v4.19.13 snapshot.
diff --git a/drivers/cpufreq/scpi-cpufreq.c b/drivers/cpufreq/scpi-cpufreq.c
new file mode 100644
index 0000000..87a98ec
--- /dev/null
+++ b/drivers/cpufreq/scpi-cpufreq.c
@@ -0,0 +1,251 @@
+/*
+ * System Control and Power Interface (SCPI) based CPUFreq Interface driver
+ *
+ * It provides necessary ops to arm_big_little cpufreq driver.
+ *
+ * Copyright (C) 2015 ARM Ltd.
+ * Sudeep Holla <sudeep.holla@arm.com>
+ *
+ * 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/cpu_cooling.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/pm_opp.h>
+#include <linux/scpi_protocol.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+struct scpi_data {
+ struct clk *clk;
+ struct device *cpu_dev;
+ struct thermal_cooling_device *cdev;
+};
+
+static struct scpi_ops *scpi_ops;
+
+static unsigned int scpi_cpufreq_get_rate(unsigned int cpu)
+{
+ struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
+ struct scpi_data *priv = policy->driver_data;
+ unsigned long rate = clk_get_rate(priv->clk);
+
+ return rate / 1000;
+}
+
+static int
+scpi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
+{
+ unsigned long freq = policy->freq_table[index].frequency;
+ struct scpi_data *priv = policy->driver_data;
+ u64 rate = freq * 1000;
+ int ret;
+
+ ret = clk_set_rate(priv->clk, rate);
+
+ if (ret)
+ return ret;
+
+ if (clk_get_rate(priv->clk) != rate)
+ return -EIO;
+
+ arch_set_freq_scale(policy->related_cpus, freq,
+ policy->cpuinfo.max_freq);
+
+ return 0;
+}
+
+static int
+scpi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
+{
+ int cpu, domain, tdomain;
+ struct device *tcpu_dev;
+
+ domain = scpi_ops->device_domain_id(cpu_dev);
+ if (domain < 0)
+ return domain;
+
+ for_each_possible_cpu(cpu) {
+ if (cpu == cpu_dev->id)
+ continue;
+
+ tcpu_dev = get_cpu_device(cpu);
+ if (!tcpu_dev)
+ continue;
+
+ tdomain = scpi_ops->device_domain_id(tcpu_dev);
+ if (tdomain == domain)
+ cpumask_set_cpu(cpu, cpumask);
+ }
+
+ return 0;
+}
+
+static int scpi_cpufreq_init(struct cpufreq_policy *policy)
+{
+ int ret;
+ unsigned int latency;
+ struct device *cpu_dev;
+ struct scpi_data *priv;
+ struct cpufreq_frequency_table *freq_table;
+
+ cpu_dev = get_cpu_device(policy->cpu);
+ if (!cpu_dev) {
+ pr_err("failed to get cpu%d device\n", policy->cpu);
+ return -ENODEV;
+ }
+
+ ret = scpi_ops->add_opps_to_device(cpu_dev);
+ if (ret) {
+ dev_warn(cpu_dev, "failed to add opps to the device\n");
+ return ret;
+ }
+
+ ret = scpi_get_sharing_cpus(cpu_dev, policy->cpus);
+ if (ret) {
+ dev_warn(cpu_dev, "failed to get sharing cpumask\n");
+ return ret;
+ }
+
+ 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);
+ return ret;
+ }
+
+ 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;
+ }
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ ret = -ENOMEM;
+ goto out_free_opp;
+ }
+
+ 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;
+ priv->clk = clk_get(cpu_dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(cpu_dev, "%s: Failed to get clk for cpu: %d\n",
+ __func__, cpu_dev->id);
+ ret = PTR_ERR(priv->clk);
+ goto out_free_cpufreq_table;
+ }
+
+ policy->driver_data = priv;
+ policy->freq_table = freq_table;
+
+ /* scpi allows DVFS request for any domain from any CPU */
+ policy->dvfs_possible_from_any_cpu = true;
+
+ latency = scpi_ops->get_transition_latency(cpu_dev);
+ if (!latency)
+ latency = CPUFREQ_ETERNAL;
+
+ policy->cpuinfo.transition_latency = latency;
+
+ policy->fast_switch_possible = false;
+ 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_cpumask_remove_table(policy->cpus);
+
+ return ret;
+}
+
+static int scpi_cpufreq_exit(struct cpufreq_policy *policy)
+{
+ struct scpi_data *priv = policy->driver_data;
+
+ cpufreq_cooling_unregister(priv->cdev);
+ clk_put(priv->clk);
+ dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table);
+ kfree(priv);
+ dev_pm_opp_cpumask_remove_table(policy->related_cpus);
+
+ return 0;
+}
+
+static void scpi_cpufreq_ready(struct cpufreq_policy *policy)
+{
+ struct scpi_data *priv = policy->driver_data;
+
+ priv->cdev = of_cpufreq_cooling_register(policy);
+}
+
+static struct cpufreq_driver scpi_cpufreq_driver = {
+ .name = "scpi-cpufreq",
+ .flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+ CPUFREQ_NEED_INITIAL_FREQ_CHECK,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .attr = cpufreq_generic_attr,
+ .get = scpi_cpufreq_get_rate,
+ .init = scpi_cpufreq_init,
+ .exit = scpi_cpufreq_exit,
+ .ready = scpi_cpufreq_ready,
+ .target_index = scpi_cpufreq_set_target,
+};
+
+static int scpi_cpufreq_probe(struct platform_device *pdev)
+{
+ int ret;
+
+ scpi_ops = get_scpi_ops();
+ if (!scpi_ops)
+ return -EIO;
+
+ ret = cpufreq_register_driver(&scpi_cpufreq_driver);
+ if (ret)
+ dev_err(&pdev->dev, "%s: registering cpufreq failed, err: %d\n",
+ __func__, ret);
+ return ret;
+}
+
+static int scpi_cpufreq_remove(struct platform_device *pdev)
+{
+ cpufreq_unregister_driver(&scpi_cpufreq_driver);
+ scpi_ops = NULL;
+ return 0;
+}
+
+static struct platform_driver scpi_cpufreq_platdrv = {
+ .driver = {
+ .name = "scpi-cpufreq",
+ },
+ .probe = scpi_cpufreq_probe,
+ .remove = scpi_cpufreq_remove,
+};
+module_platform_driver(scpi_cpufreq_platdrv);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCPI CPUFreq interface driver");
+MODULE_LICENSE("GPL v2");