aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorDavid S. Miller <davem@sunset.davemloft.net>2006-06-24 01:12:39 -0400
committerDavid S. Miller <davem@sunset.davemloft.net>2006-06-24 02:16:17 -0400
commit9eccf1b3121f7e407d3159908f29252887194a16 (patch)
treeda29cdcbe783e62dfffde79c77d0f0f846960272 /Documentation
parent3d4253d9afabd6d42c33812a839ba67b8c9bbe49 (diff)
[Documentation]: Update probing info in sbus_drivers.txt
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/sparc/sbus_drivers.txt95
1 files changed, 65 insertions, 30 deletions
diff --git a/Documentation/sparc/sbus_drivers.txt b/Documentation/sparc/sbus_drivers.txt
index 876195dc2aef..4b9351624f13 100644
--- a/Documentation/sparc/sbus_drivers.txt
+++ b/Documentation/sparc/sbus_drivers.txt
@@ -25,42 +25,84 @@ the bits necessary to run your device. The most commonly
25used members of this structure, and their typical usage, 25used members of this structure, and their typical usage,
26will be detailed below. 26will be detailed below.
27 27
28 Here is how probing is performed by an SBUS driver 28 Here is a piece of skeleton code for perofming a device
29under Linux: 29probe in an SBUS driverunder Linux:
30 30
31 static void init_one_mydevice(struct sbus_dev *sdev) 31 static int __devinit mydevice_probe_one(struct sbus_dev *sdev)
32 { 32 {
33 struct mysdevice *mp = kzalloc(sizeof(*mp), GFP_KERNEL);
34
35 if (!mp)
36 return -ENODEV;
37
38 ...
39 dev_set_drvdata(&sdev->ofdev.dev, mp);
40 return 0;
33 ... 41 ...
34 } 42 }
35 43
36 static int mydevice_match(struct sbus_dev *sdev) 44 static int __devinit mydevice_probe(struct of_device *dev,
45 const struct of_device_id *match)
37 { 46 {
38 if (some_criteria(sdev)) 47 struct sbus_dev *sdev = to_sbus_device(&dev->dev);
39 return 1; 48
40 return 0; 49 return mydevice_probe_one(sdev);
41 } 50 }
42 51
43 static void mydevice_probe(void) 52 static int __devexit mydevice_remove(struct of_device *dev)
44 { 53 {
45 struct sbus_bus *sbus; 54 struct sbus_dev *sdev = to_sbus_device(&dev->dev);
46 struct sbus_dev *sdev; 55 struct mydevice *mp = dev_get_drvdata(&dev->dev);
47 56
48 for_each_sbus(sbus) { 57 return mydevice_remove_one(sdev, mp);
49 for_each_sbusdev(sdev, sbus) {
50 if (mydevice_match(sdev))
51 init_one_mydevice(sdev);
52 }
53 }
54 } 58 }
55 59
56 All this does is walk through all SBUS devices in the 60 static struct of_device_id mydevice_match[] = {
57system, checks each to see if it is of the type which 61 {
58your driver is written for, and if so it calls the init 62 .name = "mydevice",
59routine to attach the device and prepare to drive it. 63 },
64 {},
65 };
66
67 MODULE_DEVICE_TABLE(of, mydevice_match);
60 68
61 "init_one_mydevice" might do things like allocate software 69 static struct of_platform_driver mydevice_driver = {
62state structures, map in I/O registers, place the hardware 70 .name = "mydevice",
63into an initialized state, etc. 71 .match_table = mydevice_match,
72 .probe = mydevice_probe,
73 .remove = __devexit_p(mydevice_remove),
74 };
75
76 static int __init mydevice_init(void)
77 {
78 return of_register_driver(&mydevice_driver, &sbus_bus_type);
79 }
80
81 static void __exit mydevice_exit(void)
82 {
83 of_unregister_driver(&mydevice_driver);
84 }
85
86 module_init(mydevice_init);
87 module_exit(mydevice_exit);
88
89 The mydevice_match table is a series of entries which
90describes what SBUS devices your driver is meant for. In the
91simplest case you specify a string for the 'name' field. Every
92SBUS device with a 'name' property matching your string will
93be passed one-by-one to your .probe method.
94
95 You should store away your device private state structure
96pointer in the drvdata area so that you can retrieve it later on
97in your .remove method.
98
99 Any memory allocated, registers mapped, IRQs registered,
100etc. must be undone by your .remove method so that all resources
101of your device are relased by the time it returns.
102
103 You should _NOT_ use the for_each_sbus(), for_each_sbusdev(),
104and for_all_sbusdev() interfaces. They are deprecated, will be
105removed, and no new driver should reference them ever.
64 106
65 Mapping and Accessing I/O Registers 107 Mapping and Accessing I/O Registers
66 108
@@ -263,10 +305,3 @@ discussed above and plus it handles both PCI and SBUS boards.
263 Lance driver abuses consistent mappings for data transfer. 305 Lance driver abuses consistent mappings for data transfer.
264It is a nifty trick which we do not particularly recommend... 306It is a nifty trick which we do not particularly recommend...
265Just check it out and know that it's legal. 307Just check it out and know that it's legal.
266
267 Bad examples, do NOT use
268
269 drivers/video/cgsix.c
270 This one uses result of sbus_ioremap as if it is an address.
271This does NOT work on sparc64 and therefore is broken. We will
272convert it at a later date.