), \
124     .is_output = out_not_in, \
125     .callback = cb, \
126     .offset = clock_offset_value(devstate, field), \
127 }
128 
129 /**
130  * QDEV_CLOCK_(IN|OUT):
131  * @devstate: structure type. @dev argument of qdev_init_clocks below must be
132  * a pointer to that same type.
133  * @field: a field in @_devstate (must be Clock*)
134  * @callback: (for input only) callback (or NULL) to be called with the device
135  * state as argument
136  *
137  * The name of the clock will be derived from @field
138  */
139 #define QDEV_CLOCK_IN(devstate, field, callback) \
140     QDEV_CLOCK(false, devstate, field, callback)
141 
142 #define QDEV_CLOCK_OUT(devstate, field) \
143     QDEV_CLOCK(true, devstate, field, NULL)
144 
145 #define QDEV_CLOCK_END { .name = NULL }
146 
147 typedef struct ClockPortInitElem ClockPortInitArray[];
148 
149 /**
150  * qdev_init_clocks:
151  * @dev: the device to add clocks to
152  * @clocks: a QDEV_CLOCK_END-terminated array which contains the
153  * clocks information.
154  */
155 void qdev_init_clocks(DeviceState *dev, const ClockPortInitArray clocks);
156 
157 #endif /* QDEV_CLOCK_H */
158