new file mode 100644
@@ -0,0 +1,8 @@
+What: /sys/bus/platform/devices/<dev>/always_powered_in_suspend
+Date: June 2022
+KernelVersion: 5.20
+Contact: Matthias Kaehlcke <matthias@kaehlcke.net>
+ linux-usb@vger.kernel.org
+Description:
+ (RW) Controls whether the USB hub remains always powered
+ during system suspend or not.
\ No newline at end of file
@@ -14795,6 +14795,13 @@ S: Maintained
T: git git://linuxtv.org/media_tree.git
F: drivers/media/i2c/ov9734.c
+ONBOARD USB HUB DRIVER
+M: Matthias Kaehlcke <mka@chromium.org>
+L: linux-usb@vger.kernel.org
+S: Maintained
+F: Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub
+F: drivers/usb/misc/onboard_usb_hub.c
+
ONENAND FLASH DRIVER
M: Kyungmin Park <kyungmin.park@samsung.com>
L: linux-mtd@lists.infradead.org
@@ -11,6 +11,7 @@ usbcore-y += phy.o port.o
usbcore-$(CONFIG_OF) += of.o
usbcore-$(CONFIG_USB_PCI) += hcd-pci.o
usbcore-$(CONFIG_ACPI) += usb-acpi.o
+usbcore-$(CONFIG_USB_ONBOARD_HUB) += ../misc/onboard_usb_hub_pdevs.o
obj-$(CONFIG_USB) += usbcore.o
@@ -295,3 +295,19 @@ config BRCM_USB_PINMAP
This option enables support for remapping some USB external
signals, which are typically on dedicated pins on the chip,
to any gpio.
+
+config USB_ONBOARD_HUB
+ bool "Onboard USB hub support"
+ depends on OF || COMPILE_TEST
+ help
+ Say Y here if you want to support discrete onboard USB hubs that
+ don't require an additional control bus for initialization, but
+ need some non-trivial form of initialization, such as enabling a
+ power regulator. An example for such a hub is the Realtek
+ RTS5411.
+
+ This driver can be used as a module but its state (module vs
+ builtin) must match the state of the USB subsystem. Enabling
+ this config will enable the driver and it will automatically
+ match the state of the USB subsystem. If this driver is a
+ module it will be called onboard_usb_hub.
@@ -33,3 +33,4 @@ obj-$(CONFIG_USB_CHAOSKEY) += chaoskey.o
obj-$(CONFIG_USB_SISUSBVGA) += sisusbvga/
obj-$(CONFIG_USB_LINK_LAYER_TEST) += lvstest.o
obj-$(CONFIG_BRCM_USB_PINMAP) += brcmstb-usb-pinmap.o
+obj-$(CONFIG_USB_ONBOARD_HUB) += onboard_usb_hub.o
new file mode 100644
@@ -0,0 +1,427 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for onboard USB hubs
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.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/slab.h>
+#include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/onboard_hub.h>
+#include <linux/workqueue.h>
+
+#include "onboard_usb_hub.h"
+
+static struct usb_device_driver onboard_hub_usbdev_driver;
+
+/************************** Platform driver **************************/
+
+struct usbdev_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 work_struct attach_usb_driver_work;
+ 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 usbdev_node *node;
+ bool power_off = true;
+
+ if (hub->always_powered_in_suspend)
+ return 0;
+
+ 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)
+ return 0;
+
+ return onboard_hub_power_off(hub);
+}
+
+static int __maybe_unused onboard_hub_resume(struct device *dev)
+{
+ struct onboard_hub *hub = dev_get_drvdata(dev);
+
+ if (hub->is_powered_on)
+ return 0;
+
+ return onboard_hub_power_on(hub);
+}
+
+static inline void get_udev_link_name(const struct usb_device *udev, char *buf, size_t size)
+{
+ snprintf(buf, size, "usb_dev.%s", dev_name(&udev->dev));
+}
+
+static int onboard_hub_add_usbdev(struct onboard_hub *hub, struct usb_device *udev)
+{
+ struct usbdev_node *node;
+ char link_name[64];
+ int err;
+
+ mutex_lock(&hub->lock);
+
+ if (hub->going_away) {
+ err = -EINVAL;
+ goto error;
+ }
+
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ node->udev = udev;
+
+ list_add(&node->list, &hub->udev_list);
+
+ mutex_unlock(&hub->lock);
+
+ get_udev_link_name(udev, link_name, sizeof(link_name));
+ WARN_ON(sysfs_create_link(&hub->dev->kobj, &udev->dev.kobj, link_name));
+
+ return 0;
+
+error:
+ mutex_unlock(&hub->lock);
+
+ return err;
+}
+
+static void onboard_hub_remove_usbdev(struct onboard_hub *hub, const struct usb_device *udev)
+{
+ struct usbdev_node *node;
+ char link_name[64];
+
+ get_udev_link_name(udev, link_name, sizeof(link_name));
+ sysfs_remove_link(&hub->dev->kobj, link_name);
+
+ mutex_lock(&hub->lock);
+
+ list_for_each_entry(node, &hub->udev_list, list) {
+ if (node->udev == udev) {
+ list_del(&node->list);
+ kfree(node);
+ break;
+ }
+ }
+
+ mutex_unlock(&hub->lock);
+}
+
+static ssize_t always_powered_in_suspend_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ const struct onboard_hub *hub = dev_get_drvdata(dev);
+
+ return sysfs_emit(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_attrs[] = {
+ &dev_attr_always_powered_in_suspend.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(onboard_hub);
+
+static void onboard_hub_attach_usb_driver(struct work_struct *work)
+{
+ int err;
+
+ err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
+ if (err)
+ pr_err("Failed to attach USB driver: %d\n", err);
+}
+
+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 = onboard_hub_power_on(hub);
+ if (err)
+ return err;
+
+ /*
+ * The USB driver might have been detached from the USB devices by
+ * onboard_hub_remove() (e.g. through an 'unbind' by userspace),
+ * make sure to re-attach it if needed.
+ *
+ * This needs to be done deferred to avoid self-deadlocks on systems
+ * with nested onboard hubs.
+ */
+ INIT_WORK(&hub->attach_usb_driver_work, onboard_hub_attach_usb_driver);
+ schedule_work(&hub->attach_usb_driver_work);
+
+ return 0;
+}
+
+static int onboard_hub_remove(struct platform_device *pdev)
+{
+ struct onboard_hub *hub = dev_get_drvdata(&pdev->dev);
+ struct usbdev_node *node;
+ struct usb_device *udev;
+
+ hub->going_away = true;
+
+ cancel_work_sync(&hub->attach_usb_driver_work);
+
+ 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 usbdev_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);
+}
+
+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),
+ .dev_groups = onboard_hub_groups,
+ },
+};
+
+/************************** USB driver **************************/
+
+#define VENDOR_ID_REALTEK 0x0bda
+
+/*
+ * Returns the onboard_hub platform device that is associated with the USB
+ * device passed as parameter.
+ */
+static struct onboard_hub *_find_onboard_hub(struct device *dev)
+{
+ struct platform_device *pdev;
+ struct device_node *np;
+ struct onboard_hub *hub;
+
+ pdev = of_find_device_by_node(dev->of_node);
+ if (!pdev) {
+ np = of_parse_phandle(dev->of_node, "companion-hub", 0);
+ if (!np) {
+ dev_err(dev, "failed to find device node for companion hub\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ pdev = of_find_device_by_node(np);
+ of_node_put(np);
+
+ if (!pdev)
+ return ERR_PTR(-ENODEV);
+ }
+
+ hub = dev_get_drvdata(&pdev->dev);
+ put_device(&pdev->dev);
+
+ /*
+ * The presence of drvdata ('hub') indicates that the platform driver
+ * finished probing. This handles the case where (conceivably) we could
+ * be running at the exact same time as the platform driver's probe. If
+ * we detect the race we request probe deferral and we'll come back and
+ * try again.
+ */
+ if (!hub)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return hub;
+}
+
+static int onboard_hub_usbdev_probe(struct usb_device *udev)
+{
+ struct device *dev = &udev->dev;
+ struct onboard_hub *hub;
+ int err;
+
+ /* 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);
+
+ err = onboard_hub_add_usbdev(hub, udev);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+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 3.1 */
+ { USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 */
+ { 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,
+};
+
+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");
new file mode 100644
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (c) 2022, Google LLC
+ */
+
+#ifndef _USB_MISC_ONBOARD_USB_HUB_H
+#define _USB_MISC_ONBOARD_USB_HUB_H
+
+static const struct of_device_id onboard_hub_match[] = {
+ { .compatible = "usbbda,411" },
+ { .compatible = "usbbda,5411" },
+ { .compatible = "usbbda,414" },
+ { .compatible = "usbbda,5414" },
+ {}
+};
+
+#endif /* _USB_MISC_ONBOARD_USB_HUB_H */
new file mode 100644
@@ -0,0 +1,137 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * API for creating and destroying USB onboard hub platform devices
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/of.h>
+
+#include "onboard_usb_hub.h"
+
+struct pdev_list_entry {
+ struct platform_device *pdev;
+ struct list_head node;
+};
+
+static bool of_is_onboard_usb_hub(const struct device_node *np)
+{
+ return !!of_match_node(onboard_hub_match, np);
+}
+
+/**
+ * onboard_hub_create_pdevs -- create platform devices for onboard USB hubs
+ * @parent_hub : parent hub to scan for connected onboard hubs
+ * @pdev_list : list of onboard hub platform devices owned by the parent hub
+ *
+ * Creates a platform device for each supported onboard hub that is connected to
+ * the given parent hub. The platform device is in charge of initializing the
+ * hub (enable regulators, take the hub out of reset, ...) and can optionally
+ * control whether the hub remains powered during system suspend or not.
+
+ * To keep track of the platform devices they are added to
+ * a list that is owned by the parent hub.
+ */
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list)
+{
+ int i;
+ struct usb_hcd *hcd = bus_to_hcd(parent_hub->bus);
+ struct device_node *np, *npc;
+ struct platform_device *pdev;
+ struct pdev_list_entry *pdle;
+
+ if (!parent_hub->dev.of_node)
+ return;
+
+ /*
+ * We only want one platform device for each physical hub. For root hubs
+ * this function can be called multiple times with the same root hub
+ * node (the HCD node). Only create pdevs if the root hub is the one of
+ * the primary HCD.
+ */
+ if (!parent_hub->parent && !usb_hcd_is_primary_hcd(hcd))
+ return;
+
+ for (i = 1; i <= parent_hub->maxchild; i++) {
+ np = usb_of_get_device_node(parent_hub, i);
+ if (!np)
+ continue;
+
+ if (!of_is_onboard_usb_hub(np))
+ goto node_put;
+
+ npc = of_parse_phandle(np, "companion-hub", 0);
+ if (npc) {
+ /*
+ * Hubs with companions share the same platform device.
+ * Create the plaform device only if 'parent_hub' is
+ * connected to the primary HCD (directly or through
+ * other hubs).
+ */
+ if (!usb_hcd_is_primary_hcd(hcd)) {
+ of_node_put(npc);
+ goto node_put;
+ }
+
+ pdev = of_find_device_by_node(npc);
+ of_node_put(npc);
+
+ if (pdev) {
+ /*
+ * The companion hub already has a platform device,
+ * nothing to do here.
+ */
+ put_device(&pdev->dev);
+ goto node_put;
+ }
+ }
+
+ pdev = of_platform_device_create(np, NULL, &parent_hub->dev);
+ if (!pdev) {
+ dev_err(&parent_hub->dev,
+ "failed to create platform device for onboard hub '%pOF'\n", np);
+ goto node_put;
+ }
+
+ pdle = kzalloc(sizeof(*pdle), GFP_KERNEL);
+ if (!pdle) {
+ of_platform_device_destroy(&pdev->dev, NULL);
+ goto node_put;
+ }
+
+ pdle->pdev = pdev;
+ list_add(&pdle->node, pdev_list);
+
+node_put:
+ of_node_put(np);
+ }
+}
+EXPORT_SYMBOL_GPL(onboard_hub_create_pdevs);
+
+/**
+ * onboard_hub_destroy_pdevs -- free resources of onboard hub platform devices
+ * @pdev_list : list of onboard hub platform devices
+ *
+ * Destroys the platform devices in the given list and frees the memory associated
+ * with the list entry.
+ */
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list)
+{
+ struct pdev_list_entry *pdle, *tmp;
+
+ list_for_each_entry_safe(pdle, tmp, pdev_list, node) {
+ list_del(&pdle->node);
+ of_platform_device_destroy(&pdle->pdev->dev, NULL);
+ kfree(pdle);
+ }
+}
+EXPORT_SYMBOL_GPL(onboard_hub_destroy_pdevs);
new file mode 100644
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __LINUX_USB_ONBOARD_HUB_H
+#define __LINUX_USB_ONBOARD_HUB_H
+
+struct usb_device;
+struct list_head;
+
+#if IS_ENABLED(CONFIG_USB_ONBOARD_HUB)
+void onboard_hub_create_pdevs(struct usb_device *parent_hub, struct list_head *pdev_list);
+void onboard_hub_destroy_pdevs(struct list_head *pdev_list);
+#else
+static inline void onboard_hub_create_pdevs(struct usb_device *parent_hub,
+ struct list_head *pdev_list) {}
+static inline void onboard_hub_destroy_pdevs(struct list_head *pdev_list) {}
+#endif
+
+#endif /* __LINUX_USB_ONBOARD_HUB_H */