[PATCH 2/5] OPP: Add generic key finding helpers

[Viresh Kumar]

There are three type of helpers, to find exact, ceil, and floor values,
replicated for multiple key types, freq, level, bw. And all of these
helpers share a lot of boilerplate code.

Add generic key finding helpers to reduce code redundancy.

Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
 drivers/opp/core.c | 132 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)

diff --git a/drivers/opp/core.c b/drivers/opp/core.c
index 1ee218dcb0b9..7ef6eafc7946 100644
--- a/drivers/opp/core.c
+++ b/drivers/opp/core.c
@@ -420,6 +420,138 @@ int dev_pm_opp_get_opp_count(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(dev_pm_opp_get_opp_count);
 
+/* Helpers to read keys */
+static unsigned long _read_freq(struct dev_pm_opp *opp, int index)
+{
+	return opp->rate;
+}
+
+static unsigned long _read_level(struct dev_pm_opp *opp, int index)
+{
+	return opp->level;
+}
+
+static unsigned long _read_bw(struct dev_pm_opp *opp, int index)
+{
+	return opp->bandwidth[index].peak;
+}
+
+/* Generic comparison helpers */
+static bool _compare_exact(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
+			   unsigned long opp_key, unsigned long key)
+{
+	if (opp_key == key) {
+		*opp = temp_opp;
+		return true;
+	}
+
+	return false;
+}
+
+static bool _compare_ceil(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
+			  unsigned long opp_key, unsigned long key)
+{
+	if (opp_key >= key) {
+		*opp = temp_opp;
+		return true;
+	}
+
+	return false;
+}
+
+static bool _compare_floor(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
+			   unsigned long opp_key, unsigned long key)
+{
+	if (opp_key > key)
+		return true;
+
+	*opp = temp_opp;
+	return false;
+}
+
+/* Generic key finding helpers */
+static struct dev_pm_opp *
+_opp_table_find_key(struct opp_table *opp_table, unsigned long *key, int index, bool available,
+		    unsigned long (*read)(struct dev_pm_opp *opp, int index),
+		    bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
+				    unsigned long opp_key, unsigned long key))
+{
+	struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE);
+
+	mutex_lock(&opp_table->lock);
+
+	list_for_each_entry(temp_opp, &opp_table->opp_list, node) {
+		if (temp_opp->available == available) {
+			if (compare(&opp, temp_opp, read(temp_opp, index), *key))
+				break;
+		}
+	}
+
+	/* Increment the reference count of OPP */
+	if (!IS_ERR(opp)) {
+		*key = read(opp, index);
+		dev_pm_opp_get(opp);
+	}
+
+	mutex_unlock(&opp_table->lock);
+
+	return opp;
+}
+
+static struct dev_pm_opp *
+_find_key(struct device *dev, unsigned long *key, int index, bool available,
+	  unsigned long (*read)(struct dev_pm_opp *opp, int index),
+	  bool (*compare)(struct dev_pm_opp **opp, struct dev_pm_opp *temp_opp,
+			  unsigned long opp_key, unsigned long key))
+{
+	struct opp_table *opp_table;
+	struct dev_pm_opp *opp;
+
+	opp_table = _find_opp_table(dev);
+	if (IS_ERR(opp_table)) {
+		dev_err(dev, "%s: OPP table not found (%ld)\n", __func__, PTR_ERR(opp_table));
+		return ERR_CAST(opp_table);
+	}
+
+	opp = _opp_table_find_key(opp_table, key, index, available, read, compare);
+
+	dev_pm_opp_put_opp_table(opp_table);
+
+	return opp;
+}
+
+static struct dev_pm_opp *
+_find_key_exact(struct device *dev, unsigned long key, int index, bool available,
+		unsigned long (*read)(struct dev_pm_opp *opp, int index))
+{
+	/*
+	 * The value of key will be updated here, but will be ignored as the
+	 * caller doesn't need it.
+	 */
+	return _find_key(dev, &key, index, available, read, _compare_exact);
+}
+
+static struct dev_pm_opp *
+_opp_table_find_key_ceil(struct opp_table *opp_table, unsigned long *key, int index, bool available,
+			 unsigned long (*read)(struct dev_pm_opp *opp, int index))
+{
+	return _opp_table_find_key(opp_table, key, index, available, read, _compare_ceil);
+}
+
+static struct dev_pm_opp *
+_find_key_ceil(struct device *dev, unsigned long *key, int index, bool available,
+	       unsigned long (*read)(struct dev_pm_opp *opp, int index))
+{
+	return _find_key(dev, key, index, available, read, _compare_ceil);
+}
+
+static struct dev_pm_opp *
+_find_key_floor(struct device *dev, unsigned long *key, int index, bool available,
+		unsigned long (*read)(struct dev_pm_opp *opp, int index))
+{
+	return _find_key(dev, key, index, available, read, _compare_floor);
+}
+
 /**
  * dev_pm_opp_find_freq_exact() - search for an exact frequency
  * @dev:		device for which we do this operation
-- 
2.31.1.272.g89b43f80a514