Richard-TX wrote:I think that someone should write modules for things like the MPC23017, MCP23S17, PCF8591,PCA9544. It might help the beginner with modest I2C based projects.
It looks like somebody already has done it for the MCP23*, see https://www.kernel.org/doc/Documentatio ... p23s08.txt
mcp23s08 for 8 GPIO SPI version
mcp23s17 for 16 GPIO SPI version
mcp23008 for 8 GPIO I2C version or
mcp23017 for 16 GPIO I2C version of the chip
Alas, I'm not sure if it's possible to enable the GPIO_MCP23S08 kernel option at the moment. The option is not visible for me. It depends on OF_GPIO, which depends on OF, which depends on USE_OF. That's in the Boot options with the description "Flattened Device Tree support". This issue https://github.com/raspberrypi/linux/issues/674
seems to indicate that we can't just enable it and be done with it.
Thank you, Jabss, for pointing out how to use these modules!