qemu/include/hw/qdev-clock.h
Peter Maydell 5ee0abed51 clock: Add ClockEvent parameter to callbacks
The Clock framework allows users to specify a callback which is
called after the clock's period has been updated.  Some users need to
also have a callback which is called before the clock period is
updated.

As the first step in adding support for notifying Clock users on
pre-update events, add an argument to the ClockCallback to specify
what event is being notified, and add an argument to the various
functions for registering a callback to specify which events are
of interest to that callback.

Note that the documentation update renders correct the previously
incorrect claim in 'Adding a new clock' that callbacks "will be
explained in a following section".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20210219144617.4782-2-peter.maydell@linaro.org
2021-03-08 17:20:01 +00:00

165 lines
5.1 KiB
C

/*
* Device's clock input and output
*
* Copyright GreenSocs 2016-2020
*
* Authors:
* Frederic Konrad
* Damien Hedde
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QDEV_CLOCK_H
#define QDEV_CLOCK_H
#include "hw/clock.h"
/**
* qdev_init_clock_in:
* @dev: the device to add an input clock to
* @name: the name of the clock (can't be NULL).
* @callback: optional callback to be called on update or NULL.
* @opaque: argument for the callback
* @events: the events the callback should be called for
* (logical OR of ClockEvent enum values)
* @returns: a pointer to the newly added clock
*
* Add an input clock to device @dev as a clock named @name.
* This adds a child<> property.
* The callback will be called with @opaque as opaque parameter.
*/
Clock *qdev_init_clock_in(DeviceState *dev, const char *name,
ClockCallback *callback, void *opaque,
unsigned int events);
/**
* qdev_init_clock_out:
* @dev: the device to add an output clock to
* @name: the name of the clock (can't be NULL).
* @returns: a pointer to the newly added clock
*
* Add an output clock to device @dev as a clock named @name.
* This adds a child<> property.
*/
Clock *qdev_init_clock_out(DeviceState *dev, const char *name);
/**
* qdev_get_clock_in:
* @dev: the device which has the clock
* @name: the name of the clock (can't be NULL).
* @returns: a pointer to the clock
*
* Get the input clock @name from @dev or NULL if does not exist.
*/
Clock *qdev_get_clock_in(DeviceState *dev, const char *name);
/**
* qdev_get_clock_out:
* @dev: the device which has the clock
* @name: the name of the clock (can't be NULL).
* @returns: a pointer to the clock
*
* Get the output clock @name from @dev or NULL if does not exist.
*/
Clock *qdev_get_clock_out(DeviceState *dev, const char *name);
/**
* qdev_connect_clock_in:
* @dev: a device
* @name: the name of an input clock in @dev
* @source: the source clock (an output clock of another device for example)
*
* Set the source clock of input clock @name of device @dev to @source.
* @source period update will be propagated to @name clock.
*
* Must be called before @dev is realized.
*/
void qdev_connect_clock_in(DeviceState *dev, const char *name, Clock *source);
/**
* qdev_alias_clock:
* @dev: the device which has the clock
* @name: the name of the clock in @dev (can't be NULL)
* @alias_dev: the device to add the clock
* @alias_name: the name of the clock in @container
* @returns: a pointer to the clock
*
* Add a clock @alias_name in @alias_dev which is an alias of the clock @name
* in @dev. The direction _in_ or _out_ will the same as the original.
* An alias clock must not be modified or used by @alias_dev and should
* typically be only only for device composition purpose.
*/
Clock *qdev_alias_clock(DeviceState *dev, const char *name,
DeviceState *alias_dev, const char *alias_name);
/**
* qdev_finalize_clocklist:
* @dev: the device being finalized
*
* Clear the clocklist from @dev. Only used internally in qdev.
*/
void qdev_finalize_clocklist(DeviceState *dev);
/**
* ClockPortInitElem:
* @name: name of the clock (can't be NULL)
* @output: indicates whether the clock is input or output
* @callback: for inputs, optional callback to be called on clock's update
* with device as opaque
* @callback_events: mask of ClockEvent values for when callback is called
* @offset: optional offset to store the ClockIn or ClockOut pointer in device
* state structure (0 means unused)
*/
struct ClockPortInitElem {
const char *name;
bool is_output;
ClockCallback *callback;
unsigned int callback_events;
size_t offset;
};
#define clock_offset_value(devstate, field) \
(offsetof(devstate, field) + \
type_check(Clock *, typeof_field(devstate, field)))
#define QDEV_CLOCK(out_not_in, devstate, field, cb, cbevents) { \
.name = (stringify(field)), \
.is_output = out_not_in, \
.callback = cb, \
.callback_events = cbevents, \
.offset = clock_offset_value(devstate, field), \
}
/**
* QDEV_CLOCK_(IN|OUT):
* @devstate: structure type. @dev argument of qdev_init_clocks below must be
* a pointer to that same type.
* @field: a field in @_devstate (must be Clock*)
* @callback: (for input only) callback (or NULL) to be called with the device
* state as argument
* @cbevents: (for input only) ClockEvent mask for when callback is called
*
* The name of the clock will be derived from @field
*/
#define QDEV_CLOCK_IN(devstate, field, callback, cbevents) \
QDEV_CLOCK(false, devstate, field, callback, cbevents)
#define QDEV_CLOCK_OUT(devstate, field) \
QDEV_CLOCK(true, devstate, field, NULL, 0)
#define QDEV_CLOCK_END { .name = NULL }
typedef struct ClockPortInitElem ClockPortInitArray[];
/**
* qdev_init_clocks:
* @dev: the device to add clocks to
* @clocks: a QDEV_CLOCK_END-terminated array which contains the
* clocks information.
*/
void qdev_init_clocks(DeviceState *dev, const ClockPortInitArray clocks);
#endif /* QDEV_CLOCK_H */