Re: [PATCH 3/6] watchdog: tegra_wdt: Support Tegra20

[Krzysztof Kozlowski <krzk@kernel.org>]

On 10/11/2026 13:39, Artur Kowalski wrote:
> +static int tegra20_wdt_init(struct platform_device *pdev, struct tegra_wdt *wdt,
> +			    void __iomem *regs)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np;
> +	struct resource res;
> +	int ret;
> +
> +	/*
> +	 * RST_SOURCE belongs to the clock and reset controller, whose driver
> +	 * doesn't use it. Map only this register, without requesting it, as
> +	 * the region belongs to the clock and reset controller.
> +	 */
> +	np = of_find_compatible_node(NULL, NULL, "nvidia,tegra20-car");
> +	if (!np)
> +		return dev_err_probe(dev, -ENODEV,
> +				     "clock and reset controller not found\n");
> +
> +	ret = of_address_to_resource(np, 0, &res);
> +	of_node_put(np);
> +	if (ret)

Looks like doing syscon here. This in general is more fragile.

...

> +/*
> + * Tegra30 and later list "nvidia,tegra20-timer" as well, but match their more
> + * specific compatible string.
> + */
>  static const struct of_device_id tegra_wdt_of_match[] = {
>  	{ .compatible = "nvidia,tegra30-timer", .data = &tegra30_wdt_soc },
> +	{ .compatible = "nvidia,tegra20-timer", .data = &tegra20_wdt_soc },

Why in reversed order?

>  	{ },
>  };
>  MODULE_DEVICE_TABLE(of, tegra_wdt_of_match);
> 


Best regards,
Krzysztof