static int dt_cpufreq_early_init()

in cpufreq-dt.c [191:302]

• 72 lines of code
• 18 McCabe index (conditional complexity)

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;
	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 = find_supply_name(cpu_dev);
	if (reg_name) {
		priv->opp_table = dev_pm_opp_set_regulators(cpu_dev, &reg_name,
							    1);
		if (IS_ERR(priv->opp_table)) {
			ret = PTR_ERR(priv->opp_table);
			if (ret != -EPROBE_DEFER)
				dev_err(cpu_dev, "failed to set regulators: %d\n",
					ret);
			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_table);
free_cpumask:
	free_cpumask_var(priv->cpus);
	return ret;
}