From: Cornelia Huck <[email protected]>
[patch 2/24] s390: cio documentation update.
Update documentation of the common I/O layer:
- Add MSS-specific example.
- Add more information on ccwgroup devices.
- Add channel path type attribute.
- Fix typo.
Signed-off-by: Cornelia Huck <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>
---
Documentation/s390/driver-model.txt | 15 ++++++++++++---
1 files changed, 12 insertions(+), 3 deletions(-)
diff -urpN linux-2.6/Documentation/s390/driver-model.txt linux-2.6-patched/Documentation/s390/driver-model.txt
--- linux-2.6/Documentation/s390/driver-model.txt 2006-03-20 06:53:29.000000000 +0100
+++ linux-2.6-patched/Documentation/s390/driver-model.txt 2006-03-22 14:36:10.000000000 +0100
@@ -16,10 +16,12 @@ devices/
- 0.0.0000/0.0.0815/
- 0.0.0001/0.0.4711/
- 0.0.0002/
+ - 0.1.0000/0.1.1234/
...
-In this example, device 0815 is accessed via subchannel 0, device 4711 via
-subchannel 1, and subchannel 2 is a non-I/O subchannel.
+In this example, device 0815 is accessed via subchannel 0 in subchannel set 0,
+device 4711 via subchannel 1 in subchannel set 0, and subchannel 2 is a non-I/O
+subchannel. Device 1234 is accessed via subchannel 0 in subchannel set 1.
You should address a ccw device via its bus id (e.g. 0.0.4711); the device can
be found under bus/ccw/devices/.
@@ -97,7 +99,7 @@ is not available to the device driver.
Each driver should declare in a MODULE_DEVICE_TABLE into which CU types/models
and/or device types/models it is interested. This information can later be found
-found in the struct ccw_device_id fields:
+in the struct ccw_device_id fields:
struct ccw_device_id {
__u16 match_flags;
@@ -208,6 +210,11 @@ Each ccwgroup device also provides an 'u
again (only when offline). This is a generic ccwgroup mechanism (the driver does
not need to implement anything beyond normal removal routines).
+A ccw device which is a member of a ccwgroup device carries a pointer to the
+ccwgroup device in the driver_data of its device struct. This field must not be
+touched by the driver - it should use the ccwgroup device's driver_data for its
+private data.
+
To implement a ccwgroup driver, please refer to include/asm/ccwgroup.h. Keep in
mind that most drivers will need to implement both a ccwgroup and a ccw driver
(unless you have a meta ccw driver, like cu3088 for lcs and ctc).
@@ -230,6 +237,8 @@ status - Can be 'online' or 'offline'.
a channel path the user knows to be online, but the machine hasn't
created a machine check for.
+type - The physical type of the channel path.
+
3. System devices
-----------------