1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/cpuidle/cpuidle-psci-domain.c b/drivers/cpuidle/cpuidle-psci-domain.c
new file mode 100644
index 000000000..f5d435955
--- /dev/null
+++ b/drivers/cpuidle/cpuidle-psci-domain.c
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PM domains for CPUs via genpd - managed by cpuidle-psci.
+ *
+ * Copyright (C) 2019 Linaro Ltd.
+ * Author: Ulf Hansson <ulf.hansson@linaro.org>
+ *
+ */
+
+#define pr_fmt(fmt) "CPUidle PSCI: " fmt
+
+#include <linux/cpu.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/psci.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include "cpuidle-psci.h"
+
+struct psci_pd_provider {
+	struct list_head link;
+	struct device_node *node;
+};
+
+static LIST_HEAD(psci_pd_providers);
+static bool psci_pd_allow_domain_state;
+
+static int psci_pd_power_off(struct generic_pm_domain *pd)
+{
+	struct genpd_power_state *state = &pd->states[pd->state_idx];
+	u32 *pd_state;
+
+	if (!state->data)
+		return 0;
+
+	if (!psci_pd_allow_domain_state)
+		return -EBUSY;
+
+	/* OSI mode is enabled, set the corresponding domain state. */
+	pd_state = state->data;
+	psci_set_domain_state(*pd_state);
+
+	return 0;
+}
+
+static int psci_pd_init(struct device_node *np, bool use_osi)
+{
+	struct generic_pm_domain *pd;
+	struct psci_pd_provider *pd_provider;
+	struct dev_power_governor *pd_gov;
+	int ret = -ENOMEM;
+
+	pd = dt_idle_pd_alloc(np, psci_dt_parse_state_node);
+	if (!pd)
+		goto out;
+
+	pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL);
+	if (!pd_provider)
+		goto free_pd;
+
+	pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN;
+
+	/* Allow power off when OSI has been successfully enabled. */
+	if (use_osi)
+		pd->power_off = psci_pd_power_off;
+	else
+		pd->flags |= GENPD_FLAG_ALWAYS_ON;
+
+	/* Use governor for CPU PM domains if it has some states to manage. */
+	pd_gov = pd->states ? &pm_domain_cpu_gov : NULL;
+
+	ret = pm_genpd_init(pd, pd_gov, false);
+	if (ret)
+		goto free_pd_prov;
+
+	ret = of_genpd_add_provider_simple(np, pd);
+	if (ret)
+		goto remove_pd;
+
+	pd_provider->node = of_node_get(np);
+	list_add(&pd_provider->link, &psci_pd_providers);
+
+	pr_debug("init PM domain %s\n", pd->name);
+	return 0;
+
+remove_pd:
+	pm_genpd_remove(pd);
+free_pd_prov:
+	kfree(pd_provider);
+free_pd:
+	dt_idle_pd_free(pd);
+out:
+	pr_err("failed to init PM domain ret=%d %pOF\n", ret, np);
+	return ret;
+}
+
+static void psci_pd_remove(void)
+{
+	struct psci_pd_provider *pd_provider, *it;
+	struct generic_pm_domain *genpd;
+
+	list_for_each_entry_safe_reverse(pd_provider, it,
+					 &psci_pd_providers, link) {
+		of_genpd_del_provider(pd_provider->node);
+
+		genpd = of_genpd_remove_last(pd_provider->node);
+		if (!IS_ERR(genpd))
+			kfree(genpd);
+
+		of_node_put(pd_provider->node);
+		list_del(&pd_provider->link);
+		kfree(pd_provider);
+	}
+}
+
+static void psci_cpuidle_domain_sync_state(struct device *dev)
+{
+	/*
+	 * All devices have now been attached/probed to the PM domain topology,
+	 * hence it's fine to allow domain states to be picked.
+	 */
+	psci_pd_allow_domain_state = true;
+}
+
+static const struct of_device_id psci_of_match[] = {
+	{ .compatible = "arm,psci-1.0" },
+	{}
+};
+
+static int psci_cpuidle_domain_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device_node *node;
+	bool use_osi = psci_has_osi_support();
+	int ret = 0, pd_count = 0;
+
+	if (!np)
+		return -ENODEV;
+
+	/*
+	 * Parse child nodes for the "#power-domain-cells" property and
+	 * initialize a genpd/genpd-of-provider pair when it's found.
+	 */
+	for_each_child_of_node(np, node) {
+		if (!of_find_property(node, "#power-domain-cells", NULL))
+			continue;
+
+		ret = psci_pd_init(node, use_osi);
+		if (ret) {
+			of_node_put(node);
+			goto exit;
+		}
+
+		pd_count++;
+	}
+
+	/* Bail out if not using the hierarchical CPU topology. */
+	if (!pd_count)
+		return 0;
+
+	/* Link genpd masters/subdomains to model the CPU topology. */
+	ret = dt_idle_pd_init_topology(np);
+	if (ret)
+		goto remove_pd;
+
+	/* let's try to enable OSI. */
+	ret = psci_set_osi_mode(use_osi);
+	if (ret)
+		goto remove_pd;
+
+	pr_info("Initialized CPU PM domain topology using %s mode\n",
+		use_osi ? "OSI" : "PC");
+	return 0;
+
+remove_pd:
+	dt_idle_pd_remove_topology(np);
+	psci_pd_remove();
+exit:
+	pr_err("failed to create CPU PM domains ret=%d\n", ret);
+	return ret;
+}
+
+static struct platform_driver psci_cpuidle_domain_driver = {
+	.probe  = psci_cpuidle_domain_probe,
+	.driver = {
+		.name = "psci-cpuidle-domain",
+		.of_match_table = psci_of_match,
+		.sync_state = psci_cpuidle_domain_sync_state,
+	},
+};
+
+static int __init psci_idle_init_domains(void)
+{
+	return platform_driver_register(&psci_cpuidle_domain_driver);
+}
+subsys_initcall(psci_idle_init_domains);