drivers/clk/x86/clk-pmc-atom.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Intel Atom platform clocks driver for BayTrail and CherryTrail SoCs
  *
  * Copyright (C) 2016, Intel Corporation
  * Author: Irina Tirdea <irina.tirdea@intel.com>
  */

 #include <linux/clk-provider.h>
 #include <linux/clkdev.h>
 #include <linux/err.h>
 #include <linux/io.h>
 #include <linux/platform_data/x86/clk-pmc-atom.h>
 #include <linux/platform_data/x86/pmc_atom.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

 #define PLT_CLK_NAME_BASE	"pmc_plt_clk"

 struct clk_plt_fixed {
 	struct clk_hw *clk;
 	struct clk_lookup *lookup;
 };

 struct clk_plt {
 	struct clk_hw hw;
 	void __iomem *reg;
 	struct clk_lookup *lookup;
 	/* protect access to PMC registers */
 	spinlock_t lock;
 };

 #define to_clk_plt(_hw) container_of(_hw, struct clk_plt, hw)

 struct clk_plt_data {
 	struct clk_plt_fixed **parents;
 	u8 nparents;
 	struct clk_plt *clks[PMC_CLK_NUM];
 	struct clk_lookup *mclk_lookup;
 	struct clk_lookup *ether_clk_lookup;
 };

 /* Return an index in parent table */
 static inline int plt_reg_to_parent(int reg)
 {
 	switch (reg & PMC_MASK_CLK_FREQ) {
 	default:
 	case PMC_CLK_FREQ_XTAL:
 		return 0;
 	case PMC_CLK_FREQ_PLL:
 		return 1;
 	}
 }

 /* Return clk index of parent */
 static inline int plt_parent_to_reg(int index)
 {
 	switch (index) {
 	default:
 	case 0:
 		return PMC_CLK_FREQ_XTAL;
 	case 1:
 		return PMC_CLK_FREQ_PLL;
 	}
 }

 /* Abstract status in simpler enabled/disabled value */
 static inline int plt_reg_to_enabled(int reg)
 {
 	switch (reg & PMC_MASK_CLK_CTL) {
 	case PMC_CLK_CTL_GATED_ON_D3:
 	case PMC_CLK_CTL_FORCE_ON:
 		return 1;	/* enabled */
 	case PMC_CLK_CTL_FORCE_OFF:
 	case PMC_CLK_CTL_RESERVED:
 	default:
 		return 0;	/* disabled */
 	}
 }

 static void plt_clk_reg_update(struct clk_plt *clk, u32 mask, u32 val)
 {
 	u32 tmp;
 	unsigned long flags;

 	spin_lock_irqsave(&clk->lock, flags);

 	tmp = readl(clk->reg);
 	tmp = (tmp & ~mask) | (val & mask);
 	writel(tmp, clk->reg);

 	spin_unlock_irqrestore(&clk->lock, flags);
 }

 static int plt_clk_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct clk_plt *clk = to_clk_plt(hw);

 	plt_clk_reg_update(clk, PMC_MASK_CLK_FREQ, plt_parent_to_reg(index));

 	return 0;
 }

 static u8 plt_clk_get_parent(struct clk_hw *hw)
 {
 	struct clk_plt *clk = to_clk_plt(hw);
 	u32 value;

 	value = readl(clk->reg);

 	return plt_reg_to_parent(value);
 }

 static int plt_clk_enable(struct clk_hw *hw)
 {
 	struct clk_plt *clk = to_clk_plt(hw);

 	plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_ON);

 	return 0;
 }

 static void plt_clk_disable(struct clk_hw *hw)
 {
 	struct clk_plt *clk = to_clk_plt(hw);

 	plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_OFF);
 }

 static int plt_clk_is_enabled(struct clk_hw *hw)
 {
 	struct clk_plt *clk = to_clk_plt(hw);
 	u32 value;

 	value = readl(clk->reg);

 	return plt_reg_to_enabled(value);
 }

 static const struct clk_ops plt_clk_ops = {
 	.enable = plt_clk_enable,
 	.disable = plt_clk_disable,
 	.is_enabled = plt_clk_is_enabled,
 	.get_parent = plt_clk_get_parent,
 	.set_parent = plt_clk_set_parent,
 	.determine_rate = __clk_mux_determine_rate,
 };

 static struct clk_plt *plt_clk_register(struct platform_device *pdev, int id,
 					const struct pmc_clk_data *pmc_data,
 					const char **parent_names,
 					int num_parents)
 {
 	struct clk_plt *pclk;
 	struct clk_init_data init;
 	int ret;

 	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
 	if (!pclk)
 		return ERR_PTR(-ENOMEM);

 	init.name =  kasprintf(GFP_KERNEL, "%s_%d", PLT_CLK_NAME_BASE, id);
 	init.ops = &plt_clk_ops;
 	init.flags = 0;
 	init.parent_names = parent_names;
 	init.num_parents = num_parents;

 	pclk->hw.init = &init;
 	pclk->reg = pmc_data->base + PMC_CLK_CTL_OFFSET + id * PMC_CLK_CTL_SIZE;
 	spin_lock_init(&pclk->lock);

 	/*
 	 * On some systems, the pmc_plt_clocks already enabled by the
 	 * firmware are being marked as critical to avoid them being
 	 * gated by the clock framework.
 	 */
 	if (pmc_data->critical && plt_clk_is_enabled(&pclk->hw))
 		init.flags |= CLK_IS_CRITICAL;

 	ret = devm_clk_hw_register(&pdev->dev, &pclk->hw);
 	if (ret) {
 		pclk = ERR_PTR(ret);
 		goto err_free_init;
 	}

 	pclk->lookup = clkdev_hw_create(&pclk->hw, init.name, NULL);
 	if (!pclk->lookup) {
 		pclk = ERR_PTR(-ENOMEM);
 		goto err_free_init;
 	}

 err_free_init:
 	kfree(init.name);
 	return pclk;
 }

 static void plt_clk_unregister(struct clk_plt *pclk)
 {
 	clkdev_drop(pclk->lookup);
 }

 static struct clk_plt_fixed *plt_clk_register_fixed_rate(struct platform_device *pdev,
 						 const char *name,
 						 const char *parent_name,
 						 unsigned long fixed_rate)
 {
 	struct clk_plt_fixed *pclk;

 	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
 	if (!pclk)
 		return ERR_PTR(-ENOMEM);

 	pclk->clk = clk_hw_register_fixed_rate(&pdev->dev, name, parent_name,
 					       0, fixed_rate);
 	if (IS_ERR(pclk->clk))
 		return ERR_CAST(pclk->clk);

 	pclk->lookup = clkdev_hw_create(pclk->clk, name, NULL);
 	if (!pclk->lookup) {
 		clk_hw_unregister_fixed_rate(pclk->clk);
 		return ERR_PTR(-ENOMEM);
 	}

 	return pclk;
 }

 static void plt_clk_unregister_fixed_rate(struct clk_plt_fixed *pclk)
 {
 	clkdev_drop(pclk->lookup);
 	clk_hw_unregister_fixed_rate(pclk->clk);
 }

 static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data *data,
 					       unsigned int i)
 {
 	while (i--)
 		plt_clk_unregister_fixed_rate(data->parents[i]);
 }

 static void plt_clk_free_parent_names_loop(const char **parent_names,
 					   unsigned int i)
 {
 	while (i--)
 		kfree_const(parent_names[i]);
 	kfree(parent_names);
 }

 static void plt_clk_unregister_loop(struct clk_plt_data *data,
 				    unsigned int i)
 {
 	while (i--)
 		plt_clk_unregister(data->clks[i]);
 }

 static const char **plt_clk_register_parents(struct platform_device *pdev,
 					     struct clk_plt_data *data,
 					     const struct pmc_clk *clks)
 {
 	const char **parent_names;
 	unsigned int i;
 	int err;
 	int nparents = 0;

 	data->nparents = 0;
 	while (clks[nparents].name)
 		nparents++;

 	data->parents = devm_kcalloc(&pdev->dev, nparents,
 				     sizeof(*data->parents), GFP_KERNEL);
 	if (!data->parents)
 		return ERR_PTR(-ENOMEM);

 	parent_names = kcalloc(nparents, sizeof(*parent_names),
 			       GFP_KERNEL);
 	if (!parent_names)
 		return ERR_PTR(-ENOMEM);

 	for (i = 0; i < nparents; i++) {
 		data->parents[i] =
 			plt_clk_register_fixed_rate(pdev, clks[i].name,
 						    clks[i].parent_name,
 						    clks[i].freq);
 		if (IS_ERR(data->parents[i])) {
 			err = PTR_ERR(data->parents[i]);
 			goto err_unreg;
 		}
 		parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL);
 	}

 	data->nparents = nparents;
 	return parent_names;

 err_unreg:
 	plt_clk_unregister_fixed_rate_loop(data, i);
 	plt_clk_free_parent_names_loop(parent_names, i);
 	return ERR_PTR(err);
 }

 static void plt_clk_unregister_parents(struct clk_plt_data *data)
 {
 	plt_clk_unregister_fixed_rate_loop(data, data->nparents);
 }

 static int plt_clk_probe(struct platform_device *pdev)
 {
 	const struct pmc_clk_data *pmc_data;
 	const char **parent_names;
 	struct clk_plt_data *data;
 	unsigned int i;
 	int err;

 	pmc_data = dev_get_platdata(&pdev->dev);
 	if (!pmc_data || !pmc_data->clks)
 		return -EINVAL;

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

 	parent_names = plt_clk_register_parents(pdev, data, pmc_data->clks);
 	if (IS_ERR(parent_names))
 		return PTR_ERR(parent_names);

 	for (i = 0; i < PMC_CLK_NUM; i++) {
 		data->clks[i] = plt_clk_register(pdev, i, pmc_data,
 						 parent_names, data->nparents);
 		if (IS_ERR(data->clks[i])) {
 			err = PTR_ERR(data->clks[i]);
 			goto err_unreg_clk_plt;
 		}
 	}
 	data->mclk_lookup = clkdev_hw_create(&data->clks[3]->hw, "mclk", NULL);
 	if (!data->mclk_lookup) {
 		err = -ENOMEM;
 		goto err_unreg_clk_plt;
 	}

 	data->ether_clk_lookup = clkdev_hw_create(&data->clks[4]->hw,
 						  "ether_clk", NULL);
 	if (!data->ether_clk_lookup) {
 		err = -ENOMEM;
 		goto err_drop_mclk;
 	}

 	plt_clk_free_parent_names_loop(parent_names, data->nparents);

 	platform_set_drvdata(pdev, data);
 	return 0;

 err_drop_mclk:
 	clkdev_drop(data->mclk_lookup);
 err_unreg_clk_plt:
 	plt_clk_unregister_loop(data, i);
 	plt_clk_unregister_parents(data);
 	plt_clk_free_parent_names_loop(parent_names, data->nparents);
 	return err;
 }

 static void plt_clk_remove(struct platform_device *pdev)
 {
 	struct clk_plt_data *data;

 	data = platform_get_drvdata(pdev);

 	clkdev_drop(data->ether_clk_lookup);
 	clkdev_drop(data->mclk_lookup);
 	plt_clk_unregister_loop(data, PMC_CLK_NUM);
 	plt_clk_unregister_parents(data);
 }

 static struct platform_driver plt_clk_driver = {
 	.driver = {
 		.name = "clk-pmc-atom",
 	},
 	.probe = plt_clk_probe,
 	.remove_new = plt_clk_remove,
 };
 builtin_platform_driver(plt_clk_driver);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Intel Atom platform clocks driver for BayTrail and CherryTrail SoCs
	*
	* Copyright (C) 2016, Intel Corporation
	* Author: Irina Tirdea <irina.tirdea@intel.com>
	*/

	#include <linux/clk-provider.h>
	#include <linux/clkdev.h>
	#include <linux/err.h>
	#include <linux/io.h>
	#include <linux/platform_data/x86/clk-pmc-atom.h>
	#include <linux/platform_data/x86/pmc_atom.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

	#define PLT_CLK_NAME_BASE "pmc_plt_clk"

	struct clk_plt_fixed {
	struct clk_hw *clk;
	struct clk_lookup *lookup;
	};

	struct clk_plt {
	struct clk_hw hw;
	void __iomem *reg;
	struct clk_lookup *lookup;
	/* protect access to PMC registers */
	spinlock_t lock;
	};

	#define to_clk_plt(_hw) container_of(_hw, struct clk_plt, hw)

	struct clk_plt_data {
	struct clk_plt_fixed **parents;
	u8 nparents;
	struct clk_plt *clks[PMC_CLK_NUM];
	struct clk_lookup *mclk_lookup;
	struct clk_lookup *ether_clk_lookup;
	};

	/* Return an index in parent table */
	static inline int plt_reg_to_parent(int reg)
	{
	switch (reg & PMC_MASK_CLK_FREQ) {
	default:
	case PMC_CLK_FREQ_XTAL:
	return 0;
	case PMC_CLK_FREQ_PLL:
	return 1;
	}
	}

	/* Return clk index of parent */
	static inline int plt_parent_to_reg(int index)
	{
	switch (index) {
	default:
	case 0:
	return PMC_CLK_FREQ_XTAL;
	case 1:
	return PMC_CLK_FREQ_PLL;
	}
	}

	/* Abstract status in simpler enabled/disabled value */
	static inline int plt_reg_to_enabled(int reg)
	{
	switch (reg & PMC_MASK_CLK_CTL) {
	case PMC_CLK_CTL_GATED_ON_D3:
	case PMC_CLK_CTL_FORCE_ON:
	return 1; /* enabled */
	case PMC_CLK_CTL_FORCE_OFF:
	case PMC_CLK_CTL_RESERVED:
	default:
	return 0; /* disabled */
	}
	}

	static void plt_clk_reg_update(struct clk_plt *clk, u32 mask, u32 val)
	{
	u32 tmp;
	unsigned long flags;

	spin_lock_irqsave(&clk->lock, flags);

	tmp = readl(clk->reg);
	tmp = (tmp & ~mask) \| (val & mask);
	writel(tmp, clk->reg);

	spin_unlock_irqrestore(&clk->lock, flags);
	}

	static int plt_clk_set_parent(struct clk_hw *hw, u8 index)
	{
	struct clk_plt *clk = to_clk_plt(hw);

	plt_clk_reg_update(clk, PMC_MASK_CLK_FREQ, plt_parent_to_reg(index));

	return 0;
	}

	static u8 plt_clk_get_parent(struct clk_hw *hw)
	{
	struct clk_plt *clk = to_clk_plt(hw);
	u32 value;

	value = readl(clk->reg);

	return plt_reg_to_parent(value);
	}

	static int plt_clk_enable(struct clk_hw *hw)
	{
	struct clk_plt *clk = to_clk_plt(hw);

	plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_ON);

	return 0;
	}

	static void plt_clk_disable(struct clk_hw *hw)
	{
	struct clk_plt *clk = to_clk_plt(hw);

	plt_clk_reg_update(clk, PMC_MASK_CLK_CTL, PMC_CLK_CTL_FORCE_OFF);
	}

	static int plt_clk_is_enabled(struct clk_hw *hw)
	{
	struct clk_plt *clk = to_clk_plt(hw);
	u32 value;

	value = readl(clk->reg);

	return plt_reg_to_enabled(value);
	}

	static const struct clk_ops plt_clk_ops = {
	.enable = plt_clk_enable,
	.disable = plt_clk_disable,
	.is_enabled = plt_clk_is_enabled,
	.get_parent = plt_clk_get_parent,
	.set_parent = plt_clk_set_parent,
	.determine_rate = __clk_mux_determine_rate,
	};

	static struct clk_plt plt_clk_register(struct platform_device pdev, int id,
	const struct pmc_clk_data *pmc_data,
	const char **parent_names,
	int num_parents)
	{
	struct clk_plt *pclk;
	struct clk_init_data init;
	int ret;

	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
	if (!pclk)
	return ERR_PTR(-ENOMEM);

	init.name = kasprintf(GFP_KERNEL, "%s_%d", PLT_CLK_NAME_BASE, id);
	init.ops = &plt_clk_ops;
	init.flags = 0;
	init.parent_names = parent_names;
	init.num_parents = num_parents;

	pclk->hw.init = &init;
	pclk->reg = pmc_data->base + PMC_CLK_CTL_OFFSET + id * PMC_CLK_CTL_SIZE;
	spin_lock_init(&pclk->lock);

	/*
	* On some systems, the pmc_plt_clocks already enabled by the
	* firmware are being marked as critical to avoid them being
	* gated by the clock framework.
	*/
	if (pmc_data->critical && plt_clk_is_enabled(&pclk->hw))
	init.flags \|= CLK_IS_CRITICAL;

	ret = devm_clk_hw_register(&pdev->dev, &pclk->hw);
	if (ret) {
	pclk = ERR_PTR(ret);
	goto err_free_init;
	}

	pclk->lookup = clkdev_hw_create(&pclk->hw, init.name, NULL);
	if (!pclk->lookup) {
	pclk = ERR_PTR(-ENOMEM);
	goto err_free_init;
	}

	err_free_init:
	kfree(init.name);
	return pclk;
	}

	static void plt_clk_unregister(struct clk_plt *pclk)
	{
	clkdev_drop(pclk->lookup);
	}

	static struct clk_plt_fixed plt_clk_register_fixed_rate(struct platform_device pdev,
	const char *name,
	const char *parent_name,
	unsigned long fixed_rate)
	{
	struct clk_plt_fixed *pclk;

	pclk = devm_kzalloc(&pdev->dev, sizeof(*pclk), GFP_KERNEL);
	if (!pclk)
	return ERR_PTR(-ENOMEM);

	pclk->clk = clk_hw_register_fixed_rate(&pdev->dev, name, parent_name,
	0, fixed_rate);
	if (IS_ERR(pclk->clk))
	return ERR_CAST(pclk->clk);

	pclk->lookup = clkdev_hw_create(pclk->clk, name, NULL);
	if (!pclk->lookup) {
	clk_hw_unregister_fixed_rate(pclk->clk);
	return ERR_PTR(-ENOMEM);
	}

	return pclk;
	}

	static void plt_clk_unregister_fixed_rate(struct clk_plt_fixed *pclk)
	{
	clkdev_drop(pclk->lookup);
	clk_hw_unregister_fixed_rate(pclk->clk);
	}

	static void plt_clk_unregister_fixed_rate_loop(struct clk_plt_data *data,
	unsigned int i)
	{
	while (i--)
	plt_clk_unregister_fixed_rate(data->parents[i]);
	}

	static void plt_clk_free_parent_names_loop(const char **parent_names,
	unsigned int i)
	{
	while (i--)
	kfree_const(parent_names[i]);
	kfree(parent_names);
	}

	static void plt_clk_unregister_loop(struct clk_plt_data *data,
	unsigned int i)
	{
	while (i--)
	plt_clk_unregister(data->clks[i]);
	}

	static const char *plt_clk_register_parents(struct platform_device pdev,
	struct clk_plt_data *data,
	const struct pmc_clk *clks)
	{
	const char **parent_names;
	unsigned int i;
	int err;
	int nparents = 0;

	data->nparents = 0;
	while (clks[nparents].name)
	nparents++;

	data->parents = devm_kcalloc(&pdev->dev, nparents,
	sizeof(*data->parents), GFP_KERNEL);
	if (!data->parents)
	return ERR_PTR(-ENOMEM);

	parent_names = kcalloc(nparents, sizeof(*parent_names),
	GFP_KERNEL);
	if (!parent_names)
	return ERR_PTR(-ENOMEM);

	for (i = 0; i < nparents; i++) {
	data->parents[i] =
	plt_clk_register_fixed_rate(pdev, clks[i].name,
	clks[i].parent_name,
	clks[i].freq);
	if (IS_ERR(data->parents[i])) {
	err = PTR_ERR(data->parents[i]);
	goto err_unreg;
	}
	parent_names[i] = kstrdup_const(clks[i].name, GFP_KERNEL);
	}

	data->nparents = nparents;
	return parent_names;

	err_unreg:
	plt_clk_unregister_fixed_rate_loop(data, i);
	plt_clk_free_parent_names_loop(parent_names, i);
	return ERR_PTR(err);
	}

	static void plt_clk_unregister_parents(struct clk_plt_data *data)
	{
	plt_clk_unregister_fixed_rate_loop(data, data->nparents);
	}

	static int plt_clk_probe(struct platform_device *pdev)
	{
	const struct pmc_clk_data *pmc_data;
	const char **parent_names;
	struct clk_plt_data *data;
	unsigned int i;
	int err;

	pmc_data = dev_get_platdata(&pdev->dev);
	if (!pmc_data \|\| !pmc_data->clks)
	return -EINVAL;

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

	parent_names = plt_clk_register_parents(pdev, data, pmc_data->clks);
	if (IS_ERR(parent_names))
	return PTR_ERR(parent_names);

	for (i = 0; i < PMC_CLK_NUM; i++) {
	data->clks[i] = plt_clk_register(pdev, i, pmc_data,
	parent_names, data->nparents);
	if (IS_ERR(data->clks[i])) {
	err = PTR_ERR(data->clks[i]);
	goto err_unreg_clk_plt;
	}
	}
	data->mclk_lookup = clkdev_hw_create(&data->clks[3]->hw, "mclk", NULL);
	if (!data->mclk_lookup) {
	err = -ENOMEM;
	goto err_unreg_clk_plt;
	}

	data->ether_clk_lookup = clkdev_hw_create(&data->clks[4]->hw,
	"ether_clk", NULL);
	if (!data->ether_clk_lookup) {
	err = -ENOMEM;
	goto err_drop_mclk;
	}

	plt_clk_free_parent_names_loop(parent_names, data->nparents);

	platform_set_drvdata(pdev, data);
	return 0;

	err_drop_mclk:
	clkdev_drop(data->mclk_lookup);
	err_unreg_clk_plt:
	plt_clk_unregister_loop(data, i);
	plt_clk_unregister_parents(data);
	plt_clk_free_parent_names_loop(parent_names, data->nparents);
	return err;
	}

	static void plt_clk_remove(struct platform_device *pdev)
	{
	struct clk_plt_data *data;

	data = platform_get_drvdata(pdev);

	clkdev_drop(data->ether_clk_lookup);
	clkdev_drop(data->mclk_lookup);
	plt_clk_unregister_loop(data, PMC_CLK_NUM);
	plt_clk_unregister_parents(data);
	}

	static struct platform_driver plt_clk_driver = {
	.driver = {
	.name = "clk-pmc-atom",
	},
	.probe = plt_clk_probe,
	.remove_new = plt_clk_remove,
	};
	builtin_platform_driver(plt_clk_driver);