regulator: core: simplify _regulator_get()

The code in _regulator_get() got a bit confusing over time, with control
flow jumping to a label from couple of places. Let's untangle it a bit by
doing the following:

1. Make handling of missing supplies and substituting them with dummy
regulators more explicit:

- check if we not have full constraints and refuse considering dummy
  regulators with appropriate message;

- use "switch (get_type)" to handle different types of request explicitly
  as well. "Normal" requests will get dummies, exclusive will not and
  will notify user about that; optional will fail silently.

2. Stop jumping to a label in the middle of the function but instead have
proper conditional flow. I believe jumps should be reserved for error
handling, breaking from inner loop, or restarting a loop, but not for
implementing normal conditional flow.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 3e246c82939d1f87a7eca0239dd344da49c21004..a62f5b725061c2f8e8f0dcc69029f7c1c93480e2 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1588,7 +1588,7 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 {
        struct regulator_dev *rdev;
        struct regulator *regulator;
-       const char *devname = NULL;
+       const char *devname = dev ? dev_name(dev) : "deviceless";
        int ret;
 
        if (get_type >= MAX_GET_TYPE) {
@@ -1601,45 +1601,47 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
                return ERR_PTR(-EINVAL);
        }
 
-       if (dev)
-               devname = dev_name(dev);
-
        rdev = regulator_dev_lookup(dev, id);
-       if (!IS_ERR(rdev))
-               goto found;
+       if (IS_ERR(rdev)) {
+               ret = PTR_ERR(rdev);
 
-       ret = PTR_ERR(rdev);
-       regulator = ERR_PTR(ret);
+               /*
+                * If regulator_dev_lookup() fails with error other
+                * than -ENODEV our job here is done, we simply return it.
+                */
+               if (ret != -ENODEV)
+                       return ERR_PTR(ret);
 
-       /*
-        * If we have return value from dev_lookup fail, we do not expect to
-        * succeed, so, quit with appropriate error value
-        */
-       if (ret && ret != -ENODEV)
-               return regulator;
+               if (!have_full_constraints()) {
+                       dev_warn(dev,
+                                "incomplete constraints, dummy supplies not allowed\n");
+                       return ERR_PTR(-ENODEV);
+               }
 
-       if (!devname)
-               devname = "deviceless";
+               switch (get_type) {
+               case NORMAL_GET:
+                       /*
+                        * Assume that a regulator is physically present and
+                        * enabled, even if it isn't hooked up, and just
+                        * provide a dummy.
+                        */
+                       dev_warn(dev,
+                                "%s supply %s not found, using dummy regulator\n",
+                                devname, id);
+                       rdev = dummy_regulator_rdev;
+                       get_device(&rdev->dev);
+                       break;
 
-       /*
-        * Assume that a regulator is physically present and enabled
-        * even if it isn't hooked up and just provide a dummy.
-        */
-       if (have_full_constraints() && get_type == NORMAL_GET) {
-               pr_warn("%s supply %s not found, using dummy regulator\n",
-                       devname, id);
+               case EXCLUSIVE_GET:
+                       dev_warn(dev,
+                                "dummy supplies not allowed for exclusive requests\n");
+                       /* fall through */
 
-               rdev = dummy_regulator_rdev;
-               get_device(&rdev->dev);
-               goto found;
-       /* Don't log an error when called from regulator_get_optional() */
-       } else if (!have_full_constraints() || get_type == EXCLUSIVE_GET) {
-               dev_warn(dev, "dummy supplies not allowed\n");
+               default:
+                       return ERR_PTR(-ENODEV);
+               }
        }
 
-       return regulator;
-
-found:
        if (rdev->exclusive) {
                regulator = ERR_PTR(-EPERM);
                put_device(&rdev->dev);