linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / Documentation / sparc / sbus_drivers.txt

diff --git a/Documentation/sparc/sbus_drivers.txt b/Documentation/sparc/sbus_drivers.txt
index 4b93516..876195d 100644 (file)
--- a/Documentation/sparc/sbus_drivers.txt
+++ b/Documentation/sparc/sbus_drivers.txt
@@ -25,84 +25,42 @@ the bits necessary to run your device.  The most commonly
 used members of this structure, and their typical usage,
 will be detailed below.
 
-       Here is a piece of skeleton code for perofming a device
-probe in an SBUS driverunder Linux:
+       Here is how probing is performed by an SBUS driver
+under Linux:
 
-       static int __devinit mydevice_probe_one(struct sbus_dev *sdev)
+       static void init_one_mydevice(struct sbus_dev *sdev)
        {
-               struct mysdevice *mp = kzalloc(sizeof(*mp), GFP_KERNEL);
-
-               if (!mp)
-                       return -ENODEV;
-
-               ...
-               dev_set_drvdata(&sdev->ofdev.dev, mp);
-               return 0;
                ...
        }
 
-       static int __devinit mydevice_probe(struct of_device *dev,
-                                           const struct of_device_id *match)
+       static int mydevice_match(struct sbus_dev *sdev)
        {
-               struct sbus_dev *sdev = to_sbus_device(&dev->dev);
-
-               return mydevice_probe_one(sdev);
+               if (some_criteria(sdev))
+                       return 1;
+               return 0;
        }
 
-       static int __devexit mydevice_remove(struct of_device *dev)
+       static void mydevice_probe(void)
        {
-               struct sbus_dev *sdev = to_sbus_device(&dev->dev);
-               struct mydevice *mp = dev_get_drvdata(&dev->dev);
-
-               return mydevice_remove_one(sdev, mp);
-       }
-
-       static struct of_device_id mydevice_match[] = {
-               {
-                       .name = "mydevice",
-               },
-               {},
-       };
-
-       MODULE_DEVICE_TABLE(of, mydevice_match);
-
-       static struct of_platform_driver mydevice_driver = {
-               .name           = "mydevice",
-               .match_table    = mydevice_match,
-               .probe          = mydevice_probe,
-               .remove         = __devexit_p(mydevice_remove),
-       };
-
-       static int __init mydevice_init(void)
-       {
-               return of_register_driver(&mydevice_driver, &sbus_bus_type);
-       }
+               struct sbus_bus *sbus;
+               struct sbus_dev *sdev;
 
-       static void __exit mydevice_exit(void)
-       {
-               of_unregister_driver(&mydevice_driver);
+               for_each_sbus(sbus) {
+                       for_each_sbusdev(sdev, sbus) {
+                               if (mydevice_match(sdev))
+                                       init_one_mydevice(sdev);
+                       }
+               }
        }
 
-       module_init(mydevice_init);
-       module_exit(mydevice_exit);
-
-       The mydevice_match table is a series of entries which
-describes what SBUS devices your driver is meant for.  In the
-simplest case you specify a string for the 'name' field.  Every
-SBUS device with a 'name' property matching your string will
-be passed one-by-one to your .probe method.
-
-       You should store away your device private state structure
-pointer in the drvdata area so that you can retrieve it later on
-in your .remove method.
+       All this does is walk through all SBUS devices in the
+system, checks each to see if it is of the type which
+your driver is written for, and if so it calls the init
+routine to attach the device and prepare to drive it.
 
-       Any memory allocated, registers mapped, IRQs registered,
-etc. must be undone by your .remove method so that all resources
-of your device are relased by the time it returns.
-
-       You should _NOT_ use the for_each_sbus(), for_each_sbusdev(),
-and for_all_sbusdev() interfaces.  They are deprecated, will be
-removed, and no new driver should reference them ever.
+       "init_one_mydevice" might do things like allocate software
+state structures, map in I/O registers, place the hardware
+into an initialized state, etc.
 
                Mapping and Accessing I/O Registers
 
@@ -305,3 +263,10 @@ discussed above and plus it handles both PCI and SBUS boards.
        Lance driver abuses consistent mappings for data transfer.
 It is a nifty trick which we do not particularly recommend...
 Just check it out and know that it's legal.
+
+                       Bad examples, do NOT use
+
+       drivers/video/cgsix.c
+       This one uses result of sbus_ioremap as if it is an address.
+This does NOT work on sparc64 and therefore is broken. We will
+convert it at a later date.