Commit cdb09f67 authored by Chunyan Zhang's avatar Chunyan Zhang Committed by Stephen Boyd
Browse files

clk: sprd: add gate clock support 



Some clocks on the Spreadtrum's SoCs are just simple gates. Add
support for those clocks.

Signed-off-by: default avatarChunyan Zhang <chunyan.zhang@spreadtrum.com>
Signed-off-by: default avatarStephen Boyd <sboyd@codeaurora.org>
parent d41f59fd

drivers/clk/sprd/Makefile

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obj-$(CONFIG_SPRD_COMMON_CLK)	+= clk-sprd.o



clk-sprd-y	+= common.o

clk-sprd-y	+= gate.o

drivers/clk/sprd/gate.c

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// SPDX-License-Identifier: GPL-2.0

//

// Spreadtrum gate clock driver

//

// Copyright (C) 2017 Spreadtrum, Inc.

// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>



#include <linux/clk-provider.h>

#include <linux/regmap.h>



#include "gate.h"



static void clk_gate_toggle(const struct sprd_gate *sg, bool en)

{

	const struct sprd_clk_common *common = &sg->common;

	unsigned int reg;

	bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? true : false;



	set ^= en;



	regmap_read(common->regmap, common->reg, &reg);



	if (set)

		reg |= sg->enable_mask;

	else

		reg &= ~sg->enable_mask;



	regmap_write(common->regmap, common->reg, reg);

}



static void clk_sc_gate_toggle(const struct sprd_gate *sg, bool en)

{

	const struct sprd_clk_common *common = &sg->common;

	bool set = sg->flags & CLK_GATE_SET_TO_DISABLE ? 1 : 0;

	unsigned int offset;



	set ^= en;



	/*

	 * Each set/clear gate clock has three registers:

	 * common->reg			- base register

	 * common->reg + offset		- set register

	 * common->reg + 2 * offset	- clear register

	 */

	offset = set ? sg->sc_offset : sg->sc_offset * 2;



	regmap_write(common->regmap, common->reg + offset,

			  sg->enable_mask);

}



static void sprd_gate_disable(struct clk_hw *hw)

{

	struct sprd_gate *sg = hw_to_sprd_gate(hw);



	clk_gate_toggle(sg, false);

}



static int sprd_gate_enable(struct clk_hw *hw)

{

	struct sprd_gate *sg = hw_to_sprd_gate(hw);



	clk_gate_toggle(sg, true);



	return 0;

}



static void sprd_sc_gate_disable(struct clk_hw *hw)

{

	struct sprd_gate *sg = hw_to_sprd_gate(hw);



	clk_sc_gate_toggle(sg, false);

}



static int sprd_sc_gate_enable(struct clk_hw *hw)

{

	struct sprd_gate *sg = hw_to_sprd_gate(hw);



	clk_sc_gate_toggle(sg, true);



	return 0;

}

static int sprd_gate_is_enabled(struct clk_hw *hw)

{

	struct sprd_gate *sg = hw_to_sprd_gate(hw);

	struct sprd_clk_common *common = &sg->common;

	unsigned int reg;



	regmap_read(common->regmap, common->reg, &reg);



	if (sg->flags & CLK_GATE_SET_TO_DISABLE)

		reg ^= sg->enable_mask;



	reg &= sg->enable_mask;



	return reg ? 1 : 0;

}



const struct clk_ops sprd_gate_ops = {

	.disable	= sprd_gate_disable,

	.enable		= sprd_gate_enable,

	.is_enabled	= sprd_gate_is_enabled,

};

EXPORT_SYMBOL_GPL(sprd_gate_ops);



const struct clk_ops sprd_sc_gate_ops = {

	.disable	= sprd_sc_gate_disable,

	.enable		= sprd_sc_gate_enable,

	.is_enabled	= sprd_gate_is_enabled,

};

EXPORT_SYMBOL_GPL(sprd_sc_gate_ops);

drivers/clk/sprd/gate.h

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// SPDX-License-Identifier: GPL-2.0

//

// Spreadtrum gate clock driver

//

// Copyright (C) 2017 Spreadtrum, Inc.

// Author: Chunyan Zhang <chunyan.zhang@spreadtrum.com>



#ifndef _SPRD_GATE_H_

#define _SPRD_GATE_H_



#include "common.h"



struct sprd_gate {

	u32			enable_mask;

	u16			flags;

	u16			sc_offset;



	struct sprd_clk_common	common;

};



#define SPRD_SC_GATE_CLK_OPS(_struct, _name, _parent, _reg, _sc_offset,	\

			     _enable_mask, _flags, _gate_flags, _ops)	\

	struct sprd_gate _struct = {					\

		.enable_mask	= _enable_mask,				\

		.sc_offset	= _sc_offset,				\

		.flags		= _gate_flags,				\

		.common	= {						\

			.regmap		= NULL,				\

			.reg		= _reg,				\

			.hw.init	= CLK_HW_INIT(_name,		\

						      _parent,		\

						      _ops,		\

						      _flags),		\

		}							\

	}



#define SPRD_GATE_CLK(_struct, _name, _parent, _reg,			\

		      _enable_mask, _flags, _gate_flags)		\

	SPRD_SC_GATE_CLK_OPS(_struct, _name, _parent, _reg, 0,		\

			     _enable_mask, _flags, _gate_flags,		\

			     &sprd_gate_ops)



#define SPRD_SC_GATE_CLK(_struct, _name, _parent, _reg, _sc_offset,	\

			 _enable_mask, _flags, _gate_flags)		\

	SPRD_SC_GATE_CLK_OPS(_struct, _name, _parent, _reg, _sc_offset,	\

			     _enable_mask, _flags, _gate_flags,		\

			     &sprd_sc_gate_ops)



static inline struct sprd_gate *hw_to_sprd_gate(const struct clk_hw *hw)

{

	struct sprd_clk_common *common = hw_to_sprd_clk_common(hw);



	return container_of(common, struct sprd_gate, common);

}



extern const struct clk_ops sprd_gate_ops;

extern const struct clk_ops sprd_sc_gate_ops;



#endif /* _SPRD_GATE_H_ */