usb: misc: onboard_hub: rename to onboard_dev

This patch prepares onboad_hub to support non-hub devices by renaming
the driver files and their content, the headers and their references.

The comments and descriptions have been slightly modified to keep
coherence and account for the specific cases that only affect onboard
hubs (e.g. peer-hub).

The "hub" variables in functions where "dev" (and similar names) variables
already exist have been renamed to onboard_dev for clarity, which adds a
few lines in cases where more than 80 characters are used.

No new functionality has been added.

Acked-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Javier Carrasco <javier.carrasco@wolfvision.net>
Link: https://lore.kernel.org/r/20240325-onboard_xvf3500-v8-2-29e3f9222922@wolfvision.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 521 insertions, 0 deletions

diff --git a/drivers/usb/misc/onboard_usb_dev.c b/drivers/usb/misc/onboard_usb_dev.c
new file mode 100644
index 0000000000000..6aee438962165
--- /dev/null
+++ b/drivers/usb/misc/onboard_usb_dev.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Driver for onboard USB devices
+ *
+ * Copyright (c) 2022, Google LLC
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.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_dev.h>
+#include <linux/workqueue.h>
+
+#include "onboard_usb_dev.h"
+
+static void onboard_dev_attach_usb_driver(struct work_struct *work);
+
+static struct usb_device_driver onboard_dev_usbdev_driver;
+static DECLARE_WORK(attach_usb_driver_work, onboard_dev_attach_usb_driver);
+
+/************************** Platform driver **************************/
+
+struct usbdev_node {
+	struct usb_device *udev;
+	struct list_head list;
+};
+
+struct onboard_dev {
+	struct regulator_bulk_data supplies[MAX_SUPPLIES];
+	struct device *dev;
+	const struct onboard_dev_pdata *pdata;
+	struct gpio_desc *reset_gpio;
+	bool always_powered_in_suspend;
+	bool is_powered_on;
+	bool going_away;
+	struct list_head udev_list;
+	struct mutex lock;
+	struct clk *clk;
+};
+
+static int onboard_dev_get_regulators(struct onboard_dev *onboard_dev)
+{
+	const char * const *supply_names = onboard_dev->pdata->supply_names;
+	unsigned int num_supplies = onboard_dev->pdata->num_supplies;
+	struct device *dev = onboard_dev->dev;
+	unsigned int i;
+	int err;
+
+	if (num_supplies > MAX_SUPPLIES)
+		return dev_err_probe(dev, -EINVAL, "max %d supplies supported!\n",
+				     MAX_SUPPLIES);
+
+	for (i = 0; i < num_supplies; i++)
+		onboard_dev->supplies[i].supply = supply_names[i];
+
+	err = devm_regulator_bulk_get(dev, num_supplies, onboard_dev->supplies);
+	if (err)
+		dev_err(dev, "Failed to get regulator supplies: %pe\n",
+			ERR_PTR(err));
+
+	return err;
+}
+
+static int onboard_dev_power_on(struct onboard_dev *onboard_dev)
+{
+	int err;
+
+	err = clk_prepare_enable(onboard_dev->clk);
+	if (err) {
+		dev_err(onboard_dev->dev, "failed to enable clock: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	err = regulator_bulk_enable(onboard_dev->pdata->num_supplies,
+				    onboard_dev->supplies);
+	if (err) {
+		dev_err(onboard_dev->dev, "failed to enable supplies: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	fsleep(onboard_dev->pdata->reset_us);
+	gpiod_set_value_cansleep(onboard_dev->reset_gpio, 0);
+
+	onboard_dev->is_powered_on = true;
+
+	return 0;
+}
+
+static int onboard_dev_power_off(struct onboard_dev *onboard_dev)
+{
+	int err;
+
+	gpiod_set_value_cansleep(onboard_dev->reset_gpio, 1);
+
+	err = regulator_bulk_disable(onboard_dev->pdata->num_supplies,
+				     onboard_dev->supplies);
+	if (err) {
+		dev_err(onboard_dev->dev, "failed to disable supplies: %pe\n",
+			ERR_PTR(err));
+		return err;
+	}
+
+	clk_disable_unprepare(onboard_dev->clk);
+
+	onboard_dev->is_powered_on = false;
+
+	return 0;
+}
+
+static int __maybe_unused onboard_dev_suspend(struct device *dev)
+{
+	struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
+	struct usbdev_node *node;
+	bool power_off = true;
+
+	if (onboard_dev->always_powered_in_suspend)
+		return 0;
+
+	mutex_lock(&onboard_dev->lock);
+
+	list_for_each_entry(node, &onboard_dev->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(&onboard_dev->lock);
+
+	if (!power_off)
+		return 0;
+
+	return onboard_dev_power_off(onboard_dev);
+}
+
+static int __maybe_unused onboard_dev_resume(struct device *dev)
+{
+	struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
+
+	if (onboard_dev->is_powered_on)
+		return 0;
+
+	return onboard_dev_power_on(onboard_dev);
+}
+
+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_dev_add_usbdev(struct onboard_dev *onboard_dev,
+				  struct usb_device *udev)
+{
+	struct usbdev_node *node;
+	char link_name[64];
+	int err;
+
+	mutex_lock(&onboard_dev->lock);
+
+	if (onboard_dev->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, &onboard_dev->udev_list);
+
+	mutex_unlock(&onboard_dev->lock);
+
+	get_udev_link_name(udev, link_name, sizeof(link_name));
+	WARN_ON(sysfs_create_link(&onboard_dev->dev->kobj, &udev->dev.kobj,
+				  link_name));
+
+	return 0;
+
+error:
+	mutex_unlock(&onboard_dev->lock);
+
+	return err;
+}
+
+static void onboard_dev_remove_usbdev(struct onboard_dev *onboard_dev,
+				      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(&onboard_dev->dev->kobj, link_name);
+
+	mutex_lock(&onboard_dev->lock);
+
+	list_for_each_entry(node, &onboard_dev->udev_list, list) {
+		if (node->udev == udev) {
+			list_del(&node->list);
+			kfree(node);
+			break;
+		}
+	}
+
+	mutex_unlock(&onboard_dev->lock);
+}
+
+static ssize_t always_powered_in_suspend_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	const struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", onboard_dev->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_dev *onboard_dev = dev_get_drvdata(dev);
+	bool val;
+	int ret;
+
+	ret = kstrtobool(buf, &val);
+	if (ret < 0)
+		return ret;
+
+	onboard_dev->always_powered_in_suspend = val;
+
+	return count;
+}
+static DEVICE_ATTR_RW(always_powered_in_suspend);
+
+static struct attribute *onboard_dev_attrs[] = {
+	&dev_attr_always_powered_in_suspend.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(onboard_dev);
+
+static void onboard_dev_attach_usb_driver(struct work_struct *work)
+{
+	int err;
+
+	err = driver_attach(&onboard_dev_usbdev_driver.driver);
+	if (err)
+		pr_err("Failed to attach USB driver: %pe\n", ERR_PTR(err));
+}
+
+static int onboard_dev_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct onboard_dev *onboard_dev;
+	int err;
+
+	onboard_dev = devm_kzalloc(dev, sizeof(*onboard_dev), GFP_KERNEL);
+	if (!onboard_dev)
+		return -ENOMEM;
+
+	onboard_dev->pdata = device_get_match_data(dev);
+	if (!onboard_dev->pdata)
+		return -EINVAL;
+
+	onboard_dev->dev = dev;
+
+	err = onboard_dev_get_regulators(onboard_dev);
+	if (err)
+		return err;
+
+	onboard_dev->clk = devm_clk_get_optional(dev, NULL);
+	if (IS_ERR(onboard_dev->clk))
+		return dev_err_probe(dev, PTR_ERR(onboard_dev->clk),
+				     "failed to get clock\n");
+
+	onboard_dev->reset_gpio = devm_gpiod_get_optional(dev, "reset",
+							  GPIOD_OUT_HIGH);
+	if (IS_ERR(onboard_dev->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(onboard_dev->reset_gpio),
+				     "failed to get reset GPIO\n");
+
+	mutex_init(&onboard_dev->lock);
+	INIT_LIST_HEAD(&onboard_dev->udev_list);
+
+	dev_set_drvdata(dev, onboard_dev);
+
+	err = onboard_dev_power_on(onboard_dev);
+	if (err)
+		return err;
+
+	/*
+	 * The USB driver might have been detached from the USB devices by
+	 * onboard_dev_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.
+	 */
+	schedule_work(&attach_usb_driver_work);
+
+	return 0;
+}
+
+static void onboard_dev_remove(struct platform_device *pdev)
+{
+	struct onboard_dev *onboard_dev = dev_get_drvdata(&pdev->dev);
+	struct usbdev_node *node;
+	struct usb_device *udev;
+
+	onboard_dev->going_away = true;
+
+	mutex_lock(&onboard_dev->lock);
+
+	/* unbind the USB devices to avoid dangling references to this device */
+	while (!list_empty(&onboard_dev->udev_list)) {
+		node = list_first_entry(&onboard_dev->udev_list,
+					struct usbdev_node, list);
+		udev = node->udev;
+
+		/*
+		 * Unbinding the driver will call onboard_dev_remove_usbdev(),
+		 * which acquires onboard_dev->lock. We must release the lock
+		 * first.
+		 */
+		get_device(&udev->dev);
+		mutex_unlock(&onboard_dev->lock);
+		device_release_driver(&udev->dev);
+		put_device(&udev->dev);
+		mutex_lock(&onboard_dev->lock);
+	}
+
+	mutex_unlock(&onboard_dev->lock);
+
+	onboard_dev_power_off(onboard_dev);
+}
+
+MODULE_DEVICE_TABLE(of, onboard_dev_match);
+
+static const struct dev_pm_ops __maybe_unused onboard_dev_pm_ops = {
+	SET_LATE_SYSTEM_SLEEP_PM_OPS(onboard_dev_suspend, onboard_dev_resume)
+};
+
+static struct platform_driver onboard_dev_driver = {
+	.probe = onboard_dev_probe,
+	.remove_new = onboard_dev_remove,
+
+	.driver = {
+		.name = "onboard-usb-dev",
+		.of_match_table = onboard_dev_match,
+		.pm = pm_ptr(&onboard_dev_pm_ops),
+		.dev_groups = onboard_dev_groups,
+	},
+};
+
+/************************** USB driver **************************/
+
+#define VENDOR_ID_CYPRESS	0x04b4
+#define VENDOR_ID_GENESYS	0x05e3
+#define VENDOR_ID_MICROCHIP	0x0424
+#define VENDOR_ID_REALTEK	0x0bda
+#define VENDOR_ID_TI		0x0451
+#define VENDOR_ID_VIA		0x2109
+
+/*
+ * Returns the onboard_dev platform device that is associated with the USB
+ * device passed as parameter.
+ */
+static struct onboard_dev *_find_onboard_dev(struct device *dev)
+{
+	struct platform_device *pdev;
+	struct device_node *np;
+	struct onboard_dev *onboard_dev;
+
+	pdev = of_find_device_by_node(dev->of_node);
+	if (!pdev) {
+		np = of_parse_phandle(dev->of_node, "peer-hub", 0);
+		if (!np) {
+			dev_err(dev, "failed to find device node for peer hub\n");
+			return ERR_PTR(-EINVAL);
+		}
+
+		pdev = of_find_device_by_node(np);
+		of_node_put(np);
+
+		if (!pdev)
+			return ERR_PTR(-ENODEV);
+	}
+
+	onboard_dev = dev_get_drvdata(&pdev->dev);
+	put_device(&pdev->dev);
+
+	/*
+	 * The presence of drvdata 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 (!onboard_dev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return onboard_dev;
+}
+
+static int onboard_dev_usbdev_probe(struct usb_device *udev)
+{
+	struct device *dev = &udev->dev;
+	struct onboard_dev *onboard_dev;
+	int err;
+
+	/* ignore supported devices without device tree node */
+	if (!dev->of_node)
+		return -ENODEV;
+
+	onboard_dev = _find_onboard_dev(dev);
+	if (IS_ERR(onboard_dev))
+		return PTR_ERR(onboard_dev);
+
+	dev_set_drvdata(dev, onboard_dev);
+
+	err = onboard_dev_add_usbdev(onboard_dev, udev);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static void onboard_dev_usbdev_disconnect(struct usb_device *udev)
+{
+	struct onboard_dev *onboard_dev = dev_get_drvdata(&udev->dev);
+
+	onboard_dev_remove_usbdev(onboard_dev, udev);
+}
+
+static const struct usb_device_id onboard_dev_id_table[] = {
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6504) }, /* CYUSB33{0,1,2}x/CYUSB230x 3.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6506) }, /* CYUSB33{0,1,2}x/CYUSB230x 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_CYPRESS, 0x6570) }, /* CY7C6563x 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0608) }, /* Genesys Logic GL850G USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0610) }, /* Genesys Logic GL852G USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_GENESYS, 0x0620) }, /* Genesys Logic GL3523 USB 3.1 HUB */
+	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2412) }, /* USB2412 USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2514) }, /* USB2514B USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2517) }, /* USB2517 USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x2744) }, /* USB5744 USB 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_MICROCHIP, 0x5744) }, /* USB5744 USB 3.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0411) }, /* RTS5411 USB 3.1 HUB */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5411) }, /* RTS5411 USB 2.1 HUB */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x0414) }, /* RTS5414 USB 3.2 HUB */
+	{ USB_DEVICE(VENDOR_ID_REALTEK, 0x5414) }, /* RTS5414 USB 2.1 HUB */
+	{ USB_DEVICE(VENDOR_ID_TI, 0x8025) }, /* TI USB8020B 3.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_TI, 0x8027) }, /* TI USB8020B 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_TI, 0x8140) }, /* TI USB8041 3.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_TI, 0x8142) }, /* TI USB8041 2.0 HUB */
+	{ USB_DEVICE(VENDOR_ID_VIA, 0x0817) }, /* VIA VL817 3.1 HUB */
+	{ USB_DEVICE(VENDOR_ID_VIA, 0x2817) }, /* VIA VL817 2.0 HUB */
+	{}
+};
+MODULE_DEVICE_TABLE(usb, onboard_dev_id_table);
+
+static struct usb_device_driver onboard_dev_usbdev_driver = {
+	.name = "onboard-usb-dev",
+	.probe = onboard_dev_usbdev_probe,
+	.disconnect = onboard_dev_usbdev_disconnect,
+	.generic_subclass = 1,
+	.supports_autosuspend =	1,
+	.id_table = onboard_dev_id_table,
+};
+
+static int __init onboard_dev_init(void)
+{
+	int ret;
+
+	ret = usb_register_device_driver(&onboard_dev_usbdev_driver, THIS_MODULE);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&onboard_dev_driver);
+	if (ret)
+		usb_deregister_device_driver(&onboard_dev_usbdev_driver);
+
+	return ret;
+}
+module_init(onboard_dev_init);
+
+static void __exit onboard_dev_exit(void)
+{
+	usb_deregister_device_driver(&onboard_dev_usbdev_driver);
+	platform_driver_unregister(&onboard_dev_driver);
+
+	cancel_work_sync(&attach_usb_driver_work);
+}
+module_exit(onboard_dev_exit);
+
+MODULE_AUTHOR("Matthias Kaehlcke <mka@chromium.org>");
+MODULE_DESCRIPTION("Driver for discrete onboard USB devices");
+MODULE_LICENSE("GPL v2");