On 01/31/2013 10:51 AM, Arnd Bergmann wrote:

This is what I think it would look like to do a default platform
with an empty machine descriptor on ARM. It makes the few required
entries in the descriptor optional by using the new irqchip_init()
and clocksource_of_init() functions as defaults, and adds
a fallback for the DT case to customize_machine to probe all
the default devices.

For the case that CONFIG_MULTIPLATFORM is enabled, it then
adds a machine descriptor that never matches any machine but
is used as a fallback if nothing else matches.

 static int __init customize_machine(void)
 {
-	/* customizes platform devices, or adds new ones */
+	/*
+	 * customizes platform devices, or adds new ones
+	 * On DT based machines, we fall back to populating the
+	 * machine from the device tree, if no callback is provided,
+	 * otherwise we would always need an init_machine callback.
+	 */
 	if (machine_desc->init_machine)
 		machine_desc->init_machine();
+	else
+		of_platform_populate(NULL, of_default_bus_match_table,
+					NULL, NULL);

With that change, we can remove the custom .init_machine() functions for
all of Tegra, since they just do that:-)

+#ifdef CONFIG_IRQCHIP
 void __init irqchip_init(void)
 {
 	of_irq_init(__irqchip_begin);
 }
+#else
+static inline void irqchip_init(void)
+{
+}
+#endif

That'd need to go in a header file.