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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/drivers/clk/clk-hi655x.c
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// SPDX-License-Identifier: GPL-2.0-only

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/*

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 * Clock driver for Hi655x

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 *

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 * Copyright (c) 2017, Linaro Ltd.

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 *

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 * Author: Daniel Lezcano <[email protected]>

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 */

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#include <linux/clk-provider.h>

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#include <linux/module.h>

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#include <linux/platform_device.h>

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#include <linux/regmap.h>

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#include <linux/slab.h>

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#include <linux/mfd/core.h>

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#include <linux/mfd/hi655x-pmic.h>

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#define HI655X_CLK_BASE	HI655X_BUS_ADDR(0x1c)

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#define HI655X_CLK_SET	BIT(6)

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struct hi655x_clk {

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	struct hi655x_pmic *hi655x;

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	struct clk_hw       clk_hw;

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};

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static unsigned long hi655x_clk_recalc_rate(struct clk_hw *hw,

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					    unsigned long parent_rate)

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{

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	return 32768;

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}

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static int hi655x_clk_enable(struct clk_hw *hw, bool enable)

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{

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	struct hi655x_clk *hi655x_clk =

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		container_of(hw, struct hi655x_clk, clk_hw);

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	struct hi655x_pmic *hi655x = hi655x_clk->hi655x;

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	return regmap_update_bits(hi655x->regmap, HI655X_CLK_BASE,

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				  HI655X_CLK_SET, enable ? HI655X_CLK_SET : 0);

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}

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static int hi655x_clk_prepare(struct clk_hw *hw)

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{

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	return hi655x_clk_enable(hw, true);

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}

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static void hi655x_clk_unprepare(struct clk_hw *hw)

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{

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	hi655x_clk_enable(hw, false);

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}

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static int hi655x_clk_is_prepared(struct clk_hw *hw)

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{

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	struct hi655x_clk *hi655x_clk =

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		container_of(hw, struct hi655x_clk, clk_hw);

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	struct hi655x_pmic *hi655x = hi655x_clk->hi655x;

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	int ret;

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	uint32_t val;

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	ret = regmap_read(hi655x->regmap, HI655X_CLK_BASE, &val);

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	if (ret < 0)

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		return ret;

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	return val & HI655X_CLK_BASE;

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}

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static const struct clk_ops hi655x_clk_ops = {

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	.prepare     = hi655x_clk_prepare,

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	.unprepare   = hi655x_clk_unprepare,

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	.is_prepared = hi655x_clk_is_prepared,

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	.recalc_rate = hi655x_clk_recalc_rate,

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};

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static int hi655x_clk_probe(struct platform_device *pdev)

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{

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	struct device *parent = pdev->dev.parent;

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	struct hi655x_pmic *hi655x = dev_get_drvdata(parent);

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	struct hi655x_clk *hi655x_clk;

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	const char *clk_name = "hi655x-clk";

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	struct clk_init_data init = {

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		.name = clk_name,

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		.ops = &hi655x_clk_ops

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	};

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	int ret;

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	hi655x_clk = devm_kzalloc(&pdev->dev, sizeof(*hi655x_clk), GFP_KERNEL);

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	if (!hi655x_clk)

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		return -ENOMEM;

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	of_property_read_string_index(parent->of_node, "clock-output-names",

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				      0, &clk_name);

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	hi655x_clk->clk_hw.init	= &init;

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	hi655x_clk->hi655x	= hi655x;

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	platform_set_drvdata(pdev, hi655x_clk);

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	ret = devm_clk_hw_register(&pdev->dev, &hi655x_clk->clk_hw);

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	if (ret)

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		return ret;

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	return devm_of_clk_add_hw_provider(&pdev->dev, of_clk_hw_simple_get,

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					   &hi655x_clk->clk_hw);

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}

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static struct platform_driver hi655x_clk_driver = {

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	.probe =  hi655x_clk_probe,

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	.driver		= {

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		.name	= "hi655x-clk",

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	},

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};

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module_platform_driver(hi655x_clk_driver);

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MODULE_DESCRIPTION("Clk driver for the hi655x series PMICs");

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MODULE_AUTHOR("Daniel Lezcano <[email protected]>");

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MODULE_LICENSE("GPL");

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MODULE_ALIAS("platform:hi655x-clk");

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