diff --git a/hw/avr/atmega.h b/hw/avr/atmega.h
index a99ee15c7e1..12e856386b6 100644
--- a/hw/avr/atmega.h
+++ b/hw/avr/atmega.h
@@ -11,6 +11,7 @@
 #ifndef HW_AVR_ATMEGA_H
 #define HW_AVR_ATMEGA_H
 
+#include "hw/clock.h"
 #include "hw/char/avr_usart.h"
 #include "hw/timer/avr_timer16.h"
 #include "hw/misc/avr_power.h"
@@ -41,11 +42,11 @@ struct AtmegaMcuState {
     MemoryRegion flash;
     MemoryRegion eeprom;
     MemoryRegion sram;
+    Clock *xtal_clkin;
     DeviceState *io;
     AVRMaskState pwr[POWER_MAX];
     AVRUsartState usart[USART_MAX];
     AVRTimer16State timer[TIMER_MAX];
-    uint64_t xtal_freq_hz;
 };
 
 #endif /* HW_AVR_ATMEGA_H */
diff --git a/include/hw/timer/avr_timer16.h b/include/hw/timer/avr_timer16.h
index 05362543378..86dc9e98d95 100644
--- a/include/hw/timer/avr_timer16.h
+++ b/include/hw/timer/avr_timer16.h
@@ -28,6 +28,7 @@
 #ifndef HW_TIMER_AVR_TIMER16_H
 #define HW_TIMER_AVR_TIMER16_H
 
+#include "hw/clock.h"
 #include "hw/sysbus.h"
 #include "qemu/timer.h"
 #include "hw/hw.h"
@@ -84,7 +85,8 @@ struct AVRTimer16State {
     uint8_t ifr;
 
     uint8_t id;
-    uint64_t cpu_freq_hz;
+    Clock *io_clkin;
+
     uint64_t freq_hz;
     uint64_t period_ns;
     uint64_t reset_time_ns;
diff --git a/hw/avr/arduino.c b/hw/avr/arduino.c
index 3ff31492fa6..71e69823c07 100644
--- a/hw/avr/arduino.c
+++ b/hw/avr/arduino.c
@@ -12,7 +12,9 @@
 
 #include "qemu/osdep.h"
 #include "qapi/error.h"
+#include "hw/clock.h"
 #include "hw/boards.h"
+#include "hw/qdev-clock.h"
 #include "atmega.h"
 #include "boot.h"
 #include "qom/object.h"
@@ -21,6 +23,7 @@ struct ArduinoMachineState {
     /*< private >*/
     MachineState parent_obj;
     /*< public >*/
+    Clock *xtal;
     AtmegaMcuState mcu;
 };
 typedef struct ArduinoMachineState ArduinoMachineState;
@@ -44,9 +47,10 @@ static void arduino_machine_init(MachineState *machine)
     ArduinoMachineClass *amc = ARDUINO_MACHINE_GET_CLASS(machine);
     ArduinoMachineState *ams = ARDUINO_MACHINE(machine);
 
+    ams->xtal = machine_create_constant_clock(machine, "osc", amc->xtal_hz);
+
     object_initialize_child(OBJECT(machine), "mcu", &ams->mcu, amc->mcu_type);
-    object_property_set_uint(OBJECT(&ams->mcu), "xtal-frequency-hz",
-                             amc->xtal_hz, &error_abort);
+    qdev_connect_clock_in(DEVICE(&ams->mcu), "osc-in", ams->xtal);
     sysbus_realize(SYS_BUS_DEVICE(&ams->mcu), &error_abort);
 
     if (machine->firmware) {
diff --git a/hw/avr/atmega.c b/hw/avr/atmega.c
index 44c6afebbb6..b8a11965435 100644
--- a/hw/avr/atmega.c
+++ b/hw/avr/atmega.c
@@ -15,6 +15,7 @@
 #include "exec/memory.h"
 #include "exec/address-spaces.h"
 #include "sysemu/sysemu.h"
+#include "hw/qdev-clock.h"
 #include "hw/qdev-properties.h"
 #include "hw/sysbus.h"
 #include "qom/object.h"
@@ -216,6 +217,14 @@ static void connect_power_reduction_gpio(AtmegaMcuState *s,
                        qdev_get_gpio_in(cpu, 0));
 }
 
+static void atmega_init(Object *obj)
+{
+    AtmegaMcuState *s = ATMEGA_MCU(obj);
+
+    s->xtal_clkin = qdev_init_clock_in(DEVICE(obj), "osc-in",
+                                       NULL, NULL, ClockUpdate);
+}
+
 static void atmega_realize(DeviceState *dev, Error **errp)
 {
     AtmegaMcuState *s = ATMEGA_MCU(dev);
@@ -227,11 +236,6 @@ static void atmega_realize(DeviceState *dev, Error **errp)
 
     assert(mc->io_size <= 0x200);
 
-    if (!s->xtal_freq_hz) {
-        error_setg(errp, "\"xtal-frequency-hz\" property must be provided.");
-        return;
-    }
-
     /* CPU */
     object_initialize_child(OBJECT(dev), "cpu", &s->cpu, mc->cpu_type);
     object_property_set_bool(OBJECT(&s->cpu), "realized", true, &error_abort);
@@ -328,8 +332,7 @@ static void atmega_realize(DeviceState *dev, Error **errp)
         devname = g_strdup_printf("timer%zu", i);
         object_initialize_child(OBJECT(dev), devname, &s->timer[i],
                                 TYPE_AVR_TIMER16);
-        object_property_set_uint(OBJECT(&s->timer[i]), "cpu-frequency-hz",
-                                 s->xtal_freq_hz, &error_abort);
+        qdev_connect_clock_in(DEVICE(&s->timer[i]), "io-clk", s->xtal_clkin);
         sbd = SYS_BUS_DEVICE(&s->timer[i]);
         sysbus_realize(sbd, &error_abort);
         sysbus_mmio_map(sbd, 0, OFFSET_DATA + mc->dev[idx].addr);
@@ -353,8 +356,6 @@ static void atmega_realize(DeviceState *dev, Error **errp)
 }
 
 static Property atmega_props[] = {
-    DEFINE_PROP_UINT64("xtal-frequency-hz", AtmegaMcuState,
-                       xtal_freq_hz, 0),
     DEFINE_PROP_END_OF_LIST()
 };
 
@@ -449,6 +450,7 @@ static const TypeInfo atmega_mcu_types[] = {
         .name           = TYPE_ATMEGA_MCU,
         .parent         = TYPE_SYS_BUS_DEVICE,
         .instance_size  = sizeof(AtmegaMcuState),
+        .instance_init  = atmega_init,
         .class_size     = sizeof(AtmegaMcuClass),
         .class_init     = atmega_class_init,
         .abstract       = true,
diff --git a/hw/timer/avr_timer16.c b/hw/timer/avr_timer16.c
index c48555da525..7092023d616 100644
--- a/hw/timer/avr_timer16.c
+++ b/hw/timer/avr_timer16.c
@@ -35,6 +35,7 @@
 #include "qapi/error.h"
 #include "qemu/log.h"
 #include "hw/irq.h"
+#include "hw/qdev-clock.h"
 #include "hw/qdev-properties.h"
 #include "hw/timer/avr_timer16.h"
 #include "trace.h"
@@ -167,7 +168,7 @@ static void avr_timer16_clksrc_update(AVRTimer16State *t16)
         break;
     }
     if (divider) {
-        t16->freq_hz = t16->cpu_freq_hz / divider;
+        t16->freq_hz = clock_get_hz(t16->io_clkin) / divider;
         t16->period_ns = NANOSECONDS_PER_SECOND / t16->freq_hz;
         trace_avr_timer16_clksrc_update(t16->freq_hz, t16->period_ns,
                                         (uint64_t)(1e6 / t16->freq_hz));
@@ -544,8 +545,6 @@ static const MemoryRegionOps avr_timer16_ifr_ops = {
 
 static Property avr_timer16_properties[] = {
     DEFINE_PROP_UINT8("id", struct AVRTimer16State, id, 0),
-    DEFINE_PROP_UINT64("cpu-frequency-hz", struct AVRTimer16State,
-                       cpu_freq_hz, 0),
     DEFINE_PROP_END_OF_LIST(),
 };
 
@@ -560,10 +559,20 @@ static void avr_timer16_pr(void *opaque, int irq, int level)
     }
 }
 
+static void avr_timer16_clock_update(void *opaque, ClockEvent event)
+{
+    AVRTimer16State *s = opaque;
+
+    avr_timer16_clksrc_update(s);
+}
+
 static void avr_timer16_init(Object *obj)
 {
     AVRTimer16State *s = AVR_TIMER16(obj);
 
+    s->io_clkin = qdev_init_clock_in(DEVICE(obj), "io-clk",
+                                     avr_timer16_clock_update, s, ClockUpdate);
+
     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->capt_irq);
     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->compa_irq);
     sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->compb_irq);
@@ -587,11 +596,6 @@ static void avr_timer16_realize(DeviceState *dev, Error **errp)
 {
     AVRTimer16State *s = AVR_TIMER16(dev);
 
-    if (s->cpu_freq_hz == 0) {
-        error_setg(errp, "AVR timer16: cpu-frequency-hz property must be set");
-        return;
-    }
-
     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, avr_timer16_interrupt, s);
     s->enabled = true;
 }
