aboutsummaryrefslogtreecommitdiff
path: root/Documentation/i2c/i2c-stub
diff options
context:
space:
mode:
authorSteven Whitehouse <swhiteho@redhat.com>2006-09-28 08:29:59 -0400
committerSteven Whitehouse <swhiteho@redhat.com>2006-09-28 08:29:59 -0400
commit185a257f2f73bcd89050ad02da5bedbc28fc43fa (patch)
tree5e32586114534ed3f2165614cba3d578f5d87307 /Documentation/i2c/i2c-stub
parent3f1a9aaeffd8d1cbc5ab9776c45cbd66af1c9699 (diff)
parenta77c64c1a641950626181b4857abb701d8f38ccc (diff)
Merge branch 'master' into gfs2
Diffstat (limited to 'Documentation/i2c/i2c-stub')
-rw-r--r--Documentation/i2c/i2c-stub15
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/i2c/i2c-stub b/Documentation/i2c/i2c-stub
index d6dcb138abf..9cc081e6976 100644
--- a/Documentation/i2c/i2c-stub
+++ b/Documentation/i2c/i2c-stub
@@ -6,9 +6,12 @@ This module is a very simple fake I2C/SMBus driver. It implements four
types of SMBus commands: write quick, (r/w) byte, (r/w) byte data, and
(r/w) word data.
+You need to provide a chip address as a module parameter when loading
+this driver, which will then only react to SMBus commands to this address.
+
No hardware is needed nor associated with this module. It will accept write
-quick commands to all addresses; it will respond to the other commands (also
-to all addresses) by reading from or writing to an array in memory. It will
+quick commands to one address; it will respond to the other commands (also
+to one address) by reading from or writing to an array in memory. It will
also spam the kernel logs for every command it handles.
A pointer register with auto-increment is implemented for all byte
@@ -21,6 +24,11 @@ The typical use-case is like this:
3. load the target sensors chip driver module
4. observe its behavior in the kernel log
+PARAMETERS:
+
+int chip_addr:
+ The SMBus address to emulate a chip at.
+
CAVEATS:
There are independent arrays for byte/data and word/data commands. Depending
@@ -33,6 +41,9 @@ If the hardware for your driver has banked registers (e.g. Winbond sensors
chips) this module will not work well - although it could be extended to
support that pretty easily.
+Only one chip address is supported - although this module could be
+extended to support more.
+
If you spam it hard enough, printk can be lossy. This module really wants
something like relayfs.