1 ========
2 i2c-stub
3 ========
4
5 Description
6 ===========
7
8 This module is a very simple fake I2C/SMBus dr
9 types of SMBus commands: write quick, (r/w) by
10 word data, (r/w) I2C block data, and (r/w) SMB
11
12 You need to provide chip addresses as a module
13 driver, which will then only react to SMBus co
14
15 No hardware is needed nor associated with this
16 quick commands to the specified addresses; it
17 commands (also to the specified addresses) by
18 arrays in memory. It will also spam the kerne
19 handles.
20
21 A pointer register with auto-increment is impl
22 operations. This allows for continuous byte r
23 EEPROMs, among others.
24
25 SMBus block command support is disabled by def
26 explicitly by setting the respective bits (0x0
27 module parameter.
28
29 SMBus block commands must be written to config
30 SMBus block operations. Writes can be partial.
31 return the number of bytes selected with the l
32
33 The typical use-case is like this:
34
35 1. load this module
36 2. use i2cset (from the i2c-tools proj
37 3. load the target chip driver module
38 4. observe its behavior in the kernel
39
40 There's a script named i2c-stub-from-dump in t
41 can load register values automatically from a
42
43 Parameters
44 ==========
45
46 int chip_addr[10]:
47 The SMBus addresses to emulate chips a
48
49 unsigned long functionality:
50 Functionality override, to disable som
51 constants in <linux/i2c.h> for the sui
52 value 0x1f0000 would only enable the q
53 commands.
54
55 u8 bank_reg[10], u8 bank_mask[10], u8 bank_sta
56 Optional bank settings. They tell whic
57 select the active bank, as well as the
58
59 Caveats
60 =======
61
62 If your target driver polls some byte or word
63 stub could lock it up. Use i2cset to unlock i
64
65 If you spam it hard enough, printk can be loss
66 something like relayfs.
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