drivers/cpufreq/qoriq-cpufreq.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
  * CPU Frequency Scaling driver for Freescale QorIQ SoCs.
  */

 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

 #include <linux/clk.h>
 #include <linux/clk-provider.h>
 #include <linux/cpufreq.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/slab.h>
 #include <linux/smp.h>
 #include <linux/platform_device.h>

 /**
  * struct cpu_data
  * @pclk: the parent clock of cpu
  * @table: frequency table
  */
 struct cpu_data {
 	struct clk **pclk;
 	struct cpufreq_frequency_table *table;
 };

 /**
  * struct soc_data - SoC specific data
  * @flags: SOC_xxx
  */
 struct soc_data {
 	u32 flags;
 };

 static u32 get_bus_freq(void)
 {
 	struct device_node *soc;
 	u32 sysfreq;
 	struct clk *pltclk;
 	int ret;

 	/* get platform freq by searching bus-frequency property */
 	soc = of_find_node_by_type(NULL, "soc");
 	if (soc) {
 		ret = of_property_read_u32(soc, "bus-frequency", &sysfreq);
 		of_node_put(soc);
 		if (!ret)
 			return sysfreq;
 	}

 	/* get platform freq by its clock name */
 	pltclk = clk_get(NULL, "cg-pll0-div1");
 	if (IS_ERR(pltclk)) {
 		pr_err("%s: can't get bus frequency %ld\n",
 		       __func__, PTR_ERR(pltclk));
 		return PTR_ERR(pltclk);
 	}

 	return clk_get_rate(pltclk);
 }

 static struct clk *cpu_to_clk(int cpu)
 {
 	struct device_node *np;
 	struct clk *clk;

 	if (!cpu_present(cpu))
 		return NULL;

 	np = of_get_cpu_node(cpu, NULL);
 	if (!np)
 		return NULL;

 	clk = of_clk_get(np, 0);
 	of_node_put(np);
 	return clk;
 }

 /* traverse cpu nodes to get cpu mask of sharing clock wire */
 static void set_affected_cpus(struct cpufreq_policy *policy)
 {
 	struct cpumask *dstp = policy->cpus;
 	struct clk *clk;
 	int i;

 	for_each_present_cpu(i) {
 		clk = cpu_to_clk(i);
 		if (IS_ERR(clk)) {
 			pr_err("%s: no clock for cpu %d\n", __func__, i);
 			continue;
 		}

 		if (clk_is_match(policy->clk, clk))
 			cpumask_set_cpu(i, dstp);
 	}
 }

 /* reduce the duplicated frequencies in frequency table */
 static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
 		int count)
 {
 	int i, j;

 	for (i = 1; i < count; i++) {
 		for (j = 0; j < i; j++) {
 			if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID ||
 					freq_table[j].frequency !=
 					freq_table[i].frequency)
 				continue;

 			freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
 			break;
 		}
 	}
 }

 /* sort the frequencies in frequency table in descenting order */
 static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
 		int count)
 {
 	int i, j, ind;
 	unsigned int freq, max_freq;
 	struct cpufreq_frequency_table table;

 	for (i = 0; i < count - 1; i++) {
 		max_freq = freq_table[i].frequency;
 		ind = i;
 		for (j = i + 1; j < count; j++) {
 			freq = freq_table[j].frequency;
 			if (freq == CPUFREQ_ENTRY_INVALID ||
 					freq <= max_freq)
 				continue;
 			ind = j;
 			max_freq = freq;
 		}

 		if (ind != i) {
 			/* exchange the frequencies */
 			table.driver_data = freq_table[i].driver_data;
 			table.frequency = freq_table[i].frequency;
 			freq_table[i].driver_data = freq_table[ind].driver_data;
 			freq_table[i].frequency = freq_table[ind].frequency;
 			freq_table[ind].driver_data = table.driver_data;
 			freq_table[ind].frequency = table.frequency;
 		}
 	}
 }

 static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	struct device_node *np;
 	int i, count;
 	u32 freq;
 	struct clk *clk;
 	const struct clk_hw *hwclk;
 	struct cpufreq_frequency_table *table;
 	struct cpu_data *data;
 	unsigned int cpu = policy->cpu;
 	u64 u64temp;

 	np = of_get_cpu_node(cpu, NULL);
 	if (!np)
 		return -ENODEV;

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data)
 		goto err_np;

 	policy->clk = of_clk_get(np, 0);
 	if (IS_ERR(policy->clk)) {
 		pr_err("%s: no clock information\n", __func__);
 		goto err_nomem2;
 	}

 	hwclk = __clk_get_hw(policy->clk);
 	count = clk_hw_get_num_parents(hwclk);

 	data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL);
 	if (!data->pclk)
 		goto err_nomem2;

 	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
 	if (!table)
 		goto err_pclk;

 	for (i = 0; i < count; i++) {
 		clk = clk_hw_get_parent_by_index(hwclk, i)->clk;
 		data->pclk[i] = clk;
 		freq = clk_get_rate(clk);
 		table[i].frequency = freq / 1000;
 		table[i].driver_data = i;
 	}
 	freq_table_redup(table, count);
 	freq_table_sort(table, count);
 	table[i].frequency = CPUFREQ_TABLE_END;
 	policy->freq_table = table;
 	data->table = table;

 	/* update ->cpus if we have cluster, no harm if not */
 	set_affected_cpus(policy);
 	policy->driver_data = data;

 	/* Minimum transition latency is 12 platform clocks */
 	u64temp = 12ULL * NSEC_PER_SEC;
 	do_div(u64temp, get_bus_freq());
 	policy->cpuinfo.transition_latency = u64temp + 1;

 	of_node_put(np);

 	return 0;

 err_pclk:
 	kfree(data->pclk);
 err_nomem2:
 	kfree(data);
 err_np:
 	of_node_put(np);

 	return -ENODEV;
 }

 static int qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
 	struct cpu_data *data = policy->driver_data;

 	kfree(data->pclk);
 	kfree(data->table);
 	kfree(data);
 	policy->driver_data = NULL;

 	return 0;
 }

 static int qoriq_cpufreq_target(struct cpufreq_policy *policy,
 		unsigned int index)
 {
 	struct clk *parent;
 	struct cpu_data *data = policy->driver_data;

 	parent = data->pclk[data->table[index].driver_data];
 	return clk_set_parent(policy->clk, parent);
 }

 static struct cpufreq_driver qoriq_cpufreq_driver = {
 	.name		= "qoriq_cpufreq",
 	.flags		= CPUFREQ_CONST_LOOPS |
 			  CPUFREQ_IS_COOLING_DEV,
 	.init		= qoriq_cpufreq_cpu_init,
 	.exit		= qoriq_cpufreq_cpu_exit,
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= qoriq_cpufreq_target,
 	.get		= cpufreq_generic_get,
 	.attr		= cpufreq_generic_attr,
 };

 static const struct of_device_id qoriq_cpufreq_blacklist[] = {
 	/* e6500 cannot use cpufreq due to erratum A-008083 */
 	{ .compatible = "fsl,b4420-clockgen", },
 	{ .compatible = "fsl,b4860-clockgen", },
 	{ .compatible = "fsl,t2080-clockgen", },
 	{ .compatible = "fsl,t4240-clockgen", },
 	{}
 };

 static int qoriq_cpufreq_probe(struct platform_device *pdev)
 {
 	int ret;
 	struct device_node *np;

 	np = of_find_matching_node(NULL, qoriq_cpufreq_blacklist);
 	if (np) {
 		dev_info(&pdev->dev, "Disabling due to erratum A-008083");
 		return -ENODEV;
 	}

 	ret = cpufreq_register_driver(&qoriq_cpufreq_driver);
 	if (ret)
 		return ret;

 	dev_info(&pdev->dev, "Freescale QorIQ CPU frequency scaling driver\n");
 	return 0;
 }

 static int qoriq_cpufreq_remove(struct platform_device *pdev)
 {
 	cpufreq_unregister_driver(&qoriq_cpufreq_driver);

 	return 0;
 }

 static struct platform_driver qoriq_cpufreq_platform_driver = {
 	.driver = {
 		.name = "qoriq-cpufreq",
 	},
 	.probe = qoriq_cpufreq_probe,
 	.remove = qoriq_cpufreq_remove,
 };
 module_platform_driver(qoriq_cpufreq_platform_driver);

 MODULE_ALIAS("platform:qoriq-cpufreq");
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
 MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright 2013 Freescale Semiconductor, Inc.
	*
	* CPU Frequency Scaling driver for Freescale QorIQ SoCs.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/clk.h>
	#include <linux/clk-provider.h>
	#include <linux/cpufreq.h>
	#include <linux/errno.h>
	#include <linux/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/of.h>
	#include <linux/slab.h>
	#include <linux/smp.h>
	#include <linux/platform_device.h>

	/**
	* struct cpu_data
	* @pclk: the parent clock of cpu
	* @table: frequency table
	*/
	struct cpu_data {
	struct clk **pclk;
	struct cpufreq_frequency_table *table;
	};

	/**
	* struct soc_data - SoC specific data
	* @flags: SOC_xxx
	*/
	struct soc_data {
	u32 flags;
	};

	static u32 get_bus_freq(void)
	{
	struct device_node *soc;
	u32 sysfreq;
	struct clk *pltclk;
	int ret;

	/* get platform freq by searching bus-frequency property */
	soc = of_find_node_by_type(NULL, "soc");
	if (soc) {
	ret = of_property_read_u32(soc, "bus-frequency", &sysfreq);
	of_node_put(soc);
	if (!ret)
	return sysfreq;
	}

	/* get platform freq by its clock name */
	pltclk = clk_get(NULL, "cg-pll0-div1");
	if (IS_ERR(pltclk)) {
	pr_err("%s: can't get bus frequency %ld\n",
	__func__, PTR_ERR(pltclk));
	return PTR_ERR(pltclk);
	}

	return clk_get_rate(pltclk);
	}

	static struct clk *cpu_to_clk(int cpu)
	{
	struct device_node *np;
	struct clk *clk;

	if (!cpu_present(cpu))
	return NULL;

	np = of_get_cpu_node(cpu, NULL);
	if (!np)
	return NULL;

	clk = of_clk_get(np, 0);
	of_node_put(np);
	return clk;
	}

	/* traverse cpu nodes to get cpu mask of sharing clock wire */
	static void set_affected_cpus(struct cpufreq_policy *policy)
	{
	struct cpumask *dstp = policy->cpus;
	struct clk *clk;
	int i;

	for_each_present_cpu(i) {
	clk = cpu_to_clk(i);
	if (IS_ERR(clk)) {
	pr_err("%s: no clock for cpu %d\n", __func__, i);
	continue;
	}

	if (clk_is_match(policy->clk, clk))
	cpumask_set_cpu(i, dstp);
	}
	}

	/* reduce the duplicated frequencies in frequency table */
	static void freq_table_redup(struct cpufreq_frequency_table *freq_table,
	int count)
	{
	int i, j;

	for (i = 1; i < count; i++) {
	for (j = 0; j < i; j++) {
	if (freq_table[j].frequency == CPUFREQ_ENTRY_INVALID \|\|
	freq_table[j].frequency !=
	freq_table[i].frequency)
	continue;

	freq_table[i].frequency = CPUFREQ_ENTRY_INVALID;
	break;
	}
	}
	}

	/* sort the frequencies in frequency table in descenting order */
	static void freq_table_sort(struct cpufreq_frequency_table *freq_table,
	int count)
	{
	int i, j, ind;
	unsigned int freq, max_freq;
	struct cpufreq_frequency_table table;

	for (i = 0; i < count - 1; i++) {
	max_freq = freq_table[i].frequency;
	ind = i;
	for (j = i + 1; j < count; j++) {
	freq = freq_table[j].frequency;
	if (freq == CPUFREQ_ENTRY_INVALID \|\|
	freq <= max_freq)
	continue;
	ind = j;
	max_freq = freq;
	}

	if (ind != i) {
	/* exchange the frequencies */
	table.driver_data = freq_table[i].driver_data;
	table.frequency = freq_table[i].frequency;
	freq_table[i].driver_data = freq_table[ind].driver_data;
	freq_table[i].frequency = freq_table[ind].frequency;
	freq_table[ind].driver_data = table.driver_data;
	freq_table[ind].frequency = table.frequency;
	}
	}
	}

	static int qoriq_cpufreq_cpu_init(struct cpufreq_policy *policy)
	{
	struct device_node *np;
	int i, count;
	u32 freq;
	struct clk *clk;
	const struct clk_hw *hwclk;
	struct cpufreq_frequency_table *table;
	struct cpu_data *data;
	unsigned int cpu = policy->cpu;
	u64 u64temp;

	np = of_get_cpu_node(cpu, NULL);
	if (!np)
	return -ENODEV;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data)
	goto err_np;

	policy->clk = of_clk_get(np, 0);
	if (IS_ERR(policy->clk)) {
	pr_err("%s: no clock information\n", __func__);
	goto err_nomem2;
	}

	hwclk = __clk_get_hw(policy->clk);
	count = clk_hw_get_num_parents(hwclk);

	data->pclk = kcalloc(count, sizeof(struct clk *), GFP_KERNEL);
	if (!data->pclk)
	goto err_nomem2;

	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
	if (!table)
	goto err_pclk;

	for (i = 0; i < count; i++) {
	clk = clk_hw_get_parent_by_index(hwclk, i)->clk;
	data->pclk[i] = clk;
	freq = clk_get_rate(clk);
	table[i].frequency = freq / 1000;
	table[i].driver_data = i;
	}
	freq_table_redup(table, count);
	freq_table_sort(table, count);
	table[i].frequency = CPUFREQ_TABLE_END;
	policy->freq_table = table;
	data->table = table;

	/* update ->cpus if we have cluster, no harm if not */
	set_affected_cpus(policy);
	policy->driver_data = data;

	/* Minimum transition latency is 12 platform clocks */
	u64temp = 12ULL * NSEC_PER_SEC;
	do_div(u64temp, get_bus_freq());
	policy->cpuinfo.transition_latency = u64temp + 1;

	of_node_put(np);

	return 0;

	err_pclk:
	kfree(data->pclk);
	err_nomem2:
	kfree(data);
	err_np:
	of_node_put(np);

	return -ENODEV;
	}

	static int qoriq_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	{
	struct cpu_data *data = policy->driver_data;

	kfree(data->pclk);
	kfree(data->table);
	kfree(data);
	policy->driver_data = NULL;

	return 0;
	}

	static int qoriq_cpufreq_target(struct cpufreq_policy *policy,
	unsigned int index)
	{
	struct clk *parent;
	struct cpu_data *data = policy->driver_data;

	parent = data->pclk[data->table[index].driver_data];
	return clk_set_parent(policy->clk, parent);
	}

	static struct cpufreq_driver qoriq_cpufreq_driver = {
	.name = "qoriq_cpufreq",
	.flags = CPUFREQ_CONST_LOOPS \|
	CPUFREQ_IS_COOLING_DEV,
	.init = qoriq_cpufreq_cpu_init,
	.exit = qoriq_cpufreq_cpu_exit,
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = qoriq_cpufreq_target,
	.get = cpufreq_generic_get,
	.attr = cpufreq_generic_attr,
	};

	static const struct of_device_id qoriq_cpufreq_blacklist[] = {
	/* e6500 cannot use cpufreq due to erratum A-008083 */
	{ .compatible = "fsl,b4420-clockgen", },
	{ .compatible = "fsl,b4860-clockgen", },
	{ .compatible = "fsl,t2080-clockgen", },
	{ .compatible = "fsl,t4240-clockgen", },
	{}
	};

	static int qoriq_cpufreq_probe(struct platform_device *pdev)
	{
	int ret;
	struct device_node *np;

	np = of_find_matching_node(NULL, qoriq_cpufreq_blacklist);
	if (np) {
	dev_info(&pdev->dev, "Disabling due to erratum A-008083");
	return -ENODEV;
	}

	ret = cpufreq_register_driver(&qoriq_cpufreq_driver);
	if (ret)
	return ret;

	dev_info(&pdev->dev, "Freescale QorIQ CPU frequency scaling driver\n");
	return 0;
	}

	static int qoriq_cpufreq_remove(struct platform_device *pdev)
	{
	cpufreq_unregister_driver(&qoriq_cpufreq_driver);

	return 0;
	}

	static struct platform_driver qoriq_cpufreq_platform_driver = {
	.driver = {
	.name = "qoriq-cpufreq",
	},
	.probe = qoriq_cpufreq_probe,
	.remove = qoriq_cpufreq_remove,
	};
	module_platform_driver(qoriq_cpufreq_platform_driver);

	MODULE_ALIAS("platform:qoriq-cpufreq");
	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
	MODULE_DESCRIPTION("cpufreq driver for Freescale QorIQ series SoCs");