clk: actions: Add gate clock support

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

Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/actions/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_CLK_ACTIONS)	+= clk-owl.o
 
 clk-owl-y			+= owl-common.o
+clk-owl-y			+= owl-gate.o

drivers/clk/actions/owl-gate.c

@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL gate clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#include <linux/clk-provider.h>
+#include <linux/regmap.h>
+
+#include "owl-gate.h"
+
+void owl_gate_set(const struct owl_clk_common *common,
+		 const struct owl_gate_hw *gate_hw, bool enable)
+{
+	int set = gate_hw->gate_flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;
+	u32 reg;
+
+	set ^= enable;
+
+	regmap_read(common->regmap, gate_hw->reg, &reg);
+
+	if (set)
+		reg |= BIT(gate_hw->bit_idx);
+	else
+		reg &= ~BIT(gate_hw->bit_idx);
+
+	regmap_write(common->regmap, gate_hw->reg, reg);
+}
+
+static void owl_gate_disable(struct clk_hw *hw)
+{
+	struct owl_gate *gate = hw_to_owl_gate(hw);
+	struct owl_clk_common *common = &gate->common;
+
+	owl_gate_set(common, &gate->gate_hw, false);
+}
+
+static int owl_gate_enable(struct clk_hw *hw)
+{
+	struct owl_gate *gate = hw_to_owl_gate(hw);
+	struct owl_clk_common *common = &gate->common;
+
+	owl_gate_set(common, &gate->gate_hw, true);
+
+	return 0;
+}
+
+int owl_gate_clk_is_enabled(const struct owl_clk_common *common,
+		   const struct owl_gate_hw *gate_hw)
+{
+	u32 reg;
+
+	regmap_read(common->regmap, gate_hw->reg, &reg);
+
+	if (gate_hw->gate_flags & CLK_GATE_SET_TO_DISABLE)
+		reg ^= BIT(gate_hw->bit_idx);
+
+	return !!(reg & BIT(gate_hw->bit_idx));
+}
+
+static int owl_gate_is_enabled(struct clk_hw *hw)
+{
+	struct owl_gate *gate = hw_to_owl_gate(hw);
+	struct owl_clk_common *common = &gate->common;
+
+	return owl_gate_clk_is_enabled(common, &gate->gate_hw);
+}
+
+const struct clk_ops owl_gate_ops = {
+	.disable	= owl_gate_disable,
+	.enable		= owl_gate_enable,
+	.is_enabled	= owl_gate_is_enabled,
+};

drivers/clk/actions/owl-gate.h

@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// OWL gate clock driver
+//
+// Copyright (c) 2014 Actions Semi Inc.
+// Author: David Liu <liuwei@actions-semi.com>
+//
+// Copyright (c) 2018 Linaro Ltd.
+// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
+
+#ifndef _OWL_GATE_H_
+#define _OWL_GATE_H_
+
+#include "owl-common.h"
+
+struct owl_gate_hw {
+	u32			reg;
+	u8			bit_idx;
+	u8			gate_flags;
+};
+
+struct owl_gate {
+	struct owl_gate_hw	gate_hw;
+	struct owl_clk_common	common;
+};
+
+#define OWL_GATE_HW(_reg, _bit_idx, _gate_flags)	\
+	{						\
+		.reg		= _reg,			\
+		.bit_idx	= _bit_idx,		\
+		.gate_flags	= _gate_flags,		\
+	}
+
+#define OWL_GATE(_struct, _name, _parent, _reg,				\
+		_bit_idx, _gate_flags, _flags)				\
+	struct owl_gate _struct = {					\
+		.gate_hw = OWL_GATE_HW(_reg, _bit_idx, _gate_flags),	\
+		.common = {						\
+			.regmap		= NULL,				\
+			.hw.init	= CLK_HW_INIT(_name,		\
+						      _parent,		\
+						      &owl_gate_ops,	\
+						      _flags),		\
+		}							\
+	}								\
+
+#define OWL_GATE_NO_PARENT(_struct, _name, _reg,			\
+		_bit_idx, _gate_flags, _flags)				\
+	struct owl_gate _struct = {					\
+		.gate_hw = OWL_GATE_HW(_reg, _bit_idx, _gate_flags),	\
+		.common = {						\
+			.regmap		= NULL,				\
+			.hw.init	= CLK_HW_INIT_NO_PARENT(_name,	\
+						      &owl_gate_ops,	\
+						      _flags),		\
+		},							\
+	}								\
+
+static inline struct owl_gate *hw_to_owl_gate(const struct clk_hw *hw)
+{
+	struct owl_clk_common *common = hw_to_owl_clk_common(hw);
+
+	return container_of(common, struct owl_gate, common);
+}
+
+void owl_gate_set(const struct owl_clk_common *common,
+		 const struct owl_gate_hw *gate_hw, bool enable);
+int owl_gate_clk_is_enabled(const struct owl_clk_common *common,
+		   const struct owl_gate_hw *gate_hw);
+
+extern const struct clk_ops owl_gate_ops;
+
+#endif /* _OWL_GATE_H_ */