/* * 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 int cpu_to_cluster(int cpu) { return topology_physical_package_id(cpu); } 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); return ret; } policy->cur = freqs.new; 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, "CPU %d initialized\n", 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);