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| author | Jean Delvare <khali@linux-fr.org> | 2006-08-13 23:46:44 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2006-09-26 15:38:51 -0700 |
| commit | 7a8d29cec7a53cf1a29dc5055aa9d1fa0f95830f (patch) | |
| tree | d7be7f4fe5909b34fb4ca1587bc6a981c7c0b67b /Documentation/i2c | |
| parent | 6c805d2ce9d910ea915d7dbe4aed0a91f138be07 (diff) | |
| download | lwn-7a8d29cec7a53cf1a29dc5055aa9d1fa0f95830f.tar.gz lwn-7a8d29cec7a53cf1a29dc5055aa9d1fa0f95830f.zip | |
i2c-stub: Chip address as a module parameter
i2c-stub: Chip address as a module parameter
Add a mandatory chip_addr parameter to i2c-stub. This parameter
defines to which chip address the driver will respond, instead of
reponding to all addresses as before. The idea is to prevent the
users from loading i2c-stub at random and being then confused by
the results of sensors-detect or other user-space tools.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'Documentation/i2c')
| -rw-r--r-- | Documentation/i2c/i2c-stub | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/i2c/i2c-stub b/Documentation/i2c/i2c-stub index d6dcb138abf5..9cc081e69764 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. |