DESCRIPTION:
-This module is a very simple fake I2C/SMBus driver. It implements five
+This module is a very simple fake I2C/SMBus driver. It implements six
types of SMBus commands: write quick, (r/w) byte, (r/w) byte data, (r/w)
-word data, and (r/w) I2C block data.
+word data, (r/w) I2C block data, and (r/w) SMBus block data.
You need to provide chip addresses as a module parameter when loading this
driver, which will then only react to SMBus commands to these addresses.
operations. This allows for continuous byte reads like those supported by
EEPROMs, among others.
+SMBus block command support is disabled by default, and must be enabled
+explicitly by setting the respective bits (0x03000000) in the functionality
+module parameter.
+
+SMBus block commands must be written to configure an SMBus command for
+SMBus block operations. Writes can be partial. Block read commands always
+return the number of bytes selected with the largest write so far.
+
The typical use-case is like this:
1. load this module
2. use i2cset (from the i2c-tools project) to pre-load some data
value 0x1f0000 would only enable the quick, byte and byte data
commands.
+u8 bank_reg[10]
+u8 bank_mask[10]
+u8 bank_start[10]
+u8 bank_end[10]:
+ Optional bank settings. They tell which bits in which register
+ select the active bank, as well as the range of banked registers.
+
CAVEATS:
If your target driver polls some byte or word waiting for it to change, the
stub could lock it up. Use i2cset to unlock it.
-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.
-
If you spam it hard enough, printk can be lossy. This module really wants
something like relayfs.
projects / cascardo / linux.git / blobdiff