// SPDX-License-Identifier: GPL-2.0+
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/*
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* Intel XHCI (Cherry Trail, Broxton and others) USB OTG role switch driver
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*
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* Copyright (c) 2016-2017 Hans de Goede <hdegoede@redhat.com>
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*
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* Loosely based on android x86 kernel code which is:
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*
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* Copyright (C) 2014 Intel Corp.
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*
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* Author: Wu, Hao
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*/
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#include <linux/acpi.h>
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#include <linux/delay.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/pm_runtime.h>
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#include <linux/property.h>
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#include <linux/usb/role.h>
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/* register definition */
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#define DUAL_ROLE_CFG0 0x68
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#define SW_VBUS_VALID BIT(24)
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#define SW_IDPIN_EN BIT(21)
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#define SW_IDPIN BIT(20)
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#define SW_SWITCH_EN BIT(16)
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#define DRD_CONFIG_DYNAMIC 0
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#define DRD_CONFIG_STATIC_HOST 1
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#define DRD_CONFIG_STATIC_DEVICE 2
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#define DRD_CONFIG_MASK 3
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#define DUAL_ROLE_CFG1 0x6c
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#define HOST_MODE BIT(29)
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#define DUAL_ROLE_CFG1_POLL_TIMEOUT 1000
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#define DRV_NAME "intel_xhci_usb_sw"
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struct intel_xhci_usb_data {
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struct device *dev;
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struct usb_role_switch *role_sw;
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void __iomem *base;
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bool enable_sw_switch;
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};
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static const struct software_node intel_xhci_usb_node = {
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"intel-xhci-usb-sw",
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};
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static int intel_xhci_usb_set_role(struct usb_role_switch *sw,
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enum usb_role role)
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{
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struct intel_xhci_usb_data *data = usb_role_switch_get_drvdata(sw);
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unsigned long timeout;
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acpi_status status;
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u32 glk, val;
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u32 drd_config = DRD_CONFIG_DYNAMIC;
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/*
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* On many CHT devices ACPI event (_AEI) handlers read / modify /
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* write the cfg0 register, just like we do. Take the ACPI lock
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* to avoid us racing with the AML code.
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*/
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status = acpi_acquire_global_lock(ACPI_WAIT_FOREVER, &glk);
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if (ACPI_FAILURE(status) && status != AE_NOT_CONFIGURED) {
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dev_err(data->dev, "Error could not acquire lock\n");
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return -EIO;
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}
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pm_runtime_get_sync(data->dev);
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/*
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* Set idpin value as requested.
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* Since some devices rely on firmware setting DRD_CONFIG and
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* SW_SWITCH_EN bits to be zero for role switch,
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* do not set these bits for those devices.
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*/
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val = readl(data->base + DUAL_ROLE_CFG0);
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switch (role) {
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case USB_ROLE_NONE:
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val |= SW_IDPIN;
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val &= ~SW_VBUS_VALID;
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drd_config = DRD_CONFIG_DYNAMIC;
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break;
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case USB_ROLE_HOST:
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val &= ~SW_IDPIN;
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val &= ~SW_VBUS_VALID;
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drd_config = DRD_CONFIG_STATIC_HOST;
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break;
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case USB_ROLE_DEVICE:
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val |= SW_IDPIN;
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val |= SW_VBUS_VALID;
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drd_config = DRD_CONFIG_STATIC_DEVICE;
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break;
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}
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val |= SW_IDPIN_EN;
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if (data->enable_sw_switch) {
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val &= ~DRD_CONFIG_MASK;
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val |= SW_SWITCH_EN | drd_config;
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}
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writel(val, data->base + DUAL_ROLE_CFG0);
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acpi_release_global_lock(glk);
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/* In most case it takes about 600ms to finish mode switching */
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timeout = jiffies + msecs_to_jiffies(DUAL_ROLE_CFG1_POLL_TIMEOUT);
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/* Polling on CFG1 register to confirm mode switch.*/
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do {
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val = readl(data->base + DUAL_ROLE_CFG1);
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if (!!(val & HOST_MODE) == (role == USB_ROLE_HOST)) {
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pm_runtime_put(data->dev);
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return 0;
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}
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/* Interval for polling is set to about 5 - 10 ms */
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usleep_range(5000, 10000);
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} while (time_before(jiffies, timeout));
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pm_runtime_put(data->dev);
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dev_warn(data->dev, "Timeout waiting for role-switch\n");
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return -ETIMEDOUT;
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}
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static enum usb_role intel_xhci_usb_get_role(struct usb_role_switch *sw)
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{
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struct intel_xhci_usb_data *data = usb_role_switch_get_drvdata(sw);
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enum usb_role role;
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u32 val;
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pm_runtime_get_sync(data->dev);
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val = readl(data->base + DUAL_ROLE_CFG0);
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pm_runtime_put(data->dev);
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if (!(val & SW_IDPIN))
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role = USB_ROLE_HOST;
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else if (val & SW_VBUS_VALID)
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role = USB_ROLE_DEVICE;
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else
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role = USB_ROLE_NONE;
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return role;
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}
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static int intel_xhci_usb_probe(struct platform_device *pdev)
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{
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struct usb_role_switch_desc sw_desc = { };
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struct device *dev = &pdev->dev;
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struct intel_xhci_usb_data *data;
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struct resource *res;
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int ret;
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res)
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return -EINVAL;
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data->base = devm_ioremap(dev, res->start, resource_size(res));
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if (!data->base)
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return -ENOMEM;
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platform_set_drvdata(pdev, data);
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ret = software_node_register(&intel_xhci_usb_node);
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if (ret)
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return ret;
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sw_desc.set = intel_xhci_usb_set_role,
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sw_desc.get = intel_xhci_usb_get_role,
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sw_desc.allow_userspace_control = true,
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sw_desc.fwnode = software_node_fwnode(&intel_xhci_usb_node);
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sw_desc.driver_data = data;
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data->dev = dev;
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data->enable_sw_switch = !device_property_read_bool(dev,
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"sw_switch_disable");
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data->role_sw = usb_role_switch_register(dev, &sw_desc);
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if (IS_ERR(data->role_sw)) {
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fwnode_handle_put(sw_desc.fwnode);
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return PTR_ERR(data->role_sw);
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}
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pm_runtime_set_active(dev);
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pm_runtime_enable(dev);
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return 0;
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}
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static int intel_xhci_usb_remove(struct platform_device *pdev)
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{
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struct intel_xhci_usb_data *data = platform_get_drvdata(pdev);
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pm_runtime_disable(&pdev->dev);
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usb_role_switch_unregister(data->role_sw);
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fwnode_handle_put(software_node_fwnode(&intel_xhci_usb_node));
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return 0;
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}
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static const struct platform_device_id intel_xhci_usb_table[] = {
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{ .name = DRV_NAME },
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{}
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};
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MODULE_DEVICE_TABLE(platform, intel_xhci_usb_table);
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static struct platform_driver intel_xhci_usb_driver = {
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.driver = {
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.name = DRV_NAME,
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},
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.id_table = intel_xhci_usb_table,
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.probe = intel_xhci_usb_probe,
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.remove = intel_xhci_usb_remove,
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};
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module_platform_driver(intel_xhci_usb_driver);
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MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
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MODULE_DESCRIPTION("Intel XHCI USB role switch driver");
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MODULE_LICENSE("GPL");
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