diff options
Diffstat (limited to 'drivers/cpuidle/cpuidle-psci-domain.c')
| -rw-r--r-- | drivers/cpuidle/cpuidle-psci-domain.c | 200 |
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); |