drivers/clk/samsung/clk-exynos-arm64.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2021 Linaro Ltd.
  * Copyright (C) 2021 Dávid Virág <virag.david003@gmail.com>
  * Author: Sam Protsenko <semen.protsenko@linaro.org>
  * Author: Dávid Virág <virag.david003@gmail.com>
  *
  * This file contains shared functions used by some arm64 Exynos SoCs,
  * such as Exynos7885 or Exynos850 to register and init CMUs.
  */
 #include <linux/clk.h>
 #include <linux/of_address.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>

 #include "clk-exynos-arm64.h"

 /* Gate register bits */
 #define GATE_MANUAL		BIT(20)
 #define GATE_ENABLE_HWACG	BIT(28)

 /* Gate register offsets range */
 #define GATE_OFF_START		0x2000
 #define GATE_OFF_END		0x2fff

 struct exynos_arm64_cmu_data {
 	struct samsung_clk_reg_dump *clk_save;
 	unsigned int nr_clk_save;
 	const struct samsung_clk_reg_dump *clk_suspend;
 	unsigned int nr_clk_suspend;

 	struct clk *clk;
 	struct clk **pclks;
 	int nr_pclks;

 	struct samsung_clk_provider *ctx;
 };

 /**
  * exynos_arm64_init_clocks - Set clocks initial configuration
  * @np:			CMU device tree node with "reg" property (CMU addr)
  * @reg_offs:		Register offsets array for clocks to init
  * @reg_offs_len:	Number of register offsets in reg_offs array
  *
  * Set manual control mode for all gate clocks.
  */
 static void __init exynos_arm64_init_clocks(struct device_node *np,
 		const unsigned long *reg_offs, size_t reg_offs_len)
 {
 	void __iomem *reg_base;
 	size_t i;

 	reg_base = of_iomap(np, 0);
 	if (!reg_base)
 		panic("%s: failed to map registers\n", __func__);

 	for (i = 0; i < reg_offs_len; ++i) {
 		void __iomem *reg = reg_base + reg_offs[i];
 		u32 val;

 		/* Modify only gate clock registers */
 		if (reg_offs[i] < GATE_OFF_START || reg_offs[i] > GATE_OFF_END)
 			continue;

 		val = readl(reg);
 		val |= GATE_MANUAL;
 		val &= ~GATE_ENABLE_HWACG;
 		writel(val, reg);
 	}

 	iounmap(reg_base);
 }

 /**
  * exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU
  *
  * @dev:	Device object; may be NULL if this function is not being
  *		called from platform driver probe function
  * @np:		CMU device tree node
  * @cmu:	CMU data
  *
  * Keep CMU parent clock running (needed for CMU registers access).
  *
  * Return: 0 on success or a negative error code on failure.
  */
 static int __init exynos_arm64_enable_bus_clk(struct device *dev,
 		struct device_node *np, const struct samsung_cmu_info *cmu)
 {
 	struct clk *parent_clk;

 	if (!cmu->clk_name)
 		return 0;

 	if (dev) {
 		struct exynos_arm64_cmu_data *data;

 		parent_clk = clk_get(dev, cmu->clk_name);
 		data = dev_get_drvdata(dev);
 		if (data)
 			data->clk = parent_clk;
 	} else {
 		parent_clk = of_clk_get_by_name(np, cmu->clk_name);
 	}

 	if (IS_ERR(parent_clk))
 		return PTR_ERR(parent_clk);

 	return clk_prepare_enable(parent_clk);
 }

 static int __init exynos_arm64_cmu_prepare_pm(struct device *dev,
 		const struct samsung_cmu_info *cmu)
 {
 	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
 	int i;

 	data->clk_save = samsung_clk_alloc_reg_dump(cmu->clk_regs,
 						    cmu->nr_clk_regs);
 	if (!data->clk_save)
 		return -ENOMEM;

 	data->nr_clk_save = cmu->nr_clk_regs;
 	data->clk_suspend = cmu->suspend_regs;
 	data->nr_clk_suspend = cmu->nr_suspend_regs;
 	data->nr_pclks = of_clk_get_parent_count(dev->of_node);
 	if (!data->nr_pclks)
 		return 0;

 	data->pclks = devm_kcalloc(dev, sizeof(struct clk *), data->nr_pclks,
 				   GFP_KERNEL);
 	if (!data->pclks) {
 		kfree(data->clk_save);
 		return -ENOMEM;
 	}

 	for (i = 0; i < data->nr_pclks; i++) {
 		struct clk *clk = of_clk_get(dev->of_node, i);

 		if (IS_ERR(clk)) {
 			kfree(data->clk_save);
 			while (--i >= 0)
 				clk_put(data->pclks[i]);
 			return PTR_ERR(clk);
 		}
 		data->pclks[i] = clk;
 	}

 	return 0;
 }

 /**
  * exynos_arm64_register_cmu - Register specified Exynos CMU domain
  * @dev:	Device object; may be NULL if this function is not being
  *		called from platform driver probe function
  * @np:		CMU device tree node
  * @cmu:	CMU data
  *
  * Register specified CMU domain, which includes next steps:
  *
  * 1. Enable parent clock of @cmu CMU
  * 2. Set initial registers configuration for @cmu CMU clocks
  * 3. Register @cmu CMU clocks using Samsung clock framework API
  */
 void __init exynos_arm64_register_cmu(struct device *dev,
 		struct device_node *np, const struct samsung_cmu_info *cmu)
 {
 	int err;

 	/*
 	 * Try to boot even if the parent clock enablement fails, as it might be
 	 * already enabled by bootloader.
 	 */
 	err = exynos_arm64_enable_bus_clk(dev, np, cmu);
 	if (err)
 		pr_err("%s: could not enable bus clock %s; err = %d\n",
 		       __func__, cmu->clk_name, err);

 	exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
 	samsung_cmu_register_one(np, cmu);
 }

 /**
  * exynos_arm64_register_cmu_pm - Register Exynos CMU domain with PM support
  *
  * @pdev:	Platform device object
  * @set_manual:	If true, set gate clocks to manual mode
  *
  * It's a version of exynos_arm64_register_cmu() with PM support. Should be
  * called from probe function of platform driver.
  *
  * Return: 0 on success, or negative error code on error.
  */
 int __init exynos_arm64_register_cmu_pm(struct platform_device *pdev,
 					bool set_manual)
 {
 	const struct samsung_cmu_info *cmu;
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct exynos_arm64_cmu_data *data;
 	void __iomem *reg_base;
 	int ret;

 	cmu = of_device_get_match_data(dev);

 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	platform_set_drvdata(pdev, data);

 	ret = exynos_arm64_cmu_prepare_pm(dev, cmu);
 	if (ret)
 		return ret;

 	/*
 	 * Try to boot even if the parent clock enablement fails, as it might be
 	 * already enabled by bootloader.
 	 */
 	ret = exynos_arm64_enable_bus_clk(dev, NULL, cmu);
 	if (ret)
 		dev_err(dev, "%s: could not enable bus clock %s; err = %d\n",
 		       __func__, cmu->clk_name, ret);

 	if (set_manual)
 		exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);

 	reg_base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(reg_base))
 		return PTR_ERR(reg_base);

 	data->ctx = samsung_clk_init(dev, reg_base, cmu->nr_clk_ids);

 	/*
 	 * Enable runtime PM here to allow the clock core using runtime PM
 	 * for the registered clocks. Additionally, we increase the runtime
 	 * PM usage count before registering the clocks, to prevent the
 	 * clock core from runtime suspending the device.
 	 */
 	pm_runtime_get_noresume(dev);
 	pm_runtime_set_active(dev);
 	pm_runtime_enable(dev);

 	samsung_cmu_register_clocks(data->ctx, cmu);
 	samsung_clk_of_add_provider(dev->of_node, data->ctx);
 	pm_runtime_put_sync(dev);

 	return 0;
 }

 int exynos_arm64_cmu_suspend(struct device *dev)
 {
 	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
 	int i;

 	samsung_clk_save(data->ctx->reg_base, data->clk_save,
 			 data->nr_clk_save);

 	for (i = 0; i < data->nr_pclks; i++)
 		clk_prepare_enable(data->pclks[i]);

 	/* For suspend some registers have to be set to certain values */
 	samsung_clk_restore(data->ctx->reg_base, data->clk_suspend,
 			    data->nr_clk_suspend);

 	for (i = 0; i < data->nr_pclks; i++)
 		clk_disable_unprepare(data->pclks[i]);

 	clk_disable_unprepare(data->clk);

 	return 0;
 }

 int exynos_arm64_cmu_resume(struct device *dev)
 {
 	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
 	int i;

 	clk_prepare_enable(data->clk);

 	for (i = 0; i < data->nr_pclks; i++)
 		clk_prepare_enable(data->pclks[i]);

 	samsung_clk_restore(data->ctx->reg_base, data->clk_save,
 			    data->nr_clk_save);

 	for (i = 0; i < data->nr_pclks; i++)
 		clk_disable_unprepare(data->pclks[i]);

 	return 0;
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2021 Linaro Ltd.
	* Copyright (C) 2021 Dávid Virág <virag.david003@gmail.com>
	* Author: Sam Protsenko <semen.protsenko@linaro.org>
	* Author: Dávid Virág <virag.david003@gmail.com>
	*
	* This file contains shared functions used by some arm64 Exynos SoCs,
	* such as Exynos7885 or Exynos850 to register and init CMUs.
	*/
	#include <linux/clk.h>
	#include <linux/of_address.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/pm_runtime.h>
	#include <linux/slab.h>

	#include "clk-exynos-arm64.h"

	/* Gate register bits */
	#define GATE_MANUAL BIT(20)
	#define GATE_ENABLE_HWACG BIT(28)

	/* Gate register offsets range */
	#define GATE_OFF_START 0x2000
	#define GATE_OFF_END 0x2fff

	struct exynos_arm64_cmu_data {
	struct samsung_clk_reg_dump *clk_save;
	unsigned int nr_clk_save;
	const struct samsung_clk_reg_dump *clk_suspend;
	unsigned int nr_clk_suspend;

	struct clk *clk;
	struct clk **pclks;
	int nr_pclks;

	struct samsung_clk_provider *ctx;
	};

	/**
	* exynos_arm64_init_clocks - Set clocks initial configuration
	* @np: CMU device tree node with "reg" property (CMU addr)
	* @reg_offs: Register offsets array for clocks to init
	* @reg_offs_len: Number of register offsets in reg_offs array
	*
	* Set manual control mode for all gate clocks.
	*/
	static void __init exynos_arm64_init_clocks(struct device_node *np,
	const unsigned long *reg_offs, size_t reg_offs_len)
	{
	void __iomem *reg_base;
	size_t i;

	reg_base = of_iomap(np, 0);
	if (!reg_base)
	panic("%s: failed to map registers\n", __func__);

	for (i = 0; i < reg_offs_len; ++i) {
	void __iomem *reg = reg_base + reg_offs[i];
	u32 val;

	/* Modify only gate clock registers */
	if (reg_offs[i] < GATE_OFF_START \|\| reg_offs[i] > GATE_OFF_END)
	continue;

	val = readl(reg);
	val \|= GATE_MANUAL;
	val &= ~GATE_ENABLE_HWACG;
	writel(val, reg);
	}

	iounmap(reg_base);
	}

	/**
	* exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU
	*
	* @dev: Device object; may be NULL if this function is not being
	* called from platform driver probe function
	* @np: CMU device tree node
	* @cmu: CMU data
	*
	* Keep CMU parent clock running (needed for CMU registers access).
	*
	* Return: 0 on success or a negative error code on failure.
	*/
	static int __init exynos_arm64_enable_bus_clk(struct device *dev,
	struct device_node np, const struct samsung_cmu_info cmu)
	{
	struct clk *parent_clk;

	if (!cmu->clk_name)
	return 0;

	if (dev) {
	struct exynos_arm64_cmu_data *data;

	parent_clk = clk_get(dev, cmu->clk_name);
	data = dev_get_drvdata(dev);
	if (data)
	data->clk = parent_clk;
	} else {
	parent_clk = of_clk_get_by_name(np, cmu->clk_name);
	}

	if (IS_ERR(parent_clk))
	return PTR_ERR(parent_clk);

	return clk_prepare_enable(parent_clk);
	}

	static int __init exynos_arm64_cmu_prepare_pm(struct device *dev,
	const struct samsung_cmu_info *cmu)
	{
	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
	int i;

	data->clk_save = samsung_clk_alloc_reg_dump(cmu->clk_regs,
	cmu->nr_clk_regs);
	if (!data->clk_save)
	return -ENOMEM;

	data->nr_clk_save = cmu->nr_clk_regs;
	data->clk_suspend = cmu->suspend_regs;
	data->nr_clk_suspend = cmu->nr_suspend_regs;
	data->nr_pclks = of_clk_get_parent_count(dev->of_node);
	if (!data->nr_pclks)
	return 0;

	data->pclks = devm_kcalloc(dev, sizeof(struct clk *), data->nr_pclks,
	GFP_KERNEL);
	if (!data->pclks) {
	kfree(data->clk_save);
	return -ENOMEM;
	}

	for (i = 0; i < data->nr_pclks; i++) {
	struct clk *clk = of_clk_get(dev->of_node, i);

	if (IS_ERR(clk)) {
	kfree(data->clk_save);
	while (--i >= 0)
	clk_put(data->pclks[i]);
	return PTR_ERR(clk);
	}
	data->pclks[i] = clk;
	}

	return 0;
	}

	/**
	* exynos_arm64_register_cmu - Register specified Exynos CMU domain
	* @dev: Device object; may be NULL if this function is not being
	* called from platform driver probe function
	* @np: CMU device tree node
	* @cmu: CMU data
	*
	* Register specified CMU domain, which includes next steps:
	*
	* 1. Enable parent clock of @cmu CMU
	* 2. Set initial registers configuration for @cmu CMU clocks
	* 3. Register @cmu CMU clocks using Samsung clock framework API
	*/
	void __init exynos_arm64_register_cmu(struct device *dev,
	struct device_node np, const struct samsung_cmu_info cmu)
	{
	int err;

	/*
	* Try to boot even if the parent clock enablement fails, as it might be
	* already enabled by bootloader.
	*/
	err = exynos_arm64_enable_bus_clk(dev, np, cmu);
	if (err)
	pr_err("%s: could not enable bus clock %s; err = %d\n",
	__func__, cmu->clk_name, err);

	exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);
	samsung_cmu_register_one(np, cmu);
	}

	/**
	* exynos_arm64_register_cmu_pm - Register Exynos CMU domain with PM support
	*
	* @pdev: Platform device object
	* @set_manual: If true, set gate clocks to manual mode
	*
	* It's a version of exynos_arm64_register_cmu() with PM support. Should be
	* called from probe function of platform driver.
	*
	* Return: 0 on success, or negative error code on error.
	*/
	int __init exynos_arm64_register_cmu_pm(struct platform_device *pdev,
	bool set_manual)
	{
	const struct samsung_cmu_info *cmu;
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct exynos_arm64_cmu_data *data;
	void __iomem *reg_base;
	int ret;

	cmu = of_device_get_match_data(dev);

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	platform_set_drvdata(pdev, data);

	ret = exynos_arm64_cmu_prepare_pm(dev, cmu);
	if (ret)
	return ret;

	/*
	* Try to boot even if the parent clock enablement fails, as it might be
	* already enabled by bootloader.
	*/
	ret = exynos_arm64_enable_bus_clk(dev, NULL, cmu);
	if (ret)
	dev_err(dev, "%s: could not enable bus clock %s; err = %d\n",
	__func__, cmu->clk_name, ret);

	if (set_manual)
	exynos_arm64_init_clocks(np, cmu->clk_regs, cmu->nr_clk_regs);

	reg_base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(reg_base))
	return PTR_ERR(reg_base);

	data->ctx = samsung_clk_init(dev, reg_base, cmu->nr_clk_ids);

	/*
	* Enable runtime PM here to allow the clock core using runtime PM
	* for the registered clocks. Additionally, we increase the runtime
	* PM usage count before registering the clocks, to prevent the
	* clock core from runtime suspending the device.
	*/
	pm_runtime_get_noresume(dev);
	pm_runtime_set_active(dev);
	pm_runtime_enable(dev);

	samsung_cmu_register_clocks(data->ctx, cmu);
	samsung_clk_of_add_provider(dev->of_node, data->ctx);
	pm_runtime_put_sync(dev);

	return 0;
	}

	int exynos_arm64_cmu_suspend(struct device *dev)
	{
	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
	int i;

	samsung_clk_save(data->ctx->reg_base, data->clk_save,
	data->nr_clk_save);

	for (i = 0; i < data->nr_pclks; i++)
	clk_prepare_enable(data->pclks[i]);

	/* For suspend some registers have to be set to certain values */
	samsung_clk_restore(data->ctx->reg_base, data->clk_suspend,
	data->nr_clk_suspend);

	for (i = 0; i < data->nr_pclks; i++)
	clk_disable_unprepare(data->pclks[i]);

	clk_disable_unprepare(data->clk);

	return 0;
	}

	int exynos_arm64_cmu_resume(struct device *dev)
	{
	struct exynos_arm64_cmu_data *data = dev_get_drvdata(dev);
	int i;

	clk_prepare_enable(data->clk);

	for (i = 0; i < data->nr_pclks; i++)
	clk_prepare_enable(data->pclks[i]);

	samsung_clk_restore(data->ctx->reg_base, data->clk_save,
	data->nr_clk_save);

	for (i = 0; i < data->nr_pclks; i++)
	clk_disable_unprepare(data->pclks[i]);

	return 0;
	}