Hello, With reference to the example below what is the correct way to get the gpio values from the device tree : I modified the existing leds-ns2 device tree as below : blue-sata { label = "ns2:blue:sata"; slow-gpio = <&gpio0 29 0>; cmd-gpio = <&gpio0 30 0>; + slow1-gpio=<&gpio 31 0>; + cmd1-gpio=<&gpio 32 0>; modes-map = <NS_V2_LED_OFF 0 1 NS_V2_LED_ON 1 0 NS_V2_LED_ON 0 0 NS_V2_LED_SATA 1 1>; }; And modified the driver by adding slow1 and cmd1 in all the structure (just like slow and cmd) But when I am trying to get the gpio number for slow1 and cmd1 I am getting the below error(number gpio #31 and 32 are random numbers of gpio for testing, does it matters?) : error : leds-ns2:probe of ns2-leds failed with error -2.What does error code -2 represents ?Is this a device tree parsing error? ret = of_get_named_gpio(child, "slow1-gpio", 0); if (ret < 0) return ret; same error if I try to get the cmd1-gpio Thanks in advance ! Regards, Rp On Thu, Aug 4, 2016 at 9:23 AM, Raul Piper <raulpblooper@gmail.com> wrote:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabi- <name of the dtb file>.dtb

This compiles fine.

On Thu, Aug 4, 2016 at 1:06 AM, Frank Rowand <frowand.list@gmail.com> wrote:

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On 07/25/16 04:17, Raul Piper wrote:

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Hi, Where can I find the example for the dynamic Loading of the device tree and its corresponding device driver. How can I build the dts with or without the kernel source.

I am getting this error whenever I am trying to build the below sample dts file using the dtc compiler.

dtc -O dtb -o leds-ns2.dtb leds-ns2.dts

Error: leds-ns2.dts:1.1-2 syntax error

That is an error at line 1, columns 1-2. dtc does not understand cpp directives, you need to process leds-ns2.dts with cpp. The Linux build infrastructure does this for .dtb targets in makefiles.

...

FATAL ERROR: Unable to parse input tree

Below is the content of the leds-ns2.dts

#include <dt-bindings/leds/leds-ns2.h>

ns2-leds { compatible = "lacie,ns2-leds";

blue-sata { label = "ns2:blue:sata"; slow-gpio = <&gpio0 29 0>; cmd-gpio = <&gpio0 30 0>; modes-map = <NS_V2_LED_OFF 0 1 NS_V2_LED_ON 1 0 NS_V2_LED_ON 0 0 NS_V2_LED_SATA 1 1>; }; };

Thanks, R -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html