qemu/hw/core/clock.c
Philippe Mathieu-Daudé 52405b7f69 hw/clock: Let clock_set_mul_div() return a boolean value
Let clock_set_mul_div() return a boolean value whether the
clock has been updated or not, similarly to clock_set().

Return early when clock_set_mul_div() is called with
same mul/div values the clock has.

Acked-by: Luc Michel <luc@lmichel.fr>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20240325152827.73817-2-philmd@linaro.org>
2024-03-26 14:24:06 +01:00

202 lines
4.7 KiB
C

/*
* Hardware Clocks
*
* 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.
*/
#include "qemu/osdep.h"
#include "qemu/cutils.h"
#include "hw/clock.h"
#include "trace.h"
#define CLOCK_PATH(_clk) (_clk->canonical_path)
void clock_setup_canonical_path(Clock *clk)
{
g_free(clk->canonical_path);
clk->canonical_path = object_get_canonical_path(OBJECT(clk));
}
Clock *clock_new(Object *parent, const char *name)
{
Object *obj;
Clock *clk;
obj = object_new(TYPE_CLOCK);
object_property_add_child(parent, name, obj);
object_unref(obj);
clk = CLOCK(obj);
clock_setup_canonical_path(clk);
return clk;
}
void clock_set_callback(Clock *clk, ClockCallback *cb, void *opaque,
unsigned int events)
{
clk->callback = cb;
clk->callback_opaque = opaque;
clk->callback_events = events;
}
void clock_clear_callback(Clock *clk)
{
clock_set_callback(clk, NULL, NULL, 0);
}
bool clock_set(Clock *clk, uint64_t period)
{
if (clk->period == period) {
return false;
}
trace_clock_set(CLOCK_PATH(clk), CLOCK_PERIOD_TO_HZ(clk->period),
CLOCK_PERIOD_TO_HZ(period));
clk->period = period;
return true;
}
static uint64_t clock_get_child_period(Clock *clk)
{
/*
* Return the period to be used for child clocks, which is the parent
* clock period adjusted for multiplier and divider effects.
*/
return muldiv64(clk->period, clk->multiplier, clk->divider);
}
static void clock_call_callback(Clock *clk, ClockEvent event)
{
/*
* Call the Clock's callback for this event, if it has one and
* is interested in this event.
*/
if (clk->callback && (clk->callback_events & event)) {
clk->callback(clk->callback_opaque, event);
}
}
static void clock_propagate_period(Clock *clk, bool call_callbacks)
{
Clock *child;
uint64_t child_period = clock_get_child_period(clk);
QLIST_FOREACH(child, &clk->children, sibling) {
if (child->period != child_period) {
if (call_callbacks) {
clock_call_callback(child, ClockPreUpdate);
}
child->period = child_period;
trace_clock_update(CLOCK_PATH(child), CLOCK_PATH(clk),
CLOCK_PERIOD_TO_HZ(child->period),
call_callbacks);
if (call_callbacks) {
clock_call_callback(child, ClockUpdate);
}
clock_propagate_period(child, call_callbacks);
}
}
}
void clock_propagate(Clock *clk)
{
assert(clk->source == NULL);
trace_clock_propagate(CLOCK_PATH(clk));
clock_propagate_period(clk, true);
}
void clock_set_source(Clock *clk, Clock *src)
{
/* changing clock source is not supported */
assert(!clk->source);
trace_clock_set_source(CLOCK_PATH(clk), CLOCK_PATH(src));
clk->period = clock_get_child_period(src);
QLIST_INSERT_HEAD(&src->children, clk, sibling);
clk->source = src;
clock_propagate_period(clk, false);
}
static void clock_disconnect(Clock *clk)
{
if (clk->source == NULL) {
return;
}
trace_clock_disconnect(CLOCK_PATH(clk));
clk->source = NULL;
QLIST_REMOVE(clk, sibling);
}
char *clock_display_freq(Clock *clk)
{
return freq_to_str(clock_get_hz(clk));
}
bool clock_set_mul_div(Clock *clk, uint32_t multiplier, uint32_t divider)
{
assert(divider != 0);
if (clk->multiplier == multiplier && clk->divider == divider) {
return false;
}
trace_clock_set_mul_div(CLOCK_PATH(clk), clk->multiplier, multiplier,
clk->divider, divider);
clk->multiplier = multiplier;
clk->divider = divider;
return true;
}
static void clock_initfn(Object *obj)
{
Clock *clk = CLOCK(obj);
clk->multiplier = 1;
clk->divider = 1;
QLIST_INIT(&clk->children);
}
static void clock_finalizefn(Object *obj)
{
Clock *clk = CLOCK(obj);
Clock *child, *next;
/* clear our list of children */
QLIST_FOREACH_SAFE(child, &clk->children, sibling, next) {
clock_disconnect(child);
}
/* remove us from source's children list */
clock_disconnect(clk);
g_free(clk->canonical_path);
}
static const TypeInfo clock_info = {
.name = TYPE_CLOCK,
.parent = TYPE_OBJECT,
.instance_size = sizeof(Clock),
.instance_init = clock_initfn,
.instance_finalize = clock_finalizefn,
};
static void clock_register_types(void)
{
type_register_static(&clock_info);
}
type_init(clock_register_types)