suicidal_orange
Posts: 217
Joined: Sun Mar 16, 2014 10:56 am

Re: Sharing my use of I2C GPIOs

Mon May 19, 2014 11:58 pm

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[email protected] ~ $ uname -a
Linux smallbox 3.12.13-rt21 #5 PREEMPT RT Sun May 18 22:47:44 BST 2014 armv6l GNU/Linux
Not too old :D

elmicha
Posts: 27
Joined: Tue Jul 03, 2012 4:43 pm

Re: Sharing my use of I2C GPIOs

Tue Nov 18, 2014 10:38 am

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!

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