diff options
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/Kconfig.arm | 11 | ||||
| -rw-r--r-- | drivers/cpufreq/Makefile | 1 | ||||
| -rw-r--r-- | drivers/cpufreq/scmi-cpufreq.c | 246 |
3 files changed, 258 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm index 3a88e33b0cfe..2e49673a9e21 100644 --- a/drivers/cpufreq/Kconfig.arm +++ b/drivers/cpufreq/Kconfig.arm @@ -238,6 +238,17 @@ config ARM_SA1100_CPUFREQ config ARM_SA1110_CPUFREQ bool +config ARM_SCMI_CPUFREQ + tristate "SCMI based CPUfreq driver" + depends on ARM_SCMI_PROTOCOL || COMPILE_TEST + select PM_OPP + help + This adds the CPUfreq driver support for ARM platforms using SCMI + protocol for CPU power management. + + This driver uses SCMI Message Protocol driver to interact with the + firmware providing the CPU DVFS functionality. + config ARM_SPEAR_CPUFREQ bool "SPEAr CPUFreq support" depends on PLAT_SPEAR diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile index c60c1e141d9d..4987227b67df 100644 --- a/drivers/cpufreq/Makefile +++ b/drivers/cpufreq/Makefile @@ -75,6 +75,7 @@ obj-$(CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS) += s3c24xx-cpufreq-debugfs.o obj-$(CONFIG_ARM_S5PV210_CPUFREQ) += s5pv210-cpufreq.o obj-$(CONFIG_ARM_SA1100_CPUFREQ) += sa1100-cpufreq.o obj-$(CONFIG_ARM_SA1110_CPUFREQ) += sa1110-cpufreq.o +obj-$(CONFIG_ARM_SCMI_CPUFREQ) += scmi-cpufreq.o obj-$(CONFIG_ARM_SCPI_CPUFREQ) += scpi-cpufreq.o obj-$(CONFIG_ARM_SPEAR_CPUFREQ) += spear-cpufreq.o obj-$(CONFIG_ARM_STI_CPUFREQ) += sti-cpufreq.o diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c new file mode 100644 index 000000000000..b04f07f1b1d2 --- /dev/null +++ b/drivers/cpufreq/scmi-cpufreq.c @@ -0,0 +1,246 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Power Interface (SCMI) based CPUFreq Interface driver + * + * Copyright (C) 2018 ARM Ltd. + * Sudeep Holla <sudeep.holla@arm.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#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/pm_opp.h> +#include <linux/slab.h> +#include <linux/scmi_protocol.h> +#include <linux/types.h> + +struct scmi_data { + int domain_id; + struct device *cpu_dev; + struct thermal_cooling_device *cdev; +}; + +static const struct scmi_handle *handle; + +static unsigned int scmi_cpufreq_get_rate(unsigned int cpu) +{ + struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); + struct scmi_perf_ops *perf_ops = handle->perf_ops; + struct scmi_data *priv = policy->driver_data; + unsigned long rate; + int ret; + + ret = perf_ops->freq_get(handle, priv->domain_id, &rate, false); + if (ret) + return 0; + return rate / 1000; +} + +/* + * perf_ops->freq_set is not a synchronous, the actual OPP change will + * happen asynchronously and can get notified if the events are + * subscribed for by the SCMI firmware + */ +static int +scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) +{ + int ret; + struct scmi_data *priv = policy->driver_data; + struct scmi_perf_ops *perf_ops = handle->perf_ops; + u64 freq = policy->freq_table[index].frequency * 1000; + + ret = perf_ops->freq_set(handle, priv->domain_id, freq, false); + if (!ret) + arch_set_freq_scale(policy->related_cpus, freq, + policy->cpuinfo.max_freq); + return ret; +} + +static int +scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) +{ + int cpu, domain, tdomain; + struct device *tcpu_dev; + + domain = handle->perf_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 = handle->perf_ops->device_domain_id(tcpu_dev); + if (tdomain == domain) + cpumask_set_cpu(cpu, cpumask); + } + + return 0; +} + +static int scmi_cpufreq_init(struct cpufreq_policy *policy) +{ + int ret; + unsigned int latency; + struct device *cpu_dev; + struct scmi_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 = handle->perf_ops->add_opps_to_device(handle, cpu_dev); + if (ret) { + dev_warn(cpu_dev, "failed to add opps to the device\n"); + return ret; + } + + ret = scmi_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->domain_id = handle->perf_ops->device_domain_id(cpu_dev); + + policy->driver_data = priv; + + 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; + } + + /* SCMI allows DVFS request for any domain from any CPU */ + policy->dvfs_possible_from_any_cpu = true; + + latency = handle->perf_ops->get_transition_latency(handle, cpu_dev); + if (!latency) + latency = CPUFREQ_ETERNAL; + + policy->cpuinfo.transition_latency = 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_cpumask_remove_table(policy->cpus); + + return ret; +} + +static int scmi_cpufreq_exit(struct cpufreq_policy *policy) +{ + struct scmi_data *priv = policy->driver_data; + + cpufreq_cooling_unregister(priv->cdev); + 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 scmi_cpufreq_ready(struct cpufreq_policy *policy) +{ + struct scmi_data *priv = policy->driver_data; + + priv->cdev = of_cpufreq_cooling_register(policy); +} + +static struct cpufreq_driver scmi_cpufreq_driver = { + .name = "scmi", + .flags = CPUFREQ_STICKY | CPUFREQ_HAVE_GOVERNOR_PER_POLICY | + CPUFREQ_NEED_INITIAL_FREQ_CHECK, + .verify = cpufreq_generic_frequency_table_verify, + .attr = cpufreq_generic_attr, + .target_index = scmi_cpufreq_set_target, + .get = scmi_cpufreq_get_rate, + .init = scmi_cpufreq_init, + .exit = scmi_cpufreq_exit, + .ready = scmi_cpufreq_ready, +}; + +static int scmi_cpufreq_probe(struct scmi_device *sdev) +{ + int ret; + + handle = sdev->handle; + + if (!handle || !handle->perf_ops) + return -ENODEV; + + ret = cpufreq_register_driver(&scmi_cpufreq_driver); + if (ret) { + dev_err(&sdev->dev, "%s: registering cpufreq failed, err: %d\n", + __func__, ret); + } + + return ret; +} + +static void scmi_cpufreq_remove(struct scmi_device *sdev) +{ + cpufreq_unregister_driver(&scmi_cpufreq_driver); +} + +static const struct scmi_device_id scmi_id_table[] = { + { SCMI_PROTOCOL_PERF }, + { }, +}; +MODULE_DEVICE_TABLE(scmi, scmi_id_table); + +static struct scmi_driver scmi_cpufreq_drv = { + .name = "scmi-cpufreq", + .probe = scmi_cpufreq_probe, + .remove = scmi_cpufreq_remove, + .id_table = scmi_id_table, +}; +module_scmi_driver(scmi_cpufreq_drv); + +MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>"); +MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver"); +MODULE_LICENSE("GPL v2"); |