On 04-08-17, 15:31, Sudeep Holla wrote:
I don't think its the Microsoft exchange server which screwed up tabs and
spaces, but you.
> diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
> index 2011fec2d6ad..c34633855bc7 100644
> --- a/drivers/cpufreq/Kconfig.arm
> +++ b/drivers/cpufreq/Kconfig.arm
> @@ -215,6 +215,17 @@ config ARM_SA1100_CPUFREQ
> config ARM_SA1110_CPUFREQ
> bool
>
> +config ARM_SCMI_CPUFREQ
> + tristate "SCMI based CPUfreq driver"
You have used spaces here instead of tab and at multiple other places, can you
please fix them all ?
> + 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_SCPI_CPUFREQ
> tristate "SCPI based CPUfreq driver"
> depends on ARM_BIG_LITTLE_CPUFREQ && ARM_SCPI_PROTOCOL &&
> COMMON_CLK_SCPI
> diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
> index ab3a42cd29ef..4810b45568d3 100644
> --- a/drivers/cpufreq/Makefile
> +++ b/drivers/cpufreq/Makefile
> @@ -72,6 +72,7 @@ obj-$(CONFIG_ARM_S3C64XX_CPUFREQ) += s3c64xx-cpufreq.o
> obj-$(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..034359cafea5
> --- /dev/null
> +++ b/drivers/cpufreq/scmi-cpufreq.c
> @@ -0,0 +1,268 @@
> +/*
> + * System Control and Power Interface (SCMI) based CPUFreq Interface driver
> + *
> + * Copyright (C) 2017 ARM Ltd.
> + * Sudeep Holla <sudeep.ho...@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/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/platform_device.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;
> + const struct scmi_handle *handle;
This stores the same handle pointer which is stored in the global variable
below. Right? Why keep a local variable here at all ?
> +};
> +
> +static const struct scmi_handle *handle;
> +
> +unsigned int scmi_cpufreq_get_rate(unsigned int cpu)
> +{
> + int ret;
> + unsigned long rate;
> + struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu);
> + struct scmi_data *priv = policy->driver_data;
> + struct scmi_perf_ops *perf_ops = priv->handle->perf_ops;
Normally people prefer to keep these definitions in decreasing order of their
lengths. i.e. ret and rate would be defined in the last line. Though I would
leave it to you to decide.
> +
> + ret = perf_ops->freq_get(priv->handle, priv->domain_id, &rate, false);
> + if (ret)
> + return CPUFREQ_ENTRY_INVALID;
This is something special which is used only when we are returning indexes and
I am not sure if this will have benefit here. I will rather return 0 here.
That's what other drivers are doing.
> + return rate / 1000;
> +}
> +
> +static int
> +scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
> +{
> + struct scmi_data *priv = policy->driver_data;
> + struct scmi_perf_ops *perf_ops = priv->handle->perf_ops;
> + u64 freq = policy->freq_table[index].frequency * 1000;
> +
> + return perf_ops->freq_set(priv->handle, priv->domain_id, freq, false);
> +}
I suppose any CPU can change the frequency of any other CPU here, right? You
must set policy->dvfs_possible_from_any_cpu = true, from ->init() then.
> +static int
> +scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
> +{
> + int cpu, domain, ret = 0;
You don't need to initialize ret here and I would rather name it tdomain or
something else. ret is a lot used to store error/success values, which isn't
your case.
> + struct device *tcpu_dev;
> +
> + domain = handle->perf_ops->device_domain_id(cpu_dev);
> + if (domain < 0)
> + return domain;
> +
> + cpumask_set_cpu(cpu_dev->id, cpumask);
The mask already have this set from the core, you don't need to do it again.
> + for_each_possible_cpu(cpu) {
> + if (cpu == cpu_dev->id)
> + continue;
> +
> + tcpu_dev = get_cpu_device(cpu);
> + if (!tcpu_dev)
> + continue;
> +
> + ret = handle->perf_ops->device_domain_id(tcpu_dev);
> + if (ret == 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(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;
> + }
> +
> + /*
> + * But we need OPP table to function so if it is not there let's
> + * give platform code chance to provide it for us.
> + */
How are we getting the OPPs? DT or non DT ?
> + 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->handle = handle;
> + 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;
> + }
> +
> + latency = handle->perf_ops->get_transition_latency(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);
> + dev_pm_opp_cpumask_remove_table(policy->related_cpus);
> + kfree(priv);
I would rather swap the above two lines to keep the same order as in probe.
Though nothing would fail with the current code as well.
> +
> + return 0;
> +}
> +
> +static void scmi_cpufreq_ready(struct cpufreq_policy *policy)
> +{
> + struct scmi_data *priv = policy->driver_data;
> + struct device_node *np = of_node_get(priv->cpu_dev->of_node);
> +
> + if (WARN_ON(!np))
> + return;
> +
> + if (of_find_property(np, "#cooling-cells", NULL)) {
> + u32 pcoeff = 0;
> +
> + of_property_read_u32(np, "dynamic-power-coefficient",
> + &pcoeff);
> +
> + priv->cdev = of_cpufreq_power_cooling_register(np, policy,
> + pcoeff, NULL);
> + if (IS_ERR(priv->cdev)) {
> + dev_err(priv->cpu_dev,
> + "running cpufreq without cooling device: %ld\n",
> + PTR_ERR(priv->cdev));
> +
> + priv->cdev = NULL;
> + }
> + }
> +
> + of_node_put(np);
> +}
> +
> +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,
> +};
Above block has lots of space/tab issues. Can you please use tabs before "="
instead?
> +static int scmi_cpufreq_probe(struct platform_device *pdev)
> +{
> + int ret;
> +
> + handle = devm_scmi_handle_get(&pdev->dev);
What code is creating this pdev ?
> +
> + if (IS_ERR_OR_NULL(handle) || !handle->perf_ops)
> + return -EPROBE_DEFER;
> +
> + ret = cpufreq_register_driver(&scmi_cpufreq_driver);
> + if (ret) {
> + dev_err(&pdev->dev, "%s: registering cpufreq failed, err: %d\n",
> + __func__, ret);
> + }
> +
> + return ret;
> +}
> +
> +static int scmi_cpufreq_remove(struct platform_device *pdev)
> +{
> + cpufreq_unregister_driver(&scmi_cpufreq_driver);
> + return 0;
> +}
> +
> +static struct platform_driver scmi_cpufreq_platdrv = {
> + .driver = {
> + .name = "scmi-cpufreq",
> + },
> + .probe = scmi_cpufreq_probe,
> + .remove = scmi_cpufreq_remove,
> +};
> +module_platform_driver(scmi_cpufreq_platdrv);
> +
> +MODULE_AUTHOR("Sudeep Holla <sudeep.ho...@arm.com>");
> +MODULE_DESCRIPTION("ARM SCMI CPUFreq interface driver");
> +MODULE_LICENSE("GPL v2");
--
viresh
