| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright 2020 Google LLC |
| * |
| * This driver serves as the receiver of cros_ec PD host events. |
| */ |
| |
| #include <linux/acpi.h> |
| #include <linux/mod_devicetable.h> |
| #include <linux/module.h> |
| #include <linux/platform_data/cros_ec_proto.h> |
| #include <linux/platform_data/cros_usbpd_notify.h> |
| #include <linux/platform_device.h> |
| |
| #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 <jflat@chromium.org>"); |