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.
 
 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
 
 
                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.
        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.