Major changes to the generic device framework for FreeBSD/alpha:

* Eliminate bus_t and make it possible for all devices to have
  attached children.

* Support dynamically extendable interfaces for drivers to replace
  both the function pointers in driver_t and bus_ops_t (which has been
  removed entirely.  Two system defined interfaces have been defined,
  'device' which is mandatory for all devices and 'bus' which is
  recommended for all devices which support attached children.

* In addition, the alpha port defines two simple interfaces 'clock'
  for attaching various real time clocks to the system and 'mcclock'
  for the many different variations of mc146818 clocks which can be
  attached to different alpha platforms.  This eliminates two more
  function pointer tables in favour of the generic method dispatch
  system provided by the device framework.

Future device interfaces may include:

* cdev and bdev interfaces for devfs to use in replacement for specfs
  and the fixed interfaces bdevsw and cdevsw.

* scsi interface to replace struct scsi_adapter (not sure how this
  works in CAM but I imagine there is something similar there).

* various tailored interfaces for different bus types such as pci,
  isa, pccard etc.

1 files changed, 53 insertions, 82 deletions

diff --git a/sys/sys/bus.h b/sys/sys/bus.h
index 54ca3d155519..0eb0481aeb41 100644
--- a/sys/sys/bus.h
+++ b/sys/sys/bus.h
@@ -1,5 +1,5 @@
 /*-
- * Copyright (c) 1997 Doug Rabson
+ * Copyright (c) 1997,1998 Doug Rabson
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id$
+ *	$Id: bus.h,v 1.1 1998/06/10 10:57:21 dfr Exp $
  */
 
 #ifndef _SYS_BUS_H_
@@ -34,15 +34,13 @@
 /*
  * Forward declarations
  */
-typedef struct bus	*bus_t;
-typedef struct device	*device_t;
-typedef struct driver	driver_t;
-typedef struct devclass *devclass_t;
-
-typedef int driver_probe_t(bus_t bus, device_t dev);
-typedef int driver_attach_t(bus_t bus, device_t dev);
-typedef int driver_detach_t(bus_t bus, device_t dev);
-typedef int driver_shutdown_t(bus_t bus, device_t dev);
+typedef struct device		*device_t;
+typedef struct driver		driver_t;
+typedef struct device_method	device_method_t;
+typedef struct devclass		*devclass_t;
+typedef struct device_ops	*device_ops_t;
+typedef struct device_op_desc	*device_op_desc_t;
+
 typedef void driver_intr_t(void*);
 
 typedef enum driver_type {
@@ -53,100 +51,62 @@ typedef enum driver_type {
     MAX_DRIVER_TYPE
 } driver_type_t;
 
+typedef int (*devop_t)(void);
+
+struct device_method {
+    device_op_desc_t	desc;
+    devop_t		func;
+};
+
 struct driver {
-    const char		*name;
-    driver_probe_t	*probe;
-    driver_attach_t	*attach;
-    driver_detach_t	*detach;
-    driver_shutdown_t	*shutdown;
+    const char		*name;		/* driver name */
+    device_method_t	*methods;	/* method table */
     driver_type_t	type;
-    size_t		softc;	/* size of device softc struct */
-    TAILQ_ENTRY(driver) link;	/* list of devices on bus */
-    void		*buspriv; /* private data for the owning bus */
+    size_t		softc;		/* size of device softc struct */
+    TAILQ_ENTRY(driver) link;		/* list of devices on bus */
+    device_ops_t	ops;		/* compiled method table */
 };
 
 typedef enum device_state device_state_t;
 enum device_state {
-    DS_NOTPRESENT,		/* not probed or probe failed */
-    DS_ALIVE,			/* probe succeeded */
-    DS_ATTACHED,		/* attach method called */
-    DS_BUSY			/* device is open */
+    DS_NOTPRESENT,			/* not probed or probe failed */
+    DS_ALIVE,				/* probe succeeded */
+    DS_ATTACHED,			/* attach method called */
+    DS_BUSY				/* device is open */
 };
 
 /*
- * Busses - containers of devices.
- */
-typedef void bus_print_device_t(bus_t bus, device_t dev);
-typedef int bus_read_ivar_t(bus_t bus, device_t dev,
-			    int index, u_long *result);
-typedef int bus_write_ivar_t(bus_t bus, device_t dev,
-			     int index, u_long value);
-typedef int bus_map_intr_t(bus_t bus, device_t dev,
-			   driver_intr_t *intr, void *arg);
-
-typedef struct bus_ops {
-    bus_print_device_t		*print_device;
-    bus_read_ivar_t		*read_ivar;
-    bus_write_ivar_t		*write_ivar;
-    bus_map_intr_t		*map_intr;
-} bus_ops_t;
-
-typedef TAILQ_HEAD(device_list, device) device_list_t;
-
-struct bus {
-    bus_ops_t			*ops;
-    device_t			dev; /* device instance in parent bus */
-    device_list_t		devices;
-};
-
-/*
- * Bus priorities.  This determines the order in which busses are probed.
- */
-#define BUS_PRIORITY_HIGH	1
-#define BUS_PRIORITY_MEDIUM	2
-#define BUS_PRIORITY_LOW	3
-
-/*
  * The root bus, to which all top-level busses are attached.
  */
-extern bus_t root_bus;
+extern device_t root_bus;
 extern devclass_t root_devclass;
 void root_bus_configure(void);
 
 /*
- * Access functions for bus.
+ * Access functions for busses.
  */
-device_t bus_get_device(bus_t bus);
-void bus_print_device(bus_t bus, device_t dev);
-int bus_read_ivar(bus_t bus, device_t dev,
-		  int index, u_long *result);
-int bus_write_ivar(bus_t bus, device_t dev,
-		   int index, u_long value);
-int bus_map_intr(bus_t bus, device_t dev, driver_intr_t *intr, void *arg);
-device_t bus_add_device(bus_t bus, const char *name,
-			int unit, void *ivars);
-device_t bus_add_device_after(bus_t bus, device_t place, const char *name,
-			      int unit, void *ivars);
-int bus_delete_device(bus_t bus, device_t dev);
-device_t bus_find_device(bus_t bus, const char *classname, int unit);
+device_t device_add_child(device_t dev, const char *name,
+			  int unit, void *ivars);
+device_t device_add_child_after(device_t dev, device_t place, const char *name,
+				int unit, void *ivars);
+int device_delete_child(device_t dev, device_t child);
+device_t device_find_child(device_t dev, const char *classname, int unit);
 
 /*
  * Useful functions for implementing busses.
  */
-void bus_init(bus_t bus, device_t dev, bus_ops_t *ops);
-driver_attach_t bus_generic_attach;
-driver_detach_t bus_generic_detach;
-driver_shutdown_t bus_generic_shutdown;
-bus_print_device_t null_print_device;
-bus_read_ivar_t null_read_ivar;
-bus_write_ivar_t null_write_ivar;
-bus_map_intr_t null_map_intr;
-extern bus_ops_t null_bus_ops;
+int bus_generic_attach(device_t dev);
+int bus_generic_detach(device_t dev);
+int bus_generic_shutdown(device_t dev);
+void bus_generic_print_child(device_t dev, device_t child);
+int bus_generic_read_ivar(device_t dev, device_t child, int which, u_long *result);
+int bus_generic_write_ivar(device_t dev, device_t child, int which, u_long value);
+int bus_generic_map_intr(device_t dev, device_t child, driver_intr_t *intr, void *arg);
 
 /*
  * Access functions for device.
  */
-bus_t device_get_parent(device_t dev);
+device_t device_get_parent(device_t dev);
 driver_t *device_get_driver(device_t dev);
 devclass_t device_get_devclass(device_t dev);
 int device_set_devclass(device_t dev, const char *classname);
@@ -181,6 +141,17 @@ void *devclass_get_softc(devclass_t dc, int unit);
 int devclass_get_devices(devclass_t dc, device_t **devlistp, int *devcountp);
 int devclass_get_maxunit(devclass_t dc);
 
+/*
+ * Shorthand for constructing method tables.
+ */
+#define DEVMETHOD(NAME, FUNC) { &NAME##_desc, (devop_t) FUNC }
+
+/*
+ * Some common device interfaces.
+ */
+#include "device_if.h"
+#include "bus_if.h"
+
 #ifdef _SYS_MODULE_H_
 
 /*
@@ -194,7 +165,7 @@ struct driver_module_data {
     devclass_t*		devclass;
 };
 
-int driver_module_handler __P((module_t, modeventtype_t, void*));
+int driver_module_handler(module_t, modeventtype_t, void*);
 
 #define DRIVER_MODULE(name, busname, driver, devclass, evh, arg)	\
 									\