regulator: Make core more chatty about some errors

Prevent some head scratching by making the core log about some rare but
possible errors with invalid voltage ranges and modes being set.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index f59821f..3700d09 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -151,8 +151,11 @@
 	if (*min_uV < rdev->constraints->min_uV)
 		*min_uV = rdev->constraints->min_uV;
 
-	if (*min_uV > *max_uV)
+	if (*min_uV > *max_uV) {
+		rdev_err(rdev, "unsupportable voltage range: %d-%duV\n",
+			 min_uV, max_uV);
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -205,8 +208,11 @@
 	if (*min_uA < rdev->constraints->min_uA)
 		*min_uA = rdev->constraints->min_uA;
 
-	if (*min_uA > *max_uA)
+	if (*min_uA > *max_uA) {
+		rdev_err(rdev, "unsupportable current range: %d-%duA\n",
+			 min_uA, max_uA);
 		return -EINVAL;
+	}
 
 	return 0;
 }
@@ -221,6 +227,7 @@
 	case REGULATOR_MODE_STANDBY:
 		break;
 	default:
+		rdev_err(rdev, "invalid mode %x specified\n", *mode);
 		return -EINVAL;
 	}