platform/x86: x86-android-tablets: Add support for preloading modules

Since the x86-android-tablets code does all it work from module_init() it
cannot use -EPROBE_DEFER to wait for e.g. interrupt providing GPIO-chips
or PMIC-cells to show up.

To make sure things will still work when some necessary resource providers
are build as module allow the per board info to specify a list of modules
to pre-load before instantiating the I2C clients.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20211229231431.437982-10-hdegoede@redhat.com

drivers/platform/x86/x86-android-tablets.c

@@ -142,6 +142,7 @@ struct x86_serdev_info {
 };
 
 struct x86_dev_info {
+	const char * const *modules;
 	struct gpiod_lookup_table **gpiod_lookup_tables;
 	const struct x86_i2c_client_info *i2c_client_info;
 	const struct platform_device_info *pdev_info;
@@ -428,6 +429,13 @@ static __init int x86_android_tablet_init(void)
 
 	dev_info = id->driver_data;
 
+	/*
+	 * Since this runs from module_init() it cannot use -EPROBE_DEFER,
+	 * instead pre-load any modules which are listed as requirements.
+	 */
+	for (i = 0; dev_info->modules && dev_info->modules[i]; i++)
+		request_module(dev_info->modules[i]);
+
 	gpiod_lookup_tables = dev_info->gpiod_lookup_tables;
 	for (i = 0; gpiod_lookup_tables && gpiod_lookup_tables[i]; i++)
 		gpiod_add_lookup_table(gpiod_lookup_tables[i]);