[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;
	}

	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 ve_spc_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
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;
	}

	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 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);
			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]);
	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;

	/*
	 * 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) {
		dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
				__func__, cpu_dev->id, ret);
		goto out;
	}

	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]);

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

	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
	87	pr_debug("%s: cluster: %d, max freq: %d\n", __func__, cluster,
	88	max_freq);
	89
	90	return max_freq;
	91	}
	92
	93	static unsigned int clk_get_cpu_rate(unsigned int cpu)
	94	{
	95	u32 cur_cluster = per_cpu(physical_cluster, cpu);
	96	u32 rate = clk_get_rate(clk[cur_cluster]) / 1000;
	97
	98	/* For switcher we use virtual A7 clock rates */
	99	if (is_bL_switching_enabled())
	100	rate = VIRT_FREQ(cur_cluster, rate);
	101
	102	pr_debug("%s: cpu: %d, cluster: %d, freq: %u\n", __func__, cpu,
	103	cur_cluster, rate);
	104
	105	return rate;
	106	}
	107
1f1b4650	108	static unsigned int ve_spc_cpufreq_get_rate(unsigned int cpu)
a0f950d3 SH	109	{
	110	if (is_bL_switching_enabled()) {
	111	pr_debug("%s: freq: %d\n", __func__, per_cpu(cpu_last_req_freq,
	112	cpu));
	113
	114	return per_cpu(cpu_last_req_freq, cpu);
	115	} else {
	116	return clk_get_cpu_rate(cpu);
	117	}
	118	}
	119
	120	static unsigned int
1f1b4650	121	ve_spc_cpufreq_set_rate(u32 cpu, u32 old_cluster, u32 new_cluster, u32 rate)
a0f950d3 SH	122	{
	123	u32 new_rate, prev_rate;
	124	int ret;
	125	bool bLs = is_bL_switching_enabled();
	126
	127	mutex_lock(&cluster_lock[new_cluster]);
	128
	129	if (bLs) {
	130	prev_rate = per_cpu(cpu_last_req_freq, cpu);
	131	per_cpu(cpu_last_req_freq, cpu) = rate;
	132	per_cpu(physical_cluster, cpu) = new_cluster;
	133
	134	new_rate = find_cluster_maxfreq(new_cluster);
	135	new_rate = ACTUAL_FREQ(new_cluster, new_rate);
	136	} else {
	137	new_rate = rate;
	138	}
	139
	140	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d, freq: %d\n",
	141	__func__, cpu, old_cluster, new_cluster, new_rate);
	142
	143	ret = clk_set_rate(clk[new_cluster], new_rate * 1000);
	144	if (!ret) {
	145	/*
	146	* FIXME: clk_set_rate hasn't returned an error here however it
	147	* may be that clk_change_rate failed due to hardware or
	148	* firmware issues and wasn't able to report that due to the
	149	* current design of the clk core layer. To work around this
	150	* problem we will read back the clock rate and check it is
	151	* correct. This needs to be removed once clk core is fixed.
	152	*/
	153	if (clk_get_rate(clk[new_cluster]) != new_rate * 1000)
	154	ret = -EIO;
	155	}
	156
	157	if (WARN_ON(ret)) {
	158	pr_err("clk_set_rate failed: %d, new cluster: %d\n", ret,
	159	new_cluster);
	160	if (bLs) {
	161	per_cpu(cpu_last_req_freq, cpu) = prev_rate;
	162	per_cpu(physical_cluster, cpu) = old_cluster;
	163	}
	164
	165	mutex_unlock(&cluster_lock[new_cluster]);
	166
	167	return ret;
	168	}
	169
	170	mutex_unlock(&cluster_lock[new_cluster]);
	171
	172	/* Recalc freq for old cluster when switching clusters */
	173	if (old_cluster != new_cluster) {
	174	pr_debug("%s: cpu: %d, old cluster: %d, new cluster: %d\n",
	175	__func__, cpu, old_cluster, new_cluster);
	176
	177	/* Switch cluster */
	178	bL_switch_request(cpu, new_cluster);
	179
	180	mutex_lock(&cluster_lock[old_cluster]);
	181
	182	/* Set freq of old cluster if there are cpus left on it */
	183	new_rate = find_cluster_maxfreq(old_cluster);
	184	new_rate = ACTUAL_FREQ(old_cluster, new_rate);
	185
186	if (new_rate) {
187	pr_debug("%s: Updating rate of old cluster: %d, to freq: %d\n",
188	__func__, old_cluster, new_rate);
189
190	if (clk_set_rate(clk[old_cluster], new_rate * 1000))
191	pr_err("%s: clk_set_rate failed: %d, old cluster: %d\n",
192	__func__, ret, old_cluster);
193	}
194	mutex_unlock(&cluster_lock[old_cluster]);
195	}
196
197	return 0;
198	}
199
200	/* Set clock frequency */
1f1b4650 SH	201	static int ve_spc_cpufreq_set_target(struct cpufreq_policy *policy,
1f1b4650 SH	202	unsigned int index)
a0f950d3 SH	203	{
	204	u32 cpu = policy->cpu, cur_cluster, new_cluster, actual_cluster;
	205	unsigned int freqs_new;
	206	int ret;
	207
	208	cur_cluster = cpu_to_cluster(cpu);
	209	new_cluster = actual_cluster = per_cpu(physical_cluster, cpu);
	210
	211	freqs_new = freq_table[cur_cluster][index].frequency;
	212
	213	if (is_bL_switching_enabled()) {
	214	if ((actual_cluster == A15_CLUSTER) &&
	215	(freqs_new < clk_big_min)) {
	216	new_cluster = A7_CLUSTER;
	217	} else if ((actual_cluster == A7_CLUSTER) &&
	218	(freqs_new > clk_little_max)) {
	219	new_cluster = A15_CLUSTER;
	220	}
	221	}
	222
1f1b4650 SH	223	ret = ve_spc_cpufreq_set_rate(cpu, actual_cluster, new_cluster,
1f1b4650 SH	224	freqs_new);
a0f950d3 SH	225
	226	if (!ret) {
	227	arch_set_freq_scale(policy->related_cpus, freqs_new,
	228	policy->cpuinfo.max_freq);
	229	}
	230
	231	return ret;
	232	}
	233
	234	static inline u32 get_table_count(struct cpufreq_frequency_table *table)
	235	{
	236	int count;
	237
	238	for (count = 0; table[count].frequency != CPUFREQ_TABLE_END; count++)
	239	;
	240
	241	return count;
	242	}
	243
	244	/* get the minimum frequency in the cpufreq_frequency_table */
	245	static inline u32 get_table_min(struct cpufreq_frequency_table *table)
	246	{
	247	struct cpufreq_frequency_table *pos;
	248	uint32_t min_freq = ~0;
	249	cpufreq_for_each_entry(pos, table)
	250	if (pos->frequency < min_freq)
	251	min_freq = pos->frequency;
	252	return min_freq;
	253	}
	254
	255	/* get the maximum frequency in the cpufreq_frequency_table */
	256	static inline u32 get_table_max(struct cpufreq_frequency_table *table)
	257	{
	258	struct cpufreq_frequency_table *pos;
	259	uint32_t max_freq = 0;
	260	cpufreq_for_each_entry(pos, table)
	261	if (pos->frequency > max_freq)
	262	max_freq = pos->frequency;
	263	return max_freq;
	264	}
	265
	266	static int merge_cluster_tables(void)
	267	{
	268	int i, j, k = 0, count = 1;
	269	struct cpufreq_frequency_table *table;
	270
	271	for (i = 0; i < MAX_CLUSTERS; i++)
	272	count += get_table_count(freq_table[i]);
	273
	274	table = kcalloc(count, sizeof(*table), GFP_KERNEL);
	275	if (!table)
	276	return -ENOMEM;
	277
	278	freq_table[MAX_CLUSTERS] = table;
	279
	280	/* Add in reverse order to get freqs in increasing order */
	281	for (i = MAX_CLUSTERS - 1; i >= 0; i--) {
	282	for (j = 0; freq_table[i][j].frequency != CPUFREQ_TABLE_END;
	283	j++) {
	284	table[k].frequency = VIRT_FREQ(i,
	285	freq_table[i][j].frequency);
	286	pr_debug("%s: index: %d, freq: %d\n", __func__, k,
	287	table[k].frequency);
	288	k++;
289	}
290	}
291
292	table[k].driver_data = k;
293	table[k].frequency = CPUFREQ_TABLE_END;
294
295	pr_debug("%s: End, table: %p, count: %d\n", __func__, table, k);
296
297	return 0;
298	}
299
300	static void _put_cluster_clk_and_freq_table(struct device *cpu_dev,
301	const struct cpumask *cpumask)
302	{
303	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
304
305	if (!freq_table[cluster])
306	return;
307
308	clk_put(clk[cluster]);
309	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
a0f950d3 SH	310	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	311	}
	312
	313	static void put_cluster_clk_and_freq_table(struct device *cpu_dev,
	314	const struct cpumask *cpumask)
	315	{
	316	u32 cluster = cpu_to_cluster(cpu_dev->id);
	317	int i;
	318
	319	if (atomic_dec_return(&cluster_usage[cluster]))
	320	return;
	321
	322	if (cluster < MAX_CLUSTERS)
	323	return _put_cluster_clk_and_freq_table(cpu_dev, cpumask);
	324
	325	for_each_present_cpu(i) {
	326	struct device *cdev = get_cpu_device(i);
	327	if (!cdev) {
	328	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	329	return;
	330	}
	331
	332	_put_cluster_clk_and_freq_table(cdev, cpumask);
	333	}
	334
	335	/* free virtual table */
	336	kfree(freq_table[cluster]);
	337	}
	338
	339	static int _get_cluster_clk_and_freq_table(struct device *cpu_dev,
	340	const struct cpumask *cpumask)
	341	{
	342	u32 cluster = raw_cpu_to_cluster(cpu_dev->id);
	343	int ret;
	344
	345	if (freq_table[cluster])
	346	return 0;
	347
1f1b4650 SH	348	/*
	349	* platform specific SPC code must initialise the opp table
	350	* so just check if the OPP count is non-zero
	351	*/
	352	ret = dev_pm_opp_get_opp_count(cpu_dev) <= 0;
	353	if (ret)
a0f950d3	354	goto out;
a0f950d3 SH	355
	356	ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
	357	if (ret) {
	358	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	359	__func__, cpu_dev->id, ret);
1f1b4650	360	goto out;
a0f950d3 SH	361	}
	362
	363	clk[cluster] = clk_get(cpu_dev, NULL);
	364	if (!IS_ERR(clk[cluster])) {
	365	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	366	__func__, clk[cluster], freq_table[cluster],
	367	cluster);
	368	return 0;
	369	}
	370
	371	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	372	__func__, cpu_dev->id, cluster);
	373	ret = PTR_ERR(clk[cluster]);
	374	dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	375
a0f950d3 SH	376	out:
	377	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	378	cluster);
	379	return ret;
	380	}
	381
	382	static int get_cluster_clk_and_freq_table(struct device *cpu_dev,
	383	const struct cpumask *cpumask)
	384	{
	385	u32 cluster = cpu_to_cluster(cpu_dev->id);
	386	int i, ret;
	387
	388	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	389	return 0;
	390
	391	if (cluster < MAX_CLUSTERS) {
	392	ret = _get_cluster_clk_and_freq_table(cpu_dev, cpumask);
	393	if (ret)
	394	atomic_dec(&cluster_usage[cluster]);
	395	return ret;
	396	}
	397
	398	/*
	399	* Get data for all clusters and fill virtual cluster with a merge of
	400	* both
	401	*/
	402	for_each_present_cpu(i) {
	403	struct device *cdev = get_cpu_device(i);
	404	if (!cdev) {
	405	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	406	return -ENODEV;
	407	}
	408
	409	ret = _get_cluster_clk_and_freq_table(cdev, cpumask);
	410	if (ret)
	411	goto put_clusters;
	412	}
	413
	414	ret = merge_cluster_tables();
	415	if (ret)
	416	goto put_clusters;
	417
	418	/* Assuming 2 cluster, set clk_big_min and clk_little_max */
	419	clk_big_min = get_table_min(freq_table[0]);
	420	clk_little_max = VIRT_FREQ(1, get_table_max(freq_table[1]));
	421
	422	pr_debug("%s: cluster: %d, clk_big_min: %d, clk_little_max: %d\n",
	423	__func__, cluster, clk_big_min, clk_little_max);
	424
	425	return 0;
	426
	427	put_clusters:
	428	for_each_present_cpu(i) {
	429	struct device *cdev = get_cpu_device(i);
	430	if (!cdev) {
	431	pr_err("%s: failed to get cpu%d device\n", __func__, i);
	432	return -ENODEV;
	433	}
	434
	435	_put_cluster_clk_and_freq_table(cdev, cpumask);
	436	}
	437
	438	atomic_dec(&cluster_usage[cluster]);
	439
440	return ret;
441	}
442
443	/* Per-CPU initialization */
1f1b4650	444	static int ve_spc_cpufreq_init(struct cpufreq_policy *policy)
a0f950d3 SH	445	{
	446	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	447	struct device *cpu_dev;
	448	int ret;
	449
	450	cpu_dev = get_cpu_device(policy->cpu);
	451	if (!cpu_dev) {
	452	pr_err("%s: failed to get cpu%d device\n", __func__,
	453	policy->cpu);
	454	return -ENODEV;
	455	}
	456
	457	if (cur_cluster < MAX_CLUSTERS) {
	458	int cpu;
	459
	460	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
	461
	462	for_each_cpu(cpu, policy->cpus)
	463	per_cpu(physical_cluster, cpu) = cur_cluster;
	464	} else {
	465	/* Assumption: during init, we are always running on A15 */
	466	per_cpu(physical_cluster, policy->cpu) = A15_CLUSTER;
	467	}
	468
	469	ret = get_cluster_clk_and_freq_table(cpu_dev, policy->cpus);
	470	if (ret)
	471	return ret;
	472
	473	policy->freq_table = freq_table[cur_cluster];
1f1b4650	474	policy->cpuinfo.transition_latency = 1000000; /* 1 ms */
a0f950d3 SH	475
	476	dev_pm_opp_of_register_em(policy->cpus);
	477
	478	if (is_bL_switching_enabled())
	479	per_cpu(cpu_last_req_freq, policy->cpu) = clk_get_cpu_rate(policy->cpu);
	480
	481	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
	482	return 0;
	483	}
	484
1f1b4650	485	static int ve_spc_cpufreq_exit(struct cpufreq_policy *policy)
a0f950d3 SH	486	{
	487	struct device *cpu_dev;
	488	int cur_cluster = cpu_to_cluster(policy->cpu);
	489
	490	if (cur_cluster < MAX_CLUSTERS) {
	491	cpufreq_cooling_unregister(cdev[cur_cluster]);
	492	cdev[cur_cluster] = NULL;
	493	}
	494
	495	cpu_dev = get_cpu_device(policy->cpu);
	496	if (!cpu_dev) {
	497	pr_err("%s: failed to get cpu%d device\n", __func__,
	498	policy->cpu);
	499	return -ENODEV;
	500	}
	501
	502	put_cluster_clk_and_freq_table(cpu_dev, policy->related_cpus);
	503	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	504
	505	return 0;
	506	}
	507
1f1b4650	508	static void ve_spc_cpufreq_ready(struct cpufreq_policy *policy)
a0f950d3 SH	509	{
	510	int cur_cluster = cpu_to_cluster(policy->cpu);
	511
	512	/* Do not register a cpu_cooling device if we are in IKS mode */
	513	if (cur_cluster >= MAX_CLUSTERS)
	514	return;
	515
	516	cdev[cur_cluster] = of_cpufreq_cooling_register(policy);
	517	}
	518
1f1b4650 SH	519	static struct cpufreq_driver ve_spc_cpufreq_driver = {
1f1b4650 SH	520	.name = "vexpress-spc",
a0f950d3 SH	521	.flags = CPUFREQ_STICKY \|
	522	CPUFREQ_HAVE_GOVERNOR_PER_POLICY \|
	523	CPUFREQ_NEED_INITIAL_FREQ_CHECK,
	524	.verify = cpufreq_generic_frequency_table_verify,
1f1b4650 SH	525	.target_index = ve_spc_cpufreq_set_target,
	526	.get = ve_spc_cpufreq_get_rate,
	527	.init = ve_spc_cpufreq_init,
	528	.exit = ve_spc_cpufreq_exit,
	529	.ready = ve_spc_cpufreq_ready,
a0f950d3 SH	530	.attr = cpufreq_generic_attr,
	531	};
	532
	533	#ifdef CONFIG_BL_SWITCHER
	534	static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
	535	unsigned long action, void *_arg)
	536	{
	537	pr_debug("%s: action: %ld\n", __func__, action);
	538
	539	switch (action) {
	540	case BL_NOTIFY_PRE_ENABLE:
	541	case BL_NOTIFY_PRE_DISABLE:
1f1b4650	542	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	543	break;
	544
	545	case BL_NOTIFY_POST_ENABLE:
	546	set_switching_enabled(true);
1f1b4650	547	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	548	break;
	549
	550	case BL_NOTIFY_POST_DISABLE:
	551	set_switching_enabled(false);
1f1b4650	552	cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	553	break;
	554
	555	default:
	556	return NOTIFY_DONE;
	557	}
	558
	559	return NOTIFY_OK;
	560	}
	561
	562	static struct notifier_block bL_switcher_notifier = {
	563	.notifier_call = bL_cpufreq_switcher_notifier,
	564	};
	565
	566	static int __bLs_register_notifier(void)
	567	{
	568	return bL_switcher_register_notifier(&bL_switcher_notifier);
	569	}
	570
	571	static int __bLs_unregister_notifier(void)
	572	{
	573	return bL_switcher_unregister_notifier(&bL_switcher_notifier);
	574	}
	575	#else
	576	static int __bLs_register_notifier(void) { return 0; }
	577	static int __bLs_unregister_notifier(void) { return 0; }
	578	#endif
	579
1f1b4650	580	static int ve_spc_cpufreq_probe(struct platform_device *pdev)
a0f950d3 SH	581	{
	582	int ret, i;
	583
a0f950d3 SH	584	set_switching_enabled(bL_switcher_get_enabled());
	585
	586	for (i = 0; i < MAX_CLUSTERS; i++)
	587	mutex_init(&cluster_lock[i]);
	588
1f1b4650	589	ret = cpufreq_register_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	590	if (ret) {
a0f950d3 SH	591	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
1f1b4650	592	__func__, ve_spc_cpufreq_driver.name, ret);
a0f950d3 SH	593	} else {
a0f950d3 SH	594	ret = __bLs_register_notifier();
1f1b4650 SH	595	if (ret)
	596	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
	597	else
a0f950d3	598	pr_info("%s: Registered platform driver: %s\n",
1f1b4650	599	__func__, ve_spc_cpufreq_driver.name);
a0f950d3 SH	600	}
	601
	602	bL_switcher_put_enabled();
	603	return ret;
	604	}
	605
1f1b4650	606	static int ve_spc_cpufreq_remove(struct platform_device *pdev)
a0f950d3	607	{
a0f950d3 SH	608	bL_switcher_get_enabled();
a0f950d3 SH	609	__bLs_unregister_notifier();
1f1b4650	610	cpufreq_unregister_driver(&ve_spc_cpufreq_driver);
a0f950d3 SH	611	bL_switcher_put_enabled();
a0f950d3 SH	612	pr_info("%s: Un-registered platform driver: %s\n", __func__,
1f1b4650	613	ve_spc_cpufreq_driver.name);
47ac9aa1 SH	614	return 0;
	615	}
	616
	617	static struct platform_driver ve_spc_cpufreq_platdrv = {
	618	.driver = {
	619	.name = "vexpress-spc-cpufreq",
47ac9aa1 SH	620	},
	621	.probe = ve_spc_cpufreq_probe,
	622	.remove = ve_spc_cpufreq_remove,
	623	};
	624	module_platform_driver(ve_spc_cpufreq_platdrv);
	625
a0f950d3 SH	626	MODULE_AUTHOR("Viresh Kumar <[email protected]>");
	627	MODULE_AUTHOR("Sudeep Holla <[email protected]>");
	628	MODULE_DESCRIPTION("Vexpress SPC ARM big LITTLE cpufreq driver");
	629	MODULE_LICENSE("GPL v2");