Revert "usb: misc: Add onboard_usb_hub driver" (67a7570a) · Commits · git / linux-nf

Documentation/ABI/testing/sysfs-bus-platform-onboard-usb-hub

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		What: /sys/bus/platform/devices/<dev>/always_powered_in_suspend
		Date: February 2022
		KernelVersion: 5.18
		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

MAINTAINERS

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		@@ -14631,13 +14631,6 @@ 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

drivers/usb/misc/Kconfig

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		@@ -295,26 +295,3 @@ 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.

		if USB_ONBOARD_HUB
		config USB_ONBOARD_HUB_ACTUAL
		tristate
		default m if USB=m
		default y if USB=y
		endif

drivers/usb/misc/Makefile

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		@@ -33,4 +33,3 @@ 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_ACTUAL) += onboard_usb_hub.o

drivers/usb/misc/onboard_usb_hub.c

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		// 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");