- First, as Leonid said, check that those pads are not being configured by another device for a different functionality.
- Second, adding a pinctrl node to the device tree does not automatically make Linux configure the IOMUX in it. Pinctrl nodes are linked to other nodes in the device tree (for example the UART), and those to the Linux device drivers. It is the loading of a driver by the kernel, that configures the pinctrl sets linked to such node in the DT.
For groups of pads that you need to configure but are not linked to *any* driver, you must add them to a special node that's called 'pinctrl_hog', which is linked to the IOMUX driver itself.
You will find it in the DTSI files. Add your pads there.