diff options
Diffstat (limited to 'drivers/cpufreq/cpufreq-dt.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq-dt.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c new file mode 100644 index 0000000000..8bd6e5e8f1 --- /dev/null +++ b/drivers/cpufreq/cpufreq-dt.c @@ -0,0 +1,371 @@ +// 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/list.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 list_head node; + + cpumask_var_t cpus; + struct device *cpu_dev; + struct cpufreq_frequency_table *freq_table; + bool have_static_opps; + int opp_token; +}; + +static LIST_HEAD(priv_list); + +static struct freq_attr *cpufreq_dt_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, /* Extra space for boost-attr if required */ + NULL, +}; + +static struct private_data *cpufreq_dt_find_data(int cpu) +{ + struct private_data *priv; + + list_for_each_entry(priv, &priv_list, node) { + if (cpumask_test_cpu(cpu, priv->cpus)) + return priv; + } + + return 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; + + return dev_pm_opp_set_rate(priv->cpu_dev, freq * 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 cpufreq_init(struct cpufreq_policy *policy) +{ + struct private_data *priv; + struct device *cpu_dev; + struct clk *cpu_clk; + unsigned int transition_latency; + int ret; + + priv = cpufreq_dt_find_data(policy->cpu); + if (!priv) { + pr_err("failed to find data for cpu%d\n", policy->cpu); + return -ENODEV; + } + cpu_dev = priv->cpu_dev; + + 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; + } + + transition_latency = dev_pm_opp_get_max_transition_latency(cpu_dev); + if (!transition_latency) + transition_latency = CPUFREQ_ETERNAL; + + cpumask_copy(policy->cpus, priv->cpus); + policy->driver_data = priv; + policy->clk = cpu_clk; + policy->freq_table = priv->freq_table; + policy->suspend_freq = dev_pm_opp_get_suspend_opp_freq(cpu_dev) / 1000; + policy->cpuinfo.transition_latency = transition_latency; + policy->dvfs_possible_from_any_cpu = true; + + /* 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_clk_put; + cpufreq_dt_attr[1] = &cpufreq_freq_attr_scaling_boost_freqs; + } + + return 0; + +out_clk_put: + 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) +{ + clk_put(policy->clk); + return 0; +} + +static struct cpufreq_driver dt_cpufreq_driver = { + .flags = 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, + .register_em = cpufreq_register_em_with_opp, + .name = "cpufreq-dt", + .attr = cpufreq_dt_attr, + .suspend = cpufreq_generic_suspend, +}; + +static int dt_cpufreq_early_init(struct device *dev, int cpu) +{ + struct private_data *priv; + struct device *cpu_dev; + bool fallback = false; + const char *reg_name[] = { NULL, NULL }; + int ret; + + /* Check if this CPU is already covered by some other policy */ + if (cpufreq_dt_find_data(cpu)) + return 0; + + cpu_dev = get_cpu_device(cpu); + if (!cpu_dev) + return -EPROBE_DEFER; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + if (!alloc_cpumask_var(&priv->cpus, GFP_KERNEL)) + return -ENOMEM; + + cpumask_set_cpu(cpu, priv->cpus); + priv->cpu_dev = cpu_dev; + + /* + * OPP layer will be taking care of regulators now, but it needs to know + * the name of the regulator first. + */ + reg_name[0] = find_supply_name(cpu_dev); + if (reg_name[0]) { + priv->opp_token = dev_pm_opp_set_regulators(cpu_dev, reg_name); + if (priv->opp_token < 0) { + ret = dev_err_probe(cpu_dev, priv->opp_token, + "failed to set regulators\n"); + goto free_cpumask; + } + } + + /* Get OPP-sharing information from "operating-points-v2" bindings */ + ret = dev_pm_opp_of_get_sharing_cpus(cpu_dev, priv->cpus); + if (ret) { + if (ret != -ENOENT) + goto out; + + /* + * operating-points-v2 not supported, fallback to all CPUs share + * OPP for backward compatibility if the platform hasn't set + * sharing CPUs. + */ + if (dev_pm_opp_get_sharing_cpus(cpu_dev, priv->cpus)) + fallback = true; + } + + /* + * Initialize OPP tables for all priv->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 priv->cpus. Otherwise, we will end up creating + * duplicate OPPs for the CPUs. + * + * OPPs might be populated at runtime, don't fail for error here unless + * it is -EPROBE_DEFER. + */ + ret = dev_pm_opp_of_cpumask_add_table(priv->cpus); + if (!ret) { + priv->have_static_opps = true; + } else if (ret == -EPROBE_DEFER) { + goto out; + } + + /* + * The OPP table must be initialized, statically or dynamically, by this + * point. + */ + ret = dev_pm_opp_get_opp_count(cpu_dev); + if (ret <= 0) { + dev_err(cpu_dev, "OPP table can't be empty\n"); + ret = -ENODEV; + goto out; + } + + if (fallback) { + cpumask_setall(priv->cpus); + ret = dev_pm_opp_set_sharing_cpus(cpu_dev, priv->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, &priv->freq_table); + if (ret) { + dev_err(cpu_dev, "failed to init cpufreq table: %d\n", ret); + goto out; + } + + list_add(&priv->node, &priv_list); + return 0; + +out: + if (priv->have_static_opps) + dev_pm_opp_of_cpumask_remove_table(priv->cpus); + dev_pm_opp_put_regulators(priv->opp_token); +free_cpumask: + free_cpumask_var(priv->cpus); + return ret; +} + +static void dt_cpufreq_release(void) +{ + struct private_data *priv, *tmp; + + list_for_each_entry_safe(priv, tmp, &priv_list, node) { + dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &priv->freq_table); + if (priv->have_static_opps) + dev_pm_opp_of_cpumask_remove_table(priv->cpus); + dev_pm_opp_put_regulators(priv->opp_token); + free_cpumask_var(priv->cpus); + list_del(&priv->node); + } +} + +static int dt_cpufreq_probe(struct platform_device *pdev) +{ + struct cpufreq_dt_platform_data *data = dev_get_platdata(&pdev->dev); + int ret, cpu; + + /* Request resources early so we can return in case of -EPROBE_DEFER */ + for_each_possible_cpu(cpu) { + ret = dt_cpufreq_early_init(&pdev->dev, cpu); + if (ret) + goto err; + } + + 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; + if (data->get_intermediate) { + dt_cpufreq_driver.target_intermediate = data->target_intermediate; + dt_cpufreq_driver.get_intermediate = data->get_intermediate; + } + } + + ret = cpufreq_register_driver(&dt_cpufreq_driver); + if (ret) { + dev_err(&pdev->dev, "failed register driver: %d\n", ret); + goto err; + } + + return 0; +err: + dt_cpufreq_release(); + return ret; +} + +static void dt_cpufreq_remove(struct platform_device *pdev) +{ + cpufreq_unregister_driver(&dt_cpufreq_driver); + dt_cpufreq_release(); +} + +static struct platform_driver dt_cpufreq_platdrv = { + .driver = { + .name = "cpufreq-dt", + }, + .probe = dt_cpufreq_probe, + .remove_new = 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"); |