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