1 files changed, 293 insertions, 0 deletions
diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
new file mode 100644
index 000000000..956b7e54f
--- /dev/null
+++ b/drivers/clk/clk-composite.c
@@ -0,0 +1,293 @@
+/*
+ * Copyright (c) 2013 NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+
+#define to_clk_composite(_hw) container_of(_hw, struct clk_composite, hw)
+
+static u8 clk_composite_get_parent(struct clk_hw *hw)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *mux_ops = composite->mux_ops;
+	struct clk_hw *mux_hw = composite->mux_hw;
+
+	__clk_hw_set_clk(mux_hw, hw);
+
+	return mux_ops->get_parent(mux_hw);
+}
+
+static int clk_composite_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *mux_ops = composite->mux_ops;
+	struct clk_hw *mux_hw = composite->mux_hw;
+
+	__clk_hw_set_clk(mux_hw, hw);
+
+	return mux_ops->set_parent(mux_hw, index);
+}
+
+static unsigned long clk_composite_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *rate_ops = composite->rate_ops;
+	struct clk_hw *rate_hw = composite->rate_hw;
+
+	__clk_hw_set_clk(rate_hw, hw);
+
+	return rate_ops->recalc_rate(rate_hw, parent_rate);
+}
+
+static long clk_composite_determine_rate(struct clk_hw *hw, unsigned long rate,
+					unsigned long min_rate,
+					unsigned long max_rate,
+					unsigned long *best_parent_rate,
+					struct clk_hw **best_parent_p)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *rate_ops = composite->rate_ops;
+	const struct clk_ops *mux_ops = composite->mux_ops;
+	struct clk_hw *rate_hw = composite->rate_hw;
+	struct clk_hw *mux_hw = composite->mux_hw;
+	struct clk *parent;
+	unsigned long parent_rate;
+	long tmp_rate, best_rate = 0;
+	unsigned long rate_diff;
+	unsigned long best_rate_diff = ULONG_MAX;
+	int i;
+
+	if (rate_hw && rate_ops && rate_ops->determine_rate) {
+		__clk_hw_set_clk(rate_hw, hw);
+		return rate_ops->determine_rate(rate_hw, rate, min_rate,
+						max_rate,
+						best_parent_rate,
+						best_parent_p);
+	} else if (rate_hw && rate_ops && rate_ops->round_rate &&
+		   mux_hw && mux_ops && mux_ops->set_parent) {
+		*best_parent_p = NULL;
+
+		if (__clk_get_flags(hw->clk) & CLK_SET_RATE_NO_REPARENT) {
+			parent = clk_get_parent(mux_hw->clk);
+			*best_parent_p = __clk_get_hw(parent);
+			*best_parent_rate = __clk_get_rate(parent);
+
+			return rate_ops->round_rate(rate_hw, rate,
+						    best_parent_rate);
+		}
+
+		for (i = 0; i < __clk_get_num_parents(mux_hw->clk); i++) {
+			parent = clk_get_parent_by_index(mux_hw->clk, i);
+			if (!parent)
+				continue;
+
+			parent_rate = __clk_get_rate(parent);
+
+			tmp_rate = rate_ops->round_rate(rate_hw, rate,
+							&parent_rate);
+			if (tmp_rate < 0)
+				continue;
+
+			rate_diff = abs(rate - tmp_rate);
+
+			if (!rate_diff || !*best_parent_p
+				       || best_rate_diff > rate_diff) {
+				*best_parent_p = __clk_get_hw(parent);
+				*best_parent_rate = parent_rate;
+				best_rate_diff = rate_diff;
+				best_rate = tmp_rate;
+			}
+
+			if (!rate_diff)
+				return rate;
+		}
+
+		return best_rate;
+	} else if (mux_hw && mux_ops && mux_ops->determine_rate) {
+		__clk_hw_set_clk(mux_hw, hw);
+		return mux_ops->determine_rate(mux_hw, rate, min_rate,
+					       max_rate, best_parent_rate,
+					       best_parent_p);
+	} else {
+		pr_err("clk: clk_composite_determine_rate function called, but no mux or rate callback set!\n");
+		return 0;
+	}
+}
+
+static long clk_composite_round_rate(struct clk_hw *hw, unsigned long rate,
+				  unsigned long *prate)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *rate_ops = composite->rate_ops;
+	struct clk_hw *rate_hw = composite->rate_hw;
+
+	__clk_hw_set_clk(rate_hw, hw);
+
+	return rate_ops->round_rate(rate_hw, rate, prate);
+}
+
+static int clk_composite_set_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *rate_ops = composite->rate_ops;
+	struct clk_hw *rate_hw = composite->rate_hw;
+
+	__clk_hw_set_clk(rate_hw, hw);
+
+	return rate_ops->set_rate(rate_hw, rate, parent_rate);
+}
+
+static int clk_composite_is_enabled(struct clk_hw *hw)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *gate_ops = composite->gate_ops;
+	struct clk_hw *gate_hw = composite->gate_hw;
+
+	__clk_hw_set_clk(gate_hw, hw);
+
+	return gate_ops->is_enabled(gate_hw);
+}
+
+static int clk_composite_enable(struct clk_hw *hw)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *gate_ops = composite->gate_ops;
+	struct clk_hw *gate_hw = composite->gate_hw;
+
+	__clk_hw_set_clk(gate_hw, hw);
+
+	return gate_ops->enable(gate_hw);
+}
+
+static void clk_composite_disable(struct clk_hw *hw)
+{
+	struct clk_composite *composite = to_clk_composite(hw);
+	const struct clk_ops *gate_ops = composite->gate_ops;
+	struct clk_hw *gate_hw = composite->gate_hw;
+
+	__clk_hw_set_clk(gate_hw, hw);
+
+	gate_ops->disable(gate_hw);
+}
+
+struct clk *clk_register_composite(struct device *dev, const char *name,
+			const char **parent_names, int num_parents,
+			struct clk_hw *mux_hw, const struct clk_ops *mux_ops,
+			struct clk_hw *rate_hw, const struct clk_ops *rate_ops,
+			struct clk_hw *gate_hw, const struct clk_ops *gate_ops,
+			unsigned long flags)
+{
+	struct clk *clk;
+	struct clk_init_data init;
+	struct clk_composite *composite;
+	struct clk_ops *clk_composite_ops;
+
+	composite = kzalloc(sizeof(*composite), GFP_KERNEL);
+	if (!composite) {
+		pr_err("%s: could not allocate composite clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = name;
+	init.flags = flags | CLK_IS_BASIC;
+	init.parent_names = parent_names;
+	init.num_parents = num_parents;
+
+	clk_composite_ops = &composite->ops;
+
+	if (mux_hw && mux_ops) {
+		if (!mux_ops->get_parent) {
+			clk = ERR_PTR(-EINVAL);
+			goto err;
+		}
+
+		composite->mux_hw = mux_hw;
+		composite->mux_ops = mux_ops;
+		clk_composite_ops->get_parent = clk_composite_get_parent;
+		if (mux_ops->set_parent)
+			clk_composite_ops->set_parent = clk_composite_set_parent;
+		if (mux_ops->determine_rate)
+			clk_composite_ops->determine_rate = clk_composite_determine_rate;
+	}
+
+	if (rate_hw && rate_ops) {
+		if (!rate_ops->recalc_rate) {
+			clk = ERR_PTR(-EINVAL);
+			goto err;
+		}
+		clk_composite_ops->recalc_rate = clk_composite_recalc_rate;
+
+		if (rate_ops->determine_rate)
+			clk_composite_ops->determine_rate =
+				clk_composite_determine_rate;
+		else if (rate_ops->round_rate)
+			clk_composite_ops->round_rate =
+				clk_composite_round_rate;
+
+		/* .set_rate requires either .round_rate or .determine_rate */
+		if (rate_ops->set_rate) {
+			if (rate_ops->determine_rate || rate_ops->round_rate)
+				clk_composite_ops->set_rate =
+						clk_composite_set_rate;
+			else
+				WARN(1, "%s: missing round_rate op is required\n",
+						__func__);
+		}
+
+		composite->rate_hw = rate_hw;
+		composite->rate_ops = rate_ops;
+	}
+
+	if (gate_hw && gate_ops) {
+		if (!gate_ops->is_enabled || !gate_ops->enable ||
+		    !gate_ops->disable) {
+			clk = ERR_PTR(-EINVAL);
+			goto err;
+		}
+
+		composite->gate_hw = gate_hw;
+		composite->gate_ops = gate_ops;
+		clk_composite_ops->is_enabled = clk_composite_is_enabled;
+		clk_composite_ops->enable = clk_composite_enable;
+		clk_composite_ops->disable = clk_composite_disable;
+	}
+
+	init.ops = clk_composite_ops;
+	composite->hw.init = &init;
+
+	clk = clk_register(dev, &composite->hw);
+	if (IS_ERR(clk))
+		goto err;
+
+	if (composite->mux_hw)
+		composite->mux_hw->clk = clk;
+
+	if (composite->rate_hw)
+		composite->rate_hw->clk = clk;
+
+	if (composite->gate_hw)
+		composite->gate_hw->clk = clk;
+
+	return clk;
+
+err:
+	kfree(composite);
+	return clk;
+}