static int apple_pmgr_ps_probe()

in apple/apple-pmgr-pwrstate.c [191:303]

• 89 lines of code
• 15 McCabe index (conditional complexity)

static int apple_pmgr_ps_probe(struct platform_device *pdev)
{
	struct device *dev = &pdev->dev;
	struct device_node *node = dev->of_node;
	struct apple_pmgr_ps *ps;
	struct regmap *regmap;
	struct of_phandle_iterator it;
	int ret;
	const char *name;
	bool active;

	regmap = syscon_node_to_regmap(node->parent);
	if (IS_ERR(regmap))
		return PTR_ERR(regmap);

	ps = devm_kzalloc(dev, sizeof(*ps), GFP_KERNEL);
	if (!ps)
		return -ENOMEM;

	ps->dev = dev;
	ps->regmap = regmap;

	ret = of_property_read_string(node, "label", &name);
	if (ret < 0) {
		dev_err(dev, "missing label property\n");
		return ret;
	}

	ret = of_property_read_u32(node, "reg", &ps->offset);
	if (ret < 0) {
		dev_err(dev, "missing reg property\n");
		return ret;
	}

	ps->genpd.name = name;
	ps->genpd.power_on = apple_pmgr_ps_power_on;
	ps->genpd.power_off = apple_pmgr_ps_power_off;

	ret = of_property_read_u32(node, "apple,min-state", &ps->min_state);
	if (ret == 0 && ps->min_state <= APPLE_PMGR_PS_ACTIVE)
		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_PS_MIN,
				   FIELD_PREP(APPLE_PMGR_PS_MIN, ps->min_state));

	active = apple_pmgr_ps_is_active(ps);
	if (of_property_read_bool(node, "apple,always-on")) {
		ps->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
		if (!active) {
			dev_warn(dev, "always-on domain %s is not on at boot\n", name);
			/* Turn it on so pm_genpd_init does not fail */
			active = apple_pmgr_ps_power_on(&ps->genpd) == 0;
		}
	}

	/* Turn on auto-PM if the domain is already on */
	if (active)
		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_AUTO_ENABLE,
				   APPLE_PMGR_AUTO_ENABLE);

	ret = pm_genpd_init(&ps->genpd, NULL, !active);
	if (ret < 0) {
		dev_err(dev, "pm_genpd_init failed\n");
		return ret;
	}

	ret = of_genpd_add_provider_simple(node, &ps->genpd);
	if (ret < 0) {
		dev_err(dev, "of_genpd_add_provider_simple failed\n");
		return ret;
	}

	of_for_each_phandle(&it, ret, node, "power-domains", "#power-domain-cells", -1) {
		struct of_phandle_args parent, child;

		parent.np = it.node;
		parent.args_count = of_phandle_iterator_args(&it, parent.args, MAX_PHANDLE_ARGS);
		child.np = node;
		child.args_count = 0;
		ret = of_genpd_add_subdomain(&parent, &child);

		if (ret == -EPROBE_DEFER) {
			of_node_put(parent.np);
			goto err_remove;
		} else if (ret < 0) {
			dev_err(dev, "failed to add to parent domain: %d (%s -> %s)\n",
				ret, it.node->name, node->name);
			of_node_put(parent.np);
			goto err_remove;
		}
	}

	/*
	 * Do not participate in regular PM; parent power domains are handled via the
	 * genpd hierarchy.
	 */
	pm_genpd_remove_device(dev);

	ps->rcdev.owner = THIS_MODULE;
	ps->rcdev.nr_resets = 1;
	ps->rcdev.ops = &apple_pmgr_reset_ops;
	ps->rcdev.of_node = dev->of_node;
	ps->rcdev.of_reset_n_cells = 0;
	ps->rcdev.of_xlate = apple_pmgr_reset_xlate;

	ret = devm_reset_controller_register(dev, &ps->rcdev);
	if (ret < 0)
		goto err_remove;

	return 0;
err_remove:
	of_genpd_del_provider(node);
	pm_genpd_remove(&ps->genpd);
	return ret;
}