opp: Add dev_pm_opp_find_level_exact()

Since the performance states in the OPP table are unique, implement a
dev_pm_opp_find_level_exact() in order to be able to fetch a specific OPP.

Signed-off-by: Niklas Cassel <niklas.cassel@linaro.org>
[ Viresh: Updated commit log ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index bdb4358..0ee8c01 100644 (file)
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -401,6 +401,54 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact);
 
+/**
+ * dev_pm_opp_find_level_exact() - search for an exact level
+ * @dev:               device for which we do this operation
+ * @level:             level to search for
+ *
+ * Return: Searches for exact match in the opp table and returns pointer to the
+ * matching opp if found, else returns ERR_PTR in case of error and should
+ * be handled using IS_ERR. Error return values can be:
+ * EINVAL:     for bad pointer
+ * ERANGE:     no match found for search
+ * ENODEV:     if device not found in list of registered devices
+ *
+ * The callers are required to call dev_pm_opp_put() for the returned OPP after
+ * use.
+ */
+struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
+                                              unsigned int level)
+{
+       struct opp_table *opp_table;
+       struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+       opp_table = _find_opp_table(dev);
+       if (IS_ERR(opp_table)) {
+               int r = PTR_ERR(opp_table);
+
+               dev_err(dev, "%s: OPP table not found (%d)\n", __func__, r);
+               return ERR_PTR(r);
+       }
+
+       mutex_lock(&opp_table->lock);
+
+       list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+               if (temp_opp->level == level) {
+                       opp = temp_opp;
+
+                       /* Increment the reference count of OPP */
+                       dev_pm_opp_get(opp);
+                       break;
+               }
+       }
+
+       mutex_unlock(&opp_table->lock);
+       dev_pm_opp_put_opp_table(opp_table);
+
+       return opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_find_level_exact);
+
 static noinline struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table,
                                                   unsigned long *freq)
 {

diff --git a/include/linux/pm_opp.h b/include/linux/pm_opp.h
index 5bdceca..b8197ab 100644 (file)
--- a/include/linux/pm_opp.h
+++ b/include/linux/pm_opp.h
@@ -96,6 +96,8 @@ unsigned long dev_pm_opp_get_suspend_opp_freq(struct device *dev);
 struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
                                              unsigned long freq,
                                              bool available);
+struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
+                                              unsigned int level);
 
 struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
                                              unsigned long *freq);
@@ -200,6 +202,12 @@ static inline struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev,
        return ERR_PTR(-ENOTSUPP);
 }
 
+static inline struct dev_pm_opp *dev_pm_opp_find_level_exact(struct device *dev,
+                                       unsigned int level)
+{
+       return ERR_PTR(-ENOTSUPP);
+}
+
 static inline struct dev_pm_opp *dev_pm_opp_find_freq_floor(struct device *dev,
                                        unsigned long *freq)
 {