4 * Copyright GreenSocs 2016-2020
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.
14 #ifndef QEMU_HW_CLOCK_H
15 #define QEMU_HW_CLOCK_H
17 #include "qom/object.h"
18 #include "qemu/queue.h"
20 #define TYPE_CLOCK "clock"
21 OBJECT_DECLARE_SIMPLE_TYPE(Clock
, CLOCK
)
23 typedef void ClockCallback(void *opaque
);
26 * clock store a value representing the clock's period in 2^-32ns unit.
28 * + periods from 2^-32ns up to 4seconds
29 * + frequency from ~0.25Hz 2e10Ghz
30 * Resolution of frequency representation decreases with frequency:
31 * + at 100MHz, resolution is ~2mHz
32 * + at 1Ghz, resolution is ~0.2Hz
33 * + at 10Ghz, resolution is ~20Hz
35 #define CLOCK_PERIOD_1SEC (1000000000llu << 32)
38 * macro helpers to convert to hertz / nanosecond
40 #define CLOCK_PERIOD_FROM_NS(ns) ((ns) * (CLOCK_PERIOD_1SEC / 1000000000llu))
41 #define CLOCK_PERIOD_TO_NS(per) ((per) / (CLOCK_PERIOD_1SEC / 1000000000llu))
42 #define CLOCK_PERIOD_FROM_HZ(hz) (((hz) != 0) ? CLOCK_PERIOD_1SEC / (hz) : 0u)
43 #define CLOCK_PERIOD_TO_HZ(per) (((per) != 0) ? CLOCK_PERIOD_1SEC / (per) : 0u)
47 * @parent_obj: parent class
48 * @period: unsigned integer representing the period of the clock
49 * @canonical_path: clock path string cache (used for trace purpose)
50 * @callback: called when clock changes
51 * @callback_opaque: argument for @callback
52 * @source: source (or parent in clock tree) of the clock
53 * @children: list of clocks connected to this one (it is their source)
54 * @sibling: structure used to form a clock list
62 /* all fields are private and should not be modified directly */
67 ClockCallback
*callback
;
68 void *callback_opaque
;
70 /* Clocks are organized in a clock tree */
72 QLIST_HEAD(, Clock
) children
;
73 QLIST_ENTRY(Clock
) sibling
;
77 * vmstate description entry to be added in device vmsd.
79 extern const VMStateDescription vmstate_clock
;
80 #define VMSTATE_CLOCK(field, state) \
81 VMSTATE_CLOCK_V(field, state, 0)
82 #define VMSTATE_CLOCK_V(field, state, version) \
83 VMSTATE_STRUCT_POINTER_V(field, state, version, vmstate_clock, Clock)
86 * clock_setup_canonical_path:
89 * compute the canonical path of the clock (used by log messages)
91 void clock_setup_canonical_path(Clock
*clk
);
95 * @parent: the clock parent
96 * @name: the clock object name
98 * Helper function to create a new clock and parent it to @parent. There is no
99 * need to call clock_setup_canonical_path on the returned clock as it is done
102 * @return the newly created clock
104 Clock
*clock_new(Object
*parent
, const char *name
);
107 * clock_set_callback:
108 * @clk: the clock to register the callback into
109 * @cb: the callback function
110 * @opaque: the argument to the callback
112 * Register a callback called on every clock update.
114 void clock_set_callback(Clock
*clk
, ClockCallback
*cb
, void *opaque
);
117 * clock_clear_callback:
118 * @clk: the clock to delete the callback from
120 * Unregister the callback registered with clock_set_callback.
122 void clock_clear_callback(Clock
*clk
);
127 * @src: the source clock
129 * Setup @src as the clock source of @clk. The current @src period
130 * value is also copied to @clk and its subtree but no callback is
132 * Further @src update will be propagated to @clk and its subtree.
134 void clock_set_source(Clock
*clk
, Clock
*src
);
138 * @clk: the clock to initialize.
139 * @value: the clock's value, 0 means unclocked
141 * Set the local cached period value of @clk to @value.
143 * @return: true if the clock is changed.
145 bool clock_set(Clock
*clk
, uint64_t value
);
147 static inline bool clock_set_hz(Clock
*clk
, unsigned hz
)
149 return clock_set(clk
, CLOCK_PERIOD_FROM_HZ(hz
));
152 static inline bool clock_set_ns(Clock
*clk
, unsigned ns
)
154 return clock_set(clk
, CLOCK_PERIOD_FROM_NS(ns
));
161 * Propagate the clock period that has been previously configured using
162 * @clock_set(). This will update recursively all connected clocks.
163 * It is an error to call this function on a clock which has a source.
164 * Note: this function must not be called during device inititialization
167 void clock_propagate(Clock
*clk
);
171 * @clk: the clock to update.
172 * @value: the new clock's value, 0 means unclocked
174 * Update the @clk to the new @value. All connected clocks will be informed
175 * of this update. This is equivalent to call @clock_set() then
176 * @clock_propagate().
178 static inline void clock_update(Clock
*clk
, uint64_t value
)
180 if (clock_set(clk
, value
)) {
181 clock_propagate(clk
);
185 static inline void clock_update_hz(Clock
*clk
, unsigned hz
)
187 clock_update(clk
, CLOCK_PERIOD_FROM_HZ(hz
));
190 static inline void clock_update_ns(Clock
*clk
, unsigned ns
)
192 clock_update(clk
, CLOCK_PERIOD_FROM_NS(ns
));
197 * @clk: the clk to fetch the clock
199 * @return: the current period.
201 static inline uint64_t clock_get(const Clock
*clk
)
206 static inline unsigned clock_get_hz(Clock
*clk
)
208 return CLOCK_PERIOD_TO_HZ(clock_get(clk
));
211 static inline unsigned clock_get_ns(Clock
*clk
)
213 return CLOCK_PERIOD_TO_NS(clock_get(clk
));
220 * @return: true if the clock is running.
222 static inline bool clock_is_enabled(const Clock
*clk
)
224 return clock_get(clk
) != 0;
227 #endif /* QEMU_HW_CLOCK_H */