drivers/cpufreq/qcom-cpufreq-hw.c - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
  */

 #include <linux/bitfield.h>
 #include <linux/cpufreq.h>
 #include <linux/init.h>
 #include <linux/interconnect.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_platform.h>
 #include <linux/pm_opp.h>
 #include <linux/slab.h>

 #define LUT_MAX_ENTRIES			40U
 #define LUT_SRC				GENMASK(31, 30)
 #define LUT_L_VAL			GENMASK(7, 0)
 #define LUT_CORE_COUNT			GENMASK(18, 16)
 #define LUT_VOLT			GENMASK(11, 0)
 #define CLK_HW_DIV			2
 #define LUT_TURBO_IND			1

 struct qcom_cpufreq_soc_data {
 	u32 reg_enable;
 	u32 reg_freq_lut;
 	u32 reg_volt_lut;
 	u32 reg_perf_state;
 	u8 lut_row_size;
 };

 struct qcom_cpufreq_data {
 	void __iomem *base;
 	struct resource *res;
 	const struct qcom_cpufreq_soc_data *soc_data;
 };

 static unsigned long cpu_hw_rate, xo_rate;
 static bool icc_scaling_enabled;

 static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
 			       unsigned long freq_khz)
 {
 	unsigned long freq_hz = freq_khz * 1000;
 	struct dev_pm_opp *opp;
 	struct device *dev;
 	int ret;

 	dev = get_cpu_device(policy->cpu);
 	if (!dev)
 		return -ENODEV;

 	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
 	if (IS_ERR(opp))
 		return PTR_ERR(opp);

 	ret = dev_pm_opp_set_opp(dev, opp);
 	dev_pm_opp_put(opp);
 	return ret;
 }

 static int qcom_cpufreq_update_opp(struct device *cpu_dev,
 				   unsigned long freq_khz,
 				   unsigned long volt)
 {
 	unsigned long freq_hz = freq_khz * 1000;
 	int ret;

 	/* Skip voltage update if the opp table is not available */
 	if (!icc_scaling_enabled)
 		return dev_pm_opp_add(cpu_dev, freq_hz, volt);

 	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
 	if (ret) {
 		dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
 		return ret;
 	}

 	return dev_pm_opp_enable(cpu_dev, freq_hz);
 }

 static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
 					unsigned int index)
 {
 	struct qcom_cpufreq_data *data = policy->driver_data;
 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
 	unsigned long freq = policy->freq_table[index].frequency;

 	writel_relaxed(index, data->base + soc_data->reg_perf_state);

 	if (icc_scaling_enabled)
 		qcom_cpufreq_set_bw(policy, freq);

 	return 0;
 }

 static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
 {
 	struct qcom_cpufreq_data *data;
 	const struct qcom_cpufreq_soc_data *soc_data;
 	struct cpufreq_policy *policy;
 	unsigned int index;

 	policy = cpufreq_cpu_get_raw(cpu);
 	if (!policy)
 		return 0;

 	data = policy->driver_data;
 	soc_data = data->soc_data;

 	index = readl_relaxed(data->base + soc_data->reg_perf_state);
 	index = min(index, LUT_MAX_ENTRIES - 1);

 	return policy->freq_table[index].frequency;
 }

 static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
 						unsigned int target_freq)
 {
 	struct qcom_cpufreq_data *data = policy->driver_data;
 	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
 	unsigned int index;

 	index = policy->cached_resolved_idx;
 	writel_relaxed(index, data->base + soc_data->reg_perf_state);

 	return policy->freq_table[index].frequency;
 }

 static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
 				    struct cpufreq_policy *policy)
 {
 	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
 	u32 volt;
 	struct cpufreq_frequency_table	*table;
 	struct dev_pm_opp *opp;
 	unsigned long rate;
 	int ret;
 	struct qcom_cpufreq_data *drv_data = policy->driver_data;
 	const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;

 	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
 	if (!table)
 		return -ENOMEM;

 	ret = dev_pm_opp_of_add_table(cpu_dev);
 	if (!ret) {
 		/* Disable all opps and cross-validate against LUT later */
 		icc_scaling_enabled = true;
 		for (rate = 0; ; rate++) {
 			opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
 			if (IS_ERR(opp))
 				break;

 			dev_pm_opp_put(opp);
 			dev_pm_opp_disable(cpu_dev, rate);
 		}
 	} else if (ret != -ENODEV) {
 		dev_err(cpu_dev, "Invalid opp table in device tree\n");
 		return ret;
 	} else {
 		policy->fast_switch_possible = true;
 		icc_scaling_enabled = false;
 	}

 	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
 		data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
 				      i * soc_data->lut_row_size);
 		src = FIELD_GET(LUT_SRC, data);
 		lval = FIELD_GET(LUT_L_VAL, data);
 		core_count = FIELD_GET(LUT_CORE_COUNT, data);

 		data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
 				      i * soc_data->lut_row_size);
 		volt = FIELD_GET(LUT_VOLT, data) * 1000;

 		if (src)
 			freq = xo_rate * lval / 1000;
 		else
 			freq = cpu_hw_rate / 1000;

 		if (freq != prev_freq && core_count != LUT_TURBO_IND) {
 			if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
 				table[i].frequency = freq;
 				dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
 				freq, core_count);
 			} else {
 				dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
 				table[i].frequency = CPUFREQ_ENTRY_INVALID;
 			}

 		} else if (core_count == LUT_TURBO_IND) {
 			table[i].frequency = CPUFREQ_ENTRY_INVALID;
 		}

 		/*
 		 * Two of the same frequencies with the same core counts means
 		 * end of table
 		 */
 		if (i > 0 && prev_freq == freq) {
 			struct cpufreq_frequency_table *prev = &table[i - 1];

 			/*
 			 * Only treat the last frequency that might be a boost
 			 * as the boost frequency
 			 */
 			if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
 				if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
 					prev->frequency = prev_freq;
 					prev->flags = CPUFREQ_BOOST_FREQ;
 				} else {
 					dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
 						 freq);
 				}
 			}

 			break;
 		}

 		prev_freq = freq;
 	}

 	table[i].frequency = CPUFREQ_TABLE_END;
 	policy->freq_table = table;
 	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);

 	return 0;
 }

 static void qcom_get_related_cpus(int index, struct cpumask *m)
 {
 	struct device_node *cpu_np;
 	struct of_phandle_args args;
 	int cpu, ret;

 	for_each_possible_cpu(cpu) {
 		cpu_np = of_cpu_device_node_get(cpu);
 		if (!cpu_np)
 			continue;

 		ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 						 "#freq-domain-cells", 0,
 						 &args);
 		of_node_put(cpu_np);
 		if (ret < 0)
 			continue;

 		if (index == args.args[0])
 			cpumask_set_cpu(cpu, m);
 	}
 }

 static const struct qcom_cpufreq_soc_data qcom_soc_data = {
 	.reg_enable = 0x0,
 	.reg_freq_lut = 0x110,
 	.reg_volt_lut = 0x114,
 	.reg_perf_state = 0x920,
 	.lut_row_size = 32,
 };

 static const struct qcom_cpufreq_soc_data epss_soc_data = {
 	.reg_enable = 0x0,
 	.reg_freq_lut = 0x100,
 	.reg_volt_lut = 0x200,
 	.reg_perf_state = 0x320,
 	.lut_row_size = 4,
 };

 static const struct of_device_id qcom_cpufreq_hw_match[] = {
 	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
 	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
 	{}
 };
 MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);

 static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
 {
 	struct platform_device *pdev = cpufreq_get_driver_data();
 	struct device *dev = &pdev->dev;
 	struct of_phandle_args args;
 	struct device_node *cpu_np;
 	struct device *cpu_dev;
 	struct resource *res;
 	void __iomem *base;
 	struct qcom_cpufreq_data *data;
 	int ret, index;

 	cpu_dev = get_cpu_device(policy->cpu);
 	if (!cpu_dev) {
 		pr_err("%s: failed to get cpu%d device\n", __func__,
 		       policy->cpu);
 		return -ENODEV;
 	}

 	cpu_np = of_cpu_device_node_get(policy->cpu);
 	if (!cpu_np)
 		return -EINVAL;

 	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
 					 "#freq-domain-cells", 0, &args);
 	of_node_put(cpu_np);
 	if (ret)
 		return ret;

 	index = args.args[0];

 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
 	if (!res) {
 		dev_err(dev, "failed to get mem resource %d\n", index);
 		return -ENODEV;
 	}

 	if (!request_mem_region(res->start, resource_size(res), res->name)) {
 		dev_err(dev, "failed to request resource %pR\n", res);
 		return -EBUSY;
 	}

 	base = ioremap(res->start, resource_size(res));
 	if (!base) {
 		dev_err(dev, "failed to map resource %pR\n", res);
 		ret = -ENOMEM;
 		goto release_region;
 	}

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data) {
 		ret = -ENOMEM;
 		goto unmap_base;
 	}

 	data->soc_data = of_device_get_match_data(&pdev->dev);
 	data->base = base;
 	data->res = res;

 	/* HW should be in enabled state to proceed */
 	if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
 		dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
 		ret = -ENODEV;
 		goto error;
 	}

 	qcom_get_related_cpus(index, policy->cpus);
 	if (!cpumask_weight(policy->cpus)) {
 		dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
 		ret = -ENOENT;
 		goto error;
 	}

 	policy->driver_data = data;

 	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
 	if (ret) {
 		dev_err(dev, "Domain-%d failed to read LUT\n", index);
 		goto error;
 	}

 	ret = dev_pm_opp_get_opp_count(cpu_dev);
 	if (ret <= 0) {
 		dev_err(cpu_dev, "Failed to add OPPs\n");
 		ret = -ENODEV;
 		goto error;
 	}

 	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

 	if (policy_has_boost_freq(policy)) {
 		ret = cpufreq_enable_boost_support();
 		if (ret)
 			dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
 	}

 	return 0;
 error:
 	kfree(data);
 unmap_base:
 	iounmap(base);
 release_region:
 	release_mem_region(res->start, resource_size(res));
 	return ret;
 }

 static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
 {
 	struct device *cpu_dev = get_cpu_device(policy->cpu);
 	struct qcom_cpufreq_data *data = policy->driver_data;
 	struct resource *res = data->res;
 	void __iomem *base = data->base;

 	dev_pm_opp_remove_all_dynamic(cpu_dev);
 	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
 	kfree(policy->freq_table);
 	kfree(data);
 	iounmap(base);
 	release_mem_region(res->start, resource_size(res));

 	return 0;
 }

 static struct freq_attr *qcom_cpufreq_hw_attr[] = {
 	&cpufreq_freq_attr_scaling_available_freqs,
 	&cpufreq_freq_attr_scaling_boost_freqs,
 	NULL
 };

 static struct cpufreq_driver cpufreq_qcom_hw_driver = {
 	.flags		= CPUFREQ_NEED_INITIAL_FREQ_CHECK |
 			  CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
 			  CPUFREQ_IS_COOLING_DEV,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= qcom_cpufreq_hw_target_index,
 	.get		= qcom_cpufreq_hw_get,
 	.init		= qcom_cpufreq_hw_cpu_init,
 	.exit		= qcom_cpufreq_hw_cpu_exit,
 	.fast_switch    = qcom_cpufreq_hw_fast_switch,
 	.name		= "qcom-cpufreq-hw",
 	.attr		= qcom_cpufreq_hw_attr,
 };

 static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
 {
 	struct device *cpu_dev;
 	struct clk *clk;
 	int ret;

 	clk = clk_get(&pdev->dev, "xo");
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);

 	xo_rate = clk_get_rate(clk);
 	clk_put(clk);

 	clk = clk_get(&pdev->dev, "alternate");
 	if (IS_ERR(clk))
 		return PTR_ERR(clk);

 	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
 	clk_put(clk);

 	cpufreq_qcom_hw_driver.driver_data = pdev;

 	/* Check for optional interconnect paths on CPU0 */
 	cpu_dev = get_cpu_device(0);
 	if (!cpu_dev)
 		return -EPROBE_DEFER;

 	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
 	if (ret)
 		return ret;

 	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
 	if (ret)
 		dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
 	else
 		dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");

 	return ret;
 }

 static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
 {
 	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
 }

 static struct platform_driver qcom_cpufreq_hw_driver = {
 	.probe = qcom_cpufreq_hw_driver_probe,
 	.remove = qcom_cpufreq_hw_driver_remove,
 	.driver = {
 		.name = "qcom-cpufreq-hw",
 		.of_match_table = qcom_cpufreq_hw_match,
 	},
 };

 static int __init qcom_cpufreq_hw_init(void)
 {
 	return platform_driver_register(&qcom_cpufreq_hw_driver);
 }
 postcore_initcall(qcom_cpufreq_hw_init);

 static void __exit qcom_cpufreq_hw_exit(void)
 {
 	platform_driver_unregister(&qcom_cpufreq_hw_driver);
 }
 module_exit(qcom_cpufreq_hw_exit);

 MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (c) 2018, The Linux Foundation. All rights reserved.
	*/

	#include <linux/bitfield.h>
	#include <linux/cpufreq.h>
	#include <linux/init.h>
	#include <linux/interconnect.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of_address.h>
	#include <linux/of_platform.h>
	#include <linux/pm_opp.h>
	#include <linux/slab.h>

	#define LUT_MAX_ENTRIES 40U
	#define LUT_SRC GENMASK(31, 30)
	#define LUT_L_VAL GENMASK(7, 0)
	#define LUT_CORE_COUNT GENMASK(18, 16)
	#define LUT_VOLT GENMASK(11, 0)
	#define CLK_HW_DIV 2
	#define LUT_TURBO_IND 1

	struct qcom_cpufreq_soc_data {
	u32 reg_enable;
	u32 reg_freq_lut;
	u32 reg_volt_lut;
	u32 reg_perf_state;
	u8 lut_row_size;
	};

	struct qcom_cpufreq_data {
	void __iomem *base;
	struct resource *res;
	const struct qcom_cpufreq_soc_data *soc_data;
	};

	static unsigned long cpu_hw_rate, xo_rate;
	static bool icc_scaling_enabled;

	static int qcom_cpufreq_set_bw(struct cpufreq_policy *policy,
	unsigned long freq_khz)
	{
	unsigned long freq_hz = freq_khz * 1000;
	struct dev_pm_opp *opp;
	struct device *dev;
	int ret;

	dev = get_cpu_device(policy->cpu);
	if (!dev)
	return -ENODEV;

	opp = dev_pm_opp_find_freq_exact(dev, freq_hz, true);
	if (IS_ERR(opp))
	return PTR_ERR(opp);

	ret = dev_pm_opp_set_opp(dev, opp);
	dev_pm_opp_put(opp);
	return ret;
	}

	static int qcom_cpufreq_update_opp(struct device *cpu_dev,
	unsigned long freq_khz,
	unsigned long volt)
	{
	unsigned long freq_hz = freq_khz * 1000;
	int ret;

	/* Skip voltage update if the opp table is not available */
	if (!icc_scaling_enabled)
	return dev_pm_opp_add(cpu_dev, freq_hz, volt);

	ret = dev_pm_opp_adjust_voltage(cpu_dev, freq_hz, volt, volt, volt);
	if (ret) {
	dev_err(cpu_dev, "Voltage update failed freq=%ld\n", freq_khz);
	return ret;
	}

	return dev_pm_opp_enable(cpu_dev, freq_hz);
	}

	static int qcom_cpufreq_hw_target_index(struct cpufreq_policy *policy,
	unsigned int index)
	{
	struct qcom_cpufreq_data *data = policy->driver_data;
	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
	unsigned long freq = policy->freq_table[index].frequency;

	writel_relaxed(index, data->base + soc_data->reg_perf_state);

	if (icc_scaling_enabled)
	qcom_cpufreq_set_bw(policy, freq);

	return 0;
	}

	static unsigned int qcom_cpufreq_hw_get(unsigned int cpu)
	{
	struct qcom_cpufreq_data *data;
	const struct qcom_cpufreq_soc_data *soc_data;
	struct cpufreq_policy *policy;
	unsigned int index;

	policy = cpufreq_cpu_get_raw(cpu);
	if (!policy)
	return 0;

	data = policy->driver_data;
	soc_data = data->soc_data;

	index = readl_relaxed(data->base + soc_data->reg_perf_state);
	index = min(index, LUT_MAX_ENTRIES - 1);

	return policy->freq_table[index].frequency;
	}

	static unsigned int qcom_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
	unsigned int target_freq)
	{
	struct qcom_cpufreq_data *data = policy->driver_data;
	const struct qcom_cpufreq_soc_data *soc_data = data->soc_data;
	unsigned int index;

	index = policy->cached_resolved_idx;
	writel_relaxed(index, data->base + soc_data->reg_perf_state);

	return policy->freq_table[index].frequency;
	}

	static int qcom_cpufreq_hw_read_lut(struct device *cpu_dev,
	struct cpufreq_policy *policy)
	{
	u32 data, src, lval, i, core_count, prev_freq = 0, freq;
	u32 volt;
	struct cpufreq_frequency_table *table;
	struct dev_pm_opp *opp;
	unsigned long rate;
	int ret;
	struct qcom_cpufreq_data *drv_data = policy->driver_data;
	const struct qcom_cpufreq_soc_data *soc_data = drv_data->soc_data;

	table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
	if (!table)
	return -ENOMEM;

	ret = dev_pm_opp_of_add_table(cpu_dev);
	if (!ret) {
	/* Disable all opps and cross-validate against LUT later */
	icc_scaling_enabled = true;
	for (rate = 0; ; rate++) {
	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &rate);
	if (IS_ERR(opp))
	break;

	dev_pm_opp_put(opp);
	dev_pm_opp_disable(cpu_dev, rate);
	}
	} else if (ret != -ENODEV) {
	dev_err(cpu_dev, "Invalid opp table in device tree\n");
	return ret;
	} else {
	policy->fast_switch_possible = true;
	icc_scaling_enabled = false;
	}

	for (i = 0; i < LUT_MAX_ENTRIES; i++) {
	data = readl_relaxed(drv_data->base + soc_data->reg_freq_lut +
	i * soc_data->lut_row_size);
	src = FIELD_GET(LUT_SRC, data);
	lval = FIELD_GET(LUT_L_VAL, data);
	core_count = FIELD_GET(LUT_CORE_COUNT, data);

	data = readl_relaxed(drv_data->base + soc_data->reg_volt_lut +
	i * soc_data->lut_row_size);
	volt = FIELD_GET(LUT_VOLT, data) * 1000;

	if (src)
	freq = xo_rate * lval / 1000;
	else
	freq = cpu_hw_rate / 1000;

	if (freq != prev_freq && core_count != LUT_TURBO_IND) {
	if (!qcom_cpufreq_update_opp(cpu_dev, freq, volt)) {
	table[i].frequency = freq;
	dev_dbg(cpu_dev, "index=%d freq=%d, core_count %d\n", i,
	freq, core_count);
	} else {
	dev_warn(cpu_dev, "failed to update OPP for freq=%d\n", freq);
	table[i].frequency = CPUFREQ_ENTRY_INVALID;
	}

	} else if (core_count == LUT_TURBO_IND) {
	table[i].frequency = CPUFREQ_ENTRY_INVALID;
	}

	/*
	* Two of the same frequencies with the same core counts means
	* end of table
	*/
	if (i > 0 && prev_freq == freq) {
	struct cpufreq_frequency_table *prev = &table[i - 1];

	/*
	* Only treat the last frequency that might be a boost
	* as the boost frequency
	*/
	if (prev->frequency == CPUFREQ_ENTRY_INVALID) {
	if (!qcom_cpufreq_update_opp(cpu_dev, prev_freq, volt)) {
	prev->frequency = prev_freq;
	prev->flags = CPUFREQ_BOOST_FREQ;
	} else {
	dev_warn(cpu_dev, "failed to update OPP for freq=%d\n",
	freq);
	}
	}

	break;
	}

	prev_freq = freq;
	}

	table[i].frequency = CPUFREQ_TABLE_END;
	policy->freq_table = table;
	dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus);

	return 0;
	}

	static void qcom_get_related_cpus(int index, struct cpumask *m)
	{
	struct device_node *cpu_np;
	struct of_phandle_args args;
	int cpu, ret;

	for_each_possible_cpu(cpu) {
	cpu_np = of_cpu_device_node_get(cpu);
	if (!cpu_np)
	continue;

	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
	"#freq-domain-cells", 0,
	&args);
	of_node_put(cpu_np);
	if (ret < 0)
	continue;

	if (index == args.args[0])
	cpumask_set_cpu(cpu, m);
	}
	}

	static const struct qcom_cpufreq_soc_data qcom_soc_data = {
	.reg_enable = 0x0,
	.reg_freq_lut = 0x110,
	.reg_volt_lut = 0x114,
	.reg_perf_state = 0x920,
	.lut_row_size = 32,
	};

	static const struct qcom_cpufreq_soc_data epss_soc_data = {
	.reg_enable = 0x0,
	.reg_freq_lut = 0x100,
	.reg_volt_lut = 0x200,
	.reg_perf_state = 0x320,
	.lut_row_size = 4,
	};

	static const struct of_device_id qcom_cpufreq_hw_match[] = {
	{ .compatible = "qcom,cpufreq-hw", .data = &qcom_soc_data },
	{ .compatible = "qcom,cpufreq-epss", .data = &epss_soc_data },
	{}
	};
	MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match);

	static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
	{
	struct platform_device *pdev = cpufreq_get_driver_data();
	struct device *dev = &pdev->dev;
	struct of_phandle_args args;
	struct device_node *cpu_np;
	struct device *cpu_dev;
	struct resource *res;
	void __iomem *base;
	struct qcom_cpufreq_data *data;
	int ret, index;

	cpu_dev = get_cpu_device(policy->cpu);
	if (!cpu_dev) {
	pr_err("%s: failed to get cpu%d device\n", __func__,
	policy->cpu);
	return -ENODEV;
	}

	cpu_np = of_cpu_device_node_get(policy->cpu);
	if (!cpu_np)
	return -EINVAL;

	ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
	"#freq-domain-cells", 0, &args);
	of_node_put(cpu_np);
	if (ret)
	return ret;

	index = args.args[0];

	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
	if (!res) {
	dev_err(dev, "failed to get mem resource %d\n", index);
	return -ENODEV;
	}

	if (!request_mem_region(res->start, resource_size(res), res->name)) {
	dev_err(dev, "failed to request resource %pR\n", res);
	return -EBUSY;
	}

	base = ioremap(res->start, resource_size(res));
	if (!base) {
	dev_err(dev, "failed to map resource %pR\n", res);
	ret = -ENOMEM;
	goto release_region;
	}

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
	ret = -ENOMEM;
	goto unmap_base;
	}

	data->soc_data = of_device_get_match_data(&pdev->dev);
	data->base = base;
	data->res = res;

	/* HW should be in enabled state to proceed */
	if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) {
	dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
	ret = -ENODEV;
	goto error;
	}

	qcom_get_related_cpus(index, policy->cpus);
	if (!cpumask_weight(policy->cpus)) {
	dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
	ret = -ENOENT;
	goto error;
	}

	policy->driver_data = data;

	ret = qcom_cpufreq_hw_read_lut(cpu_dev, policy);
	if (ret) {
	dev_err(dev, "Domain-%d failed to read LUT\n", index);
	goto error;
	}

	ret = dev_pm_opp_get_opp_count(cpu_dev);
	if (ret <= 0) {
	dev_err(cpu_dev, "Failed to add OPPs\n");
	ret = -ENODEV;
	goto error;
	}

	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

	if (policy_has_boost_freq(policy)) {
	ret = cpufreq_enable_boost_support();
	if (ret)
	dev_warn(cpu_dev, "failed to enable boost: %d\n", ret);
	}

	return 0;
	error:
	kfree(data);
	unmap_base:
	iounmap(base);
	release_region:
	release_mem_region(res->start, resource_size(res));
	return ret;
	}

	static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
	{
	struct device *cpu_dev = get_cpu_device(policy->cpu);
	struct qcom_cpufreq_data *data = policy->driver_data;
	struct resource *res = data->res;
	void __iomem *base = data->base;

	dev_pm_opp_remove_all_dynamic(cpu_dev);
	dev_pm_opp_of_cpumask_remove_table(policy->related_cpus);
	kfree(policy->freq_table);
	kfree(data);
	iounmap(base);
	release_mem_region(res->start, resource_size(res));

	return 0;
	}

	static struct freq_attr *qcom_cpufreq_hw_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	&cpufreq_freq_attr_scaling_boost_freqs,
	NULL
	};

	static struct cpufreq_driver cpufreq_qcom_hw_driver = {
	.flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK \|
	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
	CPUFREQ_IS_COOLING_DEV,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = qcom_cpufreq_hw_target_index,
	.get = qcom_cpufreq_hw_get,
	.init = qcom_cpufreq_hw_cpu_init,
	.exit = qcom_cpufreq_hw_cpu_exit,
	.fast_switch = qcom_cpufreq_hw_fast_switch,
	.name = "qcom-cpufreq-hw",
	.attr = qcom_cpufreq_hw_attr,
	};

	static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
	{
	struct device *cpu_dev;
	struct clk *clk;
	int ret;

	clk = clk_get(&pdev->dev, "xo");
	if (IS_ERR(clk))
	return PTR_ERR(clk);

	xo_rate = clk_get_rate(clk);
	clk_put(clk);

	clk = clk_get(&pdev->dev, "alternate");
	if (IS_ERR(clk))
	return PTR_ERR(clk);

	cpu_hw_rate = clk_get_rate(clk) / CLK_HW_DIV;
	clk_put(clk);

	cpufreq_qcom_hw_driver.driver_data = pdev;

	/* Check for optional interconnect paths on CPU0 */
	cpu_dev = get_cpu_device(0);
	if (!cpu_dev)
	return -EPROBE_DEFER;

	ret = dev_pm_opp_of_find_icc_paths(cpu_dev, NULL);
	if (ret)
	return ret;

	ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
	if (ret)
	dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
	else
	dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");

	return ret;
	}

	static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
	{
	return cpufreq_unregister_driver(&cpufreq_qcom_hw_driver);
	}

	static struct platform_driver qcom_cpufreq_hw_driver = {
	.probe = qcom_cpufreq_hw_driver_probe,
	.remove = qcom_cpufreq_hw_driver_remove,
	.driver = {
	.name = "qcom-cpufreq-hw",
	.of_match_table = qcom_cpufreq_hw_match,
	},
	};

	static int __init qcom_cpufreq_hw_init(void)
	{
	return platform_driver_register(&qcom_cpufreq_hw_driver);
	}
	postcore_initcall(qcom_cpufreq_hw_init);

	static void __exit qcom_cpufreq_hw_exit(void)
	{
	platform_driver_unregister(&qcom_cpufreq_hw_driver);
	}
	module_exit(qcom_cpufreq_hw_exit);

	MODULE_DESCRIPTION("QCOM CPUFREQ HW Driver");
	MODULE_LICENSE("GPL v2");