[mirror_ubuntu-zesty-kernel.git] / drivers / cpufreq / arm_big_little.c

/*
 * ARM big.LITTLE Platforms CPUFreq support
 *
 * Copyright (C) 2013 ARM Ltd.
 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
 *
 * Copyright (C) 2013 Linaro.
 * Viresh Kumar <viresh.kumar@linaro.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/cpufreq.h>
#include <linux/cpumask.h>
#include <linux/export.h>
#include <linux/of_platform.h>
#include <linux/opp.h>
#include <linux/slab.h>
#include <linux/topology.h>
#include <linux/types.h>

#include "arm_big_little.h"

/* Currently we support only two clusters */
#define MAX_CLUSTERS	2

static struct cpufreq_arm_bL_ops *arm_bL_ops;
static struct clk *clk[MAX_CLUSTERS];
static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)};

static unsigned int bL_cpufreq_get(unsigned int cpu)
{
	u32 cur_cluster = cpu_to_cluster(cpu);

	return clk_get_rate(clk[cur_cluster]) / 1000;
}

/* Validate policy frequency range */
static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy)
{
	u32 cur_cluster = cpu_to_cluster(policy->cpu);

	return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]);
}

/* Set clock frequency */
static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
		unsigned int target_freq, unsigned int relation)
{
	struct cpufreq_freqs freqs;
	u32 cpu = policy->cpu, freq_tab_idx, cur_cluster;
	int ret = 0;

	cur_cluster = cpu_to_cluster(policy->cpu);

	freqs.old = bL_cpufreq_get(policy->cpu);

	/* Determine valid target frequency using freq_table */
	cpufreq_frequency_table_target(policy, freq_table[cur_cluster],
			target_freq, relation, &freq_tab_idx);
	freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency;

	pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
			__func__, cpu, cur_cluster, freqs.old, target_freq,
			freqs.new);

	if (freqs.old == freqs.new)
		return 0;

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);

	ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
	if (ret) {
		pr_err("clk_set_rate failed: %d\n", ret);
		freqs.new = freqs.old;
	}

	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);

	return ret;
}

static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = cpu_to_cluster(cpu_dev->id);

	if (!atomic_dec_return(&cluster_usage[cluster])) {
		clk_put(clk[cluster]);
		opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
		dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	}
}

static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
{
	u32 cluster = cpu_to_cluster(cpu_dev->id);
	char name[14] = "cpu-cluster.";
	int ret;

	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
		return 0;

	ret = arm_bL_ops->init_opp_table(cpu_dev);
	if (ret) {
		dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
				__func__, cpu_dev->id, ret);
		goto atomic_dec;
	}

	ret = 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 atomic_dec;
	}

	name[12] = cluster + '0';
	clk[cluster] = clk_get_sys(name, 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]);
	opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);

atomic_dec:
	atomic_dec(&cluster_usage[cluster]);
	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
			cluster);
	return ret;
}

/* Per-CPU initialization */
static int bL_cpufreq_init(struct cpufreq_policy *policy)
{
	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	struct device *cpu_dev;
	int ret;

	cpu_dev = get_cpu_device(policy->cpu);
	if (!cpu_dev) {
		pr_err("%s: failed to get cpu%d device\n", __func__,
				policy->cpu);
		return -ENODEV;
	}

	ret = get_cluster_clk_and_freq_table(cpu_dev);
	if (ret)
		return ret;

	ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]);
	if (ret) {
		dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
				policy->cpu, cur_cluster);
		put_cluster_clk_and_freq_table(cpu_dev);
		return ret;
	}

	cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu);

	if (arm_bL_ops->get_transition_latency)
		policy->cpuinfo.transition_latency =
			arm_bL_ops->get_transition_latency(cpu_dev);
	else
		policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;

	policy->cur = bL_cpufreq_get(policy->cpu);

	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));

	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
	return 0;
}

static int bL_cpufreq_exit(struct cpufreq_policy *policy)
{
	struct device *cpu_dev;

	cpu_dev = get_cpu_device(policy->cpu);
	if (!cpu_dev) {
		pr_err("%s: failed to get cpu%d device\n", __func__,
				policy->cpu);
		return -ENODEV;
	}

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

	return 0;
}

/* Export freq_table to sysfs */
static struct freq_attr *bL_cpufreq_attr[] = {
	&cpufreq_freq_attr_scaling_available_freqs,
	NULL,
};

static struct cpufreq_driver bL_cpufreq_driver = {
	.name			= "arm-big-little",
	.flags			= CPUFREQ_STICKY,
	.verify			= bL_cpufreq_verify_policy,
	.target			= bL_cpufreq_set_target,
	.get			= bL_cpufreq_get,
	.init			= bL_cpufreq_init,
	.exit			= bL_cpufreq_exit,
	.have_governor_per_policy = true,
	.attr			= bL_cpufreq_attr,
};

int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
{
	int ret;

	if (arm_bL_ops) {
		pr_debug("%s: Already registered: %s, exiting\n", __func__,
				arm_bL_ops->name);
		return -EBUSY;
	}

	if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
		pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
		return -ENODEV;
	}

	arm_bL_ops = ops;

	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	if (ret) {
		pr_info("%s: Failed registering platform driver: %s, err: %d\n",
				__func__, ops->name, ret);
		arm_bL_ops = NULL;
	} else {
		pr_info("%s: Registered platform driver: %s\n", __func__,
				ops->name);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_register);

void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
{
	if (arm_bL_ops != ops) {
		pr_err("%s: Registered with: %s, can't unregister, exiting\n",
				__func__, arm_bL_ops->name);
		return;
	}

	cpufreq_unregister_driver(&bL_cpufreq_driver);
	pr_info("%s: Un-registered platform driver: %s\n", __func__,
			arm_bL_ops->name);
	arm_bL_ops = NULL;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);
Commit	Line	Data
8a67f0ef VK	1	/*
	2	* ARM big.LITTLE Platforms CPUFreq support
	3	*
	4	* Copyright (C) 2013 ARM Ltd.
	5	* Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
	6	*
	7	* Copyright (C) 2013 Linaro.
	8	* Viresh Kumar <viresh.kumar@linaro.org>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	* This program is distributed "as is" WITHOUT ANY WARRANTY of any
	15	* kind, whether express or implied; without even the implied warranty
	16	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	* GNU General Public License for more details.
	18	*/
	19
	20	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	21
	22	#include <linux/clk.h>
	23	#include <linux/cpu.h>
	24	#include <linux/cpufreq.h>
	25	#include <linux/cpumask.h>
	26	#include <linux/export.h>
	27	#include <linux/of_platform.h>
	28	#include <linux/opp.h>
	29	#include <linux/slab.h>
	30	#include <linux/topology.h>
	31	#include <linux/types.h>
	32
	33	#include "arm_big_little.h"
	34
	35	/* Currently we support only two clusters */
	36	#define MAX_CLUSTERS 2
	37
	38	static struct cpufreq_arm_bL_ops *arm_bL_ops;
	39	static struct clk *clk[MAX_CLUSTERS];
	40	static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS];
	41	static atomic_t cluster_usage[MAX_CLUSTERS] = {ATOMIC_INIT(0), ATOMIC_INIT(0)};
	42
8a67f0ef VK	43	static unsigned int bL_cpufreq_get(unsigned int cpu)
	44	{
	45	u32 cur_cluster = cpu_to_cluster(cpu);
	46
	47	return clk_get_rate(clk[cur_cluster]) / 1000;
	48	}
	49
	50	/* Validate policy frequency range */
	51	static int bL_cpufreq_verify_policy(struct cpufreq_policy *policy)
	52	{
	53	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	54
	55	return cpufreq_frequency_table_verify(policy, freq_table[cur_cluster]);
	56	}
	57
	58	/* Set clock frequency */
	59	static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
	60	unsigned int target_freq, unsigned int relation)
	61	{
	62	struct cpufreq_freqs freqs;
	63	u32 cpu = policy->cpu, freq_tab_idx, cur_cluster;
	64	int ret = 0;
	65
	66	cur_cluster = cpu_to_cluster(policy->cpu);
	67
	68	freqs.old = bL_cpufreq_get(policy->cpu);
	69
	70	/* Determine valid target frequency using freq_table */
	71	cpufreq_frequency_table_target(policy, freq_table[cur_cluster],
	72	target_freq, relation, &freq_tab_idx);
	73	freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency;
	74
8a67f0ef VK	75	pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
	76	__func__, cpu, cur_cluster, freqs.old, target_freq,
	77	freqs.new);
	78
	79	if (freqs.old == freqs.new)
	80	return 0;
	81
ad61f442	82	cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
8a67f0ef VK	83
	84	ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
	85	if (ret) {
	86	pr_err("clk_set_rate failed: %d\n", ret);
3d69dd50	87	freqs.new = freqs.old;
8a67f0ef VK	88	}
8a67f0ef VK	89
ad61f442	90	cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
8a67f0ef VK	91
	92	return ret;
	93	}
	94
	95	static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
	96	{
	97	u32 cluster = cpu_to_cluster(cpu_dev->id);
	98
	99	if (!atomic_dec_return(&cluster_usage[cluster])) {
	100	clk_put(clk[cluster]);
	101	opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	102	dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
	103	}
	104	}
	105
	106	static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
	107	{
	108	u32 cluster = cpu_to_cluster(cpu_dev->id);
	109	char name[14] = "cpu-cluster.";
	110	int ret;
	111
	112	if (atomic_inc_return(&cluster_usage[cluster]) != 1)
	113	return 0;
	114
	115	ret = arm_bL_ops->init_opp_table(cpu_dev);
	116	if (ret) {
	117	dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
	118	__func__, cpu_dev->id, ret);
	119	goto atomic_dec;
	120	}
	121
	122	ret = opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
	123	if (ret) {
	124	dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
	125	__func__, cpu_dev->id, ret);
	126	goto atomic_dec;
	127	}
	128
	129	name[12] = cluster + '0';
	130	clk[cluster] = clk_get_sys(name, NULL);
	131	if (!IS_ERR(clk[cluster])) {
	132	dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
	133	__func__, clk[cluster], freq_table[cluster],
	134	cluster);
	135	return 0;
	136	}
	137
	138	dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
	139	__func__, cpu_dev->id, cluster);
	140	ret = PTR_ERR(clk[cluster]);
	141	opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
	142
	143	atomic_dec:
	144	atomic_dec(&cluster_usage[cluster]);
	145	dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
	146	cluster);
	147	return ret;
	148	}
	149
	150	/* Per-CPU initialization */
	151	static int bL_cpufreq_init(struct cpufreq_policy *policy)
	152	{
	153	u32 cur_cluster = cpu_to_cluster(policy->cpu);
	154	struct device *cpu_dev;
155	int ret;
156
157	cpu_dev = get_cpu_device(policy->cpu);
158	if (!cpu_dev) {
159	pr_err("%s: failed to get cpu%d device\n", __func__,
160	policy->cpu);
161	return -ENODEV;
162	}
163
164	ret = get_cluster_clk_and_freq_table(cpu_dev);
165	if (ret)
166	return ret;
167
168	ret = cpufreq_frequency_table_cpuinfo(policy, freq_table[cur_cluster]);
169	if (ret) {
170	dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
171	policy->cpu, cur_cluster);
172	put_cluster_clk_and_freq_table(cpu_dev);
173	return ret;
174	}
175
176	cpufreq_frequency_table_get_attr(freq_table[cur_cluster], policy->cpu);
177
178	if (arm_bL_ops->get_transition_latency)
179	policy->cpuinfo.transition_latency =
180	arm_bL_ops->get_transition_latency(cpu_dev);
181	else
182	policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
183
184	policy->cur = bL_cpufreq_get(policy->cpu);
185
186	cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
187
2b80f313	188	dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
8a67f0ef VK	189	return 0;
	190	}
	191
	192	static int bL_cpufreq_exit(struct cpufreq_policy *policy)
	193	{
	194	struct device *cpu_dev;
	195
	196	cpu_dev = get_cpu_device(policy->cpu);
	197	if (!cpu_dev) {
	198	pr_err("%s: failed to get cpu%d device\n", __func__,
	199	policy->cpu);
	200	return -ENODEV;
	201	}
	202
	203	put_cluster_clk_and_freq_table(cpu_dev);
	204	dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
	205
	206	return 0;
	207	}
	208
	209	/* Export freq_table to sysfs */
	210	static struct freq_attr *bL_cpufreq_attr[] = {
	211	&cpufreq_freq_attr_scaling_available_freqs,
	212	NULL,
	213	};
	214
	215	static struct cpufreq_driver bL_cpufreq_driver = {
	216	.name = "arm-big-little",
	217	.flags = CPUFREQ_STICKY,
	218	.verify = bL_cpufreq_verify_policy,
	219	.target = bL_cpufreq_set_target,
	220	.get = bL_cpufreq_get,
	221	.init = bL_cpufreq_init,
	222	.exit = bL_cpufreq_exit,
ad61f442	223	.have_governor_per_policy = true,
8a67f0ef VK	224	.attr = bL_cpufreq_attr,
	225	};
	226
	227	int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
	228	{
	229	int ret;
	230
	231	if (arm_bL_ops) {
	232	pr_debug("%s: Already registered: %s, exiting\n", __func__,
	233	arm_bL_ops->name);
	234	return -EBUSY;
	235	}
	236
	237	if (!ops \|\| !strlen(ops->name) \|\| !ops->init_opp_table) {
	238	pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
	239	return -ENODEV;
	240	}
	241
	242	arm_bL_ops = ops;
	243
	244	ret = cpufreq_register_driver(&bL_cpufreq_driver);
	245	if (ret) {
	246	pr_info("%s: Failed registering platform driver: %s, err: %d\n",
	247	__func__, ops->name, ret);
	248	arm_bL_ops = NULL;
	249	} else {
	250	pr_info("%s: Registered platform driver: %s\n", __func__,
	251	ops->name);
	252	}
	253
	254	return ret;
	255	}
	256	EXPORT_SYMBOL_GPL(bL_cpufreq_register);
	257
	258	void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
	259	{
	260	if (arm_bL_ops != ops) {
	261	pr_err("%s: Registered with: %s, can't unregister, exiting\n",
	262	__func__, arm_bL_ops->name);
	263	return;
	264	}
	265
	266	cpufreq_unregister_driver(&bL_cpufreq_driver);
	267	pr_info("%s: Un-registered platform driver: %s\n", __func__,
	268	arm_bL_ops->name);
	269	arm_bL_ops = NULL;
	270	}
	271	EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);