-// 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/suspend.h>
-#include <linux/sysfs.h>
-#include <linux/usb.h>
-#include <linux/usb/hcd.h>
-#include <linux/usb/of.h>
-#include <linux/usb/onboard_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 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 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(), make sure to re-attach it if needed.
- */
- err = driver_attach(&onboard_hub_usbdev_driver.drvwrap.driver);
- if (err) {
- onboard_hub_power_off(hub);
- return err;
- }
-
- 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;
-
- 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);
-}
-
-static const struct of_device_id onboard_hub_match[] = {
- { .compatible = "usbbda,411" },
- { .compatible = "usbbda,5411" },
- { .compatible = "usbbda,414" },
- { .compatible = "usbbda,5414" },
- {}
-};
-MODULE_DEVICE_TABLE(of, onboard_hub_match);
-
-static bool of_is_onboard_usb_hub(const struct device_node *np)
-{
- return !!of_match_node(onboard_hub_match, np);
-}
-
-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,
-};
-
-/*** Helpers for creating/destroying platform devices for onboard hubs ***/
-
-struct pdev_list_entry {
- struct platform_device *pdev;
- struct list_head node;
-};
-
-/**
- * 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. 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 device_node *np, *npc;
- struct platform_device *pdev = NULL;
- struct pdev_list_entry *pdle;
-
- INIT_LIST_HEAD(pdev_list);
-
- 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) {
- 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 = devm_kzalloc(&pdev->dev, 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);
- }
-}
-EXPORT_SYMBOL_GPL(onboard_hub_destroy_pdevs);
-
-/************************** 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");
projects / linux-2.6-microblaze.git / commitdiff