Hi Jacky, On Tue, Jun 1, 2021 at 3:13 AM Jacky Bai <ping.bai@xxxxxxx> wrote: > + pin_reg = &ipctl->pin_regs[offset]; > + if (pin_reg->mux_reg == -1) Can this condition happen? > + return -EINVAL; > +static const struct of_device_id imx8ulp_pinctrl_of_match[] = { > + { .compatible = "fsl,imx8ulp-iomuxc1", }, In the bindings doc patch it is documented "fsl,imx8ulp-iomuxc", so there is a mismatch between the driver and the binding doc.