dm: power: Add a function to set up all regulators

The device tree provides information about which regulators should be
on at boot, or always on. Use this to set them up automatically.

Signed-off-by: Simon Glass <sjg@chromium.org>
Tested-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

drivers/power/regulator/regulator-uclass.c

@@ -306,6 +306,28 @@ static int regulator_pre_probe(struct udevice *dev)
 	return 0;
 }
 
+int regulators_enable_boot_on(bool verbose)
+{
+	struct udevice *dev;
+	struct uclass *uc;
+	int ret;
+
+	ret = uclass_get(UCLASS_REGULATOR, &uc);
+	if (ret)
+		return ret;
+	for (uclass_first_device(UCLASS_REGULATOR, &dev);
+	     dev && !ret;
+	     uclass_next_device(&dev)) {
+		ret = regulator_autoset(dev);
+		if (ret == -EMEDIUMTYPE)
+			continue;
+		if (verbose)
+			regulator_show(dev, ret);
+	}
+
+	return ret;
+}
+
 UCLASS_DRIVER(regulator) = {
 	.id		= UCLASS_REGULATOR,
 	.name		= "regulator",

include/power/regulator.h

@@ -316,6 +316,17 @@ int regulator_get_mode(struct udevice *dev);
 int regulator_set_mode(struct udevice *dev, int mode_id);
 
 /**
+ * regulators_enable_boot_on() - enable regulators needed for boot
+ *
+ * This enables all regulators which are marked to be on at boot time. This
+ * only works for regulators which don't have a range for voltage/current,
+ * since in that case it is not possible to know which value to use.
+ *
+ * This effectively calls regulator_autoset() for every regulator.
+ */
+int regulators_enable_boot_on(bool verbose);
+
+/**
  * regulator_autoset: setup the voltage/current on a regulator
  *
  * The setup depends on constraints found in device's uclass's platform data