1 files changed, 58 insertions, 19 deletions

diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 10368ed8fd13..cd739d2fa160 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -41,7 +41,7 @@ struct reset_control {
         struct list_head list;
         unsigned int id;
         unsigned int refcnt;
-        int shared;
+        bool shared;
         atomic_t deassert_count;
         atomic_t triggered_count;
 };
@@ -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)
@@ -163,7 +169,7 @@ int reset_control_reset(struct reset_control *rstc)
         }
 
         ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
-        if (rstc->shared && !ret)
+        if (rstc->shared && ret)
                 atomic_dec(&rstc->triggered_count);
 
         return ret;
@@ -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)
@@ -252,9 +275,9 @@ int reset_control_status(struct reset_control *rstc)
 }
 EXPORT_SYMBOL_GPL(reset_control_status);
 
-static struct reset_control *__reset_control_get(
+static struct reset_control *__reset_control_get_internal(
                                 struct reset_controller_dev *rcdev,
-                                unsigned int index, int shared)
+                                unsigned int index, bool shared)
 {
         struct reset_control *rstc;
 
@@ -285,7 +308,7 @@ static struct reset_control *__reset_control_get(
         return rstc;
 }
 
-static void __reset_control_put(struct reset_control *rstc)
+static void __reset_control_put_internal(struct reset_control *rstc)
 {
         lockdep_assert_held(&reset_list_mutex);
 
@@ -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, int 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;
@@ -349,7 +377,7 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
         }
 
         /* reset_list_mutex also protects the rcdev's reset_control list */
-        rstc = __reset_control_get(rcdev, rstc_id, shared);
+        rstc = __reset_control_get_internal(rcdev, rstc_id, shared);
 
         mutex_unlock(&reset_list_mutex);
 
@@ -357,6 +385,17 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
 }
 EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
+struct reset_control *__reset_control_get(struct device *dev, const char *id,
+                                          int index, bool shared, bool optional)
+{
+        if (dev->of_node)
+                return __of_reset_control_get(dev->of_node, id, index, shared,
+                                              optional);
+
+        return optional ? NULL : ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL_GPL(__reset_control_get);
+
 /**
  * reset_control_put - free the reset controller
  * @rstc: reset controller
@@ -364,11 +403,11 @@ EXPORT_SYMBOL_GPL(__of_reset_control_get);
 
 void reset_control_put(struct reset_control *rstc)
 {
-        if (IS_ERR(rstc))
+        if (IS_ERR_OR_NULL(rstc))
                 return;
 
         mutex_lock(&reset_list_mutex);
-        __reset_control_put(rstc);
+        __reset_control_put_internal(rstc);
         mutex_unlock(&reset_list_mutex);
 }
 EXPORT_SYMBOL_GPL(reset_control_put);
@@ -379,7 +418,8 @@ 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, int shared)
+                                     const char *id, int index, bool shared,
+                                     bool optional)
 {
         struct reset_control **ptr, *rstc;
 
@@ -388,8 +428,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
         if (!ptr)
                 return ERR_PTR(-ENOMEM);
 
-        rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
-                                      id, index, shared);
+        rstc = __reset_control_get(dev, id, index, shared, optional);
         if (!IS_ERR(rstc)) {
                 *ptr = rstc;
                 devres_add(dev, ptr);