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Problems modifying device tree to blink an LED

Question asked by Ben Rathke on Feb 5, 2014
Latest reply on Feb 18, 2014 by Ben Rathke

Hello All -

I've had a surprising amount of difficulty trying to figure out how to use dts to configure the hardware to heartbeat-blink the debug led on the i.MX6SL EVK. I'm running kernel 3.10.17, building core-image-minimal, and tried adding the following code in the appropriate places in imx6sl-evk.dts (as well as enabling the appropriate items in the kernel menuconfig):

 

  leds {

  compatible = "gpio-leds";

  debug-led {

  label = "Heartbeat";

  gpios = <&gpio3 20 0>; //HSIC_STROBE -> GPIO3_20

  linux,default-trigger = "heartbeat";

  };

  };

 

and

 

  MX6SL_PAD_HSIC_STROBE__GPIO3_IO20 0x110b0

 

After much trial and error, I was able to get this to work after modifying the init function register_init_complete (in .../git/drivers/regulator/core.c) to return early without doing anything.

 

I'm looking into this further, but in the meantime, does anyone have any ideas about what is going on here?

 

Thanks! -Ben

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