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| -rw-r--r-- | Documentation/i2c/slave-interface | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/Documentation/i2c/slave-interface b/Documentation/i2c/slave-interface index 389bb5d61854..02b086510b6c 100644 --- a/Documentation/i2c/slave-interface +++ b/Documentation/i2c/slave-interface @@ -3,16 +3,16 @@ Linux I2C slave interface description by Wolfram Sang <wsa@sang-engineering.com> in 2014-15 -Linux can also be an I2C slave in case I2C controllers have slave support. -Besides this HW requirement, one also needs a software backend providing the -actual functionality. An example for this is the slave-eeprom driver, which -acts as a dual memory driver. While another I2C master on the bus can access it -like a regular EEPROM, the Linux I2C slave can access the content via sysfs and -retrieve/provide information as needed. The software backend driver and the I2C -bus driver communicate via events. Here is a small graph visualizing the data -flow and the means by which data is transported. The dotted line marks only one -example. The backend could also use e.g. a character device, be in-kernel -only, or something completely different: +Linux can also be an I2C slave if the I2C controller in use has slave +functionality. For that to work, one needs slave support in the bus driver plus +a hardware independent software backend providing the actual functionality. An +example for the latter is the slave-eeprom driver, which acts as a dual memory +driver. While another I2C master on the bus can access it like a regular +EEPROM, the Linux I2C slave can access the content via sysfs and handle data as +needed. The backend driver and the I2C bus driver communicate via events. Here +is a small graph visualizing the data flow and the means by which data is +transported. The dotted line marks only one example. The backend could also +use a character device, be in-kernel only, or something completely different: e.g. sysfs I2C slave events I/O registers @@ -43,6 +43,11 @@ behaviour and setup. Developer manual ================ +First, the events which are used by the bus driver and the backend will be +described in detail. After that, some implementation hints for extending bus +drivers and writing backends will be given. + + I2C slave events ---------------- |