clk: actions: Add mux clock support

Add support for Actions Semi mux clock together with helper
functions to be used in composite clock.

Signed-off-by: Manivannan Sadhasivam <[e-mail]>
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/actions/Makefile

···
 
 clk-owl-y			+= owl-common.o
 clk-owl-y			+= owl-gate.o
+clk-owl-y			+= owl-mux.o

drivers/clk/actions/owl-mux.c

···
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL mux clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <[e-mail]>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <[e-mail]>
+
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+#include "owl-mux.h"
+
+u8 owl_mux_helper_get_parent(const struct owl_clk_common *common,
+			     const struct owl_mux_hw *mux_hw)
+{
+	u32 reg;
+	u8 parent;
+
+	regmap_read(common->regmap, mux_hw->reg, &reg);
+	parent = reg >> mux_hw->shift;
+	parent &= BIT(mux_hw->width) - 1;
+
+	return parent;
+}
+
+static u8 owl_mux_get_parent(struct clk_hw *hw)
+{
+	struct owl_mux *mux = hw_to_owl_mux(hw);
+
+	return owl_mux_helper_get_parent(&mux->common, &mux->mux_hw);
+}
+
+int owl_mux_helper_set_parent(const struct owl_clk_common *common,
+			      struct owl_mux_hw *mux_hw, u8 index)
+{
+	u32 reg;
+
+	regmap_read(common->regmap, mux_hw->reg, &reg);
+	reg &= ~GENMASK(mux_hw->width + mux_hw->shift - 1, mux_hw->shift);
+	regmap_write(common->regmap, mux_hw->reg,
+			reg | (index << mux_hw->shift));
+
+	return 0;
+}
+
+static int owl_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+	struct owl_mux *mux = hw_to_owl_mux(hw);
+
+	return owl_mux_helper_set_parent(&mux->common, &mux->mux_hw, index);
+}
+
+const struct clk_ops owl_mux_ops = {
+	.get_parent = owl_mux_get_parent,
+	.set_parent = owl_mux_set_parent,
+	.determine_rate = __clk_mux_determine_rate,
+};

drivers/clk/actions/owl-mux.h

···
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL mux clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <[e-mail]>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <[e-mail]>
+
+#ifndef _OWL_MUX_H_
+#define _OWL_MUX_H_
+
+#include "owl-common.h"
+
+struct owl_mux_hw {
+	u32			reg;
+	u8			shift;
+	u8			width;
+};
+
+struct owl_mux {
+	struct owl_mux_hw	mux_hw;
+	struct owl_clk_common	common;
+};
+
+#define OWL_MUX_HW(_reg, _shift, _width)		\
+	{						\
+		.reg	= _reg,				\
+		.shift	= _shift,			\
+		.width	= _width,			\
+	}
+
+#define OWL_MUX(_struct, _name, _parents, _reg,				\
+		_shift, _width, _flags)					\
+	struct owl_mux _struct = {					\
+		.mux_hw	= OWL_MUX_HW(_reg, _shift, _width),		\
+		.common = {						\
+			.regmap = NULL,					\
+			.hw.init = CLK_HW_INIT_PARENTS(_name,		\
+						       _parents,	\
+						       &owl_mux_ops,	\
+						       _flags),		\
+		},							\
+	}
+
+static inline struct owl_mux *hw_to_owl_mux(const struct clk_hw *hw)
+{
+	struct owl_clk_common *common = hw_to_owl_clk_common(hw);
+
+	return container_of(common, struct owl_mux, common);
+}
+
+u8 owl_mux_helper_get_parent(const struct owl_clk_common *common,
+			     const struct owl_mux_hw *mux_hw);
+int owl_mux_helper_set_parent(const struct owl_clk_common *common,
+			      struct owl_mux_hw *mux_hw, u8 index);
+
+extern const struct clk_ops owl_mux_ops;
+
+#endif /* _OWL_MUX_H_ */