--- /dev/null
- return err;
+ // 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));
++ goto disable_clk;
+ }
+
+ fsleep(onboard_dev->pdata->reset_us);
+ gpiod_set_value_cansleep(onboard_dev->reset_gpio, 0);
+
+ onboard_dev->is_powered_on = true;
+
+ return 0;
++
++disable_clk:
++ clk_disable_unprepare(onboard_dev->clk);
++ return err;
+ }
+
+ 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,
+ };
+
+ static umode_t onboard_dev_attrs_are_visible(struct kobject *kobj,
+ struct attribute *attr,
+ int n)
+ {
+ struct device *dev = kobj_to_dev(kobj);
+ struct onboard_dev *onboard_dev = dev_get_drvdata(dev);
+
+ if (attr == &dev_attr_always_powered_in_suspend.attr &&
+ !onboard_dev->pdata->is_hub)
+ return 0;
+
+ return attr->mode;
+ }
+
+ static const struct attribute_group onboard_dev_group = {
+ .is_visible = onboard_dev_attrs_are_visible,
+ .attrs = onboard_dev_attrs,
+ };
+ __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;
+
+ if (!onboard_dev->pdata->is_hub)
+ onboard_dev->always_powered_in_suspend = true;
+
+ 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
+ #define VENDOR_ID_XMOS 0x20B1
+
+ /*
+ * 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 */
+ { USB_DEVICE(VENDOR_ID_XMOS, 0x0013) }, /* XMOS XVF3500 Voice Processor */
+ {}
+ };
+ 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");
projects / linux-stable / commitdiff