[Documentation]: Update probing info in sbus_drivers.txt
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/Documentation/sparc/sbus_drivers.txt b/Documentation/sparc/sbus_drivers.txt
index 876195d..4b93516 100644
--- a/Documentation/sparc/sbus_drivers.txt
+++ b/Documentation/sparc/sbus_drivers.txt
@@ -25,42 +25,84 @@
used members of this structure, and their typical usage,
will be detailed below.
- Here is how probing is performed by an SBUS driver
-under Linux:
+ Here is a piece of skeleton code for perofming a device
+probe in an SBUS driverunder Linux:
- static void init_one_mydevice(struct sbus_dev *sdev)
+ static int __devinit mydevice_probe_one(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 mydevice_match(struct sbus_dev *sdev)
+ static int __devinit mydevice_probe(struct of_device *dev,
+ const struct of_device_id *match)
{
- if (some_criteria(sdev))
- return 1;
- return 0;
+ struct sbus_dev *sdev = to_sbus_device(&dev->dev);
+
+ return mydevice_probe_one(sdev);
}
- static void mydevice_probe(void)
+ static int __devexit mydevice_remove(struct of_device *dev)
{
- struct sbus_bus *sbus;
- struct sbus_dev *sdev;
+ struct sbus_dev *sdev = to_sbus_device(&dev->dev);
+ struct mydevice *mp = dev_get_drvdata(&dev->dev);
- for_each_sbus(sbus) {
- for_each_sbusdev(sdev, sbus) {
- if (mydevice_match(sdev))
- init_one_mydevice(sdev);
- }
- }
+ return mydevice_remove_one(sdev, mp);
}
- 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.
+ static struct of_device_id mydevice_match[] = {
+ {
+ .name = "mydevice",
+ },
+ {},
+ };
- "init_one_mydevice" might do things like allocate software
-state structures, map in I/O registers, place the hardware
-into an initialized state, etc.
+ 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);
+ }
+
+ static void __exit mydevice_exit(void)
+ {
+ of_unregister_driver(&mydevice_driver);
+ }
+
+ 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.
+
+ 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.
Mapping and Accessing I/O Registers
@@ -263,10 +305,3 @@
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.