2 * ARM big.LITTLE Platforms CPUFreq support
4 * Copyright (C) 2013 ARM Ltd.
5 * Sudeep KarkadaNagesha <sudeep.karkadanagesha@arm.com>
7 * Copyright (C) 2013 Linaro.
8 * Viresh Kumar <viresh.kumar@linaro.org>
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.
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.
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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>
33 #include "arm_big_little.h"
35 /* Currently we support only two clusters */
36 #define MAX_CLUSTERS 2
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)};
43 static unsigned int bL_cpufreq_get(unsigned int cpu)
45 u32 cur_cluster = cpu_to_cluster(cpu);
47 return clk_get_rate(clk[cur_cluster]) / 1000;
50 /* Set clock frequency */
51 static int bL_cpufreq_set_target(struct cpufreq_policy *policy,
52 unsigned int target_freq, unsigned int relation)
54 struct cpufreq_freqs freqs;
55 u32 cpu = policy->cpu, freq_tab_idx, cur_cluster;
58 cur_cluster = cpu_to_cluster(policy->cpu);
60 freqs.old = bL_cpufreq_get(policy->cpu);
62 /* Determine valid target frequency using freq_table */
63 cpufreq_frequency_table_target(policy, freq_table[cur_cluster],
64 target_freq, relation, &freq_tab_idx);
65 freqs.new = freq_table[cur_cluster][freq_tab_idx].frequency;
67 pr_debug("%s: cpu: %d, cluster: %d, oldfreq: %d, target freq: %d, new freq: %d\n",
68 __func__, cpu, cur_cluster, freqs.old, target_freq,
71 if (freqs.old == freqs.new)
74 cpufreq_notify_transition(policy, &freqs, CPUFREQ_PRECHANGE);
76 ret = clk_set_rate(clk[cur_cluster], freqs.new * 1000);
78 pr_err("clk_set_rate failed: %d\n", ret);
79 freqs.new = freqs.old;
82 cpufreq_notify_transition(policy, &freqs, CPUFREQ_POSTCHANGE);
87 static void put_cluster_clk_and_freq_table(struct device *cpu_dev)
89 u32 cluster = cpu_to_cluster(cpu_dev->id);
91 if (!atomic_dec_return(&cluster_usage[cluster])) {
92 clk_put(clk[cluster]);
93 opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
94 dev_dbg(cpu_dev, "%s: cluster: %d\n", __func__, cluster);
98 static int get_cluster_clk_and_freq_table(struct device *cpu_dev)
100 u32 cluster = cpu_to_cluster(cpu_dev->id);
101 char name[14] = "cpu-cluster.";
104 if (atomic_inc_return(&cluster_usage[cluster]) != 1)
107 ret = arm_bL_ops->init_opp_table(cpu_dev);
109 dev_err(cpu_dev, "%s: init_opp_table failed, cpu: %d, err: %d\n",
110 __func__, cpu_dev->id, ret);
114 ret = opp_init_cpufreq_table(cpu_dev, &freq_table[cluster]);
116 dev_err(cpu_dev, "%s: failed to init cpufreq table, cpu: %d, err: %d\n",
117 __func__, cpu_dev->id, ret);
121 name[12] = cluster + '0';
122 clk[cluster] = clk_get(cpu_dev, name);
123 if (!IS_ERR(clk[cluster])) {
124 dev_dbg(cpu_dev, "%s: clk: %p & freq table: %p, cluster: %d\n",
125 __func__, clk[cluster], freq_table[cluster],
130 dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d, cluster: %d\n",
131 __func__, cpu_dev->id, cluster);
132 ret = PTR_ERR(clk[cluster]);
133 opp_free_cpufreq_table(cpu_dev, &freq_table[cluster]);
136 atomic_dec(&cluster_usage[cluster]);
137 dev_err(cpu_dev, "%s: Failed to get data for cluster: %d\n", __func__,
142 /* Per-CPU initialization */
143 static int bL_cpufreq_init(struct cpufreq_policy *policy)
145 u32 cur_cluster = cpu_to_cluster(policy->cpu);
146 struct device *cpu_dev;
149 cpu_dev = get_cpu_device(policy->cpu);
151 pr_err("%s: failed to get cpu%d device\n", __func__,
156 ret = get_cluster_clk_and_freq_table(cpu_dev);
160 ret = cpufreq_table_validate_and_show(policy, freq_table[cur_cluster]);
162 dev_err(cpu_dev, "CPU %d, cluster: %d invalid freq table\n",
163 policy->cpu, cur_cluster);
164 put_cluster_clk_and_freq_table(cpu_dev);
168 if (arm_bL_ops->get_transition_latency)
169 policy->cpuinfo.transition_latency =
170 arm_bL_ops->get_transition_latency(cpu_dev);
172 policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
174 cpumask_copy(policy->cpus, topology_core_cpumask(policy->cpu));
176 dev_info(cpu_dev, "%s: CPU %d initialized\n", __func__, policy->cpu);
180 static int bL_cpufreq_exit(struct cpufreq_policy *policy)
182 struct device *cpu_dev;
184 cpu_dev = get_cpu_device(policy->cpu);
186 pr_err("%s: failed to get cpu%d device\n", __func__,
191 cpufreq_frequency_table_put_attr(policy->cpu);
192 put_cluster_clk_and_freq_table(cpu_dev);
193 dev_dbg(cpu_dev, "%s: Exited, cpu: %d\n", __func__, policy->cpu);
198 static struct cpufreq_driver bL_cpufreq_driver = {
199 .name = "arm-big-little",
200 .flags = CPUFREQ_STICKY |
201 CPUFREQ_HAVE_GOVERNOR_PER_POLICY,
202 .verify = cpufreq_generic_frequency_table_verify,
203 .target = bL_cpufreq_set_target,
204 .get = bL_cpufreq_get,
205 .init = bL_cpufreq_init,
206 .exit = bL_cpufreq_exit,
207 .attr = cpufreq_generic_attr,
210 int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
215 pr_debug("%s: Already registered: %s, exiting\n", __func__,
220 if (!ops || !strlen(ops->name) || !ops->init_opp_table) {
221 pr_err("%s: Invalid arm_bL_ops, exiting\n", __func__);
227 ret = cpufreq_register_driver(&bL_cpufreq_driver);
229 pr_info("%s: Failed registering platform driver: %s, err: %d\n",
230 __func__, ops->name, ret);
233 pr_info("%s: Registered platform driver: %s\n", __func__,
239 EXPORT_SYMBOL_GPL(bL_cpufreq_register);
241 void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
243 if (arm_bL_ops != ops) {
244 pr_err("%s: Registered with: %s, can't unregister, exiting\n",
245 __func__, arm_bL_ops->name);
249 cpufreq_unregister_driver(&bL_cpufreq_driver);
250 pr_info("%s: Un-registered platform driver: %s\n", __func__,
254 EXPORT_SYMBOL_GPL(bL_cpufreq_unregister);