[mirror_ubuntu-jammy-kernel.git] / drivers / cpufreq / vexpress-spc-cpufreq.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Versatile Express SPC CPUFreq Interface driver
 *
 * Copyright (C) 2013 - 2019 ARM Ltd.
 * Sudeep Holla <sudeep.holla@arm.com>
 *
 * Copyright (C) 2013 Linaro.
 * Viresh Kumar <viresh.kumar@linaro.org>
 */

#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/device.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_opp.h>
#include <linux/slab.h>
#include <linux/topology.h>
#include <linux/types.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 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;
	}

	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);

	return rate;
}

static unsigned int ve_spc_cpufreq_get_rate(unsigned int cpu)
{
	if (is_bL_switching_enabled())
		return per_cpu(cpu_last_req_freq, cpu);
	else
		return clk_get_cpu_rate(cpu);
}

static unsigned int
ve_spc_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;
	}

	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)) {
		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) {
		/* 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 &&
		    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 ve_spc_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 ve_spc_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;
	u32 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;
	u32 max_freq = 0;

	cpufreq_for_each_entry(pos, table)
		if (pos->frequency > max_freq)
			max_freq = pos->frequency;
	return max_freq;
}

static bool search_frequency(struct cpufreq_frequency_table *table, int size,
			     unsigned int freq)
{
	int count;

	for (count = 0; count < size; count++) {
		if (table[count].frequency == freq)
			return true;
	}

	return false;
}

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 = kcalloc(count, sizeof(*table), 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--, count = k) {
		for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
		     j++) {
			if (i == A15_CLUSTER &&
			    search_frequency(table, count, freq_table[i][j].frequency))
				continue; /* skip duplicates */
			table[k++].frequency =
				VIRT_FREQ(i, freq_table[i][j].frequency);
		}
	}

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

	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]);
}

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)
			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;

	/*
	 * platform specific SPC code must initialise the opp table
	 * so just check if the OPP count is non-zero
	 */
	ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0;
	if (ret)
		goto out;

	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
	if (ret)
		goto out;

	clk[cluster] = clk_get(cpu_dev, NULL);
	if (!IS_ERR(clk[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]);

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)
			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[A15_CLUSTER]);
	clk_little_max = VIRT_FREQ(A7_CLUSTER,
				   get_table_max(freq_table[A7_CLUSTER]));

	return 0;

put_clusters:
	for_each_present_cpu(i) {
		struct device *cdev = get_cpu_device(i);

		if (!cdev)
			return -ENODEV;

		_put_cluster_clk_and_freq_table(cdev, cpumask);
	}

	atomic_dec(&cluster_usage[cluster]);

	return ret;
}

/* Per-CPU initialization */
static int ve_spc_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;

		dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus);

		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;

	policy->freq_table = freq_table[cur_cluster];
	policy->cpuinfo.transition_latency = 1000000; /* 1 ms */

	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);

	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 ve_spc_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);
	return 0;
}

static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy)
{
	int cur_cluster = cpu_to_cluster(policy->cpu);

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

	cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
}

static struct cpufreq_driver ve_spc_cpufreq_driver = {
	.name			= "vexpress-spc",
	.flags			= CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
					CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	.verify			= cpufreq_generic_frequency_table_verify,
	.target_index		= ve_spc_cpufreq_set_target,
	.get			= ve_spc_cpufreq_get_rate,
	.init			= ve_spc_cpufreq_init,
	.exit			= ve_spc_cpufreq_exit,
	.ready			= ve_spc_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(&ve_spc_cpufreq_driver);
		break;

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

	case BL_NOTIFY_POST_DISABLE:
		set_switching_enabled(false);
		cpufreq_register_driver(&ve_spc_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

static int ve_spc_cpufreq_probe(struct platform_device *pdev)
{
	int ret, i;

	set_switching_enabled(bL_switcher_get_enabled());

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

	ret = cpufreq_register_driver(&ve_spc_cpufreq_driver);
	if (ret) {
		pr_info("%s: Failed registering platform driver: %s, err: %d\n",
			__func__, ve_spc_cpufreq_driver.name, ret);
	} else {
		ret = __bLs_register_notifier();
		if (ret)
			cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
		else
			pr_info("%s: Registered platform driver: %s\n",
				__func__, ve_spc_cpufreq_driver.name);
	}

	bL_switcher_put_enabled();
	return ret;
}

static int ve_spc_cpufreq_remove(struct platform_device *pdev)
{
	bL_switcher_get_enabled();
	__bLs_unregister_notifier();
	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
	bL_switcher_put_enabled();
	pr_info("%s: Un-registered platform driver: %s\n", __func__,
		ve_spc_cpufreq_driver.name);
	return 0;
}

static struct platform_driver ve_spc_cpufreq_platdrv = {
	.driver = {
		.name	= "vexpress-spc-cpufreq",
	},
	.probe		= ve_spc_cpufreq_probe,
	.remove		= ve_spc_cpufreq_remove,
};
module_platform_driver(ve_spc_cpufreq_platdrv);

MODULE_ALIAS("platform:vexpress-spc-cpufreq");
MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
a0f950d3	1	// SPDX-License-Identifier: GPL-2.0
47ac9aa1 SH	2	/*
	3	* Versatile Express SPC CPUFreq Interface driver
	4	*
a0f950d3 SH	5	* Copyright (C) 2013 - 2019 ARM Ltd.
a0f950d3 SH	6	* Sudeep Holla <sudeep.holla@arm.com>
47ac9aa1	7	*
a0f950d3 SH	8	* Copyright (C) 2013 Linaro.
a0f950d3 SH	9	* Viresh Kumar <viresh.kumar@linaro.org>
47ac9aa1 SH	10	*/
	11
	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	13
a0f950d3	14	#include <linux/clk.h>
d9975b0b	15	#include <linux/cpu.h>
47ac9aa1	16	#include <linux/cpufreq.h>
a0f950d3 SH	17	#include <linux/cpumask.h>
	18	#include <linux/cpu_cooling.h>
	19	#include <linux/device.h>
47ac9aa1	20	#include <linux/module.h>
a0f950d3 SH	21	#include <linux/mutex.h>
a0f950d3 SH	22	#include <linux/of_platform.h>
47ac9aa1 SH	23	#include <linux/platform_device.h>
47ac9aa1 SH	24	#include <linux/pm_opp.h>
a0f950d3 SH	25	#include <linux/slab.h>
a0f950d3 SH	26	#include <linux/topology.h>
47ac9aa1 SH	27	#include <linux/types.h>
47ac9aa1 SH	28
a0f950d3 SH	29	/* Currently we support only two clusters */
	30	#define A15_CLUSTER 0
	31	#define A7_CLUSTER 1
	32	#define MAX_CLUSTERS 2
	33
	34	#ifdef CONFIG_BL_SWITCHER
	35	#include <asm/bL_switcher.h>
	36	static bool bL_switching_enabled;
	37	#define is_bL_switching_enabled() bL_switching_enabled
	38	#define set_switching_enabled(x) (bL_switching_enabled = (x))
	39	#else
	40	#define is_bL_switching_enabled() false
	41	#define set_switching_enabled(x) do { } while (0)
	42	#define bL_switch_request(...) do { } while (0)
	43	#define bL_switcher_put_enabled() do { } while (0)
	44	#define bL_switcher_get_enabled() do { } while (0)
	45	#endif
	46
	47	#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
	48	#define VIRT_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
	49
	50	static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
a0f950d3 SH	51	static struct clk *clk[MAX_CLUSTERS];
	52	static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
	53	static atomic_t cluster_usage[MAX_CLUSTERS + 1];
	54
	55	static unsigned int clk_big_min; /* (Big) clock frequencies */
	56	static unsigned int clk_little_max; /* Maximum clock frequency (Little) */
	57
	58	static DEFINE_PER_CPU(unsigned int, physical_cluster);
	59	static DEFINE_PER_CPU(unsigned int, cpu_last_req_freq);
	60
	61	static struct mutex cluster_lock[MAX_CLUSTERS];
	62
	63	static inline int raw_cpu_to_cluster(int cpu)
	64	{
	65	return topology_physical_package_id(cpu);
	66	}
	67
	68	static inline int cpu_to_cluster(int cpu)
	69	{
	70	return is_bL_switching_enabled() ?
	71	MAX_CLUSTERS : raw_cpu_to_cluster(cpu);
	72	}
	73
	74	static unsigned int find_cluster_maxfreq(int cluster)
	75	{
	76	int j;
	77	u32 max_freq = 0, cpu_freq;
	78
	79	for_each_online_cpu(j) {
	80	cpu_freq = per_cpu(cpu_last_req_freq, j);
	81
e318d2c8 SH	82	if (cluster == per_cpu(physical_cluster, j) &&
e318d2c8 SH	83	max_freq < cpu_freq)
a0f950d3 SH	84	max_freq = cpu_freq;
	85	}
	86
a0f950d3 SH	87	return max_freq;
	88	}
	89
	90	static unsigned int clk_get_cpu_rate(unsigned int cpu)
	91	{
	92	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	93	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
	94
	95	/* For switcher we use virtual A7 clock rates */
	96	if (is_bL_switching_enabled())
	97	rate = VIRT_FREQ(cur_cluster, rate);
	98
a0f950d3 SH	99	return rate;
	100	}
	101
1f1b4650	102	static unsigned int ve_spc_cpufreq_get_rate(unsigned int cpu)
a0f950d3	103	{
09402d57	104	if (is_bL_switching_enabled())
a0f950d3	105	return per_cpu(cpu_last_req_freq, cpu);
09402d57	106	else
a0f950d3	107	return clk_get_cpu_rate(cpu);
a0f950d3 SH	108	}
	109
	110	static unsigned int
1f1b4650	111	ve_spc_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
a0f950d3 SH	112	{
	113	u32 new_rate, prev_rate;
	114	int ret;
	115	bool bLs = is_bL_switching_enabled();
	116
	117	mutex_lock(&cluster_lock[new_cluster]);
	118
	119	if (bLs) {
	120	prev_rate = per_cpu(cpu_last_req_freq, cpu);
	121	per_cpu(cpu_last_req_freq, cpu) = rate;
	122	per_cpu(physical_cluster, cpu) = new_cluster;
	123
	124	new_rate = find_cluster_maxfreq(new_cluster);
	125	new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	126	} else {
	127	new_rate = rate;
	128	}
	129
a0f950d3 SH	130	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
	131	if (!ret) {
	132	/*
	133	* FIXME: clk_set_rate hasn't returned an error here however it
	134	* may be that clk_change_rate failed due to hardware or
	135	* firmware issues and wasn't able to report that due to the
	136	* current design of the clk core layer. To work around this
	137	* problem we will read back the clock rate and check it is
	138	* correct. This needs to be removed once clk core is fixed.
	139	*/
	140	if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
	141	ret = -EIO;
	142	}
	143
	144	if (WARN_ON(ret)) {
a0f950d3 SH	145	if (bLs) {
	146	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	147	per_cpu(physical_cluster, cpu) = old_cluster;
	148	}
	149
	150	mutex_unlock(&cluster_lock[new_cluster]);
	151
	152	return ret;
	153	}
	154
	155	mutex_unlock(&cluster_lock[new_cluster]);
	156
	157	/* Recalc freq for old cluster when switching clusters */
	158	if (old_cluster != new_cluster) {
a0f950d3 SH	159	/* Switch cluster */
	160	bL_switch_request(cpu, new_cluster);
	161
	162	mutex_lock(&cluster_lock[old_cluster]);
	163
	164	/* Set freq of old cluster if there are cpus left on it */
	165	new_rate = find_cluster_maxfreq(old_cluster);
	166	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	167
09402d57 SH	168	if (new_rate &&
	169	clk_set_rate(clk[old_cluster], new_rate * 1000)) {
	170	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
	171	__func__, ret, old_cluster);
a0f950d3 SH	172	}
	173	mutex_unlock(&cluster_lock[old_cluster]);
	174	}
	175
	176	return 0;
	177	}
	178
	179	/* Set clock frequency */
1f1b4650 SH	180	static int ve_spc_cpufreq_set_target(struct cpufreq_policy *policy,
1f1b4650 SH	181	unsigned int index)
a0f950d3 SH	182	{
	183	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
	184	unsigned int freqs_new;
a0f950d3 SH	185
	186	cur_cluster = cpu_to_cluster(cpu);
	187	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
	188
	189	freqs_new = freq_table[cur_cluster][index].frequency;
	190
	191	if (is_bL_switching_enabled()) {
e318d2c8	192	if (actual_cluster == A15_CLUSTER && freqs_new < clk_big_min)
a0f950d3	193	new_cluster = A7_CLUSTER;
e318d2c8 SH	194	else if (actual_cluster == A7_CLUSTER &&
e318d2c8 SH	195	freqs_new > clk_little_max)
a0f950d3	196	new_cluster = A15_CLUSTER;
a0f950d3 SH	197	}
a0f950d3 SH	198
1a0419b0 IV	199	return ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster,
1a0419b0 IV	200	freqs_new);
a0f950d3 SH	201	}
	202
	203	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	204	{
	205	int count;
	206
	207	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	208	;
	209
	210	return count;
	211	}
	212
	213	/* get the minimum frequency in the cpufreq_frequency_table */
	214	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	215	{
	216	struct cpufreq_frequency_table *pos;
e318d2c8 SH	217	u32 min_freq = ~0;
e318d2c8 SH	218
a0f950d3 SH	219	cpufreq_for_each_entry(pos, table)
	220	if (pos->frequency < min_freq)
	221	min_freq = pos->frequency;
	222	return min_freq;
	223	}
	224
	225	/* get the maximum frequency in the cpufreq_frequency_table */
	226	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	227	{
	228	struct cpufreq_frequency_table *pos;
e318d2c8 SH	229	u32 max_freq = 0;
e318d2c8 SH	230
a0f950d3 SH	231	cpufreq_for_each_entry(pos, table)
	232	if (pos->frequency > max_freq)
	233	max_freq = pos->frequency;
	234	return max_freq;
	235	}
	236
e32beb06 SH	237	static bool search_frequency(struct cpufreq_frequency_table *table, int size,
	238	unsigned int freq)
	239	{
	240	int count;
	241
	242	for (count = 0; count < size; count++) {
	243	if (table[count].frequency == freq)
	244	return true;
	245	}
	246
	247	return false;
	248	}
	249
a0f950d3 SH	250	static int merge_cluster_tables(void)
	251	{
	252	int i, j, k = 0, count = 1;
	253	struct cpufreq_frequency_table *table;
	254
	255	for (i = 0; i < MAX_CLUSTERS; i++)
	256	count += get_table_count(freq_table[i]);
	257
	258	table = kcalloc(count, sizeof(*table), GFP_KERNEL);
	259	if (!table)
	260	return -ENOMEM;
	261
	262	freq_table[MAX_CLUSTERS] = table;
	263
	264	/* Add in reverse order to get freqs in increasing order */
e32beb06	265	for (i = MAX_CLUSTERS - 1; i >= 0; i--, count = k) {
a0f950d3	266	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
e32beb06 SH	267	j++) {
	268	if (i == A15_CLUSTER &&
	269	search_frequency(table, count, freq_table[i][j].frequency))
	270	continue; /* skip duplicates */
	271	table[k++].frequency =
e318d2c8	272	VIRT_FREQ(i, freq_table[i][j].frequency);
a0f950d3 SH	273	}
	274	}
	275
	276	table[k].driver_data = k;
	277	table[k].frequency = CPUFREQ_TABLE_END;
	278
a0f950d3 SH	279	return 0;
	280	}
	281
	282	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
	283	const struct cpumask *cpumask)
	284	{
	285	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	286
	287	if (!freq_table[cluster])
	288	return;
	289
	290	clk_put(clk[cluster]);
	291	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
a0f950d3 SH	292	}
	293
	294	static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
	295	const struct cpumask *cpumask)
	296	{
	297	u32 cluster = cpu_to_cluster(cpu_dev->id);
	298	int i;
	299
	300	if (atomic_dec_return(&cluster_usage[cluster]))
	301	return;
	302
	303	if (cluster < MAX_CLUSTERS)
	304	return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
	305
	306	for_each_present_cpu(i) {
	307	struct device *cdev = get_cpu_device(i);
09402d57 SH	308
09402d57 SH	309	if (!cdev)
a0f950d3	310	return;
a0f950d3 SH	311
	312	_put_cluster_clk_and_freq_table(cdev, cpumask);
	313	}
	314
	315	/* free virtual table */
	316	kfree(freq_table[cluster]);
	317	}
	318
	319	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
	320	const struct cpumask *cpumask)
	321	{
	322	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	323	int ret;
	324
	325	if (freq_table[cluster])
	326	return 0;
	327
1f1b4650 SH	328	/*
	329	* platform specific SPC code must initialise the opp table
	330	* so just check if the OPP count is non-zero
	331	*/
	332	ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0;
	333	if (ret)
a0f950d3	334	goto out;
a0f950d3 SH	335
a0f950d3 SH	336	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
09402d57	337	if (ret)
1f1b4650	338	goto out;
a0f950d3 SH	339
a0f950d3 SH	340	clk[cluster] = clk_get(cpu_dev, NULL);
09402d57	341	if (!IS_ERR(clk[cluster]))
a0f950d3	342	return 0;
a0f950d3 SH	343
a0f950d3 SH	344	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
e318d2c8	345	__func__, cpu_dev->id, cluster);
a0f950d3 SH	346	ret = PTR_ERR(clk[cluster]);
	347	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	348
a0f950d3 SH	349	out:
a0f950d3 SH	350	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
e318d2c8	351	cluster);
a0f950d3 SH	352	return ret;
	353	}
	354
	355	static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
	356	const struct cpumask *cpumask)
	357	{
	358	u32 cluster = cpu_to_cluster(cpu_dev->id);
	359	int i, ret;
	360
	361	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	362	return 0;
	363
	364	if (cluster < MAX_CLUSTERS) {
	365	ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
	366	if (ret)
	367	atomic_dec(&cluster_usage[cluster]);
	368	return ret;
	369	}
	370
	371	/*
	372	* Get data for all clusters and fill virtual cluster with a merge of
	373	* both
	374	*/
	375	for_each_present_cpu(i) {
	376	struct device *cdev = get_cpu_device(i);
09402d57 SH	377
09402d57 SH	378	if (!cdev)
a0f950d3	379	return -ENODEV;
a0f950d3 SH	380
	381	ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
	382	if (ret)
	383	goto put_clusters;
	384	}
	385
	386	ret = merge_cluster_tables();
	387	if (ret)
	388	goto put_clusters;
	389
	390	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
4a6e1352 SH	391	clk_big_min = get_table_min(freq_table[A15_CLUSTER]);
	392	clk_little_max = VIRT_FREQ(A7_CLUSTER,
	393	get_table_max(freq_table[A7_CLUSTER]));
a0f950d3	394
a0f950d3 SH	395	return 0;
	396
	397	put_clusters:
	398	for_each_present_cpu(i) {
	399	struct device *cdev = get_cpu_device(i);
09402d57 SH	400
09402d57 SH	401	if (!cdev)
a0f950d3	402	return -ENODEV;
a0f950d3 SH	403
	404	_put_cluster_clk_and_freq_table(cdev, cpumask);
	405	}
	406
	407	atomic_dec(&cluster_usage[cluster]);
	408
	409	return ret;
	410	}
	411
	412	/* Per-CPU initialization */
1f1b4650	413	static int ve_spc_cpufreq_init(struct cpufreq_policy *policy)
a0f950d3 SH	414	{
	415	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	416	struct device *cpu_dev;
	417	int ret;
	418
	419	cpu_dev = get_cpu_device(policy->cpu);
	420	if (!cpu_dev) {
	421	pr_err("%s: failed to get cpu%d device\n", __func__,
e318d2c8	422	policy->cpu);
a0f950d3 SH	423	return -ENODEV;
	424	}
	425
	426	if (cur_cluster < MAX_CLUSTERS) {
	427	int cpu;
	428
c9385887	429	dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus);
a0f950d3 SH	430
	431	for_each_cpu(cpu, policy->cpus)
	432	per_cpu(physical_cluster, cpu) = cur_cluster;
	433	} else {
	434	/* Assumption: during init, we are always running on A15 */
	435	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	436	}
	437
	438	ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	439	if (ret)
	440	return ret;
	441
	442	policy->freq_table = freq_table[cur_cluster];
1f1b4650	443	policy->cpuinfo.transition_latency = 1000000; /* 1 ms */
a0f950d3	444
0e0ffa85	445	dev_pm_opp_of_register_em(cpu_dev, policy->cpus);
a0f950d3 SH	446
a0f950d3 SH	447	if (is_bL_switching_enabled())
e318d2c8 SH	448	per_cpu(cpu_last_req_freq, policy->cpu) =
e318d2c8 SH	449	clk_get_cpu_rate(policy->cpu);
a0f950d3 SH	450
	451	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
	452	return 0;
	453	}
	454
1f1b4650	455	static int ve_spc_cpufreq_exit(struct cpufreq_policy *policy)
a0f950d3 SH	456	{
	457	struct device *cpu_dev;
	458	int cur_cluster = cpu_to_cluster(policy->cpu);
	459
	460	if (cur_cluster < MAX_CLUSTERS) {
	461	cpufreq_cooling_unregister(cdev[cur_cluster]);
	462	cdev[cur_cluster] = NULL;
	463	}
	464
	465	cpu_dev = get_cpu_device(policy->cpu);
	466	if (!cpu_dev) {
	467	pr_err("%s: failed to get cpu%d device\n", __func__,
e318d2c8	468	policy->cpu);
a0f950d3 SH	469	return -ENODEV;
	470	}
	471
	472	put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
a0f950d3 SH	473	return 0;
	474	}
	475
1f1b4650	476	static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy)
a0f950d3 SH	477	{
	478	int cur_cluster = cpu_to_cluster(policy->cpu);
	479
	480	/* Do not register a cpu_cooling device if we are in IKS mode */
	481	if (cur_cluster >= MAX_CLUSTERS)
	482	return;
	483
	484	cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
	485	}
	486
1f1b4650 SH	487	static struct cpufreq_driver ve_spc_cpufreq_driver = {
1f1b4650 SH	488	.name = "vexpress-spc",
5ae4a4b4	489	.flags = CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
a0f950d3 SH	490	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
a0f950d3 SH	491	.verify = cpufreq_generic_frequency_table_verify,
1f1b4650 SH	492	.target_index = ve_spc_cpufreq_set_target,
	493	.get = ve_spc_cpufreq_get_rate,
	494	.init = ve_spc_cpufreq_init,
	495	.exit = ve_spc_cpufreq_exit,
	496	.ready = ve_spc_cpufreq_ready,
a0f950d3 SH	497	.attr = cpufreq_generic_attr,
	498	};
	499
	500	#ifdef CONFIG_BL_SWITCHER
	501	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	502	unsigned long action, void *_arg)
	503	{
	504	pr_debug("%s: action: %ld\n", __func__, action);
	505
	506	switch (action) {
	507	case BL_NOTIFY_PRE_ENABLE:
	508	case BL_NOTIFY_PRE_DISABLE:
1f1b4650	509	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	510	break;
	511
	512	case BL_NOTIFY_POST_ENABLE:
	513	set_switching_enabled(true);
1f1b4650	514	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	515	break;
	516
	517	case BL_NOTIFY_POST_DISABLE:
	518	set_switching_enabled(false);
1f1b4650	519	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	520	break;
	521
	522	default:
	523	return NOTIFY_DONE;
	524	}
	525
	526	return NOTIFY_OK;
	527	}
	528
	529	static struct notifier_block bL_switcher_notifier = {
	530	.notifier_call = bL_cpufreq_switcher_notifier,
	531	};
	532
	533	static int __bLs_register_notifier(void)
	534	{
	535	return bL_switcher_register_notifier(&bL_switcher_notifier);
	536	}
	537
	538	static int __bLs_unregister_notifier(void)
	539	{
	540	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	541	}
	542	#else
	543	static int __bLs_register_notifier(void) { return 0; }
	544	static int __bLs_unregister_notifier(void) { return 0; }
	545	#endif
	546
1f1b4650	547	static int ve_spc_cpufreq_probe(struct platform_device *pdev)
a0f950d3 SH	548	{
	549	int ret, i;
	550
a0f950d3 SH	551	set_switching_enabled(bL_switcher_get_enabled());
	552
	553	for (i = 0; i < MAX_CLUSTERS; i++)
	554	mutex_init(&cluster_lock[i]);
	555
1f1b4650	556	ret = cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	557	if (ret) {
a0f950d3 SH	558	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
1f1b4650	559	__func__, ve_spc_cpufreq_driver.name, ret);
a0f950d3 SH	560	} else {
a0f950d3 SH	561	ret = __bLs_register_notifier();
1f1b4650 SH	562	if (ret)
	563	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
	564	else
a0f950d3	565	pr_info("%s: Registered platform driver: %s\n",
1f1b4650	566	__func__, ve_spc_cpufreq_driver.name);
a0f950d3 SH	567	}
	568
	569	bL_switcher_put_enabled();
	570	return ret;
	571	}
	572
1f1b4650	573	static int ve_spc_cpufreq_remove(struct platform_device *pdev)
a0f950d3	574	{
a0f950d3 SH	575	bL_switcher_get_enabled();
a0f950d3 SH	576	__bLs_unregister_notifier();
1f1b4650	577	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	578	bL_switcher_put_enabled();
a0f950d3 SH	579	pr_info("%s: Un-registered platform driver: %s\n", __func__,
1f1b4650	580	ve_spc_cpufreq_driver.name);
47ac9aa1 SH	581	return 0;
	582	}
	583
	584	static struct platform_driver ve_spc_cpufreq_platdrv = {
	585	.driver = {
	586	.name = "vexpress-spc-cpufreq",
47ac9aa1 SH	587	},
	588	.probe = ve_spc_cpufreq_probe,
	589	.remove = ve_spc_cpufreq_remove,
	590	};
	591	module_platform_driver(ve_spc_cpufreq_platdrv);
	592
d1518399	593	MODULE_ALIAS("platform:vexpress-spc-cpufreq");
a0f950d3 SH	594	MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
	595	MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
	596	MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
	597	MODULE_LICENSE("GPL v2");