Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...

[~andy/linux] / drivers / base / power / opp.c

diff --git a/drivers/base/power/opp.c b/drivers/base/power/opp.c
index ac993eafec82ecd707cfc6e2654b5a8f30703fc6..d9468642fc414c22f8578c82e57e2cac9ba224e5 100644 (file)
--- a/drivers/base/power/opp.c
+++ b/drivers/base/power/opp.c
@@ -22,6 +22,7 @@
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/opp.h>
+#include <linux/of.h>
 
 /*
  * Internal data structure organization with the OPP layer library is as
@@ -674,3 +675,49 @@ struct srcu_notifier_head *opp_get_notifier(struct device *dev)
 
        return &dev_opp->head;
 }
+
+#ifdef CONFIG_OF
+/**
+ * of_init_opp_table() - Initialize opp table from device tree
+ * @dev:       device pointer used to lookup device OPPs.
+ *
+ * Register the initial OPP table with the OPP library for given device.
+ */
+int of_init_opp_table(struct device *dev)
+{
+       const struct property *prop;
+       const __be32 *val;
+       int nr;
+
+       prop = of_find_property(dev->of_node, "operating-points", NULL);
+       if (!prop)
+               return -ENODEV;
+       if (!prop->value)
+               return -ENODATA;
+
+       /*
+        * Each OPP is a set of tuples consisting of frequency and
+        * voltage like <freq-kHz vol-uV>.
+        */
+       nr = prop->length / sizeof(u32);
+       if (nr % 2) {
+               dev_err(dev, "%s: Invalid OPP list\n", __func__);
+               return -EINVAL;
+       }
+
+       val = prop->value;
+       while (nr) {
+               unsigned long freq = be32_to_cpup(val++) * 1000;
+               unsigned long volt = be32_to_cpup(val++);
+
+               if (opp_add(dev, freq, volt)) {
+                       dev_warn(dev, "%s: Failed to add OPP %ld\n",
+                                __func__, freq);
+                       continue;
+               }
+               nr -= 2;
+       }
+
+       return 0;
+}
+#endif