[linux-2.6-block.git] / drivers / cpufreq / arm_big_little.c

/*
 * ARM big.LITTLE Platforms CPUFreq support
 *
 * Copyright (C) 2013 ARM Ltd.
 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
 *
 * Copyright (C) 2013 Linaro.
 * Viresh Kumar <viresh.kumar@linaro.org>
 *
 * 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.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/topology.h>
#include <linux/types.h>
#include <asm/bL_switcher.h>

#include "arm_big_little.h"

/* Currently we support only two clusters */
#define A15_CLUSTER	0
#define A7_CLUSTER	1
#define MAX_CLUSTERS	2

#ifdef CONFIG_BL_SWITCHER
static bool bL_switching_enabled;
#define is_bL_switching_enabled()	bL_switching_enabled
#define set_switching_enabled(x)	(bL_switching_enabled = (x))
#else
#define is_bL_switching_enabled()	false
#define set_switching_enabled(x)	do { } while (0)
#endif

#define ACTUAL_FREQ(cluster, freq)  ((cluster == A7_CLUSTER) ? freq << 1 : freq)
#define VIRT_FREQ(cluster, freq)    ((cluster == A7_CLUSTER) ? freq >> 1 : freq)

static struct cpufreq_arm_bL_ops *arm_bL_ops;
static struct clk *clk[MAX_CLUSTERS];
static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
static atomic_t cluster_usage[MAX_CLUSTERS + 1];

static unsigned int clk_big_min;	/* (Big) clock frequencies */
static unsigned int clk_little_max;	/* Maximum clock frequency (Little) */

static DEFINE_PER_CPU(unsigned int, physical_cluster);
static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);

static struct mutex cluster_lock[MAX_CLUSTERS];

static inline int raw_cpu_to_cluster(int cpu)
{
	return topology_physical_package_id(cpu);
}

static inline int cpu_to_cluster(int cpu)
{
	return is_bL_switching_enabled() ?
		MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
}

static unsigned int find_cluster_maxfreq(int cluster)
{
	int j;
	u32 max_freq = 0, cpu_freq;

	for_each_online_cpu(j) {
		cpu_freq = per_cpu(cpu_last_req_freq, j);

		if ((cluster == per_cpu(physical_cluster, j)) &&
				(max_freq < cpu_freq))
			max_freq = cpu_freq;
	}

	pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
			max_freq);

	return max_freq;
}

static unsigned int clk_get_cpu_rate(unsigned int cpu)
{
	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;

	/* For switcher we use virtual A7 clock rates */
	if (is_bL_switching_enabled())
		rate = VIRT_FREQ(cur_cluster, rate);

	pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
			cur_cluster, rate);

	return rate;
}

static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
{
	if (is_bL_switching_enabled()) {
		pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
					cpu));

		return per_cpu(cpu_last_req_freq, cpu);
	} else {
		return clk_get_cpu_rate(cpu);
	}
}

static unsigned int
bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
{
	u32 new_rate, prev_rate;
	int ret;
	bool bLs = is_bL_switching_enabled();

	mutex_lock(&cluster_lock[new_cluster]);

	if (bLs) {
		prev_rate = per_cpu(cpu_last_req_freq, cpu);
		per_cpu(cpu_last_req_freq, cpu) = rate;
		per_cpu(physical_cluster, cpu) = new_cluster;

		new_rate = find_cluster_maxfreq(new_cluster);
		new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	} else {
		new_rate = rate;
	}

	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
			__func__, cpu, old_cluster, new_cluster, new_rate);

	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
	if (WARN_ON(ret)) {
		pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
				new_cluster);
		if (bLs) {
			per_cpu(cpu_last_req_freq, cpu) = prev_rate;
			per_cpu(physical_cluster, cpu) = old_cluster;
		}

		mutex_unlock(&cluster_lock[new_cluster]);

		return ret;
	}

	mutex_unlock(&cluster_lock[new_cluster]);

	/* Recalc freq for old cluster when switching clusters */
	if (old_cluster != new_cluster) {
		pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
				__func__, cpu, old_cluster, new_cluster);

		/* Switch cluster */
		bL_switch_request(cpu, new_cluster);

		mutex_lock(&cluster_lock[old_cluster]);

		/* Set freq of old cluster if there are cpus left on it */
		new_rate = find_cluster_maxfreq(old_cluster);
		new_rate = ACTUAL_FREQ(old_cluster, new_rate);

		if (new_rate) {
			pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
					__func__, old_cluster, new_rate);

			if (clk_set_rate(clk[old_cluster], new_rate * 1000))
				pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
						__func__, ret, old_cluster);
		}
		mutex_unlock(&cluster_lock[old_cluster]);
	}

	return 0;
}

/* Set clock frequency */
static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
		unsigned int index)
{
	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
	unsigned int freqs_new;

	cur_cluster = cpu_to_cluster(cpu);
	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);

	freqs_new = freq_table[cur_cluster][index].frequency;

	if (is_bL_switching_enabled()) {
		if ((actual_cluster == A15_CLUSTER) &&
				(freqs_new < clk_big_min)) {
			new_cluster = A7_CLUSTER;
		} else if ((actual_cluster == A7_CLUSTER) &&
				(freqs_new > clk_little_max)) {
			new_cluster = A15_CLUSTER;
		}
	}

	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
}

static inline u32 get_table_count(struct cpufreq_frequency_table *table)
{
	int count;

	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
		;

	return count;
}

/* get the minimum frequency in the cpufreq_frequency_table */
static inline u32 get_table_min(struct cpufreq_frequency_table *table)
{
	struct cpufreq_frequency_table *pos;
	uint32_t min_freq = ~0;
	cpufreq_for_each_entry(pos, table)
		if (pos->frequency < min_freq)
			min_freq = pos->frequency;
	return min_freq;
}

/* get the maximum frequency in the cpufreq_frequency_table */
static inline u32 get_table_max(struct cpufreq_frequency_table *table)
{
	struct cpufreq_frequency_table *pos;
	uint32_t max_freq = 0;
	cpufreq_for_each_entry(pos, table)
		if (pos->frequency > max_freq)
			max_freq = pos->frequency;
	return max_freq;
}

static int merge_cluster_tables(void)
{
	int i, j, k = 0, count = 1;
	struct cpufreq_frequency_table *table;

	for (i = 0; i < MAX_CLUSTERS; i++)
		count += get_table_count(freq_table[i]);

	table = kzalloc(sizeof(*table) * count, GFP_KERNEL);
	if (!table)
		return -ENOMEM;

	freq_table[MAX_CLUSTERS] = table;

	/* Add in reverse order to get freqs in increasing order */
	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
		for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
				j++) {
			table[k].frequency = VIRT_FREQ(i,
					freq_table[i][j].frequency);
			pr_debug("%s: index: %d, freq: %d\n", __func__, k,
					table[k].frequency);
			k++;
		}
	}

	table[k].driver_data = k;
	table[k].frequency = CPUFREQ_TABLE_END;

	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);

	return 0;
}

static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);

	if (!freq_table[cluster])
		return;

	clk_put(clk[cluster]);
	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	if (arm_bL_ops->free_opp_table)
		arm_bL_ops->free_opp_table(cpu_dev);
	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
}

static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = cpu_to_cluster(cpu_dev->id);
	int i;

	if (atomic_dec_return(&cluster_usage[cluster]))
		return;

	if (cluster < MAX_CLUSTERS)
		return _put_cluster_clk_and_freq_table(cpu_dev);

	for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
			pr_err("%s: failed to get cpu%d device\n", __func__, i);
			return;
		}

		_put_cluster_clk_and_freq_table(cdev);
	}

	/* free virtual table */
	kfree(freq_table[cluster]);
}

static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	char name[14] = "cpu-cluster.";
	int ret;

	if (freq_table[cluster])
		return 0;

	ret = arm_bL_ops->init_opp_table(cpu_dev);
	if (ret) {
		dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
				__func__, cpu_dev->id, ret);
		goto out;
	}

	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
	if (ret) {
		dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
				__func__, cpu_dev->id, ret);
		goto free_opp_table;
	}

	name[12] = cluster + '0';
	clk[cluster] = clk_get(cpu_dev, name);
	if (!IS_ERR(clk[cluster])) {
		dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
				__func__, clk[cluster], freq_table[cluster],
				cluster);
		return 0;
	}

	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
			__func__, cpu_dev->id, cluster);
	ret = PTR_ERR(clk[cluster]);
	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);

free_opp_table:
	if (arm_bL_ops->free_opp_table)
		arm_bL_ops->free_opp_table(cpu_dev);
out:
	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
			cluster);
	return ret;
}

static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = cpu_to_cluster(cpu_dev->id);
	int i, ret;

	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
		return 0;

	if (cluster < MAX_CLUSTERS) {
		ret = _get_cluster_clk_and_freq_table(cpu_dev);
		if (ret)
			atomic_dec(&cluster_usage[cluster]);
		return ret;
	}

	/*
	 * Get data for all clusters and fill virtual cluster with a merge of
	 * both
	 */
	for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
			pr_err("%s: failed to get cpu%d device\n", __func__, i);
			return -ENODEV;
		}

		ret = _get_cluster_clk_and_freq_table(cdev);
		if (ret)
			goto put_clusters;
	}

	ret = merge_cluster_tables();
	if (ret)
		goto put_clusters;

	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	clk_big_min = get_table_min(freq_table[0]);
	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));

	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
			__func__, cluster, clk_big_min, clk_little_max);

	return 0;

put_clusters:
	for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);
		if (!cdev) {
			pr_err("%s: failed to get cpu%d device\n", __func__, i);
			return -ENODEV;
		}

		_put_cluster_clk_and_freq_table(cdev);
	}

	atomic_dec(&cluster_usage[cluster]);

	return ret;
}

/* Per-CPU initialization */
static int bL_cpufreq_init(struct cpufreq_policy *policy)
{
	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	struct device *cpu_dev;
	int ret;

	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;
	}

	ret = get_cluster_clk_and_freq_table(cpu_dev);
	if (ret)
		return ret;

	ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
	if (ret) {
		dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
				policy->cpu, cur_cluster);
		put_cluster_clk_and_freq_table(cpu_dev);
		return ret;
	}

	if (cur_cluster < MAX_CLUSTERS) {
		int cpu;

		cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));

		for_each_cpu(cpu, policy->cpus)
			per_cpu(physical_cluster, cpu) = cur_cluster;
	} else {
		/* Assumption: during init, we are always running on A15 */
		per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	}

	if (arm_bL_ops->get_transition_latency)
		policy->cpuinfo.transition_latency =
			arm_bL_ops->get_transition_latency(cpu_dev);
	else
		policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;

	if (is_bL_switching_enabled())
		per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);

	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
	return 0;
}

static int bL_cpufreq_exit(struct cpufreq_policy *policy)
{
	struct device *cpu_dev;

	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;
	}

	put_cluster_clk_and_freq_table(cpu_dev);
	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);

	return 0;
}

static struct cpufreq_driver bL_cpufreq_driver = {
	.name			= "arm-big-little",
	.flags			= CPUFREQ_STICKY |
					CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
					CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	.verify			= cpufreq_generic_frequency_table_verify,
	.target_index		= bL_cpufreq_set_target,
	.get			= bL_cpufreq_get_rate,
	.init			= bL_cpufreq_init,
	.exit			= bL_cpufreq_exit,
	.attr			= cpufreq_generic_attr,
};

static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
					unsigned long action, void *_arg)
{
	pr_debug("%s: action: %ld\n", __func__, action);

	switch (action) {
	case BL_NOTIFY_PRE_ENABLE:
	case BL_NOTIFY_PRE_DISABLE:
		cpufreq_unregister_driver(&bL_cpufreq_driver);
		break;

	case BL_NOTIFY_POST_ENABLE:
		set_switching_enabled(true);
		cpufreq_register_driver(&bL_cpufreq_driver);
		break;

	case BL_NOTIFY_POST_DISABLE:
		set_switching_enabled(false);
		cpufreq_register_driver(&bL_cpufreq_driver);
		break;

	default:
		return NOTIFY_DONE;
	}

	return NOTIFY_OK;
}

static struct notifier_block bL_switcher_notifier = {
	.notifier_call = bL_cpufreq_switcher_notifier,
};

int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
{
	int ret, i;

	if (arm_bL_ops) {
		pr_debug("%s: Already registered: %s, exiting\n", __func__,
				arm_bL_ops->name);
		return -EBUSY;
	}

	if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
		pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
		return -ENODEV;
	}

	arm_bL_ops = ops;

	ret = bL_switcher_get_enabled();
	set_switching_enabled(ret);

	for (i = 0; i < MAX_CLUSTERS; i++)
		mutex_init(&cluster_lock[i]);

	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	if (ret) {
		pr_info("%s: Failed registering platform driver: %s, err: %d\n",
				__func__, ops->name, ret);
		arm_bL_ops = NULL;
	} else {
		ret = bL_switcher_register_notifier(&bL_switcher_notifier);
		if (ret) {
			cpufreq_unregister_driver(&bL_cpufreq_driver);
			arm_bL_ops = NULL;
		} else {
			pr_info("%s: Registered platform driver: %s\n",
					__func__, ops->name);
		}
	}

	bL_switcher_put_enabled();
	return ret;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_register);

void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
{
	if (arm_bL_ops != ops) {
		pr_err("%s: Registered with: %s, can't unregister, exiting\n",
				__func__, arm_bL_ops->name);
		return;
	}

	bL_switcher_get_enabled();
	bL_switcher_unregister_notifier(&bL_switcher_notifier);
	cpufreq_unregister_driver(&bL_cpufreq_driver);
	bL_switcher_put_enabled();
	pr_info("%s: Un-registered platform driver: %s\n", __func__,
			arm_bL_ops->name);
	arm_bL_ops = NULL;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);

MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
8a67f0ef VK	1	/*
	2	* ARM big.LITTLE Platforms CPUFreq support
	3	*
	4	* Copyright (C) 2013 ARM Ltd.
	5	* Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
	6	*
	7	* Copyright (C) 2013 Linaro.
	8	* Viresh Kumar <viresh.kumar@linaro.org>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	15	* kind, whether express or implied; without even the implied warranty
	16	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*/
	19
	20	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	21
	22	#include <linux/clk.h>
	23	#include <linux/cpu.h>
	24	#include <linux/cpufreq.h>
	25	#include <linux/cpumask.h>
	26	#include <linux/export.h>
39c8bbaf	27	#include <linux/module.h>
e79a23c5	28	#include <linux/mutex.h>
8a67f0ef	29	#include <linux/of_platform.h>
e4db1c74	30	#include <linux/pm_opp.h>
8a67f0ef VK	31	#include <linux/slab.h>
	32	#include <linux/topology.h>
	33	#include <linux/types.h>
e79a23c5	34	#include <asm/bL_switcher.h>
8a67f0ef VK	35
	36	#include "arm_big_little.h"
	37
	38	/* Currently we support only two clusters */
e79a23c5 VK	39	#define A15_CLUSTER 0
e79a23c5 VK	40	#define A7_CLUSTER 1
8a67f0ef VK	41	#define MAX_CLUSTERS 2
8a67f0ef VK	42
e79a23c5	43	#ifdef CONFIG_BL_SWITCHER
45cac118 NP	44	static bool bL_switching_enabled;
	45	#define is_bL_switching_enabled() bL_switching_enabled
	46	#define set_switching_enabled(x) (bL_switching_enabled = (x))
e79a23c5 VK	47	#else
e79a23c5 VK	48	#define is_bL_switching_enabled() false
45cac118	49	#define set_switching_enabled(x) do { } while (0)
e79a23c5 VK	50	#endif
	51
	52	#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
	53	#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
	54
8a67f0ef VK	55	static struct cpufreq_arm_bL_ops *arm_bL_ops;
8a67f0ef VK	56	static struct clk *clk[MAX_CLUSTERS];
e79a23c5 VK	57	static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
	58	static atomic_t cluster_usage[MAX_CLUSTERS + 1];
	59
	60	static unsigned int clk_big_min; /* (Big) clock frequencies */
	61	static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
	62
	63	static DEFINE_PER_CPU(unsigned int, physical_cluster);
	64	static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
	65
	66	static struct mutex cluster_lock[MAX_CLUSTERS];
	67
	68	static inline int raw_cpu_to_cluster(int cpu)
	69	{
	70	return topology_physical_package_id(cpu);
	71	}
	72
	73	static inline int cpu_to_cluster(int cpu)
	74	{
	75	return is_bL_switching_enabled() ?
	76	MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
	77	}
	78
	79	static unsigned int find_cluster_maxfreq(int cluster)
	80	{
	81	int j;
	82	u32 max_freq = 0, cpu_freq;
	83
	84	for_each_online_cpu(j) {
	85	cpu_freq = per_cpu(cpu_last_req_freq, j);
	86
	87	if ((cluster == per_cpu(physical_cluster, j)) &&
	88	(max_freq < cpu_freq))
	89	max_freq = cpu_freq;
	90	}
	91
	92	pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
	93	max_freq);
	94
	95	return max_freq;
	96	}
	97
	98	static unsigned int clk_get_cpu_rate(unsigned int cpu)
	99	{
	100	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	101	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
	102
	103	/* For switcher we use virtual A7 clock rates */
	104	if (is_bL_switching_enabled())
	105	rate = VIRT_FREQ(cur_cluster, rate);
	106
	107	pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
	108	cur_cluster, rate);
	109
	110	return rate;
	111	}
	112
	113	static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
	114	{
	115	if (is_bL_switching_enabled()) {
	116	pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
	117	cpu));
	118
	119	return per_cpu(cpu_last_req_freq, cpu);
	120	} else {
121	return clk_get_cpu_rate(cpu);
122	}
123	}
8a67f0ef	124
e79a23c5 VK	125	static unsigned int
e79a23c5 VK	126	bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
8a67f0ef	127	{
e79a23c5 VK	128	u32 new_rate, prev_rate;
	129	int ret;
	130	bool bLs = is_bL_switching_enabled();
	131
	132	mutex_lock(&cluster_lock[new_cluster]);
	133
	134	if (bLs) {
	135	prev_rate = per_cpu(cpu_last_req_freq, cpu);
	136	per_cpu(cpu_last_req_freq, cpu) = rate;
	137	per_cpu(physical_cluster, cpu) = new_cluster;
	138
	139	new_rate = find_cluster_maxfreq(new_cluster);
	140	new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	141	} else {
	142	new_rate = rate;
	143	}
	144
	145	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
	146	__func__, cpu, old_cluster, new_cluster, new_rate);
	147
	148	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
	149	if (WARN_ON(ret)) {
	150	pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
	151	new_cluster);
	152	if (bLs) {
	153	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	154	per_cpu(physical_cluster, cpu) = old_cluster;
	155	}
	156
	157	mutex_unlock(&cluster_lock[new_cluster]);
	158
	159	return ret;
	160	}
	161
	162	mutex_unlock(&cluster_lock[new_cluster]);
	163
	164	/* Recalc freq for old cluster when switching clusters */
	165	if (old_cluster != new_cluster) {
	166	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
	167	__func__, cpu, old_cluster, new_cluster);
	168
	169	/* Switch cluster */
	170	bL_switch_request(cpu, new_cluster);
	171
	172	mutex_lock(&cluster_lock[old_cluster]);
8a67f0ef	173
e79a23c5 VK	174	/* Set freq of old cluster if there are cpus left on it */
	175	new_rate = find_cluster_maxfreq(old_cluster);
	176	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	177
	178	if (new_rate) {
	179	pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
	180	__func__, old_cluster, new_rate);
	181
	182	if (clk_set_rate(clk[old_cluster], new_rate * 1000))
	183	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
	184	__func__, ret, old_cluster);
	185	}
	186	mutex_unlock(&cluster_lock[old_cluster]);
	187	}
	188
	189	return 0;
8a67f0ef VK	190	}
8a67f0ef VK	191
8a67f0ef VK	192	/* Set clock frequency */
8a67f0ef VK	193	static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
9c0ebcf7	194	unsigned int index)
8a67f0ef	195	{
e79a23c5	196	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
d4019f0a	197	unsigned int freqs_new;
8a67f0ef	198
e79a23c5 VK	199	cur_cluster = cpu_to_cluster(cpu);
e79a23c5 VK	200	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
8a67f0ef	201
d4019f0a	202	freqs_new = freq_table[cur_cluster][index].frequency;
8a67f0ef	203
e79a23c5 VK	204	if (is_bL_switching_enabled()) {
e79a23c5 VK	205	if ((actual_cluster == A15_CLUSTER) &&
d4019f0a	206	(freqs_new < clk_big_min)) {
e79a23c5 VK	207	new_cluster = A7_CLUSTER;
e79a23c5 VK	208	} else if ((actual_cluster == A7_CLUSTER) &&
d4019f0a	209	(freqs_new > clk_little_max)) {
e79a23c5 VK	210	new_cluster = A15_CLUSTER;
	211	}
	212	}
	213
d4019f0a	214	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
8a67f0ef VK	215	}
8a67f0ef VK	216
e79a23c5 VK	217	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	218	{
	219	int count;
	220
	221	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	222	;
	223
	224	return count;
	225	}
	226
	227	/* get the minimum frequency in the cpufreq_frequency_table */
	228	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	229	{
041526f9	230	struct cpufreq_frequency_table *pos;
e79a23c5	231	uint32_t min_freq = ~0;
041526f9 SK	232	cpufreq_for_each_entry(pos, table)
	233	if (pos->frequency < min_freq)
	234	min_freq = pos->frequency;
e79a23c5 VK	235	return min_freq;
	236	}
	237
	238	/* get the maximum frequency in the cpufreq_frequency_table */
	239	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	240	{
041526f9	241	struct cpufreq_frequency_table *pos;
e79a23c5	242	uint32_t max_freq = 0;
041526f9 SK	243	cpufreq_for_each_entry(pos, table)
	244	if (pos->frequency > max_freq)
	245	max_freq = pos->frequency;
e79a23c5 VK	246	return max_freq;
	247	}
	248
	249	static int merge_cluster_tables(void)
	250	{
	251	int i, j, k = 0, count = 1;
	252	struct cpufreq_frequency_table *table;
	253
	254	for (i = 0; i < MAX_CLUSTERS; i++)
	255	count += get_table_count(freq_table[i]);
	256
	257	table = kzalloc(sizeof(table) count, GFP_KERNEL);
	258	if (!table)
	259	return -ENOMEM;
	260
	261	freq_table[MAX_CLUSTERS] = table;
	262
	263	/* Add in reverse order to get freqs in increasing order */
	264	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	265	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	266	j++) {
	267	table[k].frequency = VIRT_FREQ(i,
	268	freq_table[i][j].frequency);
	269	pr_debug("%s: index: %d, freq: %d\n", __func__, k,
	270	table[k].frequency);
	271	k++;
	272	}
	273	}
	274
	275	table[k].driver_data = k;
	276	table[k].frequency = CPUFREQ_TABLE_END;
	277
	278	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
	279
	280	return 0;
	281	}
	282
	283	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
	284	{
	285	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	286
	287	if (!freq_table[cluster])
	288	return;
	289
	290	clk_put(clk[cluster]);
	291	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
493b4cd2 VK	292	if (arm_bL_ops->free_opp_table)
493b4cd2 VK	293	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5 VK	294	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	295	}
	296
8a67f0ef VK	297	static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
	298	{
	299	u32 cluster = cpu_to_cluster(cpu_dev->id);
e79a23c5 VK	300	int i;
	301
	302	if (atomic_dec_return(&cluster_usage[cluster]))
	303	return;
	304
	305	if (cluster < MAX_CLUSTERS)
	306	return _put_cluster_clk_and_freq_table(cpu_dev);
8a67f0ef	307
e79a23c5 VK	308	for_each_present_cpu(i) {
	309	struct device *cdev = get_cpu_device(i);
	310	if (!cdev) {
	311	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	312	return;
	313	}
	314
	315	_put_cluster_clk_and_freq_table(cdev);
8a67f0ef	316	}
e79a23c5 VK	317
	318	/* free virtual table */
	319	kfree(freq_table[cluster]);
8a67f0ef VK	320	}
8a67f0ef VK	321
e79a23c5	322	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
8a67f0ef	323	{
e79a23c5	324	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
8a67f0ef VK	325	char name[14] = "cpu-cluster.";
	326	int ret;
	327
e79a23c5	328	if (freq_table[cluster])
8a67f0ef VK	329	return 0;
	330
	331	ret = arm_bL_ops->init_opp_table(cpu_dev);
	332	if (ret) {
	333	dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
	334	__func__, cpu_dev->id, ret);
e79a23c5	335	goto out;
8a67f0ef VK	336	}
8a67f0ef VK	337
5d4879cd	338	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef VK	339	if (ret) {
	340	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	341	__func__, cpu_dev->id, ret);
493b4cd2	342	goto free_opp_table;
8a67f0ef VK	343	}
	344
	345	name[12] = cluster + '0';
076dec90	346	clk[cluster] = clk_get(cpu_dev, name);
8a67f0ef VK	347	if (!IS_ERR(clk[cluster])) {
	348	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	349	__func__, clk[cluster], freq_table[cluster],
	350	cluster);
	351	return 0;
	352	}
	353
	354	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	355	__func__, cpu_dev->id, cluster);
	356	ret = PTR_ERR(clk[cluster]);
5d4879cd	357	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef	358
493b4cd2 VK	359	free_opp_table:
	360	if (arm_bL_ops->free_opp_table)
	361	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5	362	out:
8a67f0ef VK	363	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	364	cluster);
	365	return ret;
	366	}
	367
e79a23c5 VK	368	static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
	369	{
	370	u32 cluster = cpu_to_cluster(cpu_dev->id);
	371	int i, ret;
	372
	373	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	374	return 0;
	375
	376	if (cluster < MAX_CLUSTERS) {
	377	ret = _get_cluster_clk_and_freq_table(cpu_dev);
	378	if (ret)
	379	atomic_dec(&cluster_usage[cluster]);
	380	return ret;
	381	}
	382
	383	/*
	384	* Get data for all clusters and fill virtual cluster with a merge of
	385	* both
	386	*/
	387	for_each_present_cpu(i) {
	388	struct device *cdev = get_cpu_device(i);
	389	if (!cdev) {
	390	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	391	return -ENODEV;
	392	}
	393
	394	ret = _get_cluster_clk_and_freq_table(cdev);
	395	if (ret)
	396	goto put_clusters;
	397	}
	398
	399	ret = merge_cluster_tables();
	400	if (ret)
	401	goto put_clusters;
	402
	403	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	404	clk_big_min = get_table_min(freq_table[0]);
	405	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	406
	407	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
	408	__func__, cluster, clk_big_min, clk_little_max);
	409
	410	return 0;
	411
	412	put_clusters:
	413	for_each_present_cpu(i) {
	414	struct device *cdev = get_cpu_device(i);
	415	if (!cdev) {
	416	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	417	return -ENODEV;
	418	}
	419
	420	_put_cluster_clk_and_freq_table(cdev);
	421	}
	422
	423	atomic_dec(&cluster_usage[cluster]);
	424
	425	return ret;
	426	}
	427
8a67f0ef VK	428	/* Per-CPU initialization */
	429	static int bL_cpufreq_init(struct cpufreq_policy *policy)
	430	{
	431	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	432	struct device *cpu_dev;
	433	int ret;
	434
	435	cpu_dev = get_cpu_device(policy->cpu);
	436	if (!cpu_dev) {
	437	pr_err("%s: failed to get cpu%d device\n", __func__,
	438	policy->cpu);
	439	return -ENODEV;
	440	}
	441
	442	ret = get_cluster_clk_and_freq_table(cpu_dev);
	443	if (ret)
	444	return ret;
	445
39b10ebe	446	ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
8a67f0ef VK	447	if (ret) {
	448	dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
	449	policy->cpu, cur_cluster);
	450	put_cluster_clk_and_freq_table(cpu_dev);
	451	return ret;
	452	}
	453
e79a23c5	454	if (cur_cluster < MAX_CLUSTERS) {
8f3ba3d3	455	int cpu;
8f3ba3d3	456
e79a23c5 VK	457	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
e79a23c5 VK	458
8f3ba3d3	459	for_each_cpu(cpu, policy->cpus)
8f3ba3d3	460	per_cpu(physical_cluster, cpu) = cur_cluster;
e79a23c5 VK	461	} else {
	462	/* Assumption: during init, we are always running on A15 */
	463	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	464	}
	465
8a67f0ef VK	466	if (arm_bL_ops->get_transition_latency)
	467	policy->cpuinfo.transition_latency =
	468	arm_bL_ops->get_transition_latency(cpu_dev);
	469	else
	470	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	471
e79a23c5 VK	472	if (is_bL_switching_enabled())
e79a23c5 VK	473	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
8a67f0ef	474
2b80f313	475	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
8a67f0ef VK	476	return 0;
	477	}
	478
	479	static int bL_cpufreq_exit(struct cpufreq_policy *policy)
	480	{
	481	struct device *cpu_dev;
	482
	483	cpu_dev = get_cpu_device(policy->cpu);
	484	if (!cpu_dev) {
	485	pr_err("%s: failed to get cpu%d device\n", __func__,
	486	policy->cpu);
	487	return -ENODEV;
	488	}
	489
	490	put_cluster_clk_and_freq_table(cpu_dev);
	491	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	492
	493	return 0;
	494	}
	495
8a67f0ef VK	496	static struct cpufreq_driver bL_cpufreq_driver = {
8a67f0ef VK	497	.name = "arm-big-little",
0b981e70	498	.flags = CPUFREQ_STICKY \|
ae6b4271 VK	499	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
ae6b4271 VK	500	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
3c75a150	501	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	502	.target_index = bL_cpufreq_set_target,
e79a23c5	503	.get = bL_cpufreq_get_rate,
8a67f0ef VK	504	.init = bL_cpufreq_init,
8a67f0ef VK	505	.exit = bL_cpufreq_exit,
3c75a150	506	.attr = cpufreq_generic_attr,
8a67f0ef VK	507	};
8a67f0ef VK	508
45cac118 NP	509	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	510	unsigned long action, void *_arg)
	511	{
	512	pr_debug("%s: action: %ld\n", __func__, action);
	513
	514	switch (action) {
	515	case BL_NOTIFY_PRE_ENABLE:
	516	case BL_NOTIFY_PRE_DISABLE:
	517	cpufreq_unregister_driver(&bL_cpufreq_driver);
	518	break;
	519
	520	case BL_NOTIFY_POST_ENABLE:
	521	set_switching_enabled(true);
	522	cpufreq_register_driver(&bL_cpufreq_driver);
	523	break;
	524
	525	case BL_NOTIFY_POST_DISABLE:
	526	set_switching_enabled(false);
	527	cpufreq_register_driver(&bL_cpufreq_driver);
	528	break;
	529
	530	default:
	531	return NOTIFY_DONE;
	532	}
	533
	534	return NOTIFY_OK;
	535	}
	536
	537	static struct notifier_block bL_switcher_notifier = {
	538	.notifier_call = bL_cpufreq_switcher_notifier,
	539	};
	540
8a67f0ef VK	541	int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
8a67f0ef VK	542	{
e79a23c5	543	int ret, i;
8a67f0ef VK	544
	545	if (arm_bL_ops) {
	546	pr_debug("%s: Already registered: %s, exiting\n", __func__,
	547	arm_bL_ops->name);
	548	return -EBUSY;
	549	}
	550
	551	if (!ops \|\| !strlen(ops->name) \|\| !ops->init_opp_table) {
	552	pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
	553	return -ENODEV;
	554	}
	555
	556	arm_bL_ops = ops;
	557
45cac118 NP	558	ret = bL_switcher_get_enabled();
	559	set_switching_enabled(ret);
	560
e79a23c5 VK	561	for (i = 0; i < MAX_CLUSTERS; i++)
	562	mutex_init(&cluster_lock[i]);
	563
8a67f0ef VK	564	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	565	if (ret) {
	566	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
	567	__func__, ops->name, ret);
	568	arm_bL_ops = NULL;
	569	} else {
45cac118 NP	570	ret = bL_switcher_register_notifier(&bL_switcher_notifier);
	571	if (ret) {
	572	cpufreq_unregister_driver(&bL_cpufreq_driver);
	573	arm_bL_ops = NULL;
	574	} else {
	575	pr_info("%s: Registered platform driver: %s\n",
	576	__func__, ops->name);
	577	}
8a67f0ef VK	578	}
8a67f0ef VK	579
45cac118	580	bL_switcher_put_enabled();
8a67f0ef VK	581	return ret;
	582	}
	583	EXPORT_SYMBOL_GPL(bL_cpufreq_register);
	584
	585	void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
	586	{
	587	if (arm_bL_ops != ops) {
	588	pr_err("%s: Registered with: %s, can't unregister, exiting\n",
	589	__func__, arm_bL_ops->name);
	590	return;
	591	}
	592
45cac118 NP	593	bL_switcher_get_enabled();
45cac118 NP	594	bL_switcher_unregister_notifier(&bL_switcher_notifier);
8a67f0ef	595	cpufreq_unregister_driver(&bL_cpufreq_driver);
45cac118	596	bL_switcher_put_enabled();
8a67f0ef VK	597	pr_info("%s: Un-registered platform driver: %s\n", __func__,
	598	arm_bL_ops->name);
	599	arm_bL_ops = NULL;
	600	}
	601	EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
39c8bbaf UKK	602
	603	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	604	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
	605	MODULE_LICENSE("GPL v2");