// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2020 Google LLC * * This driver serves as the receiver of cros_ec PD host events. */ #include #include #include #include #include #include #define DRV_NAME "cros-usbpd-notify" #define DRV_NAME_PLAT_ACPI "cros-usbpd-notify-acpi" #define ACPI_DRV_NAME "GOOG0003" static BLOCKING_NOTIFIER_HEAD(cros_usbpd_notifier_list); struct cros_usbpd_notify_data { struct device *dev; struct cros_ec_device *ec; struct notifier_block nb; }; /** * cros_usbpd_register_notify - Register a notifier callback for PD events. * @nb: Notifier block pointer to register * * On ACPI platforms this corresponds to host events on the ECPD * "GOOG0003" ACPI device. On non-ACPI platforms this will filter mkbp events * for USB PD events. * * Return: 0 on success or negative error code. */ int cros_usbpd_register_notify(struct notifier_block *nb) { return blocking_notifier_chain_register(&cros_usbpd_notifier_list, nb); } EXPORT_SYMBOL_GPL(cros_usbpd_register_notify); /** * cros_usbpd_unregister_notify - Unregister notifier callback for PD events. * @nb: Notifier block pointer to unregister * * Unregister a notifier callback that was previously registered with * cros_usbpd_register_notify(). */ void cros_usbpd_unregister_notify(struct notifier_block *nb) { blocking_notifier_chain_unregister(&cros_usbpd_notifier_list, nb); } EXPORT_SYMBOL_GPL(cros_usbpd_unregister_notify); static void cros_usbpd_get_event_and_notify(struct device *dev, struct cros_ec_device *ec_dev) { struct ec_response_host_event_status host_event_status; u32 event = 0; int ret; /* * We still send a 0 event out to older devices which don't * have the updated device heirarchy. */ if (!ec_dev) { dev_dbg(dev, "EC device inaccessible; sending 0 event status.\n"); goto send_notify; } /* Check for PD host events on EC. */ ret = cros_ec_cmd(ec_dev, 0, EC_CMD_PD_HOST_EVENT_STATUS, NULL, 0, &host_event_status, sizeof(host_event_status)); if (ret < 0) { dev_warn(dev, "Can't get host event status (err: %d)\n", ret); goto send_notify; } event = host_event_status.status; send_notify: blocking_notifier_call_chain(&cros_usbpd_notifier_list, event, NULL); } #ifdef CONFIG_ACPI static void cros_usbpd_notify_acpi(acpi_handle device, u32 event, void *data) { struct cros_usbpd_notify_data *pdnotify = data; cros_usbpd_get_event_and_notify(pdnotify->dev, pdnotify->ec); } static int cros_usbpd_notify_probe_acpi(struct platform_device *pdev) { struct cros_usbpd_notify_data *pdnotify; struct device *dev = &pdev->dev; struct acpi_device *adev; struct cros_ec_device *ec_dev; acpi_status status; adev = ACPI_COMPANION(dev); pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); if (!pdnotify) return -ENOMEM; /* Get the EC device pointer needed to talk to the EC. */ ec_dev = dev_get_drvdata(dev->parent); if (!ec_dev) { /* * We continue even for older devices which don't have the * correct device heirarchy, namely, GOOG0003 is a child * of GOOG0004. */ dev_warn(dev, "Couldn't get Chrome EC device pointer.\n"); } pdnotify->dev = dev; pdnotify->ec = ec_dev; status = acpi_install_notify_handler(adev->handle, ACPI_ALL_NOTIFY, cros_usbpd_notify_acpi, pdnotify); if (ACPI_FAILURE(status)) { dev_warn(dev, "Failed to register notify handler %08x\n", status); return -EINVAL; } return 0; } static void cros_usbpd_notify_remove_acpi(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct acpi_device *adev = ACPI_COMPANION(dev); acpi_remove_notify_handler(adev->handle, ACPI_ALL_NOTIFY, cros_usbpd_notify_acpi); } static const struct acpi_device_id cros_usbpd_notify_acpi_device_ids[] = { { ACPI_DRV_NAME, 0 }, { } }; MODULE_DEVICE_TABLE(acpi, cros_usbpd_notify_acpi_device_ids); static struct platform_driver cros_usbpd_notify_acpi_driver = { .driver = { .name = DRV_NAME_PLAT_ACPI, .acpi_match_table = cros_usbpd_notify_acpi_device_ids, }, .probe = cros_usbpd_notify_probe_acpi, .remove = cros_usbpd_notify_remove_acpi, }; #endif /* CONFIG_ACPI */ static int cros_usbpd_notify_plat(struct notifier_block *nb, unsigned long queued_during_suspend, void *data) { struct cros_usbpd_notify_data *pdnotify = container_of(nb, struct cros_usbpd_notify_data, nb); struct cros_ec_device *ec_dev = (struct cros_ec_device *)data; u32 host_event = cros_ec_get_host_event(ec_dev); if (!host_event) return NOTIFY_DONE; if (host_event & (EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) | EC_HOST_EVENT_MASK(EC_HOST_EVENT_USB_MUX))) { cros_usbpd_get_event_and_notify(pdnotify->dev, ec_dev); return NOTIFY_OK; } return NOTIFY_DONE; } static int cros_usbpd_notify_probe_plat(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); struct cros_usbpd_notify_data *pdnotify; int ret; pdnotify = devm_kzalloc(dev, sizeof(*pdnotify), GFP_KERNEL); if (!pdnotify) return -ENOMEM; pdnotify->dev = dev; pdnotify->ec = ecdev->ec_dev; pdnotify->nb.notifier_call = cros_usbpd_notify_plat; dev_set_drvdata(dev, pdnotify); ret = blocking_notifier_chain_register(&ecdev->ec_dev->event_notifier, &pdnotify->nb); if (ret < 0) { dev_err(dev, "Failed to register notifier\n"); return ret; } return 0; } static void cros_usbpd_notify_remove_plat(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct cros_ec_dev *ecdev = dev_get_drvdata(dev->parent); struct cros_usbpd_notify_data *pdnotify = (struct cros_usbpd_notify_data *)dev_get_drvdata(dev); blocking_notifier_chain_unregister(&ecdev->ec_dev->event_notifier, &pdnotify->nb); } static const struct platform_device_id cros_usbpd_notify_id[] = { { DRV_NAME, 0 }, {} }; MODULE_DEVICE_TABLE(platform, cros_usbpd_notify_id); static struct platform_driver cros_usbpd_notify_plat_driver = { .driver = { .name = DRV_NAME, }, .probe = cros_usbpd_notify_probe_plat, .remove = cros_usbpd_notify_remove_plat, .id_table = cros_usbpd_notify_id, }; static int __init cros_usbpd_notify_init(void) { int ret; ret = platform_driver_register(&cros_usbpd_notify_plat_driver); if (ret < 0) return ret; #ifdef CONFIG_ACPI ret = platform_driver_register(&cros_usbpd_notify_acpi_driver); if (ret) { platform_driver_unregister(&cros_usbpd_notify_plat_driver); return ret; } #endif return 0; } static void __exit cros_usbpd_notify_exit(void) { #ifdef CONFIG_ACPI platform_driver_unregister(&cros_usbpd_notify_acpi_driver); #endif platform_driver_unregister(&cros_usbpd_notify_plat_driver); } module_init(cros_usbpd_notify_init); module_exit(cros_usbpd_notify_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("ChromeOS power delivery notifier device"); MODULE_AUTHOR("Jon Flatley ");