int dtpm_register()

in dtpm.c [410:462]

• 40 lines of code
• 19 McCabe index (conditional complexity)

int dtpm_register(const char *name, struct dtpm *dtpm, struct dtpm *parent)
{
	struct powercap_zone *pcz;

	if (!pct)
		return -EAGAIN;

	if (root && !parent)
		return -EBUSY;

	if (!root && parent)
		return -EINVAL;

	if (parent && parent->ops)
		return -EINVAL;

	if (!dtpm)
		return -EINVAL;

	if (dtpm->ops && !(dtpm->ops->set_power_uw &&
			   dtpm->ops->get_power_uw &&
			   dtpm->ops->update_power_uw &&
			   dtpm->ops->release))
		return -EINVAL;

	pcz = powercap_register_zone(&dtpm->zone, pct, name,
				     parent ? &parent->zone : NULL,
				     &zone_ops, MAX_DTPM_CONSTRAINTS,
				     &constraint_ops);
	if (IS_ERR(pcz))
		return PTR_ERR(pcz);

	mutex_lock(&dtpm_lock);

	if (parent) {
		list_add_tail(&dtpm->sibling, &parent->children);
		dtpm->parent = parent;
	} else {
		root = dtpm;
	}

	if (dtpm->ops && !dtpm->ops->update_power_uw(dtpm)) {
		__dtpm_add_power(dtpm);
		dtpm->power_limit = dtpm->power_max;
	}

	pr_debug("Registered dtpm node '%s' / %llu-%llu uW, \n",
		 dtpm->zone.name, dtpm->power_min, dtpm->power_max);

	mutex_unlock(&dtpm_lock);

	return 0;
}