Change device reset so that the resets proceed hierarchically. Added

a device_reset_after_children() hook for things that need to wait for
the children to finish. Moved calling the driver/machine/sound/video
reset callbacks to the after children time, to align more with how it
was happening before.

Fixed siblingdevice("") so that it returns the current device and not
the owner.

src/emu/device.c

@@ -262,6 +262,13 @@ void device_t::reset()
 
 	// reset the device
 	device_reset();
+	
+	// reset all child devices
+	for (device_t *child = m_subdevice_list.first(); child != NULL; child = child->next())
+		child->reset();
+	
+	// now allow for some post-child reset action
+	device_reset_after_children();
 
 	// let the interfaces do their post-work
 	for (device_interface *intf = m_interface_list; intf != NULL; intf = intf->interface_next())
@@ -579,6 +586,19 @@ void device_t::device_reset()
 }
 
 
+//-------------------------------------------------
+//  device_reset_after_children - hook to do
+//  reset logic that must happen after the children
+//  are reset; designed to be overriden by the
+//  actual device implementation
+//-------------------------------------------------
+
+void device_t::device_reset_after_children()
+{
+	// do nothing by default
+}
+
+
 //-------------------------------------------------
 //  device_stop - clean up anything that needs to
 //  happen before the running_machine goes away

src/emu/device.h

@@ -186,7 +186,7 @@ public:
 	astring &siblingtag(astring &dest, const char *tag) const { return (this != NULL && m_owner != NULL) ? m_owner->subtag(dest, tag) : dest.cpy(tag); }
 	const memory_region *subregion(const char *tag) const;
 	device_t *subdevice(const char *tag) const;
-	device_t *siblingdevice(const char *tag) const { return (this != NULL && m_owner != NULL) ? m_owner->subdevice(tag) : NULL; }
+	device_t *siblingdevice(const char *tag) const;
 	template<class _DeviceClass> inline _DeviceClass *subdevice(const char *tag) const { return downcast<_DeviceClass *>(subdevice(tag)); }
 	template<class _DeviceClass> inline _DeviceClass *siblingdevice(const char *tag) const { return downcast<_DeviceClass *>(siblingdevice(tag)); }
 	const memory_region *region() const { return m_region; }
@@ -248,6 +248,7 @@ protected:
 	virtual void device_start() ATTR_COLD = 0;
 	virtual void device_stop() ATTR_COLD;
 	virtual void device_reset() ATTR_COLD;
+	virtual void device_reset_after_children() ATTR_COLD;
 	virtual void device_pre_save() ATTR_COLD;
 	virtual void device_post_load() ATTR_COLD;
 	virtual void device_clock_changed();
@@ -753,6 +754,26 @@ inline device_t *device_t::subdevice(const char *tag) const
 }
 
 
+//-------------------------------------------------
+//  siblingdevice - given a tag, find the device 
+//  by name relative to this device's parent
+//-------------------------------------------------
+
+inline device_t *device_t::siblingdevice(const char *tag) const
+{
+	// safety first
+	if (this == NULL)
+		return NULL;
+
+	// empty string or NULL means this device
+	if (tag == NULL || *tag == 0)
+		return const_cast<device_t *>(this);
+
+	// query relative to the parent
+	return (m_owner != NULL) ? m_owner->subdevice(tag) : NULL;
+}
+
+
 //-------------------------------------------------
 //  bind_relative_to - perform a late binding of
 //  a device_delegate

src/emu/machine.c

@@ -932,10 +932,8 @@ void running_machine::start_all_devices()
 
 void running_machine::reset_all_devices()
 {
-	// iterate over devices and reset them
-	device_iterator iter(root_device());
-	for (device_t *device = iter.first(); device != NULL; device = iter.next())
-		device->reset();
+	// reset the root and it will reset children
+	root_device().reset();
 }
 
 
@@ -1268,11 +1266,12 @@ void driver_device::device_start()
 
 
 //-------------------------------------------------
-//  device_reset - device override which calls
-//  the various helpers
+//  device_reset_after_children - device override 
+//  which calls the various helpers; must happen
+//  after all child devices are reset
 //-------------------------------------------------
 
-void driver_device::device_reset()
+void driver_device::device_reset_after_children()
 {
 	// reset each piece
 	driver_reset();

src/emu/machine.h

@@ -682,7 +682,7 @@ protected:
 	virtual const rom_entry *device_rom_region() const;
 	virtual ioport_constructor device_input_ports() const;
 	virtual void device_start();
-	virtual void device_reset();
+	virtual void device_reset_after_children();
 
 	// internal helpers
 	inline UINT16 paletteram16_le(offs_t offset) const { return m_generic_paletteram[offset & ~1] | (m_generic_paletteram[offset |  1] << 8); }