PM / OPP: of_property_count_u32_elems() can return errors

[firefly-linux-kernel-4.4.55.git] / drivers / base / power / opp.c

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index eb254497a4944454650fb220e4967f5110cec737..1194669c2bb554ac46b95c263fb5eb6f4e016942 100644 (file)
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -340,6 +340,34 @@ unsigned long dev_pm_opp_get_max_clock_latency(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_max_clock_latency);
 
+/**
+ * dev_pm_opp_get_suspend_opp() - Get suspend opp
+ * @dev:       device for which we do this operation
+ *
+ * Return: This function returns pointer to the suspend opp if it is
+ * defined and available, otherwise it returns NULL.
+ *
+ * Locking: This function must be called under rcu_read_lock(). opp is a rcu
+ * protected pointer. The reason for the same is that the opp pointer which is
+ * returned will remain valid for use with opp_get_{voltage, freq} only while
+ * under the locked area. The pointer returned must be used prior to unlocking
+ * with rcu_read_unlock() to maintain the integrity of the pointer.
+ */
+struct dev_pm_opp *dev_pm_opp_get_suspend_opp(struct device *dev)
+{
+       struct device_opp *dev_opp;
+
+       opp_rcu_lockdep_assert();
+
+       dev_opp = _find_device_opp(dev);
+       if (IS_ERR(dev_opp) || !dev_opp->suspend_opp ||
+           !dev_opp->suspend_opp->available)
+               return NULL;
+
+       return dev_opp->suspend_opp;
+}
+EXPORT_SYMBOL_GPL(dev_pm_opp_get_suspend_opp);
+
 /**
  * dev_pm_opp_get_opp_count() - Get number of opps available in the opp list
  * @dev:       device for which we do this operation
@@ -864,10 +892,17 @@ static int opp_get_microvolt(struct dev_pm_opp *opp, struct device *dev)
        u32 microvolt[3] = {0};
        int count, ret;
 
-       count = of_property_count_u32_elems(opp->np, "opp-microvolt");
-       if (!count)
+       /* Missing property isn't a problem, but an invalid entry is */
+       if (!of_find_property(opp->np, "opp-microvolt", NULL))
                return 0;
 
+       count = of_property_count_u32_elems(opp->np, "opp-microvolt");
+       if (count < 0) {
+               dev_err(dev, "%s: Invalid opp-microvolt property (%d)\n",
+                       __func__, count);
+               return count;
+       }
+
        /* There can be one or three elements here */
        if (count != 1 && count != 3) {
                dev_err(dev, "%s: Invalid number of elements in opp-microvolt property (%d)\n",