drivers/cpufreq/ppc-corenet-cpufreq.c - maze/linux - Git at Google

 /*
  * Copyright 2013 Freescale Semiconductor, Inc.
  *
  * CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

 #include <linux/clk.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 <sysdev/fsl_soc.h>

 /**
  * struct cpu_data - per CPU data struct
  * @parent: the parent node of cpu clock
  * @table: frequency table
  */
 struct cpu_data {
 	struct device_node *parent;
 	struct cpufreq_frequency_table *table;
 };

 /**
  * struct soc_data - SoC specific data
  * @freq_mask: mask the disallowed frequencies
  * @flag: unique flags
  */
 struct soc_data {
 	u32 freq_mask[4];
 	u32 flag;
 };

 #define FREQ_MASK	1
 /* see hardware specification for the allowed frqeuencies */
 static const struct soc_data sdata[] = {
 	{ /* used by p2041 and p3041 */
 		.freq_mask = {0x8, 0x8, 0x2, 0x2},
 		.flag = FREQ_MASK,
 	},
 	{ /* used by p5020 */
 		.freq_mask = {0x8, 0x2},
 		.flag = FREQ_MASK,
 	},
 	{ /* used by p4080, p5040 */
 		.freq_mask = {0},
 		.flag = 0,
 	},
 };

 /*
  * the minimum allowed core frequency, in Hz
  * for chassis v1.0, >= platform frequency
  * for chassis v2.0, >= platform frequency / 2
  */
 static u32 min_cpufreq;
 static const u32 *fmask;

 static DEFINE_PER_CPU(struct cpu_data *, cpu_data);

 /* cpumask in a cluster */
 static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);

 #ifndef CONFIG_SMP
 static inline const struct cpumask *cpu_core_mask(int cpu)
 {
 	return cpumask_of(0);
 }
 #endif

 /* 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 corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
 {
 	struct device_node *np;
 	int i, count, ret;
 	u32 freq, mask;
 	struct clk *clk;
 	struct cpufreq_frequency_table *table;
 	struct cpu_data *data;
 	unsigned int cpu = policy->cpu;

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

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data) {
 		pr_err("%s: no memory\n", __func__);
 		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;
 	}

 	data->parent = of_parse_phandle(np, "clocks", 0);
 	if (!data->parent) {
 		pr_err("%s: could not get clock information\n", __func__);
 		goto err_nomem2;
 	}

 	count = of_property_count_strings(data->parent, "clock-names");
 	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
 	if (!table) {
 		pr_err("%s: no memory\n", __func__);
 		goto err_node;
 	}

 	if (fmask)
 		mask = fmask[get_hard_smp_processor_id(cpu)];
 	else
 		mask = 0x0;

 	for (i = 0; i < count; i++) {
 		clk = of_clk_get(data->parent, i);
 		freq = clk_get_rate(clk);
 		/*
 		 * the clock is valid if its frequency is not masked
 		 * and large than minimum allowed frequency.
 		 */
 		if (freq < min_cpufreq || (mask & (1 << i)))
 			table[i].frequency = CPUFREQ_ENTRY_INVALID;
 		else
 			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;

 	/* set the min and max frequency properly */
 	ret = cpufreq_table_validate_and_show(policy, table);
 	if (ret) {
 		pr_err("invalid frequency table: %d\n", ret);
 		goto err_nomem1;
 	}

 	data->table = table;
 	per_cpu(cpu_data, cpu) = data;

 	/* update ->cpus if we have cluster, no harm if not */
 	cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
 	for_each_cpu(i, per_cpu(cpu_mask, cpu))
 		per_cpu(cpu_data, i) = data;

 	policy->cpuinfo.transition_latency =
 				(12 * NSEC_PER_SEC) / fsl_get_sys_freq();
 	of_node_put(np);

 	return 0;

 err_nomem1:
 	kfree(table);
 err_node:
 	of_node_put(data->parent);
 err_nomem2:
 	per_cpu(cpu_data, cpu) = NULL;
 	kfree(data);
 err_np:
 	of_node_put(np);

 	return -ENODEV;
 }

 static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 {
 	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
 	unsigned int cpu;

 	of_node_put(data->parent);
 	kfree(data->table);
 	kfree(data);

 	for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
 		per_cpu(cpu_data, cpu) = NULL;

 	return 0;
 }

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

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

 static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
 	.name		= "ppc_cpufreq",
 	.flags		= CPUFREQ_CONST_LOOPS,
 	.init		= corenet_cpufreq_cpu_init,
 	.exit		= __exit_p(corenet_cpufreq_cpu_exit),
 	.verify		= cpufreq_generic_frequency_table_verify,
 	.target_index	= corenet_cpufreq_target,
 	.get		= cpufreq_generic_get,
 	.attr		= cpufreq_generic_attr,
 };

 static const struct of_device_id node_matches[] __initdata = {
 	{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
 	{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
 	{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
 	{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
 	{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
 	{ .compatible = "fsl,qoriq-clockgen-2.0", },
 	{}
 };

 static int __init ppc_corenet_cpufreq_init(void)
 {
 	int ret;
 	struct device_node  *np;
 	const struct of_device_id *match;
 	const struct soc_data *data;
 	unsigned int cpu;

 	np = of_find_matching_node(NULL, node_matches);
 	if (!np)
 		return -ENODEV;

 	for_each_possible_cpu(cpu) {
 		if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
 			goto err_mask;
 		cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
 	}

 	match = of_match_node(node_matches, np);
 	data = match->data;
 	if (data) {
 		if (data->flag)
 			fmask = data->freq_mask;
 		min_cpufreq = fsl_get_sys_freq();
 	} else {
 		min_cpufreq = fsl_get_sys_freq() / 2;
 	}

 	of_node_put(np);

 	ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
 	if (!ret)
 		pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");

 	return ret;

 err_mask:
 	for_each_possible_cpu(cpu)
 		free_cpumask_var(per_cpu(cpu_mask, cpu));

 	return -ENOMEM;
 }
 module_init(ppc_corenet_cpufreq_init);

 static void __exit ppc_corenet_cpufreq_exit(void)
 {
 	unsigned int cpu;

 	for_each_possible_cpu(cpu)
 		free_cpumask_var(per_cpu(cpu_mask, cpu));

 	cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
 }
 module_exit(ppc_corenet_cpufreq_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
 MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");
	/*
	* Copyright 2013 Freescale Semiconductor, Inc.
	*
	* CPU Frequency Scaling driver for Freescale PowerPC corenet SoCs.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/clk.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 <sysdev/fsl_soc.h>

	/**
	* struct cpu_data - per CPU data struct
	* @parent: the parent node of cpu clock
	* @table: frequency table
	*/
	struct cpu_data {
	struct device_node *parent;
	struct cpufreq_frequency_table *table;
	};

	/**
	* struct soc_data - SoC specific data
	* @freq_mask: mask the disallowed frequencies
	* @flag: unique flags
	*/
	struct soc_data {
	u32 freq_mask[4];
	u32 flag;
	};

	#define FREQ_MASK 1
	/* see hardware specification for the allowed frqeuencies */
	static const struct soc_data sdata[] = {
	{ /* used by p2041 and p3041 */
	.freq_mask = {0x8, 0x8, 0x2, 0x2},
	.flag = FREQ_MASK,
	},
	{ /* used by p5020 */
	.freq_mask = {0x8, 0x2},
	.flag = FREQ_MASK,
	},
	{ /* used by p4080, p5040 */
	.freq_mask = {0},
	.flag = 0,
	},
	};

	/*
	* the minimum allowed core frequency, in Hz
	* for chassis v1.0, >= platform frequency
	* for chassis v2.0, >= platform frequency / 2
	*/
	static u32 min_cpufreq;
	static const u32 *fmask;

	static DEFINE_PER_CPU(struct cpu_data *, cpu_data);

	/* cpumask in a cluster */
	static DEFINE_PER_CPU(cpumask_var_t, cpu_mask);

	#ifndef CONFIG_SMP
	static inline const struct cpumask *cpu_core_mask(int cpu)
	{
	return cpumask_of(0);
	}
	#endif

	/* 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 corenet_cpufreq_cpu_init(struct cpufreq_policy *policy)
	{
	struct device_node *np;
	int i, count, ret;
	u32 freq, mask;
	struct clk *clk;
	struct cpufreq_frequency_table *table;
	struct cpu_data *data;
	unsigned int cpu = policy->cpu;

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

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
	pr_err("%s: no memory\n", __func__);
	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;
	}

	data->parent = of_parse_phandle(np, "clocks", 0);
	if (!data->parent) {
	pr_err("%s: could not get clock information\n", __func__);
	goto err_nomem2;
	}

	count = of_property_count_strings(data->parent, "clock-names");
	table = kcalloc(count + 1, sizeof(*table), GFP_KERNEL);
	if (!table) {
	pr_err("%s: no memory\n", __func__);
	goto err_node;
	}

	if (fmask)
	mask = fmask[get_hard_smp_processor_id(cpu)];
	else
	mask = 0x0;

	for (i = 0; i < count; i++) {
	clk = of_clk_get(data->parent, i);
	freq = clk_get_rate(clk);
	/*
	* the clock is valid if its frequency is not masked
	* and large than minimum allowed frequency.
	*/
	if (freq < min_cpufreq \|\| (mask & (1 << i)))
	table[i].frequency = CPUFREQ_ENTRY_INVALID;
	else
	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;

	/* set the min and max frequency properly */
	ret = cpufreq_table_validate_and_show(policy, table);
	if (ret) {
	pr_err("invalid frequency table: %d\n", ret);
	goto err_nomem1;
	}

	data->table = table;
	per_cpu(cpu_data, cpu) = data;

	/* update ->cpus if we have cluster, no harm if not */
	cpumask_copy(policy->cpus, per_cpu(cpu_mask, cpu));
	for_each_cpu(i, per_cpu(cpu_mask, cpu))
	per_cpu(cpu_data, i) = data;

	policy->cpuinfo.transition_latency =
	(12 * NSEC_PER_SEC) / fsl_get_sys_freq();
	of_node_put(np);

	return 0;

	err_nomem1:
	kfree(table);
	err_node:
	of_node_put(data->parent);
	err_nomem2:
	per_cpu(cpu_data, cpu) = NULL;
	kfree(data);
	err_np:
	of_node_put(np);

	return -ENODEV;
	}

	static int __exit corenet_cpufreq_cpu_exit(struct cpufreq_policy *policy)
	{
	struct cpu_data *data = per_cpu(cpu_data, policy->cpu);
	unsigned int cpu;

	of_node_put(data->parent);
	kfree(data->table);
	kfree(data);

	for_each_cpu(cpu, per_cpu(cpu_mask, policy->cpu))
	per_cpu(cpu_data, cpu) = NULL;

	return 0;
	}

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

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

	static struct cpufreq_driver ppc_corenet_cpufreq_driver = {
	.name = "ppc_cpufreq",
	.flags = CPUFREQ_CONST_LOOPS,
	.init = corenet_cpufreq_cpu_init,
	.exit = __exit_p(corenet_cpufreq_cpu_exit),
	.verify = cpufreq_generic_frequency_table_verify,
	.target_index = corenet_cpufreq_target,
	.get = cpufreq_generic_get,
	.attr = cpufreq_generic_attr,
	};

	static const struct of_device_id node_matches[] __initdata = {
	{ .compatible = "fsl,p2041-clockgen", .data = &sdata[0], },
	{ .compatible = "fsl,p3041-clockgen", .data = &sdata[0], },
	{ .compatible = "fsl,p5020-clockgen", .data = &sdata[1], },
	{ .compatible = "fsl,p4080-clockgen", .data = &sdata[2], },
	{ .compatible = "fsl,p5040-clockgen", .data = &sdata[2], },
	{ .compatible = "fsl,qoriq-clockgen-2.0", },
	{}
	};

	static int __init ppc_corenet_cpufreq_init(void)
	{
	int ret;
	struct device_node *np;
	const struct of_device_id *match;
	const struct soc_data *data;
	unsigned int cpu;

	np = of_find_matching_node(NULL, node_matches);
	if (!np)
	return -ENODEV;

	for_each_possible_cpu(cpu) {
	if (!alloc_cpumask_var(&per_cpu(cpu_mask, cpu), GFP_KERNEL))
	goto err_mask;
	cpumask_copy(per_cpu(cpu_mask, cpu), cpu_core_mask(cpu));
	}

	match = of_match_node(node_matches, np);
	data = match->data;
	if (data) {
	if (data->flag)
	fmask = data->freq_mask;
	min_cpufreq = fsl_get_sys_freq();
	} else {
	min_cpufreq = fsl_get_sys_freq() / 2;
	}

	of_node_put(np);

	ret = cpufreq_register_driver(&ppc_corenet_cpufreq_driver);
	if (!ret)
	pr_info("Freescale PowerPC corenet CPU frequency scaling driver\n");

	return ret;

	err_mask:
	for_each_possible_cpu(cpu)
	free_cpumask_var(per_cpu(cpu_mask, cpu));

	return -ENOMEM;
	}
	module_init(ppc_corenet_cpufreq_init);

	static void __exit ppc_corenet_cpufreq_exit(void)
	{
	unsigned int cpu;

	for_each_possible_cpu(cpu)
	free_cpumask_var(per_cpu(cpu_mask, cpu));

	cpufreq_unregister_driver(&ppc_corenet_cpufreq_driver);
	}
	module_exit(ppc_corenet_cpufreq_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Tang Yuantian <Yuantian.Tang@freescale.com>");
	MODULE_DESCRIPTION("cpufreq driver for Freescale e500mc series SoCs");