| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) 2012 Freescale Semiconductor, Inc. |
| * |
| * Copyright (C) 2014 Linaro. |
| * Viresh Kumar <viresh.kumar@linaro.org> |
| */ |
| |
| #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/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> |
| |
| #include "cpufreq-dt.h" |
| |
| struct private_data { |
| struct opp_table *opp_table; |
| struct device *cpu_dev; |
| const char *reg_name; |
| bool have_static_opps; |
| }; |
| |
| 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; |
| unsigned long freq = policy->freq_table[index].frequency; |
| int ret; |
| |
| ret = dev_pm_opp_set_rate(priv->cpu_dev, freq * 1000); |
| |
| if (!ret) { |
| arch_set_freq_scale(policy->related_cpus, freq, |
| policy->cpuinfo.max_freq); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * 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 opp_table *opp_table = NULL; |
| struct private_data *priv; |
| struct device *cpu_dev; |
| struct clk *cpu_clk; |
| 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) { |
| opp_table = dev_pm_opp_set_regulators(cpu_dev, &name, 1); |
| if (IS_ERR(opp_table)) { |
| ret = PTR_ERR(opp_table); |
| dev_err(cpu_dev, "Failed to set regulator for cpu%d: %d\n", |
| policy->cpu, ret); |
| goto out_put_clk; |
| } |
| } |
| |
| priv = kzalloc(sizeof(*priv), GFP_KERNEL); |
| if (!priv) { |
| ret = -ENOMEM; |
| goto out_put_regulator; |
| } |
| |
| priv->reg_name = name; |
| priv->opp_table = opp_table; |
| |
| /* |
| * 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 |
| */ |
| if (!dev_pm_opp_of_cpumask_add_table(policy->cpus)) |
| priv->have_static_opps = true; |
| |
| /* |
| * 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); |
| } |
| |
| 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_opp; |
| } |
| |
| priv->cpu_dev = cpu_dev; |
| policy->driver_data = priv; |
| policy->clk = cpu_clk; |
| policy->freq_table = freq_table; |
| |
| policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; |
| |
| /* 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; |
| policy->dvfs_possible_from_any_cpu = true; |
| |
| dev_pm_opp_of_register_em(policy->cpus); |
| |
| return 0; |
| |
| out_free_cpufreq_table: |
| dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); |
| out_free_opp: |
| if (priv->have_static_opps) |
| dev_pm_opp_of_cpumask_remove_table(policy->cpus); |
| kfree(priv); |
| out_put_regulator: |
| if (name) |
| dev_pm_opp_put_regulators(opp_table); |
| out_put_clk: |
| clk_put(cpu_clk); |
| |
| return ret; |
| } |
| |
| static int cpufreq_online(struct cpufreq_policy *policy) |
| { |
| /* We did light-weight tear down earlier, nothing to do here */ |
| return 0; |
| } |
| |
| static int cpufreq_offline(struct cpufreq_policy *policy) |
| { |
| /* |
| * Preserve policy->driver_data and don't free resources on light-weight |
| * tear down. |
| */ |
| return 0; |
| } |
| |
| static int cpufreq_exit(struct cpufreq_policy *policy) |
| { |
| struct private_data *priv = policy->driver_data; |
| |
| dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); |
| if (priv->have_static_opps) |
| dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); |
| if (priv->reg_name) |
| dev_pm_opp_put_regulators(priv->opp_table); |
| |
| clk_put(policy->clk); |
| kfree(priv); |
| |
| return 0; |
| } |
| |
| static struct cpufreq_driver dt_cpufreq_driver = { |
| .flags = CPUFREQ_STICKY | CPUFREQ_NEED_INITIAL_FREQ_CHECK | |
| CPUFREQ_IS_COOLING_DEV, |
| .verify = cpufreq_generic_frequency_table_verify, |
| .target_index = set_target, |
| .get = cpufreq_generic_get, |
| .init = cpufreq_init, |
| .exit = cpufreq_exit, |
| .online = cpufreq_online, |
| .offline = cpufreq_offline, |
| .name = "cpufreq-dt", |
| .attr = cpufreq_dt_attr, |
| .suspend = cpufreq_generic_suspend, |
| }; |
| |
| static int dt_cpufreq_probe(struct platform_device *pdev) |
| { |
| struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); |
| 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; |
| |
| if (data) { |
| if (data->have_governor_per_policy) |
| dt_cpufreq_driver.flags |= CPUFREQ_HAVE_GOVERNOR_PER_POLICY; |
| |
| dt_cpufreq_driver.resume = data->resume; |
| if (data->suspend) |
| dt_cpufreq_driver.suspend = data->suspend; |
| } |
| |
| 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"); |