[mirror_ubuntu-artful-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/cpu_cooling.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 thermal_cooling_device *cdev[MAX_CLUSTERS];
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,
					    const struct cpumask *cpumask)
{
	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(cpumask);
	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
}

static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
					   const struct cpumask *cpumask)
{
	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, cpumask);

	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, cpumask);
	}

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

static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
					   const struct cpumask *cpumask)
{
	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	int ret;

	if (freq_table[cluster])
		return 0;

	ret = arm_bL_ops->init_opp_table(cpumask);
	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(cpumask);
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,
					  const struct cpumask *cpumask)
{
	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, cpumask);
		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, cpumask);
		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, cpumask);
	}

	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;
	}

	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;
	}

	ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	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, policy->cpus);
		return ret;
	}

	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;
	int cur_cluster = cpu_to_cluster(policy->cpu);

	if (cur_cluster < MAX_CLUSTERS) {
		cpufreq_cooling_unregister(cdev[cur_cluster]);
		cdev[cur_cluster] = NULL;
	}

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

	return 0;
}

static void bL_cpufreq_ready(struct cpufreq_policy *policy)
{
	struct device *cpu_dev = get_cpu_device(policy->cpu);
	int cur_cluster = cpu_to_cluster(policy->cpu);
	struct device_node *np;

	/* Do not register a cpu_cooling device if we are in IKS mode */
	if (cur_cluster >= MAX_CLUSTERS)
		return;

	np = of_node_get(cpu_dev->of_node);
	if (WARN_ON(!np))
		return;

	if (of_find_property(np, "#cooling-cells", NULL)) {
		u32 power_coefficient = 0;

		of_property_read_u32(np, "dynamic-power-coefficient",
				     &power_coefficient);

		cdev[cur_cluster] = of_cpufreq_power_cooling_register(np,
				policy, power_coefficient, NULL);
		if (IS_ERR(cdev[cur_cluster])) {
			dev_err(cpu_dev,
				"running cpufreq without cooling device: %ld\n",
				PTR_ERR(cdev[cur_cluster]));
			cdev[cur_cluster] = NULL;
		}
	}
	of_node_put(np);
}

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,
	.ready			= bL_cpufreq_ready,
	.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>
2f7e8a17	26	#include <linux/cpu_cooling.h>
8a67f0ef	27	#include <linux/export.h>
39c8bbaf	28	#include <linux/module.h>
e79a23c5	29	#include <linux/mutex.h>
8a67f0ef	30	#include <linux/of_platform.h>
e4db1c74	31	#include <linux/pm_opp.h>
8a67f0ef VK	32	#include <linux/slab.h>
	33	#include <linux/topology.h>
	34	#include <linux/types.h>
	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
14730145	44	#include <asm/bL_switcher.h>
45cac118 NP	45	static bool bL_switching_enabled;
	46	#define is_bL_switching_enabled() bL_switching_enabled
	47	#define set_switching_enabled(x) (bL_switching_enabled = (x))
e79a23c5 VK	48	#else
e79a23c5 VK	49	#define is_bL_switching_enabled() false
45cac118	50	#define set_switching_enabled(x) do { } while (0)
14730145 SH	51	#define bL_switch_request(...) do { } while (0)
	52	#define bL_switcher_put_enabled() do { } while (0)
	53	#define bL_switcher_get_enabled() do { } while (0)
e79a23c5 VK	54	#endif
	55
	56	#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
	57	#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
	58
2f7e8a17	59	static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
8a67f0ef VK	60	static struct cpufreq_arm_bL_ops *arm_bL_ops;
8a67f0ef VK	61	static struct clk *clk[MAX_CLUSTERS];
e79a23c5 VK	62	static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
	63	static atomic_t cluster_usage[MAX_CLUSTERS + 1];
	64
	65	static unsigned int clk_big_min; /* (Big) clock frequencies */
	66	static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
	67
	68	static DEFINE_PER_CPU(unsigned int, physical_cluster);
	69	static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
	70
	71	static struct mutex cluster_lock[MAX_CLUSTERS];
	72
	73	static inline int raw_cpu_to_cluster(int cpu)
	74	{
	75	return topology_physical_package_id(cpu);
	76	}
	77
	78	static inline int cpu_to_cluster(int cpu)
	79	{
	80	return is_bL_switching_enabled() ?
	81	MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
	82	}
	83
	84	static unsigned int find_cluster_maxfreq(int cluster)
	85	{
	86	int j;
	87	u32 max_freq = 0, cpu_freq;
	88
	89	for_each_online_cpu(j) {
	90	cpu_freq = per_cpu(cpu_last_req_freq, j);
	91
	92	if ((cluster == per_cpu(physical_cluster, j)) &&
	93	(max_freq < cpu_freq))
	94	max_freq = cpu_freq;
	95	}
	96
	97	pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
	98	max_freq);
	99
	100	return max_freq;
	101	}
	102
	103	static unsigned int clk_get_cpu_rate(unsigned int cpu)
	104	{
	105	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	106	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
	107
	108	/* For switcher we use virtual A7 clock rates */
	109	if (is_bL_switching_enabled())
	110	rate = VIRT_FREQ(cur_cluster, rate);
	111
	112	pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
	113	cur_cluster, rate);
	114
	115	return rate;
	116	}
	117
	118	static unsigned int bL_cpufreq_get_rate(unsigned int cpu)
	119	{
	120	if (is_bL_switching_enabled()) {
	121	pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
	122	cpu));
	123
	124	return per_cpu(cpu_last_req_freq, cpu);
	125	} else {
126	return clk_get_cpu_rate(cpu);
127	}
128	}
8a67f0ef	129
e79a23c5 VK	130	static unsigned int
e79a23c5 VK	131	bL_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
8a67f0ef	132	{
e79a23c5 VK	133	u32 new_rate, prev_rate;
	134	int ret;
	135	bool bLs = is_bL_switching_enabled();
	136
	137	mutex_lock(&cluster_lock[new_cluster]);
	138
	139	if (bLs) {
	140	prev_rate = per_cpu(cpu_last_req_freq, cpu);
	141	per_cpu(cpu_last_req_freq, cpu) = rate;
	142	per_cpu(physical_cluster, cpu) = new_cluster;
	143
	144	new_rate = find_cluster_maxfreq(new_cluster);
	145	new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	146	} else {
	147	new_rate = rate;
	148	}
	149
	150	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
	151	__func__, cpu, old_cluster, new_cluster, new_rate);
	152
	153	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
14f1ba3a JMT	154	if (!ret) {
	155	/*
	156	* FIXME: clk_set_rate hasn't returned an error here however it
	157	* may be that clk_change_rate failed due to hardware or
	158	* firmware issues and wasn't able to report that due to the
	159	* current design of the clk core layer. To work around this
	160	* problem we will read back the clock rate and check it is
	161	* correct. This needs to be removed once clk core is fixed.
	162	*/
	163	if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
	164	ret = -EIO;
	165	}
	166
e79a23c5 VK	167	if (WARN_ON(ret)) {
	168	pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
	169	new_cluster);
	170	if (bLs) {
	171	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	172	per_cpu(physical_cluster, cpu) = old_cluster;
	173	}
	174
	175	mutex_unlock(&cluster_lock[new_cluster]);
	176
	177	return ret;
	178	}
	179
	180	mutex_unlock(&cluster_lock[new_cluster]);
	181
	182	/* Recalc freq for old cluster when switching clusters */
	183	if (old_cluster != new_cluster) {
	184	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
	185	__func__, cpu, old_cluster, new_cluster);
	186
	187	/* Switch cluster */
	188	bL_switch_request(cpu, new_cluster);
	189
	190	mutex_lock(&cluster_lock[old_cluster]);
8a67f0ef	191
e79a23c5 VK	192	/* Set freq of old cluster if there are cpus left on it */
	193	new_rate = find_cluster_maxfreq(old_cluster);
	194	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	195
	196	if (new_rate) {
	197	pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
	198	__func__, old_cluster, new_rate);
	199
	200	if (clk_set_rate(clk[old_cluster], new_rate * 1000))
	201	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
	202	__func__, ret, old_cluster);
	203	}
	204	mutex_unlock(&cluster_lock[old_cluster]);
	205	}
	206
	207	return 0;
8a67f0ef VK	208	}
8a67f0ef VK	209
8a67f0ef VK	210	/* Set clock frequency */
8a67f0ef VK	211	static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
9c0ebcf7	212	unsigned int index)
8a67f0ef	213	{
e79a23c5	214	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
d4019f0a	215	unsigned int freqs_new;
8a67f0ef	216
e79a23c5 VK	217	cur_cluster = cpu_to_cluster(cpu);
e79a23c5 VK	218	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
8a67f0ef	219
d4019f0a	220	freqs_new = freq_table[cur_cluster][index].frequency;
8a67f0ef	221
e79a23c5 VK	222	if (is_bL_switching_enabled()) {
e79a23c5 VK	223	if ((actual_cluster == A15_CLUSTER) &&
d4019f0a	224	(freqs_new < clk_big_min)) {
e79a23c5 VK	225	new_cluster = A7_CLUSTER;
e79a23c5 VK	226	} else if ((actual_cluster == A7_CLUSTER) &&
d4019f0a	227	(freqs_new > clk_little_max)) {
e79a23c5 VK	228	new_cluster = A15_CLUSTER;
	229	}
	230	}
	231
d4019f0a	232	return bL_cpufreq_set_rate(cpu, actual_cluster, new_cluster, freqs_new);
8a67f0ef VK	233	}
8a67f0ef VK	234
e79a23c5 VK	235	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	236	{
	237	int count;
	238
	239	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	240	;
	241
	242	return count;
	243	}
	244
	245	/* get the minimum frequency in the cpufreq_frequency_table */
	246	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	247	{
041526f9	248	struct cpufreq_frequency_table *pos;
e79a23c5	249	uint32_t min_freq = ~0;
041526f9 SK	250	cpufreq_for_each_entry(pos, table)
	251	if (pos->frequency < min_freq)
	252	min_freq = pos->frequency;
e79a23c5 VK	253	return min_freq;
	254	}
	255
	256	/* get the maximum frequency in the cpufreq_frequency_table */
	257	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	258	{
041526f9	259	struct cpufreq_frequency_table *pos;
e79a23c5	260	uint32_t max_freq = 0;
041526f9 SK	261	cpufreq_for_each_entry(pos, table)
	262	if (pos->frequency > max_freq)
	263	max_freq = pos->frequency;
e79a23c5 VK	264	return max_freq;
	265	}
	266
	267	static int merge_cluster_tables(void)
	268	{
	269	int i, j, k = 0, count = 1;
	270	struct cpufreq_frequency_table *table;
	271
	272	for (i = 0; i < MAX_CLUSTERS; i++)
	273	count += get_table_count(freq_table[i]);
	274
	275	table = kzalloc(sizeof(table) count, GFP_KERNEL);
	276	if (!table)
	277	return -ENOMEM;
	278
	279	freq_table[MAX_CLUSTERS] = table;
	280
	281	/* Add in reverse order to get freqs in increasing order */
	282	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	283	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	284	j++) {
	285	table[k].frequency = VIRT_FREQ(i,
	286	freq_table[i][j].frequency);
	287	pr_debug("%s: index: %d, freq: %d\n", __func__, k,
	288	table[k].frequency);
	289	k++;
	290	}
	291	}
	292
	293	table[k].driver_data = k;
	294	table[k].frequency = CPUFREQ_TABLE_END;
	295
	296	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
	297
	298	return 0;
	299	}
	300
d9975b0b SH	301	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
d9975b0b SH	302	const struct cpumask *cpumask)
e79a23c5 VK	303	{
	304	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	305
	306	if (!freq_table[cluster])
	307	return;
	308
	309	clk_put(clk[cluster]);
	310	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
493b4cd2	311	if (arm_bL_ops->free_opp_table)
d9975b0b	312	arm_bL_ops->free_opp_table(cpumask);
e79a23c5 VK	313	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	314	}
	315
d9975b0b SH	316	static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
d9975b0b SH	317	const struct cpumask *cpumask)
8a67f0ef VK	318	{
8a67f0ef VK	319	u32 cluster = cpu_to_cluster(cpu_dev->id);
e79a23c5 VK	320	int i;
	321
	322	if (atomic_dec_return(&cluster_usage[cluster]))
	323	return;
	324
	325	if (cluster < MAX_CLUSTERS)
d9975b0b	326	return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
8a67f0ef	327
e79a23c5 VK	328	for_each_present_cpu(i) {
	329	struct device *cdev = get_cpu_device(i);
	330	if (!cdev) {
	331	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	332	return;
	333	}
	334
d9975b0b	335	_put_cluster_clk_and_freq_table(cdev, cpumask);
8a67f0ef	336	}
e79a23c5 VK	337
	338	/* free virtual table */
	339	kfree(freq_table[cluster]);
8a67f0ef VK	340	}
8a67f0ef VK	341
d9975b0b SH	342	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
d9975b0b SH	343	const struct cpumask *cpumask)
8a67f0ef	344	{
e79a23c5	345	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
8a67f0ef VK	346	int ret;
8a67f0ef VK	347
e79a23c5	348	if (freq_table[cluster])
8a67f0ef VK	349	return 0;
8a67f0ef VK	350
d9975b0b	351	ret = arm_bL_ops->init_opp_table(cpumask);
8a67f0ef VK	352	if (ret) {
	353	dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
	354	__func__, cpu_dev->id, ret);
e79a23c5	355	goto out;
8a67f0ef VK	356	}
8a67f0ef VK	357
5d4879cd	358	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef VK	359	if (ret) {
	360	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	361	__func__, cpu_dev->id, ret);
493b4cd2	362	goto free_opp_table;
8a67f0ef VK	363	}
8a67f0ef VK	364
b904f5cc	365	clk[cluster] = clk_get(cpu_dev, NULL);
8a67f0ef VK	366	if (!IS_ERR(clk[cluster])) {
	367	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	368	__func__, clk[cluster], freq_table[cluster],
	369	cluster);
	370	return 0;
	371	}
	372
	373	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	374	__func__, cpu_dev->id, cluster);
	375	ret = PTR_ERR(clk[cluster]);
5d4879cd	376	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
8a67f0ef	377
493b4cd2 VK	378	free_opp_table:
493b4cd2 VK	379	if (arm_bL_ops->free_opp_table)
d9975b0b	380	arm_bL_ops->free_opp_table(cpumask);
e79a23c5	381	out:
8a67f0ef VK	382	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	383	cluster);
	384	return ret;
	385	}
	386
d9975b0b SH	387	static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
d9975b0b SH	388	const struct cpumask *cpumask)
e79a23c5 VK	389	{
	390	u32 cluster = cpu_to_cluster(cpu_dev->id);
	391	int i, ret;
	392
	393	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	394	return 0;
	395
	396	if (cluster < MAX_CLUSTERS) {
d9975b0b	397	ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
e79a23c5 VK	398	if (ret)
	399	atomic_dec(&cluster_usage[cluster]);
	400	return ret;
	401	}
	402
	403	/*
	404	* Get data for all clusters and fill virtual cluster with a merge of
	405	* both
	406	*/
	407	for_each_present_cpu(i) {
	408	struct device *cdev = get_cpu_device(i);
	409	if (!cdev) {
	410	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	411	return -ENODEV;
	412	}
	413
d9975b0b	414	ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
e79a23c5 VK	415	if (ret)
	416	goto put_clusters;
	417	}
	418
	419	ret = merge_cluster_tables();
	420	if (ret)
	421	goto put_clusters;
	422
	423	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	424	clk_big_min = get_table_min(freq_table[0]);
	425	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	426
	427	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
	428	__func__, cluster, clk_big_min, clk_little_max);
	429
	430	return 0;
	431
	432	put_clusters:
	433	for_each_present_cpu(i) {
	434	struct device *cdev = get_cpu_device(i);
	435	if (!cdev) {
	436	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	437	return -ENODEV;
	438	}
	439
d9975b0b	440	_put_cluster_clk_and_freq_table(cdev, cpumask);
e79a23c5 VK	441	}
	442
	443	atomic_dec(&cluster_usage[cluster]);
	444
	445	return ret;
	446	}
	447
8a67f0ef VK	448	/* Per-CPU initialization */
	449	static int bL_cpufreq_init(struct cpufreq_policy *policy)
	450	{
	451	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	452	struct device *cpu_dev;
	453	int ret;
	454
	455	cpu_dev = get_cpu_device(policy->cpu);
	456	if (!cpu_dev) {
	457	pr_err("%s: failed to get cpu%d device\n", __func__,
	458	policy->cpu);
	459	return -ENODEV;
	460	}
	461
e79a23c5	462	if (cur_cluster < MAX_CLUSTERS) {
8f3ba3d3	463	int cpu;
8f3ba3d3	464
e79a23c5 VK	465	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
e79a23c5 VK	466
8f3ba3d3	467	for_each_cpu(cpu, policy->cpus)
8f3ba3d3	468	per_cpu(physical_cluster, cpu) = cur_cluster;
e79a23c5 VK	469	} else {
	470	/* Assumption: during init, we are always running on A15 */
	471	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	472	}
	473
d9975b0b SH	474	ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	475	if (ret)
	476	return ret;
	477
	478	ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
	479	if (ret) {
	480	dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
	481	policy->cpu, cur_cluster);
	482	put_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	483	return ret;
	484	}
	485
8a67f0ef VK	486	if (arm_bL_ops->get_transition_latency)
	487	policy->cpuinfo.transition_latency =
	488	arm_bL_ops->get_transition_latency(cpu_dev);
	489	else
	490	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
	491
e79a23c5 VK	492	if (is_bL_switching_enabled())
e79a23c5 VK	493	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
8a67f0ef	494
2b80f313	495	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
8a67f0ef VK	496	return 0;
	497	}
	498
	499	static int bL_cpufreq_exit(struct cpufreq_policy *policy)
	500	{
	501	struct device *cpu_dev;
2f7e8a17 PA	502	int cur_cluster = cpu_to_cluster(policy->cpu);
	503
	504	if (cur_cluster < MAX_CLUSTERS) {
	505	cpufreq_cooling_unregister(cdev[cur_cluster]);
	506	cdev[cur_cluster] = NULL;
	507	}
8a67f0ef VK	508
	509	cpu_dev = get_cpu_device(policy->cpu);
	510	if (!cpu_dev) {
	511	pr_err("%s: failed to get cpu%d device\n", __func__,
	512	policy->cpu);
	513	return -ENODEV;
	514	}
	515
d9975b0b	516	put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
8a67f0ef VK	517	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	518
	519	return 0;
	520	}
	521
2f7e8a17 PA	522	static void bL_cpufreq_ready(struct cpufreq_policy *policy)
	523	{
	524	struct device *cpu_dev = get_cpu_device(policy->cpu);
	525	int cur_cluster = cpu_to_cluster(policy->cpu);
	526	struct device_node *np;
	527
	528	/* Do not register a cpu_cooling device if we are in IKS mode */
	529	if (cur_cluster >= MAX_CLUSTERS)
	530	return;
	531
	532	np = of_node_get(cpu_dev->of_node);
	533	if (WARN_ON(!np))
	534	return;
	535
	536	if (of_find_property(np, "#cooling-cells", NULL)) {
	537	u32 power_coefficient = 0;
	538
	539	of_property_read_u32(np, "dynamic-power-coefficient",
	540	&power_coefficient);
	541
	542	cdev[cur_cluster] = of_cpufreq_power_cooling_register(np,
4d753aa7	543	policy, power_coefficient, NULL);
2f7e8a17 PA	544	if (IS_ERR(cdev[cur_cluster])) {
	545	dev_err(cpu_dev,
	546	"running cpufreq without cooling device: %ld\n",
	547	PTR_ERR(cdev[cur_cluster]));
	548	cdev[cur_cluster] = NULL;
	549	}
	550	}
	551	of_node_put(np);
	552	}
	553
8a67f0ef VK	554	static struct cpufreq_driver bL_cpufreq_driver = {
8a67f0ef VK	555	.name = "arm-big-little",
0b981e70	556	.flags = CPUFREQ_STICKY \|
ae6b4271 VK	557	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
ae6b4271 VK	558	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
3c75a150	559	.verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7	560	.target_index = bL_cpufreq_set_target,
e79a23c5	561	.get = bL_cpufreq_get_rate,
8a67f0ef VK	562	.init = bL_cpufreq_init,
8a67f0ef VK	563	.exit = bL_cpufreq_exit,
2f7e8a17	564	.ready = bL_cpufreq_ready,
3c75a150	565	.attr = cpufreq_generic_attr,
8a67f0ef VK	566	};
8a67f0ef VK	567
14730145	568	#ifdef CONFIG_BL_SWITCHER
45cac118 NP	569	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	570	unsigned long action, void *_arg)
	571	{
	572	pr_debug("%s: action: %ld\n", __func__, action);
	573
	574	switch (action) {
	575	case BL_NOTIFY_PRE_ENABLE:
	576	case BL_NOTIFY_PRE_DISABLE:
	577	cpufreq_unregister_driver(&bL_cpufreq_driver);
	578	break;
	579
	580	case BL_NOTIFY_POST_ENABLE:
	581	set_switching_enabled(true);
	582	cpufreq_register_driver(&bL_cpufreq_driver);
	583	break;
	584
	585	case BL_NOTIFY_POST_DISABLE:
	586	set_switching_enabled(false);
	587	cpufreq_register_driver(&bL_cpufreq_driver);
	588	break;
	589
	590	default:
	591	return NOTIFY_DONE;
	592	}
	593
	594	return NOTIFY_OK;
	595	}
	596
	597	static struct notifier_block bL_switcher_notifier = {
	598	.notifier_call = bL_cpufreq_switcher_notifier,
	599	};
	600
14730145 SH	601	static int __bLs_register_notifier(void)
	602	{
	603	return bL_switcher_register_notifier(&bL_switcher_notifier);
	604	}
	605
	606	static int __bLs_unregister_notifier(void)
	607	{
	608	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	609	}
	610	#else
	611	static int __bLs_register_notifier(void) { return 0; }
	612	static int __bLs_unregister_notifier(void) { return 0; }
	613	#endif
	614
8a67f0ef VK	615	int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
8a67f0ef VK	616	{
e79a23c5	617	int ret, i;
8a67f0ef VK	618
	619	if (arm_bL_ops) {
	620	pr_debug("%s: Already registered: %s, exiting\n", __func__,
	621	arm_bL_ops->name);
	622	return -EBUSY;
	623	}
	624
	625	if (!ops \|\| !strlen(ops->name) \|\| !ops->init_opp_table) {
	626	pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
	627	return -ENODEV;
	628	}
	629
	630	arm_bL_ops = ops;
	631
14730145	632	set_switching_enabled(bL_switcher_get_enabled());
45cac118	633
e79a23c5 VK	634	for (i = 0; i < MAX_CLUSTERS; i++)
	635	mutex_init(&cluster_lock[i]);
	636
8a67f0ef VK	637	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	638	if (ret) {
	639	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
	640	__func__, ops->name, ret);
	641	arm_bL_ops = NULL;
	642	} else {
14730145	643	ret = __bLs_register_notifier();
45cac118 NP	644	if (ret) {
	645	cpufreq_unregister_driver(&bL_cpufreq_driver);
	646	arm_bL_ops = NULL;
	647	} else {
	648	pr_info("%s: Registered platform driver: %s\n",
	649	__func__, ops->name);
	650	}
8a67f0ef VK	651	}
8a67f0ef VK	652
45cac118	653	bL_switcher_put_enabled();
8a67f0ef VK	654	return ret;
	655	}
	656	EXPORT_SYMBOL_GPL(bL_cpufreq_register);
	657
	658	void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
	659	{
	660	if (arm_bL_ops != ops) {
	661	pr_err("%s: Registered with: %s, can't unregister, exiting\n",
	662	__func__, arm_bL_ops->name);
	663	return;
	664	}
	665
45cac118	666	bL_switcher_get_enabled();
14730145	667	__bLs_unregister_notifier();
8a67f0ef	668	cpufreq_unregister_driver(&bL_cpufreq_driver);
45cac118	669	bL_switcher_put_enabled();
8a67f0ef VK	670	pr_info("%s: Un-registered platform driver: %s\n", __func__,
	671	arm_bL_ops->name);
	672	arm_bL_ops = NULL;
	673	}
	674	EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
39c8bbaf UKK	675
	676	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	677	MODULE_DESCRIPTION("Generic ARM big LITTLE cpufreq driver");
	678	MODULE_LICENSE("GPL v2");