[linux.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 <[email protected]>
 *
 * Copyright (C) 2013 Linaro.
 * Viresh Kumar <[email protected]>
 */

#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;
	int ret;

	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;
		}
	}

	ret = ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster,
				      freqs_new);

	if (!ret) {
		arch_set_freq_scale(policy->related_cpus, freqs_new,
				    policy->cpuinfo.max_freq);
	}

	return ret;
}

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 = 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--) {
		for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
				j++) {
			table[k].frequency = VIRT_FREQ(i,
					freq_table[i][j].frequency);
			k++;
		}
	}

	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[0]);
	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));

	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;

		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;

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

	dev_pm_opp_of_register_em(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_STICKY |
					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_AUTHOR("Viresh Kumar <[email protected]>");
MODULE_AUTHOR("Sudeep Holla <[email protected]>");
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 <[email protected]>
47ac9aa1	7	*
a0f950d3 SH	8	* Copyright (C) 2013 Linaro.
a0f950d3 SH	9	* Viresh Kumar <[email protected]>
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
	82	if ((cluster == per_cpu(physical_cluster, j)) &&
	83	(max_freq < cpu_freq))
	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;
	185	int ret;
	186
	187	cur_cluster = cpu_to_cluster(cpu);
	188	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
	189
	190	freqs_new = freq_table[cur_cluster][index].frequency;
	191
	192	if (is_bL_switching_enabled()) {
	193	if ((actual_cluster == A15_CLUSTER) &&
	194	(freqs_new < clk_big_min)) {
	195	new_cluster = A7_CLUSTER;
	196	} else if ((actual_cluster == A7_CLUSTER) &&
	197	(freqs_new > clk_little_max)) {
	198	new_cluster = A15_CLUSTER;
	199	}
	200	}
	201
1f1b4650 SH	202	ret = ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster,
1f1b4650 SH	203	freqs_new);
a0f950d3 SH	204
	205	if (!ret) {
	206	arch_set_freq_scale(policy->related_cpus, freqs_new,
	207	policy->cpuinfo.max_freq);
	208	}
	209
	210	return ret;
	211	}
	212
	213	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	214	{
	215	int count;
	216
	217	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	218	;
	219
	220	return count;
	221	}
	222
	223	/* get the minimum frequency in the cpufreq_frequency_table */
	224	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	225	{
	226	struct cpufreq_frequency_table *pos;
	227	uint32_t min_freq = ~0;
	228	cpufreq_for_each_entry(pos, table)
	229	if (pos->frequency < min_freq)
	230	min_freq = pos->frequency;
	231	return min_freq;
	232	}
	233
	234	/* get the maximum frequency in the cpufreq_frequency_table */
	235	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	236	{
	237	struct cpufreq_frequency_table *pos;
	238	uint32_t max_freq = 0;
	239	cpufreq_for_each_entry(pos, table)
	240	if (pos->frequency > max_freq)
	241	max_freq = pos->frequency;
	242	return max_freq;
	243	}
	244
	245	static int merge_cluster_tables(void)
	246	{
	247	int i, j, k = 0, count = 1;
	248	struct cpufreq_frequency_table *table;
	249
	250	for (i = 0; i < MAX_CLUSTERS; i++)
	251	count += get_table_count(freq_table[i]);
	252
	253	table = kcalloc(count, sizeof(*table), GFP_KERNEL);
	254	if (!table)
	255	return -ENOMEM;
	256
	257	freq_table[MAX_CLUSTERS] = table;
	258
	259	/* Add in reverse order to get freqs in increasing order */
	260	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	261	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	262	j++) {
	263	table[k].frequency = VIRT_FREQ(i,
	264	freq_table[i][j].frequency);
a0f950d3 SH	265	k++;
	266	}
	267	}
	268
	269	table[k].driver_data = k;
	270	table[k].frequency = CPUFREQ_TABLE_END;
	271
a0f950d3 SH	272	return 0;
	273	}
	274
	275	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
	276	const struct cpumask *cpumask)
	277	{
	278	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	279
	280	if (!freq_table[cluster])
	281	return;
	282
	283	clk_put(clk[cluster]);
	284	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
a0f950d3 SH	285	}
	286
	287	static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
	288	const struct cpumask *cpumask)
	289	{
	290	u32 cluster = cpu_to_cluster(cpu_dev->id);
	291	int i;
	292
	293	if (atomic_dec_return(&cluster_usage[cluster]))
	294	return;
	295
	296	if (cluster < MAX_CLUSTERS)
	297	return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
	298
	299	for_each_present_cpu(i) {
	300	struct device *cdev = get_cpu_device(i);
09402d57 SH	301
09402d57 SH	302	if (!cdev)
a0f950d3	303	return;
a0f950d3 SH	304
	305	_put_cluster_clk_and_freq_table(cdev, cpumask);
	306	}
	307
	308	/* free virtual table */
	309	kfree(freq_table[cluster]);
	310	}
	311
	312	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
	313	const struct cpumask *cpumask)
	314	{
	315	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	316	int ret;
	317
	318	if (freq_table[cluster])
	319	return 0;
	320
1f1b4650 SH	321	/*
	322	* platform specific SPC code must initialise the opp table
	323	* so just check if the OPP count is non-zero
	324	*/
	325	ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0;
	326	if (ret)
a0f950d3	327	goto out;
a0f950d3 SH	328
a0f950d3 SH	329	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
09402d57	330	if (ret)
1f1b4650	331	goto out;
a0f950d3 SH	332
a0f950d3 SH	333	clk[cluster] = clk_get(cpu_dev, NULL);
09402d57	334	if (!IS_ERR(clk[cluster]))
a0f950d3	335	return 0;
a0f950d3 SH	336
	337	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	338	__func__, cpu_dev->id, cluster);
	339	ret = PTR_ERR(clk[cluster]);
	340	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	341
a0f950d3 SH	342	out:
	343	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	344	cluster);
	345	return ret;
	346	}
	347
	348	static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
	349	const struct cpumask *cpumask)
	350	{
	351	u32 cluster = cpu_to_cluster(cpu_dev->id);
	352	int i, ret;
	353
	354	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	355	return 0;
	356
	357	if (cluster < MAX_CLUSTERS) {
	358	ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
	359	if (ret)
	360	atomic_dec(&cluster_usage[cluster]);
	361	return ret;
	362	}
	363
	364	/*
	365	* Get data for all clusters and fill virtual cluster with a merge of
	366	* both
	367	*/
	368	for_each_present_cpu(i) {
	369	struct device *cdev = get_cpu_device(i);
09402d57 SH	370
09402d57 SH	371	if (!cdev)
a0f950d3	372	return -ENODEV;
a0f950d3 SH	373
	374	ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
	375	if (ret)
	376	goto put_clusters;
	377	}
	378
	379	ret = merge_cluster_tables();
	380	if (ret)
	381	goto put_clusters;
	382
	383	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	384	clk_big_min = get_table_min(freq_table[0]);
	385	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	386
a0f950d3 SH	387	return 0;
	388
	389	put_clusters:
	390	for_each_present_cpu(i) {
	391	struct device *cdev = get_cpu_device(i);
09402d57 SH	392
09402d57 SH	393	if (!cdev)
a0f950d3	394	return -ENODEV;
a0f950d3 SH	395
	396	_put_cluster_clk_and_freq_table(cdev, cpumask);
	397	}
	398
	399	atomic_dec(&cluster_usage[cluster]);
	400
	401	return ret;
	402	}
	403
	404	/* Per-CPU initialization */
1f1b4650	405	static int ve_spc_cpufreq_init(struct cpufreq_policy *policy)
a0f950d3 SH	406	{
	407	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	408	struct device *cpu_dev;
	409	int ret;
	410
	411	cpu_dev = get_cpu_device(policy->cpu);
	412	if (!cpu_dev) {
	413	pr_err("%s: failed to get cpu%d device\n", __func__,
	414	policy->cpu);
	415	return -ENODEV;
	416	}
	417
	418	if (cur_cluster < MAX_CLUSTERS) {
	419	int cpu;
	420
	421	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
	422
	423	for_each_cpu(cpu, policy->cpus)
	424	per_cpu(physical_cluster, cpu) = cur_cluster;
	425	} else {
	426	/* Assumption: during init, we are always running on A15 */
	427	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	428	}
	429
	430	ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	431	if (ret)
	432	return ret;
	433
	434	policy->freq_table = freq_table[cur_cluster];
1f1b4650	435	policy->cpuinfo.transition_latency = 1000000; /* 1 ms */
a0f950d3 SH	436
	437	dev_pm_opp_of_register_em(policy->cpus);
	438
	439	if (is_bL_switching_enabled())
	440	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
	441
	442	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
	443	return 0;
	444	}
	445
1f1b4650	446	static int ve_spc_cpufreq_exit(struct cpufreq_policy *policy)
a0f950d3 SH	447	{
	448	struct device *cpu_dev;
	449	int cur_cluster = cpu_to_cluster(policy->cpu);
	450
	451	if (cur_cluster < MAX_CLUSTERS) {
	452	cpufreq_cooling_unregister(cdev[cur_cluster]);
	453	cdev[cur_cluster] = NULL;
	454	}
	455
	456	cpu_dev = get_cpu_device(policy->cpu);
	457	if (!cpu_dev) {
	458	pr_err("%s: failed to get cpu%d device\n", __func__,
	459	policy->cpu);
	460	return -ENODEV;
	461	}
	462
	463	put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
a0f950d3 SH	464	return 0;
	465	}
	466
1f1b4650	467	static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy)
a0f950d3 SH	468	{
	469	int cur_cluster = cpu_to_cluster(policy->cpu);
	470
	471	/* Do not register a cpu_cooling device if we are in IKS mode */
	472	if (cur_cluster >= MAX_CLUSTERS)
	473	return;
	474
	475	cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
	476	}
	477
1f1b4650 SH	478	static struct cpufreq_driver ve_spc_cpufreq_driver = {
1f1b4650 SH	479	.name = "vexpress-spc",
a0f950d3 SH	480	.flags = CPUFREQ_STICKY \|
	481	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
	482	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	483	.verify = cpufreq_generic_frequency_table_verify,
1f1b4650 SH	484	.target_index = ve_spc_cpufreq_set_target,
	485	.get = ve_spc_cpufreq_get_rate,
	486	.init = ve_spc_cpufreq_init,
	487	.exit = ve_spc_cpufreq_exit,
	488	.ready = ve_spc_cpufreq_ready,
a0f950d3 SH	489	.attr = cpufreq_generic_attr,
	490	};
	491
	492	#ifdef CONFIG_BL_SWITCHER
	493	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	494	unsigned long action, void *_arg)
	495	{
	496	pr_debug("%s: action: %ld\n", __func__, action);
	497
	498	switch (action) {
	499	case BL_NOTIFY_PRE_ENABLE:
	500	case BL_NOTIFY_PRE_DISABLE:
1f1b4650	501	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	502	break;
	503
	504	case BL_NOTIFY_POST_ENABLE:
	505	set_switching_enabled(true);
1f1b4650	506	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	507	break;
	508
	509	case BL_NOTIFY_POST_DISABLE:
	510	set_switching_enabled(false);
1f1b4650	511	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	512	break;
	513
	514	default:
	515	return NOTIFY_DONE;
	516	}
	517
	518	return NOTIFY_OK;
	519	}
	520
	521	static struct notifier_block bL_switcher_notifier = {
	522	.notifier_call = bL_cpufreq_switcher_notifier,
	523	};
	524
	525	static int __bLs_register_notifier(void)
	526	{
	527	return bL_switcher_register_notifier(&bL_switcher_notifier);
	528	}
	529
	530	static int __bLs_unregister_notifier(void)
	531	{
	532	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	533	}
	534	#else
	535	static int __bLs_register_notifier(void) { return 0; }
	536	static int __bLs_unregister_notifier(void) { return 0; }
	537	#endif
	538
1f1b4650	539	static int ve_spc_cpufreq_probe(struct platform_device *pdev)
a0f950d3 SH	540	{
	541	int ret, i;
	542
a0f950d3 SH	543	set_switching_enabled(bL_switcher_get_enabled());
	544
	545	for (i = 0; i < MAX_CLUSTERS; i++)
	546	mutex_init(&cluster_lock[i]);
	547
1f1b4650	548	ret = cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	549	if (ret) {
a0f950d3 SH	550	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
1f1b4650	551	__func__, ve_spc_cpufreq_driver.name, ret);
a0f950d3 SH	552	} else {
a0f950d3 SH	553	ret = __bLs_register_notifier();
1f1b4650 SH	554	if (ret)
	555	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
	556	else
a0f950d3	557	pr_info("%s: Registered platform driver: %s\n",
1f1b4650	558	__func__, ve_spc_cpufreq_driver.name);
a0f950d3 SH	559	}
	560
	561	bL_switcher_put_enabled();
	562	return ret;
	563	}
	564
1f1b4650	565	static int ve_spc_cpufreq_remove(struct platform_device *pdev)
a0f950d3	566	{
a0f950d3 SH	567	bL_switcher_get_enabled();
a0f950d3 SH	568	__bLs_unregister_notifier();
1f1b4650	569	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	570	bL_switcher_put_enabled();
a0f950d3 SH	571	pr_info("%s: Un-registered platform driver: %s\n", __func__,
1f1b4650	572	ve_spc_cpufreq_driver.name);
47ac9aa1 SH	573	return 0;
	574	}
	575
	576	static struct platform_driver ve_spc_cpufreq_platdrv = {
	577	.driver = {
	578	.name = "vexpress-spc-cpufreq",
47ac9aa1 SH	579	},
	580	.probe = ve_spc_cpufreq_probe,
	581	.remove = ve_spc_cpufreq_remove,
	582	};
	583	module_platform_driver(ve_spc_cpufreq_platdrv);
	584
a0f950d3 SH	585	MODULE_AUTHOR("Viresh Kumar <[email protected]>");
	586	MODULE_AUTHOR("Sudeep Holla <[email protected]>");
	587	MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
	588	MODULE_LICENSE("GPL v2");