// 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 bool psci_pd_try_set_osi_mode(void) { int ret; if (!psci_has_osi_support()) return false; ret = psci_set_osi_mode(true); if (ret) return false; return true; } 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; int ret = 0, pd_count = 0; if (!np) return -ENODEV; /* If OSI mode is supported, let's try to enable it. */ use_osi = psci_pd_try_set_osi_mode(); /* * 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) goto put_node; pd_count++; } /* Bail out if not using the hierarchical CPU topology. */ if (!pd_count) goto no_pd; /* Link genpd masters/subdomains to model the CPU topology. */ ret = dt_idle_pd_init_topology(np); if (ret) goto remove_pd; pr_info("Initialized CPU PM domain topology\n"); return 0; put_node: of_node_put(node); remove_pd: psci_pd_remove(); pr_err("failed to create CPU PM domains ret=%d\n", ret); no_pd: if (use_osi) psci_set_osi_mode(false); 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);