summaryrefslogtreecommitdiffstats
path: root/drivers/cpufreq/cpufreq-dt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/cpufreq/cpufreq-dt.c')
-rw-r--r--drivers/cpufreq/cpufreq-dt.c371
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");