Introduce clock port objects: ClockIn and ClockOut.
Theses ports may be used to distribute a clock from a object to several
other objects. The ClockIn object contains the current state of the
clock: the frequency.
A ClockIn may be connected to a ClockOut so that it receives update,
through the callback, whenever the Clockout is updated using the
ClockOut's set function.
This is based on the original work of Frederic Konrad.
Signed-off-by: Damien Hedde <damien.he...@greensocs.com>
---
Makefile.objs | 1 +
include/hw/clock-port.h | 136 ++++++++++++++++++++++++++++++++++
hw/core/clock-port.c | 159 ++++++++++++++++++++++++++++++++++++++++
hw/core/Makefile.objs | 1 +
hw/core/trace-events | 7 ++
5 files changed, 304 insertions(+)
create mode 100644 include/hw/clock-port.h
create mode 100644 hw/core/clock-port.c
create mode 100644 hw/core/trace-events
diff --git a/Makefile.objs b/Makefile.objs
index ce9c79235e..b29747075f 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -210,6 +210,7 @@ trace-events-subdirs += hw/audio
trace-events-subdirs += hw/block
trace-events-subdirs += hw/block/dataplane
trace-events-subdirs += hw/char
+trace-events-subdirs += hw/core
trace-events-subdirs += hw/display
trace-events-subdirs += hw/dma
trace-events-subdirs += hw/hppa
diff --git a/include/hw/clock-port.h b/include/hw/clock-port.h
new file mode 100644
index 0000000000..8266549350
--- /dev/null
+++ b/include/hw/clock-port.h
@@ -0,0 +1,136 @@
+#ifndef CLOCK_PORT_H
+#define CLOCK_PORT_H
+
+#include "qom/object.h"
+#include "hw/qdev-core.h"
+#include "qemu/queue.h"
+#include "migration/vmstate.h"
+
+#define TYPE_CLOCK_IN "clock-in"
+#define CLOCK_IN(obj) OBJECT_CHECK(ClockIn, (obj), TYPE_CLOCK_IN)
+#define TYPE_CLOCK_OUT "clock-out"
+#define CLOCK_OUT(obj) OBJECT_CHECK(ClockOut, (obj), TYPE_CLOCK_OUT)
+
+typedef void ClockCallback(void *opaque);
+
+typedef struct ClockOut ClockOut;
+typedef struct ClockIn ClockIn;
+
+struct ClockIn {
+ /*< private >*/
+ Object parent_obj;
+ /*< private >*/
+ uint64_t frequency;
+ char *canonical_path; /* clock path cache */
+ ClockOut *driver; /* clock output controlling this clock */
+ ClockCallback *callback; /* local callback */
+ void *callback_opaque; /* opaque argument for the callback */
+ QLIST_ENTRY(ClockIn) sibling; /* entry in a followers list */
+};
+
+struct ClockOut {
+ /*< private >*/
+ Object parent_obj;
+ /*< private >*/
+ char *canonical_path; /* clock path cache */
+ QLIST_HEAD(, ClockIn) followers; /* list of registered clocks */
+};
+
+extern const VMStateDescription vmstate_clockin;
+
+/*
+ * vmstate description entry to be added in device vmsd.
+ */
+#define VMSTATE_CLOCKIN(_field, _state) \
+ VMSTATE_CLOCKIN_V(_field, _state, 0)
+#define VMSTATE_CLOCKIN_V(_field, _state, _version) \
+ VMSTATE_STRUCT_POINTER_V(_field, _state, _version, vmstate_clockin,
ClockIn)
+
+/**
+ * clock_out_setup_canonical_path:
+ * @clk: clock
+ *
+ * compute the canonical path of the clock (used by log messages)
+ */
+void clock_out_setup_canonical_path(ClockOut *clk);
+
+/**
+ * clock_in_setup_canonical_path:
+ * @clk: clock
+ *
+ * compute the canonical path of the clock (used by log messages)
+ */
+void clock_in_setup_canonical_path(ClockIn *clk);
+
+/**
+ * clock_add_callback:
+ * @clk: the clock to register the callback into
+ * @cb: the callback function
+ * @opaque: the argument to the callback
+ *
+ * Register a callback called on every clock update.
+ */
+void clock_set_callback(ClockIn *clk, ClockCallback *cb, void *opaque);
+
+/**
+ * clock_clear_callback:
+ * @clk: the clock to delete the callback from
+ *
+ * Unregister the callback registered with clock_set_callback.
+ */
+void clock_clear_callback(ClockIn *clk);
+
+/**
+ * clock_init_frequency:
+ * @clk: the clock to initialize.
+ * @freq: the clock's frequency in Hz or 0 if unclocked.
+ *
+ * Initialize the local cached frequency value of @clk to @freq.
+ * Note: this function must only be called during device inititialization
+ * or migration.
+ */
+void clock_init_frequency(ClockIn *clk, uint64_t freq);
+
+/**
+ * clock_connect:
+ * @clkin: the drived clock.
+ * @clkout: the driving clock.
+ *
+ * Setup @clkout to drive @clkin: Any @clkout update will be propagated
+ * to @clkin.
+ */
+void clock_connect(ClockIn *clkin, ClockOut *clkout);
+
+/**
+ * clock_set_frequency:
+ * @clk: the clock to update.
+ * @freq: the new clock's frequency in Hz or 0 if unclocked.
+ *
+ * Update the @clk to the new @freq.
+ * This change will be propagated through registered clock inputs.
+ */
+void clock_set_frequency(ClockOut *clk, uint64_t freq);
+
+/**
+ * clock_get_frequency:
+ * @clk: the clk to fetch the clock
+ *
+ * @return: the current frequency of @clk in Hz. If @clk is NULL, return 0.
+ */
+static inline uint64_t clock_get_frequency(const ClockIn *clk)
+{
+ return clk ? clk->frequency : 0;
+}
+
+/**
+ * clock_is_enabled:
+ * @clk: a clock state
+ *
+ * @return: true if the clock is running. If @clk is NULL return false.
+ */
+static inline bool clock_is_enabled(const ClockIn *clk)
+{
+ return clock_get_frequency(clk) != 0;
+}
+
+#endif /* CLOCK_PORT_H */
diff --git a/hw/core/clock-port.c b/hw/core/clock-port.c
new file mode 100644
index 0000000000..25bab0fbed
--- /dev/null
+++ b/hw/core/clock-port.c
@@ -0,0 +1,159 @@
+/*
+ * Clock inputs and outputs
+ *
+ * Copyright GreenSocs 2016-2018
+ *
+ * Authors:
+ * Frederic Konrad <fred.kon...@greensocs.com>
+ * Damien Hedde <damien.he...@greensocs.com>
+ *
+ * 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/module.h"
+#include "hw/clock-port.h"
+#include "hw/qdev-core.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qapi/error.h"
+#include "trace.h"
+
+const VMStateDescription vmstate_clockin = {
+ .name = "clockin",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(frequency, ClockIn),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+#define CLOCK_PATH(_clk) (_clk->canonical_path)
+
+void clock_out_setup_canonical_path(ClockOut *clk)
+{
+ g_free(clk->canonical_path);
+ clk->canonical_path = object_get_canonical_path(OBJECT(clk));
+}
+
+void clock_in_setup_canonical_path(ClockIn *clk)
+{
+ g_free(clk->canonical_path);
+ clk->canonical_path = object_get_canonical_path(OBJECT(clk));
+}
+
+void clock_set_callback(ClockIn *clk, ClockCallback *cb, void *opaque)
+{
+ assert(clk);
+
+ clk->callback = cb;
+ clk->callback_opaque = opaque;
+}
+
+void clock_init_frequency(ClockIn *clk, uint64_t freq)
+{
+ assert(clk);
+
+ clk->frequency = freq;
+}
+
+void clock_clear_callback(ClockIn *clk)
+{
+ clock_set_callback(clk, NULL, NULL);
+}
+
+void clock_connect(ClockIn *clkin, ClockOut *clkout)
+{
+ assert(clkin && clkin->driver == NULL);
+ assert(clkout);
+
+ trace_clock_connect(CLOCK_PATH(clkin), CLOCK_PATH(clkout));
+
+ QLIST_INSERT_HEAD(&clkout->followers, clkin, sibling);
+ clkin->driver = clkout;
+}
+
+static void clock_disconnect(ClockIn *clk)
+{
+ if (clk->driver == NULL) {
+ return;
+ }
+
+ trace_clock_disconnect(CLOCK_PATH(clk));
+
+ clk->driver = NULL;
+ QLIST_REMOVE(clk, sibling);
+}
+
+void clock_set_frequency(ClockOut *clk, uint64_t freq)
+{
+ ClockIn *follower;
+ trace_clock_update(CLOCK_PATH(clk), freq);
+
+ QLIST_FOREACH(follower, &clk->followers, sibling) {
+ trace_clock_propagate(CLOCK_PATH(clk), CLOCK_PATH(follower));
+ if (follower->frequency != freq) {
+ follower->frequency = freq;
+ if (follower->callback) {
+ follower->callback(follower->callback_opaque);
+ }
+ }
+ }
+}
+
+static void clock_out_initfn(Object *obj)
+{
+ ClockOut *clk = CLOCK_OUT(obj);
+
+ QLIST_INIT(&clk->followers);
+}
+
+static void clock_out_finalizefn(Object *obj)
+{
+ ClockOut *clk = CLOCK_OUT(obj);
+ ClockIn *follower, *next;
+
+ /* clear our list of followers */
+ QLIST_FOREACH_SAFE(follower, &clk->followers, sibling, next) {
+ clock_disconnect(follower);
+ }
+
+ g_free(clk->canonical_path);
+ clk->canonical_path = NULL;
+}
+
+static void clock_in_finalizefn(Object *obj)
+{
+ ClockIn *clk = CLOCK_IN(obj);
+
+ /* remove us from driver's followers list */
+ clock_disconnect(clk);
+
+ g_free(clk->canonical_path);
+ clk->canonical_path = NULL;
+}
+
+static const TypeInfo clock_out_info = {
+ .name = TYPE_CLOCK_OUT,
+ .parent = TYPE_OBJECT,
+ .instance_size = sizeof(ClockOut),
+ .instance_init = clock_out_initfn,
+ .instance_finalize = clock_out_finalizefn,
+};
+
+static const TypeInfo clock_in_info = {
+ .name = TYPE_CLOCK_IN,
+ .parent = TYPE_OBJECT,
+ .instance_size = sizeof(ClockIn),
+ .instance_finalize = clock_in_finalizefn,
+};
+
+static void clock_register_types(void)
+{
+ type_register_static(&clock_in_info);
+ type_register_static(&clock_out_info);
+}
+
+type_init(clock_register_types)
diff --git a/hw/core/Makefile.objs b/hw/core/Makefile.objs
index eb88ca979e..f7102121f4 100644
--- a/hw/core/Makefile.objs
+++ b/hw/core/Makefile.objs
@@ -6,6 +6,7 @@ common-obj-$(CONFIG_SOFTMMU) += fw-path-provider.o
# irq.o needed for qdev GPIO handling:
common-obj-y += irq.o
common-obj-y += hotplug.o
+common-obj-y += clock-port.o
common-obj-$(CONFIG_SOFTMMU) += nmi.o
common-obj-$(CONFIG_EMPTY_SLOT) += empty_slot.o
diff --git a/hw/core/trace-events b/hw/core/trace-events
new file mode 100644
index 0000000000..d4880ec138
--- /dev/null
+++ b/hw/core/trace-events
@@ -0,0 +1,7 @@
+# See docs/devel/tracing.txt for syntax documentation.
+
+# hw/core/clock-port.c
+clock_connect(const char *clk, const char *driver) "'%s' drived-by '%s'"
+clock_disconnect(const char *clk) "'%s'"
+clock_update(const char *clk, uint64_t freq) "'%s' frequency %" PRIu64 "Hz"
+clock_propagate(const char *clko, const char *clki) "'%s' => '%s'"
--
2.19.0
