/* * Copyright (C) 2012 Freescale Semiconductor, Inc. * * Copyright (C) 2014 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. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/clk.h> #include <linux/cpu.h> #include <linux/cpu_cooling.h> #include <linux/cpufreq.h> #include <linux/cpumask.h> #include <linux/err.h> #include <linux/module.h> #include <linux/of.h> #include <linux/pm_opp.h> #include <linux/platform_device.h> #include <linux/regulator/consumer.h> #include <linux/slab.h> #include <linux/thermal.h> struct private_data { struct device *cpu_dev; struct thermal_cooling_device *cdev; const char *reg_name; }; static struct freq_attr *cpufreq_dt_attr[] = { &cpufreq_freq_attr_scaling_available_freqs, NULL, /* Extra space for boost-attr if required */ NULL, }; static int set_target(struct cpufreq_policy *policy, unsigned int index) { struct private_data *priv = policy->driver_data; return dev_pm_opp_set_rate(priv->cpu_dev, policy->freq_table[index].frequency * 1000); } /* * An earlier version of opp-v1 bindings used to name the regulator * "cpu0-supply", we still need to handle that for backwards compatibility. */ static const char *find_supply_name(struct device *dev) { struct device_node *np; struct property *pp; int cpu = dev->id; const char *name = NULL; np = of_node_get(dev->of_node); /* This must be valid for sure */ if (WARN_ON(!np)) return NULL; /* Try "cpu0" for older DTs */ if (!cpu) { pp = of_find_property(np, "cpu0-supply", NULL); if (pp) { name = "cpu0"; goto node_put; } } pp = of_find_property(np, "cpu-supply", NULL); if (pp) { name = "cpu"; goto node_put; } dev_dbg(dev, "no regulator for cpu%d\n", cpu); node_put: of_node_put(np); return name; } static int resources_available(void) { struct device *cpu_dev; struct regulator *cpu_reg; struct clk *cpu_clk; int ret = 0; const char *name; cpu_dev = get_cpu_device(0); if (!cpu_dev) { pr_err("failed to get cpu0 device\n"); return -ENODEV; } cpu_clk = clk_get(cpu_dev, NULL); ret = PTR_ERR_OR_ZERO(cpu_clk); if (ret) { /* * If cpu's clk node is present, but clock is not yet * registered, we should try defering probe. */ if (ret == -EPROBE_DEFER) dev_dbg(cpu_dev, "clock not ready, retry\n"); else dev_err(cpu_dev, "failed to get clock: %d\n", ret); return ret; } clk_put(cpu_clk); name = find_supply_name(cpu_dev); /* Platform doesn't require regulator */ if (!name) return 0; cpu_reg = regulator_get_optional(cpu_dev, name); ret = PTR_ERR_OR_ZERO(cpu_reg); if (ret) { /* * If cpu's regulator supply node is present, but regulator is * not yet registered, we should try defering probe. */ if (ret == -EPROBE_DEFER) dev_dbg(cpu_dev, "cpu0 regulator not ready, retry\n"); else dev_dbg(cpu_dev, "no regulator for cpu0: %d\n", ret); return ret; } regulator_put(cpu_reg); return 0; } static int cpufreq_init(struct cpufreq_policy *policy) { struct cpufreq_frequency_table *freq_table; struct private_data *priv; struct device *cpu_dev; struct clk *cpu_clk; struct dev_pm_opp *suspend_opp; unsigned int transition_latency; bool fallback = false; const char *name; int ret; cpu_dev = get_cpu_device(policy->cpu); if (!cpu_dev) { pr_err("failed to get cpu%d device\n", policy->cpu); return -ENODEV; } cpu_clk = clk_get(cpu_dev, NULL); if (IS_ERR(cpu_clk)) { ret = PTR_ERR(cpu_clk); dev_err(cpu_dev, "%s: failed to get clk: %d\n", __func__, ret); return ret; } /* Get OPP-sharing information from "operating-points-v2" bindings */ ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, policy->cpus); if (ret) { if (ret != -ENOENT) goto out_put_clk; /* * operating-points-v2 not supported, fallback to old method of * finding shared-OPPs for backward compatibility if the * platform hasn't set sharing CPUs. */ if (dev_pm_opp_get_sharing_cpus(cpu_dev, policy->cpus)) fallback = true; } /* * OPP layer will be taking care of regulators now, but it needs to know * the name of the regulator first. */ name = find_supply_name(cpu_dev); if (name) { ret = dev_pm_opp_set_regulator(cpu_dev, name); if (ret) { dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", policy->cpu, ret); goto out_put_clk; } } /* * Initialize OPP tables for all policy->cpus. They will be shared by * all CPUs which have marked their CPUs shared with OPP bindings. * * For platforms not using operating-points-v2 bindings, we do this * before updating policy->cpus. Otherwise, we will end up creating * duplicate OPPs for policy->cpus. * * OPPs might be populated at runtime, don't check for error here */ dev_pm_opp_of_cpumask_add_table(policy->cpus); /* * But we need OPP table to function so if it is not there let's * give platform code chance to provide it for us. */ ret = dev_pm_opp_get_opp_count(cpu_dev); if (ret <= 0) { dev_dbg(cpu_dev, "OPP table is not ready, deferring probe\n"); ret = -EPROBE_DEFER; goto out_free_opp; } if (fallback) { cpumask_setall(policy->cpus); /* * OPP tables are initialized only for policy->cpu, do it for * others as well. */ ret = dev_pm_opp_set_sharing_cpus(cpu_dev, policy->cpus); if (ret) dev_err(cpu_dev, "%s: failed to mark OPPs as shared: %d\n", __func__, ret); } priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) { ret = -ENOMEM; goto out_free_opp; } priv->reg_name = name; ret = dev_pm_opp_init_cpufreq_table(cpu_dev, &freq_table); if (ret) { dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); goto out_free_priv; } priv->cpu_dev = cpu_dev; policy->driver_data = priv; policy->clk = cpu_clk; rcu_read_lock(); suspend_opp = dev_pm_opp_get_suspend_opp(cpu_dev); if (suspend_opp) policy->suspend_freq = dev_pm_opp_get_freq(suspend_opp) / 1000; rcu_read_unlock(); ret = cpufreq_table_validate_and_show(policy, freq_table); if (ret) { dev_err(cpu_dev, "%s: invalid frequency table: %d\n", __func__, ret); goto out_free_cpufreq_table; } /* Support turbo/boost mode */ if (policy_has_boost_freq(policy)) { /* This gets disabled by core on driver unregister */ ret = cpufreq_enable_boost_support(); if (ret) goto out_free_cpufreq_table; cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; } transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); if (!transition_latency) transition_latency = CPUFREQ_ETERNAL; policy->cpuinfo.transition_latency = transition_latency; return 0; out_free_cpufreq_table: dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); out_free_priv: kfree(priv); out_free_opp: dev_pm_opp_of_cpumask_remove_table(policy->cpus); if (name) dev_pm_opp_put_regulator(cpu_dev); out_put_clk: clk_put(cpu_clk); return ret; } static int cpufreq_exit(struct cpufreq_policy *policy) { struct private_data *priv = policy->driver_data; cpufreq_cooling_unregister(priv->cdev); dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); if (priv->reg_name) dev_pm_opp_put_regulator(priv->cpu_dev); clk_put(policy->clk); kfree(priv); return 0; } static void cpufreq_ready(struct cpufreq_policy *policy) { struct private_data *priv = policy->driver_data; struct device_node *np = of_node_get(priv->cpu_dev->of_node); if (WARN_ON(!np)) return; /* * For now, just loading the cooling device; * thermal DT code takes care of matching them. */ if (of_find_property(np, "#cooling-cells", NULL)) { u32 power_coefficient = 0; of_property_read_u32(np, "dynamic-power-coefficient", &power_coefficient); priv->cdev = of_cpufreq_power_cooling_register(np, policy->related_cpus, power_coefficient, NULL); if (IS_ERR(priv->cdev)) { dev_err(priv->cpu_dev, "running cpufreq without cooling device: %ld\n", PTR_ERR(priv->cdev)); priv->cdev = NULL; } } of_node_put(np); } static struct cpufreq_driver dt_cpufreq_driver = { .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK, .verify = cpufreq_generic_frequency_table_verify, .target_index = set_target, .get = cpufreq_generic_get, .init = cpufreq_init, .exit = cpufreq_exit, .ready = cpufreq_ready, .name = "cpufreq-dt", .attr = cpufreq_dt_attr, .suspend = cpufreq_generic_suspend, }; static int dt_cpufreq_probe(struct platform_device *pdev) { int ret; /* * All per-cluster (CPUs sharing clock/voltages) initialization is done * from ->init(). In probe(), we just need to make sure that clk and * regulators are available. Else defer probe and retry. * * FIXME: Is checking this only for CPU0 sufficient ? */ ret = resources_available(); if (ret) return ret; dt_cpufreq_driver.driver_data = dev_get_platdata(&pdev->dev); ret = cpufreq_register_driver(&dt_cpufreq_driver); if (ret) dev_err(&pdev->dev, "failed register driver: %d\n", ret); return ret; } static int dt_cpufreq_remove(struct platform_device *pdev) { cpufreq_unregister_driver(&dt_cpufreq_driver); return 0; } static struct platform_driver dt_cpufreq_platdrv = { .driver = { .name = "cpufreq-dt", }, .probe = dt_cpufreq_probe, .remove = dt_cpufreq_remove, }; module_platform_driver(dt_cpufreq_platdrv); MODULE_ALIAS("platform:cpufreq-dt"); MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>"); MODULE_AUTHOR("Shawn Guo <shawn.guo@linaro.org>"); MODULE_DESCRIPTION("Generic cpufreq driver"); MODULE_LICENSE("GPL");