reset: make optional functions really optional

The *_get_optional_* functions weren't really optional so this patch
makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.

Signed-off-by: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 39 insertions, 10 deletions

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 272c1e4ecb5c..c79cce3a7b6d 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -143,12 +143,18 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
  * a no-op.
  * Consumers must not use reset_control_(de)assert on shared reset lines when
  * reset_control_reset has been used.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_reset(struct reset_control *rstc)
 {
         int ret;
 
-        if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+        if (!rstc)
+                return 0;
+
+        if (WARN_ON(IS_ERR(rstc)))
                 return -EINVAL;
 
         if (!rstc->rcdev->ops->reset)
@@ -182,10 +188,17 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
  * internal state to be reset, but must be prepared for this to happen.
  * Consumers must not use reset_control_reset on shared reset lines when
  * reset_control_(de)assert has been used.
+ * return 0.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_assert(struct reset_control *rstc)
 {
-        if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+        if (!rstc)
+                return 0;
+
+        if (WARN_ON(IS_ERR(rstc)))
                 return -EINVAL;
 
         if (!rstc->rcdev->ops->assert)
@@ -213,10 +226,17 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
  * After calling this function, the reset is guaranteed to be deasserted.
  * Consumers must not use reset_control_reset on shared reset lines when
  * reset_control_(de)assert has been used.
+ * return 0.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
  */
 int reset_control_deassert(struct reset_control *rstc)
 {
-        if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+        if (!rstc)
+                return 0;
+
+        if (WARN_ON(IS_ERR(rstc)))
                 return -EINVAL;
 
         if (!rstc->rcdev->ops->deassert)
@@ -237,12 +257,15 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
 /**
  * reset_control_status - returns a negative errno if not supported, a
  * positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
  * @rstc: reset controller
  */
 int reset_control_status(struct reset_control *rstc)
 {
-        if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+        if (!rstc)
+                return 0;
+
+        if (WARN_ON(IS_ERR(rstc)))
                 return -EINVAL;
 
         if (rstc->rcdev->ops->status)
@@ -299,7 +322,8 @@ static void __reset_control_put(struct reset_control *rstc)
 }
 
 struct reset_control *__of_reset_control_get(struct device_node *node,
-                                     const char *id, int index, bool shared)
+                                     const char *id, int index, bool shared,
+                                     bool optional)
 {
         struct reset_control *rstc;
         struct reset_controller_dev *r, *rcdev;
@@ -313,14 +337,18 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
         if (id) {
                 index = of_property_match_string(node,
                                                  "reset-names", id);
+                if (index == -EILSEQ)
+                        return ERR_PTR(index);
                 if (index < 0)
-                        return ERR_PTR(-ENOENT);
+                        return optional ? NULL : ERR_PTR(-ENOENT);
         }
 
         ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
                                          index, &args);
-        if (ret)
+        if (ret == -EINVAL)
                 return ERR_PTR(ret);
+        if (ret)
+                return optional ? NULL : ERR_PTR(ret);
 
         mutex_lock(&reset_list_mutex);
         rcdev = NULL;
@@ -379,7 +407,8 @@ static void devm_reset_control_release(struct device *dev, void *res)
 }
 
 struct reset_control *__devm_reset_control_get(struct device *dev,
-                                     const char *id, int index, bool shared)
+                                     const char *id, int index, bool shared,
+                                     bool optional)
 {
         struct reset_control **ptr, *rstc;
 
@@ -389,7 +418,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
                 return ERR_PTR(-ENOMEM);
 
         rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-                                      id, index, shared);
+                                      id, index, shared, optional);
         if (!IS_ERR(rstc)) {
                 *ptr = rstc;
                 devres_add(dev, ptr);