Hi, in a watchdog driver on an ARM platform, I have the need to write a hw register managed by another driver (system reset controller). I'm wondering what is the correct/clean way of doing that. What I've done until now is adding a second couple in the "reg" property of the device-tree &wdog1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_wdog>; reg = <0x30280000 0x10000>, <0x30390000 0x10000>; fsl,wdog_b; }; and then in the wdog driver adding the following code: static void __iomem *src_base; ... res = platform_get_resource(pdev, IORESOURCE_MEM, 1); src_base = devm_ioremap(&pdev->dev, res->start, res->end - res->start + 1); if (IS_ERR(src_base)) return PTR_ERR(src_base); ... writel(0x3, src_base + 4); In this way it works as expected, but I'm not sure if this is correct? Thanks Best regards Luca