// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2019-2020, The Linux Foundation. All rights reserved. * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "qcom_common.h" #define CLIENT_STATE_OFFSET 4 #define SUBSYS_STATE_OFFSET 8 static void __iomem *base_reg; enum subsystem_type { VIRTUAL, NATIVE, }; struct subsystem_descriptor { const char *name; u32 offset; enum subsystem_type type; struct notifier_block nb; void *handle; int ssr_irq; struct list_head subsystem_list; struct work_struct work; }; static LIST_HEAD(subsystem_descriptor_list); static struct workqueue_struct *ssr_wq; static void subsystem_notif_wq_func(struct work_struct *work) { struct subsystem_descriptor *subsystem = container_of(work, struct subsystem_descriptor, work); void *subsystem_handle; int state, ret; state = readl_relaxed(base_reg + subsystem->offset); subsystem_handle = qcom_ssr_get_subsys(subsystem->name); ret = qcom_notify_ssr_clients(subsystem_handle, state, NULL); writel_relaxed(ret, base_reg + subsystem->offset + CLIENT_STATE_OFFSET); } static int subsystem_state_callback(struct notifier_block *this, unsigned long value, void *priv) { struct subsystem_descriptor *subsystem = container_of(this, struct subsystem_descriptor, nb); writel_relaxed(value, base_reg + subsystem->offset + SUBSYS_STATE_OFFSET); return NOTIFY_OK; } static irqreturn_t subsystem_restart_irq_handler(int irq, void *dev_id) { struct subsystem_descriptor *subsystem = dev_id; queue_work(ssr_wq, &subsystem->work); return IRQ_HANDLED; } static int get_resources(struct platform_device *pdev) { struct device_node *node; struct device_node *child = NULL; const char *ss_type; struct resource *res; struct subsystem_descriptor *subsystem = NULL; int ret = 0; res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "vdev_base"); base_reg = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR_OR_NULL(base_reg)) { dev_err(&pdev->dev, "Memory mapping failed\n"); return -ENOMEM; } node = pdev->dev.of_node; for_each_child_of_node(node, child) { subsystem = devm_kzalloc(&pdev->dev, sizeof(struct subsystem_descriptor), GFP_KERNEL); if (!subsystem) return -ENOMEM; subsystem->name = of_get_property(child, "subsys-name", NULL); if (IS_ERR_OR_NULL(subsystem->name)) { dev_err(&pdev->dev, "Could not find subsystem name\n"); return -EINVAL; } ret = of_property_read_u32(child, "offset", &subsystem->offset); if (ret) { dev_err(&pdev->dev, "offset reading for %s failed\n", subsystem->name); return -EINVAL; } ret = of_property_read_string(child, "type", &ss_type); if (ret) { dev_err(&pdev->dev, "type reading for %s failed\n", subsystem->name); return -EINVAL; } if (!strcmp(ss_type, "virtual")) subsystem->type = VIRTUAL; if (!strcmp(ss_type, "native")) subsystem->type = NATIVE; switch (subsystem->type) { case NATIVE: subsystem->nb.notifier_call = subsystem_state_callback; subsystem->handle = qcom_register_ssr_notifier( subsystem->name, &subsystem->nb); if (IS_ERR_OR_NULL(subsystem->handle)) { dev_err(&pdev->dev, "Could not register SSR notifier cb\n"); return -EINVAL; } list_add_tail(&subsystem->subsystem_list, &subsystem_descriptor_list); break; case VIRTUAL: subsystem->ssr_irq = of_irq_get_byname(child, "state-irq"); if (subsystem->ssr_irq < 0) { dev_err(&pdev->dev, "Could not find IRQ\n"); return -EINVAL; } ret = devm_request_threaded_irq(&pdev->dev, subsystem->ssr_irq, NULL, subsystem_restart_irq_handler, IRQF_ONESHOT | IRQF_TRIGGER_RISING, subsystem->name, subsystem); INIT_WORK(&subsystem->work, subsystem_notif_wq_func); break; default: dev_err(&pdev->dev, "Unsupported type %d\n", subsystem->type); } } return 0; } static void release_resources(void) { struct subsystem_descriptor *subsystem, *node; list_for_each_entry_safe(subsystem, node, &subsystem_descriptor_list, subsystem_list) { qcom_unregister_ssr_notifier(subsystem->handle, &subsystem->nb); list_del(&subsystem->subsystem_list); } } static int subsys_notif_virt_probe(struct platform_device *pdev) { int ret = 0; if (!pdev) { pr_err("%s: pdev is NULL\n", __func__); return -EINVAL; } ssr_wq = create_singlethread_workqueue("ssr_wq"); if (!ssr_wq) { dev_err(&pdev->dev, "Workqueue creation failed\n"); return -ENOMEM; } ret = get_resources(pdev); if (ret) destroy_workqueue(ssr_wq); return ret; } static int subsys_notif_virt_remove(struct platform_device *pdev) { destroy_workqueue(ssr_wq); release_resources(); return 0; } static const struct of_device_id match_table[] = { { .compatible = "qcom,subsys-notif-virt" }, {}, }; static struct platform_driver subsys_notif_virt_driver = { .probe = subsys_notif_virt_probe, .remove = subsys_notif_virt_remove, .driver = { .name = "subsys_notif_virt", .of_match_table = match_table, }, }; static int __init subsys_notif_virt_init(void) { return platform_driver_register(&subsys_notif_virt_driver); } module_init(subsys_notif_virt_init); static void __exit subsys_notif_virt_exit(void) { platform_driver_unregister(&subsys_notif_virt_driver); } module_exit(subsys_notif_virt_exit); MODULE_DESCRIPTION("Subsystem Notification Virtual Driver"); MODULE_LICENSE("GPL");