[deliverable/linux.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 (!ret) {
		/*
		 * FIXME: clk_set_rate hasn't returned an error here however it
		 * may be that clk_change_rate failed due to hardware or
		 * firmware issues and wasn't able to report that due to the
		 * current design of the clk core layer. To work around this
		 * problem we will read back the clock rate and check it is
		 * correct. This needs to be removed once clk core is fixed.
		 */
		if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
			ret = -EIO;
	}

	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);
	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);
14f1ba3a JMT	152	if (!ret) {
	153	/*
	154	* FIXME: clk_set_rate hasn't returned an error here however it
	155	* may be that clk_change_rate failed due to hardware or
	156	* firmware issues and wasn't able to report that due to the
	157	* current design of the clk core layer. To work around this
	158	* problem we will read back the clock rate and check it is
	159	* correct. This needs to be removed once clk core is fixed.
	160	*/
	161	if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
	162	ret = -EIO;
	163	}
	164
e79a23c5 VK	165	if (WARN_ON(ret)) {
	166	pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
	167	new_cluster);
	168	if (bLs) {
	169	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	170	per_cpu(physical_cluster, cpu) = old_cluster;
	171	}
	172
	173	mutex_unlock(&cluster_lock[new_cluster]);
	174
	175	return ret;
	176	}
	177
	178	mutex_unlock(&cluster_lock[new_cluster]);
	179
	180	/* Recalc freq for old cluster when switching clusters */
	181	if (old_cluster != new_cluster) {
	182	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
	183	__func__, cpu, old_cluster, new_cluster);
	184
	185	/* Switch cluster */
	186	bL_switch_request(cpu, new_cluster);
	187
	188	mutex_lock(&cluster_lock[old_cluster]);
8a67f0ef	189
e79a23c5 VK	190	/* Set freq of old cluster if there are cpus left on it */
	191	new_rate = find_cluster_maxfreq(old_cluster);
	192	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	193
	194	if (new_rate) {
	195	pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
	196	__func__, old_cluster, new_rate);
	197
	198	if (clk_set_rate(clk[old_cluster], new_rate * 1000))
	199	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
	200	__func__, ret, old_cluster);
	201	}
	202	mutex_unlock(&cluster_lock[old_cluster]);
	203	}
	204
	205	return 0;
8a67f0ef VK	206	}
8a67f0ef VK	207
8a67f0ef VK	208	/* Set clock frequency */
8a67f0ef VK	209	static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
9c0ebcf7	210	unsigned int index)
8a67f0ef	211	{
e79a23c5	212	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
d4019f0a	213	unsigned int freqs_new;
8a67f0ef	214
e79a23c5 VK	215	cur_cluster = cpu_to_cluster(cpu);
e79a23c5 VK	216	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
8a67f0ef	217
d4019f0a	218	freqs_new = freq_table[cur_cluster][index].frequency;
8a67f0ef	219
e79a23c5 VK	220	if (is_bL_switching_enabled()) {
e79a23c5 VK	221	if ((actual_cluster == A15_CLUSTER) &&
d4019f0a	222	(freqs_new < clk_big_min)) {
e79a23c5 VK	223	new_cluster = A7_CLUSTER;
e79a23c5 VK	224	} else if ((actual_cluster == A7_CLUSTER) &&
d4019f0a	225	(freqs_new > clk_little_max)) {
e79a23c5 VK	226	new_cluster = A15_CLUSTER;
	227	}
	228	}
	229
d4019f0a	230	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
8a67f0ef VK	231	}
8a67f0ef VK	232
e79a23c5 VK	233	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	234	{
	235	int count;
	236
	237	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	238	;
	239
	240	return count;
	241	}
	242
	243	/* get the minimum frequency in the cpufreq_frequency_table */
	244	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	245	{
041526f9	246	struct cpufreq_frequency_table *pos;
e79a23c5	247	uint32_t min_freq = ~0;
041526f9 SK	248	cpufreq_for_each_entry(pos, table)
	249	if (pos->frequency < min_freq)
	250	min_freq = pos->frequency;
e79a23c5 VK	251	return min_freq;
	252	}
	253
	254	/* get the maximum frequency in the cpufreq_frequency_table */
	255	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	256	{
041526f9	257	struct cpufreq_frequency_table *pos;
e79a23c5	258	uint32_t max_freq = 0;
041526f9 SK	259	cpufreq_for_each_entry(pos, table)
	260	if (pos->frequency > max_freq)
	261	max_freq = pos->frequency;
e79a23c5 VK	262	return max_freq;
	263	}
	264
	265	static int merge_cluster_tables(void)
	266	{
	267	int i, j, k = 0, count = 1;
	268	struct cpufreq_frequency_table *table;
	269
	270	for (i = 0; i < MAX_CLUSTERS; i++)
	271	count += get_table_count(freq_table[i]);
	272
	273	table = kzalloc(sizeof(table) count, GFP_KERNEL);
	274	if (!table)
	275	return -ENOMEM;
	276
	277	freq_table[MAX_CLUSTERS] = table;
	278
	279	/* Add in reverse order to get freqs in increasing order */
	280	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	281	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	282	j++) {
	283	table[k].frequency = VIRT_FREQ(i,
	284	freq_table[i][j].frequency);
	285	pr_debug("%s: index: %d, freq: %d\n", __func__, k,
	286	table[k].frequency);
	287	k++;
	288	}
	289	}
	290
	291	table[k].driver_data = k;
	292	table[k].frequency = CPUFREQ_TABLE_END;
	293
	294	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
	295
	296	return 0;
	297	}
	298
	299	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev)
	300	{
	301	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	302
	303	if (!freq_table[cluster])
	304	return;
	305
	306	clk_put(clk[cluster]);
	307	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
493b4cd2 VK	308	if (arm_bL_ops->free_opp_table)
493b4cd2 VK	309	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5 VK	310	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	311	}
	312
8a67f0ef VK	313	static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
	314	{
	315	u32 cluster = cpu_to_cluster(cpu_dev->id);
e79a23c5 VK	316	int i;
	317
	318	if (atomic_dec_return(&cluster_usage[cluster]))
	319	return;
	320
	321	if (cluster < MAX_CLUSTERS)
	322	return _put_cluster_clk_and_freq_table(cpu_dev);
8a67f0ef	323
e79a23c5 VK	324	for_each_present_cpu(i) {
	325	struct device *cdev = get_cpu_device(i);
	326	if (!cdev) {
	327	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	328	return;
	329	}
	330
	331	_put_cluster_clk_and_freq_table(cdev);
8a67f0ef	332	}
e79a23c5 VK	333
	334	/* free virtual table */
	335	kfree(freq_table[cluster]);
8a67f0ef VK	336	}
8a67f0ef VK	337
e79a23c5	338	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev)
8a67f0ef	339	{
e79a23c5	340	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
8a67f0ef VK	341	int ret;
8a67f0ef VK	342
e79a23c5	343	if (freq_table[cluster])
8a67f0ef VK	344	return 0;
	345
	346	ret = arm_bL_ops->init_opp_table(cpu_dev);
	347	if (ret) {
	348	dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
	349	__func__, cpu_dev->id, ret);
e79a23c5	350	goto out;
8a67f0ef VK	351	}
8a67f0ef VK	352
5d4879cd	353	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef VK	354	if (ret) {
	355	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	356	__func__, cpu_dev->id, ret);
493b4cd2	357	goto free_opp_table;
8a67f0ef VK	358	}
8a67f0ef VK	359
b904f5cc	360	clk[cluster] = clk_get(cpu_dev, NULL);
8a67f0ef VK	361	if (!IS_ERR(clk[cluster])) {
	362	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	363	__func__, clk[cluster], freq_table[cluster],
	364	cluster);
	365	return 0;
	366	}
	367
	368	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	369	__func__, cpu_dev->id, cluster);
	370	ret = PTR_ERR(clk[cluster]);
5d4879cd	371	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef	372
493b4cd2 VK	373	free_opp_table:
	374	if (arm_bL_ops->free_opp_table)
	375	arm_bL_ops->free_opp_table(cpu_dev);
e79a23c5	376	out:
8a67f0ef VK	377	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	378	cluster);
	379	return ret;
	380	}
	381
e79a23c5 VK	382	static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
	383	{
	384	u32 cluster = cpu_to_cluster(cpu_dev->id);
	385	int i, ret;
	386
	387	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	388	return 0;
	389
	390	if (cluster < MAX_CLUSTERS) {
	391	ret = _get_cluster_clk_and_freq_table(cpu_dev);
	392	if (ret)
	393	atomic_dec(&cluster_usage[cluster]);
	394	return ret;
	395	}
	396
	397	/*
	398	* Get data for all clusters and fill virtual cluster with a merge of
	399	* both
	400	*/
	401	for_each_present_cpu(i) {
	402	struct device *cdev = get_cpu_device(i);
	403	if (!cdev) {
	404	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	405	return -ENODEV;
	406	}
	407
	408	ret = _get_cluster_clk_and_freq_table(cdev);
	409	if (ret)
	410	goto put_clusters;
	411	}
	412
	413	ret = merge_cluster_tables();
	414	if (ret)
	415	goto put_clusters;
	416
	417	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	418	clk_big_min = get_table_min(freq_table[0]);
	419	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	420
	421	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
	422	__func__, cluster, clk_big_min, clk_little_max);
	423
	424	return 0;
	425
	426	put_clusters:
	427	for_each_present_cpu(i) {
	428	struct device *cdev = get_cpu_device(i);
	429	if (!cdev) {
	430	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	431	return -ENODEV;
	432	}
	433
	434	_put_cluster_clk_and_freq_table(cdev);
	435	}
	436
	437	atomic_dec(&cluster_usage[cluster]);
	438
	439	return ret;
	440	}
	441
8a67f0ef VK	442	/* Per-CPU initialization */
	443	static int bL_cpufreq_init(struct cpufreq_policy *policy)
	444	{
	445	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	446	struct device *cpu_dev;
	447	int ret;
	448
	449	cpu_dev = get_cpu_device(policy->cpu);
	450	if (!cpu_dev) {
	451	pr_err("%s: failed to get cpu%d device\n", __func__,
	452	policy->cpu);
	453	return -ENODEV;
	454	}
	455
	456	ret = get_cluster_clk_and_freq_table(cpu_dev);
	457	if (ret)
	458	return ret;
	459
39b10ebe	460	ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
8a67f0ef VK	461	if (ret) {
	462	dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
	463	policy->cpu, cur_cluster);
	464	put_cluster_clk_and_freq_table(cpu_dev);
	465	return ret;
	466	}
	467
e79a23c5	468	if (cur_cluster < MAX_CLUSTERS) {
8f3ba3d3	469	int cpu;
8f3ba3d3	470
e79a23c5 VK	471	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
e79a23c5 VK	472
8f3ba3d3	473	for_each_cpu(cpu, policy->cpus)
8f3ba3d3	474	per_cpu(physical_cluster, cpu) = cur_cluster;
e79a23c5 VK	475	} else {
	476	/* Assumption: during init, we are always running on A15 */
	477	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	478	}
	479
8a67f0ef VK	480	if (arm_bL_ops->get_transition_latency)
	481	policy->cpuinfo.transition_latency =
	482	arm_bL_ops->get_transition_latency(cpu_dev);
	483	else
	484	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	485
e79a23c5 VK	486	if (is_bL_switching_enabled())
e79a23c5 VK	487	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
8a67f0ef	488
2b80f313	489	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
8a67f0ef VK	490	return 0;
	491	}
	492
	493	static int bL_cpufreq_exit(struct cpufreq_policy *policy)
	494	{
	495	struct device *cpu_dev;
	496
	497	cpu_dev = get_cpu_device(policy->cpu);
	498	if (!cpu_dev) {
	499	pr_err("%s: failed to get cpu%d device\n", __func__,
	500	policy->cpu);
	501	return -ENODEV;
	502	}
	503
	504	put_cluster_clk_and_freq_table(cpu_dev);
	505	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	506
	507	return 0;
	508	}
	509
8a67f0ef VK	510	static struct cpufreq_driver bL_cpufreq_driver = {
8a67f0ef VK	511	.name = "arm-big-little",
0b981e70	512	.flags = CPUFREQ_STICKY \|
ae6b4271 VK	513	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
ae6b4271 VK	514	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
3c75a150	515	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	516	.target_index = bL_cpufreq_set_target,
e79a23c5	517	.get = bL_cpufreq_get_rate,
8a67f0ef VK	518	.init = bL_cpufreq_init,
8a67f0ef VK	519	.exit = bL_cpufreq_exit,
3c75a150	520	.attr = cpufreq_generic_attr,
8a67f0ef VK	521	};
8a67f0ef VK	522
14730145	523	#ifdef CONFIG_BL_SWITCHER
45cac118 NP	524	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	525	unsigned long action, void *_arg)
	526	{
	527	pr_debug("%s: action: %ld\n", __func__, action);
	528
	529	switch (action) {
	530	case BL_NOTIFY_PRE_ENABLE:
	531	case BL_NOTIFY_PRE_DISABLE:
	532	cpufreq_unregister_driver(&bL_cpufreq_driver);
	533	break;
	534
	535	case BL_NOTIFY_POST_ENABLE:
	536	set_switching_enabled(true);
	537	cpufreq_register_driver(&bL_cpufreq_driver);
	538	break;
	539
	540	case BL_NOTIFY_POST_DISABLE:
	541	set_switching_enabled(false);
	542	cpufreq_register_driver(&bL_cpufreq_driver);
	543	break;
	544
	545	default:
	546	return NOTIFY_DONE;
	547	}
	548
	549	return NOTIFY_OK;
	550	}
	551
	552	static struct notifier_block bL_switcher_notifier = {
	553	.notifier_call = bL_cpufreq_switcher_notifier,
	554	};
	555
14730145 SH	556	static int __bLs_register_notifier(void)
	557	{
	558	return bL_switcher_register_notifier(&bL_switcher_notifier);
	559	}
	560
	561	static int __bLs_unregister_notifier(void)
	562	{
	563	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	564	}
	565	#else
	566	static int __bLs_register_notifier(void) { return 0; }
	567	static int __bLs_unregister_notifier(void) { return 0; }
	568	#endif
	569
8a67f0ef VK	570	int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
8a67f0ef VK	571	{
e79a23c5	572	int ret, i;
8a67f0ef VK	573
	574	if (arm_bL_ops) {
	575	pr_debug("%s: Already registered: %s, exiting\n", __func__,
	576	arm_bL_ops->name);
	577	return -EBUSY;
	578	}
	579
	580	if (!ops \|\| !strlen(ops->name) \|\| !ops->init_opp_table) {
	581	pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
	582	return -ENODEV;
	583	}
	584
	585	arm_bL_ops = ops;
	586
14730145	587	set_switching_enabled(bL_switcher_get_enabled());
45cac118	588
e79a23c5 VK	589	for (i = 0; i < MAX_CLUSTERS; i++)
	590	mutex_init(&cluster_lock[i]);
	591
8a67f0ef VK	592	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	593	if (ret) {
	594	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
	595	__func__, ops->name, ret);
	596	arm_bL_ops = NULL;
	597	} else {
14730145	598	ret = __bLs_register_notifier();
45cac118 NP	599	if (ret) {
	600	cpufreq_unregister_driver(&bL_cpufreq_driver);
	601	arm_bL_ops = NULL;
	602	} else {
	603	pr_info("%s: Registered platform driver: %s\n",
	604	__func__, ops->name);
	605	}
8a67f0ef VK	606	}
8a67f0ef VK	607
45cac118	608	bL_switcher_put_enabled();
8a67f0ef VK	609	return ret;
	610	}
	611	EXPORT_SYMBOL_GPL(bL_cpufreq_register);
	612
	613	void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
	614	{
	615	if (arm_bL_ops != ops) {
	616	pr_err("%s: Registered with: %s, can't unregister, exiting\n",
	617	__func__, arm_bL_ops->name);
	618	return;
	619	}
	620
45cac118	621	bL_switcher_get_enabled();
14730145	622	__bLs_unregister_notifier();
8a67f0ef	623	cpufreq_unregister_driver(&bL_cpufreq_driver);
45cac118	624	bL_switcher_put_enabled();
8a67f0ef VK	625	pr_info("%s: Un-registered platform driver: %s\n", __func__,
	626	arm_bL_ops->name);
	627	arm_bL_ops = NULL;
	628	}
	629	EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
39c8bbaf UKK	630
	631	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	632	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
	633	MODULE_LICENSE("GPL v2");