[mirror_ubuntu-zesty-kernel.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 "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
#include <asm/bL_switcher.h>
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)
#define bL_switch_request(...)		do { } while (0)
#define bL_switcher_put_enabled()	do { } while (0)
#define bL_switcher_get_enabled()	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]);
	}

	/*
	 * FIXME: clk_set_rate has to handle the case where clk_change_rate
	 * can fail due to hardware or firmware issues. Until the clk core
	 * layer is fixed, we can check here. In most of the cases we will
	 * be reading only the cached value anyway. This needs to  be removed
	 * once clk core is fixed.
	 */
	if (bL_cpufreq_get_rate(cpu) != new_rate)
		return -EIO;
	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);
	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;
	}

	clk[cluster] = clk_get(cpu_dev, NULL);
	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,
};

#ifdef CONFIG_BL_SWITCHER
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,
};

static int __bLs_register_notifier(void)
{
	return bL_switcher_register_notifier(&bL_switcher_notifier);
}

static int __bLs_unregister_notifier(void)
{
	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
}
#else
static int __bLs_register_notifier(void) { return 0; }
static int __bLs_unregister_notifier(void) { return 0; }
#endif

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;

	set_switching_enabled(bL_switcher_get_enabled());

	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 = __bLs_register_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();
	__bLs_unregister_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>
	34
	35	#include "arm_big_little.h"
	36
	37	/* Currently we support only two clusters */
e79a23c5 VK	38	#define A15_CLUSTER 0
e79a23c5 VK	39	#define A7_CLUSTER 1
8a67f0ef VK	40	#define MAX_CLUSTERS 2
8a67f0ef VK	41
e79a23c5	42	#ifdef CONFIG_BL_SWITCHER
14730145	43	#include <asm/bL_switcher.h>
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)
14730145 SH	50	#define bL_switch_request(...) do { } while (0)
	51	#define bL_switcher_put_enabled() do { } while (0)
	52	#define bL_switcher_get_enabled() do { } while (0)
e79a23c5 VK	53	#endif
	54
	55	#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
	56	#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
	57
8a67f0ef VK	58	static struct cpufreq_arm_bL_ops *arm_bL_ops;
8a67f0ef VK	59	static struct clk *clk[MAX_CLUSTERS];
e79a23c5 VK	60	static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
	61	static atomic_t cluster_usage[MAX_CLUSTERS + 1];
	62
	63	static unsigned int clk_big_min; /* (Big) clock frequencies */
	64	static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
	65
	66	static DEFINE_PER_CPU(unsigned int, physical_cluster);
	67	static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
	68
	69	static struct mutex cluster_lock[MAX_CLUSTERS];
	70
	71	static inline int raw_cpu_to_cluster(int cpu)
	72	{
	73	return topology_physical_package_id(cpu);
	74	}
	75
	76	static inline int cpu_to_cluster(int cpu)
	77	{
	78	return is_bL_switching_enabled() ?
	79	MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
	80	}
	81
	82	static unsigned int find_cluster_maxfreq(int cluster)
	83	{
	84	int j;
	85	u32 max_freq = 0, cpu_freq;
	86
	87	for_each_online_cpu(j) {
	88	cpu_freq = per_cpu(cpu_last_req_freq, j);
	89
	90	if ((cluster == per_cpu(physical_cluster, j)) &&
	91	(max_freq < cpu_freq))
	92	max_freq = cpu_freq;
	93	}
	94
	95	pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
	96	max_freq);
	97
	98	return max_freq;
	99	}
	100
	101	static unsigned int clk_get_cpu_rate(unsigned int cpu)
	102	{
	103	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	104	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
	105
	106	/* For switcher we use virtual A7 clock rates */
	107	if (is_bL_switching_enabled())
	108	rate = VIRT_FREQ(cur_cluster, rate);
	109
	110	pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
	111	cur_cluster, rate);
	112
	113	return rate;
	114	}
	115
	116	static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
	117	{
	118	if (is_bL_switching_enabled()) {
	119	pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
	120	cpu));
	121
	122	return per_cpu(cpu_last_req_freq, cpu);
	123	} else {
124	return clk_get_cpu_rate(cpu);
125	}
126	}
8a67f0ef	127
e79a23c5 VK	128	static unsigned int
e79a23c5 VK	129	bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
8a67f0ef	130	{
e79a23c5 VK	131	u32 new_rate, prev_rate;
	132	int ret;
	133	bool bLs = is_bL_switching_enabled();
	134
	135	mutex_lock(&cluster_lock[new_cluster]);
	136
	137	if (bLs) {
	138	prev_rate = per_cpu(cpu_last_req_freq, cpu);
	139	per_cpu(cpu_last_req_freq, cpu) = rate;
	140	per_cpu(physical_cluster, cpu) = new_cluster;
	141
	142	new_rate = find_cluster_maxfreq(new_cluster);
	143	new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	144	} else {
	145	new_rate = rate;
	146	}
	147
	148	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
	149	__func__, cpu, old_cluster, new_cluster, new_rate);
	150
	151	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
	152	if (WARN_ON(ret)) {
	153	pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
	154	new_cluster);
	155	if (bLs) {
	156	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	157	per_cpu(physical_cluster, cpu) = old_cluster;
	158	}
	159
	160	mutex_unlock(&cluster_lock[new_cluster]);
	161
	162	return ret;
	163	}
	164
	165	mutex_unlock(&cluster_lock[new_cluster]);
	166
	167	/* Recalc freq for old cluster when switching clusters */
	168	if (old_cluster != new_cluster) {
	169	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
	170	__func__, cpu, old_cluster, new_cluster);
	171
	172	/* Switch cluster */
	173	bL_switch_request(cpu, new_cluster);
	174
	175	mutex_lock(&cluster_lock[old_cluster]);
8a67f0ef	176
e79a23c5 VK	177	/* Set freq of old cluster if there are cpus left on it */
	178	new_rate = find_cluster_maxfreq(old_cluster);
	179	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	180
	181	if (new_rate) {
	182	pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
	183	__func__, old_cluster, new_rate);
	184
	185	if (clk_set_rate(clk[old_cluster], new_rate * 1000))
	186	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
	187	__func__, ret, old_cluster);
	188	}
	189	mutex_unlock(&cluster_lock[old_cluster]);
	190	}
	191
0a95e630 SH	192	/*
	193	* FIXME: clk_set_rate has to handle the case where clk_change_rate
	194	* can fail due to hardware or firmware issues. Until the clk core
	195	* layer is fixed, we can check here. In most of the cases we will
	196	* be reading only the cached value anyway. This needs to be removed
	197	* once clk core is fixed.
	198	*/
	199	if (bL_cpufreq_get_rate(cpu) != new_rate)
	200	return -EIO;
e79a23c5	201	return 0;
8a67f0ef VK	202	}
8a67f0ef VK	203
8a67f0ef VK	204	/* Set clock frequency */
8a67f0ef VK	205	static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
9c0ebcf7	206	unsigned int index)
8a67f0ef	207	{
e79a23c5	208	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
d4019f0a	209	unsigned int freqs_new;
8a67f0ef	210
e79a23c5 VK	211	cur_cluster = cpu_to_cluster(cpu);
e79a23c5 VK	212	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
8a67f0ef	213
d4019f0a	214	freqs_new = freq_table[cur_cluster][index].frequency;
8a67f0ef	215
e79a23c5 VK	216	if (is_bL_switching_enabled()) {
e79a23c5 VK	217	if ((actual_cluster == A15_CLUSTER) &&
d4019f0a	218	(freqs_new < clk_big_min)) {
e79a23c5 VK	219	new_cluster = A7_CLUSTER;
e79a23c5 VK	220	} else if ((actual_cluster == A7_CLUSTER) &&
d4019f0a	221	(freqs_new > clk_little_max)) {
e79a23c5 VK	222	new_cluster = A15_CLUSTER;
	223	}
	224	}
	225
d4019f0a	226	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
8a67f0ef VK	227	}
8a67f0ef VK	228
e79a23c5 VK	229	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	230	{
	231	int count;
	232
	233	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	234	;
	235
	236	return count;
	237	}
	238
	239	/* get the minimum frequency in the cpufreq_frequency_table */
	240	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	241	{
041526f9	242	struct cpufreq_frequency_table *pos;
e79a23c5	243	uint32_t min_freq = ~0;
041526f9 SK	244	cpufreq_for_each_entry(pos, table)
	245	if (pos->frequency < min_freq)
	246	min_freq = pos->frequency;
e79a23c5 VK	247	return min_freq;
	248	}
	249
	250	/* get the maximum frequency in the cpufreq_frequency_table */
	251	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	252	{
041526f9	253	struct cpufreq_frequency_table *pos;
e79a23c5	254	uint32_t max_freq = 0;
041526f9 SK	255	cpufreq_for_each_entry(pos, table)
	256	if (pos->frequency > max_freq)
	257	max_freq = pos->frequency;
e79a23c5 VK	258	return max_freq;
	259	}
	260
	261	static int merge_cluster_tables(void)
	262	{
	263	int i, j, k = 0, count = 1;
	264	struct cpufreq_frequency_table *table;
	265
	266	for (i = 0; i < MAX_CLUSTERS; i++)
	267	count += get_table_count(freq_table[i]);
	268
	269	table = kzalloc(sizeof(table) count, GFP_KERNEL);
	270	if (!table)
	271	return -ENOMEM;
	272
	273	freq_table[MAX_CLUSTERS] = table;
	274
	275	/* Add in reverse order to get freqs in increasing order */
	276	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	277	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	278	j++) {
	279	table[k].frequency = VIRT_FREQ(i,
	280	freq_table[i][j].frequency);
	281	pr_debug("%s: index: %d, freq: %d\n", __func__, k,
	282	table[k].frequency);
	283	k++;
	284	}
	285	}
	286
	287	table[k].driver_data = k;
	288	table[k].frequency = CPUFREQ_TABLE_END;
	289
	290	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
	291
	292	return 0;
	293	}
	294
	295	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
	296	{
	297	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	298
	299	if (!freq_table[cluster])
	300	return;
	301
	302	clk_put(clk[cluster]);
	303	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
493b4cd2 VK	304	if (arm_bL_ops->free_opp_table)
493b4cd2 VK	305	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5 VK	306	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	307	}
	308
8a67f0ef VK	309	static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
	310	{
	311	u32 cluster = cpu_to_cluster(cpu_dev->id);
e79a23c5 VK	312	int i;
	313
	314	if (atomic_dec_return(&cluster_usage[cluster]))
	315	return;
	316
	317	if (cluster < MAX_CLUSTERS)
	318	return _put_cluster_clk_and_freq_table(cpu_dev);
8a67f0ef	319
e79a23c5 VK	320	for_each_present_cpu(i) {
	321	struct device *cdev = get_cpu_device(i);
	322	if (!cdev) {
	323	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	324	return;
	325	}
	326
	327	_put_cluster_clk_and_freq_table(cdev);
8a67f0ef	328	}
e79a23c5 VK	329
	330	/* free virtual table */
	331	kfree(freq_table[cluster]);
8a67f0ef VK	332	}
8a67f0ef VK	333
e79a23c5	334	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
8a67f0ef	335	{
e79a23c5	336	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
8a67f0ef VK	337	int ret;
8a67f0ef VK	338
e79a23c5	339	if (freq_table[cluster])
8a67f0ef VK	340	return 0;
	341
	342	ret = arm_bL_ops->init_opp_table(cpu_dev);
	343	if (ret) {
	344	dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
	345	__func__, cpu_dev->id, ret);
e79a23c5	346	goto out;
8a67f0ef VK	347	}
8a67f0ef VK	348
5d4879cd	349	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef VK	350	if (ret) {
	351	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	352	__func__, cpu_dev->id, ret);
493b4cd2	353	goto free_opp_table;
8a67f0ef VK	354	}
8a67f0ef VK	355
b904f5cc	356	clk[cluster] = clk_get(cpu_dev, NULL);
8a67f0ef VK	357	if (!IS_ERR(clk[cluster])) {
	358	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	359	__func__, clk[cluster], freq_table[cluster],
	360	cluster);
	361	return 0;
	362	}
	363
	364	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	365	__func__, cpu_dev->id, cluster);
	366	ret = PTR_ERR(clk[cluster]);
5d4879cd	367	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef	368
493b4cd2 VK	369	free_opp_table:
	370	if (arm_bL_ops->free_opp_table)
	371	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5	372	out:
8a67f0ef VK	373	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	374	cluster);
	375	return ret;
	376	}
	377
e79a23c5 VK	378	static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
	379	{
	380	u32 cluster = cpu_to_cluster(cpu_dev->id);
	381	int i, ret;
	382
	383	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	384	return 0;
	385
	386	if (cluster < MAX_CLUSTERS) {
	387	ret = _get_cluster_clk_and_freq_table(cpu_dev);
	388	if (ret)
	389	atomic_dec(&cluster_usage[cluster]);
	390	return ret;
	391	}
	392
	393	/*
	394	* Get data for all clusters and fill virtual cluster with a merge of
	395	* both
	396	*/
	397	for_each_present_cpu(i) {
	398	struct device *cdev = get_cpu_device(i);
	399	if (!cdev) {
	400	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	401	return -ENODEV;
	402	}
	403
	404	ret = _get_cluster_clk_and_freq_table(cdev);
	405	if (ret)
	406	goto put_clusters;
	407	}
	408
	409	ret = merge_cluster_tables();
	410	if (ret)
	411	goto put_clusters;
	412
	413	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	414	clk_big_min = get_table_min(freq_table[0]);
	415	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	416
	417	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
	418	__func__, cluster, clk_big_min, clk_little_max);
	419
	420	return 0;
	421
	422	put_clusters:
	423	for_each_present_cpu(i) {
	424	struct device *cdev = get_cpu_device(i);
	425	if (!cdev) {
	426	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	427	return -ENODEV;
	428	}
	429
	430	_put_cluster_clk_and_freq_table(cdev);
	431	}
	432
	433	atomic_dec(&cluster_usage[cluster]);
	434
	435	return ret;
	436	}
	437
8a67f0ef VK	438	/* Per-CPU initialization */
	439	static int bL_cpufreq_init(struct cpufreq_policy *policy)
	440	{
	441	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	442	struct device *cpu_dev;
	443	int ret;
	444
	445	cpu_dev = get_cpu_device(policy->cpu);
	446	if (!cpu_dev) {
	447	pr_err("%s: failed to get cpu%d device\n", __func__,
	448	policy->cpu);
	449	return -ENODEV;
	450	}
	451
	452	ret = get_cluster_clk_and_freq_table(cpu_dev);
	453	if (ret)
	454	return ret;
	455
39b10ebe	456	ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
8a67f0ef VK	457	if (ret) {
	458	dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
	459	policy->cpu, cur_cluster);
	460	put_cluster_clk_and_freq_table(cpu_dev);
	461	return ret;
	462	}
	463
e79a23c5	464	if (cur_cluster < MAX_CLUSTERS) {
8f3ba3d3	465	int cpu;
8f3ba3d3	466
e79a23c5 VK	467	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
e79a23c5 VK	468
8f3ba3d3	469	for_each_cpu(cpu, policy->cpus)
8f3ba3d3	470	per_cpu(physical_cluster, cpu) = cur_cluster;
e79a23c5 VK	471	} else {
	472	/* Assumption: during init, we are always running on A15 */
	473	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	474	}
	475
8a67f0ef VK	476	if (arm_bL_ops->get_transition_latency)
	477	policy->cpuinfo.transition_latency =
	478	arm_bL_ops->get_transition_latency(cpu_dev);
	479	else
	480	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	481
e79a23c5 VK	482	if (is_bL_switching_enabled())
e79a23c5 VK	483	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
8a67f0ef	484
2b80f313	485	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
8a67f0ef VK	486	return 0;
	487	}
	488
	489	static int bL_cpufreq_exit(struct cpufreq_policy *policy)
	490	{
	491	struct device *cpu_dev;
	492
	493	cpu_dev = get_cpu_device(policy->cpu);
	494	if (!cpu_dev) {
	495	pr_err("%s: failed to get cpu%d device\n", __func__,
	496	policy->cpu);
	497	return -ENODEV;
	498	}
	499
	500	put_cluster_clk_and_freq_table(cpu_dev);
	501	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	502
	503	return 0;
	504	}
	505
8a67f0ef VK	506	static struct cpufreq_driver bL_cpufreq_driver = {
8a67f0ef VK	507	.name = "arm-big-little",
0b981e70	508	.flags = CPUFREQ_STICKY \|
ae6b4271 VK	509	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
ae6b4271 VK	510	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
3c75a150	511	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	512	.target_index = bL_cpufreq_set_target,
e79a23c5	513	.get = bL_cpufreq_get_rate,
8a67f0ef VK	514	.init = bL_cpufreq_init,
8a67f0ef VK	515	.exit = bL_cpufreq_exit,
3c75a150	516	.attr = cpufreq_generic_attr,
8a67f0ef VK	517	};
8a67f0ef VK	518
14730145	519	#ifdef CONFIG_BL_SWITCHER
45cac118 NP	520	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	521	unsigned long action, void *_arg)
	522	{
	523	pr_debug("%s: action: %ld\n", __func__, action);
	524
	525	switch (action) {
	526	case BL_NOTIFY_PRE_ENABLE:
	527	case BL_NOTIFY_PRE_DISABLE:
	528	cpufreq_unregister_driver(&bL_cpufreq_driver);
	529	break;
	530
	531	case BL_NOTIFY_POST_ENABLE:
	532	set_switching_enabled(true);
	533	cpufreq_register_driver(&bL_cpufreq_driver);
	534	break;
	535
	536	case BL_NOTIFY_POST_DISABLE:
	537	set_switching_enabled(false);
	538	cpufreq_register_driver(&bL_cpufreq_driver);
	539	break;
	540
	541	default:
	542	return NOTIFY_DONE;
	543	}
	544
	545	return NOTIFY_OK;
	546	}
	547
	548	static struct notifier_block bL_switcher_notifier = {
	549	.notifier_call = bL_cpufreq_switcher_notifier,
	550	};
	551
14730145 SH	552	static int __bLs_register_notifier(void)
	553	{
	554	return bL_switcher_register_notifier(&bL_switcher_notifier);
	555	}
	556
	557	static int __bLs_unregister_notifier(void)
	558	{
	559	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	560	}
	561	#else
	562	static int __bLs_register_notifier(void) { return 0; }
	563	static int __bLs_unregister_notifier(void) { return 0; }
	564	#endif
	565
8a67f0ef VK	566	int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
8a67f0ef VK	567	{
e79a23c5	568	int ret, i;
8a67f0ef VK	569
	570	if (arm_bL_ops) {
	571	pr_debug("%s: Already registered: %s, exiting\n", __func__,
	572	arm_bL_ops->name);
	573	return -EBUSY;
	574	}
	575
	576	if (!ops \|\| !strlen(ops->name) \|\| !ops->init_opp_table) {
	577	pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
	578	return -ENODEV;
	579	}
	580
	581	arm_bL_ops = ops;
	582
14730145	583	set_switching_enabled(bL_switcher_get_enabled());
45cac118	584
e79a23c5 VK	585	for (i = 0; i < MAX_CLUSTERS; i++)
	586	mutex_init(&cluster_lock[i]);
	587
8a67f0ef VK	588	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	589	if (ret) {
	590	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
	591	__func__, ops->name, ret);
	592	arm_bL_ops = NULL;
	593	} else {
14730145	594	ret = __bLs_register_notifier();
45cac118 NP	595	if (ret) {
	596	cpufreq_unregister_driver(&bL_cpufreq_driver);
	597	arm_bL_ops = NULL;
	598	} else {
	599	pr_info("%s: Registered platform driver: %s\n",
	600	__func__, ops->name);
	601	}
8a67f0ef VK	602	}
8a67f0ef VK	603
45cac118	604	bL_switcher_put_enabled();
8a67f0ef VK	605	return ret;
	606	}
	607	EXPORT_SYMBOL_GPL(bL_cpufreq_register);
	608
	609	void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
	610	{
	611	if (arm_bL_ops != ops) {
	612	pr_err("%s: Registered with: %s, can't unregister, exiting\n",
	613	__func__, arm_bL_ops->name);
	614	return;
	615	}
	616
45cac118	617	bL_switcher_get_enabled();
14730145	618	__bLs_unregister_notifier();
8a67f0ef	619	cpufreq_unregister_driver(&bL_cpufreq_driver);
45cac118	620	bL_switcher_put_enabled();
8a67f0ef VK	621	pr_info("%s: Un-registered platform driver: %s\n", __func__,
	622	arm_bL_ops->name);
	623	arm_bL_ops = NULL;
	624	}
	625	EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
39c8bbaf UKK	626
	627	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	628	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
	629	MODULE_LICENSE("GPL v2");