| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Driver for onboard USB hubs |
| * |
| * Copyright (c) 2020, Google LLC |
| */ |
| |
| #include <linux/device.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mutex.h> |
| #include <linux/of.h> |
| #include <linux/of_platform.h> |
| #include <linux/platform_device.h> |
| #include <linux/regulator/consumer.h> |
| #include <linux/suspend.h> |
| #include <linux/usb.h> |
| #include <linux/usb/hcd.h> |
| |
| /************************** Platform driver **************************/ |
| |
| struct udev_node { |
| struct usb_device *udev; |
| struct list_head list; |
| }; |
| |
| struct onboard_hub { |
| struct regulator *vdd; |
| struct device *dev; |
| bool always_powered_in_suspend; |
| bool is_powered_on; |
| bool going_away; |
| struct list_head udev_list; |
| struct mutex lock; |
| }; |
| |
| static int onboard_hub_power_on(struct onboard_hub *hub) |
| { |
| int err; |
| |
| err = regulator_enable(hub->vdd); |
| if (err) { |
| dev_err(hub->dev, "failed to enable regulator: %d\n", err); |
| return err; |
| } |
| |
| hub->is_powered_on = true; |
| |
| return 0; |
| } |
| |
| static int onboard_hub_power_off(struct onboard_hub *hub) |
| { |
| int err; |
| |
| err = regulator_disable(hub->vdd); |
| if (err) { |
| dev_err(hub->dev, "failed to disable regulator: %d\n", err); |
| return err; |
| } |
| |
| hub->is_powered_on = false; |
| |
| return 0; |
| } |
| |
| static int __maybe_unused onboard_hub_suspend(struct device *dev) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(dev); |
| struct udev_node *node; |
| bool power_off; |
| int rc = 0; |
| |
| if (hub->always_powered_in_suspend) |
| return 0; |
| |
| power_off = true; |
| |
| mutex_lock(&hub->lock); |
| |
| list_for_each_entry(node, &hub->udev_list, list) { |
| if (!device_may_wakeup(node->udev->bus->controller)) |
| continue; |
| |
| if (usb_wakeup_enabled_descendants(node->udev)) { |
| power_off = false; |
| break; |
| } |
| } |
| |
| mutex_unlock(&hub->lock); |
| |
| if (power_off) |
| rc = onboard_hub_power_off(hub); |
| |
| return rc; |
| } |
| |
| static int __maybe_unused onboard_hub_resume(struct device *dev) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(dev); |
| int rc = 0; |
| |
| if (!hub->is_powered_on) |
| rc = onboard_hub_power_on(hub); |
| |
| return rc; |
| } |
| |
| static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev) |
| { |
| struct udev_node *node; |
| int ret = 0; |
| |
| mutex_lock(&hub->lock); |
| |
| if (hub->going_away) { |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| node = devm_kzalloc(hub->dev, sizeof(*node), GFP_KERNEL); |
| if (!node) { |
| ret = -ENOMEM; |
| goto unlock; |
| } |
| |
| node->udev = udev; |
| |
| list_add(&node->list, &hub->udev_list); |
| |
| unlock: |
| mutex_unlock(&hub->lock); |
| |
| return ret; |
| } |
| |
| static void onboard_hub_remove_usbdev(struct onboard_hub *hub, struct usb_device *udev) |
| { |
| struct udev_node *node; |
| |
| mutex_lock(&hub->lock); |
| |
| list_for_each_entry(node, &hub->udev_list, list) { |
| if (node->udev == udev) { |
| list_del(&node->list); |
| break; |
| } |
| } |
| |
| mutex_unlock(&hub->lock); |
| } |
| |
| static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(dev); |
| |
| return sprintf(buf, "%d\n", hub->always_powered_in_suspend); |
| } |
| |
| static ssize_t always_powered_in_suspend_store(struct device *dev, struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(dev); |
| bool val; |
| int ret; |
| |
| ret = kstrtobool(buf, &val); |
| if (ret < 0) |
| return ret; |
| |
| hub->always_powered_in_suspend = val; |
| |
| return count; |
| } |
| static DEVICE_ATTR_RW(always_powered_in_suspend); |
| |
| static struct attribute *onboard_hub_sysfs_entries[] = { |
| &dev_attr_always_powered_in_suspend.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group onboard_hub_sysfs_group = { |
| .attrs = onboard_hub_sysfs_entries, |
| }; |
| |
| static int onboard_hub_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct onboard_hub *hub; |
| int err; |
| |
| hub = devm_kzalloc(dev, sizeof(*hub), GFP_KERNEL); |
| if (!hub) |
| return -ENOMEM; |
| |
| hub->vdd = devm_regulator_get(dev, "vdd"); |
| if (IS_ERR(hub->vdd)) |
| return PTR_ERR(hub->vdd); |
| |
| hub->dev = dev; |
| mutex_init(&hub->lock); |
| INIT_LIST_HEAD(&hub->udev_list); |
| |
| dev_set_drvdata(dev, hub); |
| |
| err = devm_device_add_group(dev, &onboard_hub_sysfs_group); |
| if (err) { |
| dev_err(dev, "failed to create sysfs entries: %d\n", err); |
| return err; |
| } |
| |
| return onboard_hub_power_on(hub); |
| } |
| |
| static int onboard_hub_remove(struct platform_device *pdev) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(&pdev->dev); |
| struct udev_node *node; |
| struct usb_device *udev; |
| |
| hub->going_away = true; |
| |
| mutex_lock(&hub->lock); |
| |
| /* unbind the USB devices to avoid dangling references to this device */ |
| while (!list_empty(&hub->udev_list)) { |
| node = list_first_entry(&hub->udev_list, struct udev_node, list); |
| udev = node->udev; |
| |
| /* |
| * Unbinding the driver will call onboard_hub_remove_usbdev(), |
| * which acquires hub->lock. We must release the lock first. |
| */ |
| get_device(&udev->dev); |
| mutex_unlock(&hub->lock); |
| device_release_driver(&udev->dev); |
| put_device(&udev->dev); |
| mutex_lock(&hub->lock); |
| } |
| |
| mutex_unlock(&hub->lock); |
| |
| return onboard_hub_power_off(hub); |
| } |
| |
| static const struct of_device_id onboard_hub_match[] = { |
| { .compatible = "onboard-usb-hub" }, |
| {} |
| }; |
| MODULE_DEVICE_TABLE(of, onboard_hub_match); |
| |
| static const struct dev_pm_ops __maybe_unused onboard_hub_pm_ops = { |
| SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_hub_suspend, onboard_hub_resume) |
| }; |
| |
| static struct platform_driver onboard_hub_driver = { |
| .probe = onboard_hub_probe, |
| .remove = onboard_hub_remove, |
| |
| .driver = { |
| .name = "onboard-usb-hub", |
| .of_match_table = onboard_hub_match, |
| .pm = pm_ptr(&onboard_hub_pm_ops), |
| }, |
| }; |
| |
| /************************** USB driver **************************/ |
| |
| #define VENDOR_ID_REALTEK 0x0bda |
| |
| static struct onboard_hub *_find_onboard_hub(struct device *dev) |
| { |
| phandle ph; |
| struct device_node *np; |
| struct platform_device *pdev; |
| |
| if (of_property_read_u32(dev->of_node, "hub", &ph)) { |
| dev_err(dev, "failed to read 'hub' property\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| np = of_find_node_by_phandle(ph); |
| if (!np) { |
| dev_err(dev, "failed find device node for onboard hub\n"); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| pdev = of_find_device_by_node(np); |
| of_node_put(np); |
| if (!pdev) |
| return ERR_PTR(-EPROBE_DEFER); |
| |
| put_device(&pdev->dev); |
| |
| return dev_get_drvdata(&pdev->dev); |
| } |
| |
| static int onboard_hub_usbdev_probe(struct usb_device *udev) |
| { |
| struct device *dev = &udev->dev; |
| struct onboard_hub *hub; |
| |
| /* ignore supported hubs without device tree node */ |
| if (!dev->of_node) |
| return -ENODEV; |
| |
| hub = _find_onboard_hub(dev); |
| if (IS_ERR(hub)) |
| return PTR_ERR(hub); |
| |
| dev_set_drvdata(dev, hub); |
| |
| return onboard_hub_add_usbdev(hub, udev); |
| } |
| |
| static void onboard_hub_usbdev_disconnect(struct usb_device *udev) |
| { |
| struct onboard_hub *hub = dev_get_drvdata(&udev->dev); |
| |
| onboard_hub_remove_usbdev(hub, udev); |
| } |
| |
| static const struct usb_device_id onboard_hub_id_table[] = { |
| { USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.0 */ |
| { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.0 */ |
| { USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 */ |
| { USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 */ |
| {}, |
| }; |
| |
| MODULE_DEVICE_TABLE(usb, onboard_hub_id_table); |
| |
| static struct usb_device_driver onboard_hub_usbdev_driver = { |
| |
| .name = "onboard-usb-hub", |
| .probe = onboard_hub_usbdev_probe, |
| .disconnect = onboard_hub_usbdev_disconnect, |
| .generic_subclass = 1, |
| .supports_autosuspend = 1, |
| .id_table = onboard_hub_id_table, |
| }; |
| |
| /************************** Driver (de)registration **************************/ |
| |
| static int __init onboard_hub_init(void) |
| { |
| int ret; |
| |
| ret = platform_driver_register(&onboard_hub_driver); |
| if (ret) |
| return ret; |
| |
| ret = usb_register_device_driver(&onboard_hub_usbdev_driver, THIS_MODULE); |
| if (ret) |
| platform_driver_unregister(&onboard_hub_driver); |
| |
| return ret; |
| } |
| module_init(onboard_hub_init); |
| |
| static void __exit onboard_hub_exit(void) |
| { |
| usb_deregister_device_driver(&onboard_hub_usbdev_driver); |
| platform_driver_unregister(&onboard_hub_driver); |
| } |
| module_exit(onboard_hub_exit); |
| |
| MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>"); |
| MODULE_DESCRIPTION("Driver for discrete onboard USB hubs"); |
| MODULE_LICENSE("GPL v2"); |