regulator: core: do not silently ignore provided init_data

On DT platforms, if a regulator init_data is provided in config, it is
silently ignored in favor of the DT parsing done by the framework, if
of_match is set.

of_match is an indication that init_data is expected to be set based on DT
and the parsing should be done by the regulator framework.

If the regulator provider passed init_data it must be because it is useful
somehow, in such case of_match should be clear.

If the driver expects the framework to initialize this data on its
own, it should leave init_data clear.

Warn if both init_data and of_match are set, then default to the provided
init_data.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://patch.msgid.link/20241008-regulator-ignored-data-v2-1-d1251e0ee507@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/core.c

@@ -5681,32 +5681,43 @@ regulator_register(struct device *dev,
 		goto clean;
 	}
 
-	init_data = regulator_of_get_init_data(dev, regulator_desc, config,
-					       &rdev->dev.of_node);
-
-	/*
-	 * Sometimes not all resources are probed already so we need to take
-	 * that into account. This happens most the time if the ena_gpiod comes
-	 * from a gpio extender or something else.
-	 */
-	if (PTR_ERR(init_data) == -EPROBE_DEFER) {
-		ret = -EPROBE_DEFER;
-		goto clean;
-	}
+	if (config->init_data) {
+		/*
+		 * Providing of_match means the framework is expected to parse
+		 * DT to get the init_data. This would conflict with provided
+		 * init_data, if set. Warn if it happens.
+		 */
+		if (regulator_desc->of_match)
+			dev_warn(dev, "Using provided init data - OF match ignored\n");
 
-	/*
-	 * We need to keep track of any GPIO descriptor coming from the
-	 * device tree until we have handled it over to the core. If the
-	 * config that was passed in to this function DOES NOT contain
-	 * a descriptor, and the config after this call DOES contain
-	 * a descriptor, we definitely got one from parsing the device
-	 * tree.
-	 */
-	if (!cfg->ena_gpiod && config->ena_gpiod)
-		dangling_of_gpiod = true;
-	if (!init_data) {
 		init_data = config->init_data;
 		rdev->dev.of_node = of_node_get(config->of_node);
+
+	} else {
+		init_data = regulator_of_get_init_data(dev, regulator_desc,
+						       config,
+						       &rdev->dev.of_node);
+
+		/*
+		 * Sometimes not all resources are probed already so we need to
+		 * take that into account. This happens most the time if the
+		 * ena_gpiod comes from a gpio extender or something else.
+		 */
+		if (PTR_ERR(init_data) == -EPROBE_DEFER) {
+			ret = -EPROBE_DEFER;
+			goto clean;
+		}
+
+		/*
+		 * We need to keep track of any GPIO descriptor coming from the
+		 * device tree until we have handled it over to the core. If the
+		 * config that was passed in to this function DOES NOT contain a
+		 * descriptor, and the config after this call DOES contain a
+		 * descriptor, we definitely got one from parsing the device
+		 * tree.
+		 */
+		if (!cfg->ena_gpiod && config->ena_gpiod)
+			dangling_of_gpiod = true;
 	}
 
 	ww_mutex_init(&rdev->mutex, &regulator_ww_class);