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![Hans de Goede](/assets/img/avatar_default.png)
The xHCI controller on various Intel SoCs has an extended cap mmio-range which contains registers to control the muxing to the xHCI (host mode) or the dwc3 (device mode) and vbus-detection for the otg usb-phy. Having a role-sw driver included in the xHCI code (under drivers/usb/host) is not desirable. So this commit adds a simple handler for this extended capability, which creates a platform device with the caps mmio region as resource, this allows us to write a separate platform role-sw driver for the role-switch. Note this commit adds a call to the new xhci_ext_cap_init() function to xhci_pci_probe(), it is added here because xhci_ext_cap_init() must be called only once. If in the future we also want to handle ext-caps on non pci xHCI HCDs from xhci_ext_cap_init() a call to it should also be added to other bus probe paths. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
90 lines
2 KiB
C
90 lines
2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* XHCI extended capability handling
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*
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* Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
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*/
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#include <linux/platform_device.h>
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#include "xhci.h"
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#define USB_SW_DRV_NAME "intel_xhci_usb_sw"
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#define USB_SW_RESOURCE_SIZE 0x400
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static void xhci_intel_unregister_pdev(void *arg)
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{
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platform_device_unregister(arg);
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}
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static int xhci_create_intel_xhci_sw_pdev(struct xhci_hcd *xhci, u32 cap_offset)
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{
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struct usb_hcd *hcd = xhci_to_hcd(xhci);
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struct device *dev = hcd->self.controller;
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struct platform_device *pdev;
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struct resource res = { 0, };
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int ret;
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pdev = platform_device_alloc(USB_SW_DRV_NAME, PLATFORM_DEVID_NONE);
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if (!pdev) {
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xhci_err(xhci, "couldn't allocate %s platform device\n",
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USB_SW_DRV_NAME);
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return -ENOMEM;
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}
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res.start = hcd->rsrc_start + cap_offset;
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res.end = res.start + USB_SW_RESOURCE_SIZE - 1;
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res.name = USB_SW_DRV_NAME;
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res.flags = IORESOURCE_MEM;
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ret = platform_device_add_resources(pdev, &res, 1);
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if (ret) {
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dev_err(dev, "couldn't add resources to intel_xhci_usb_sw pdev\n");
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platform_device_put(pdev);
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return ret;
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}
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pdev->dev.parent = dev;
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ret = platform_device_add(pdev);
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if (ret) {
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dev_err(dev, "couldn't register intel_xhci_usb_sw pdev\n");
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platform_device_put(pdev);
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return ret;
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}
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ret = devm_add_action_or_reset(dev, xhci_intel_unregister_pdev, pdev);
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if (ret) {
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dev_err(dev, "couldn't add unregister action for intel_xhci_usb_sw pdev\n");
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return ret;
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}
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return 0;
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}
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int xhci_ext_cap_init(struct xhci_hcd *xhci)
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{
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void __iomem *base = &xhci->cap_regs->hc_capbase;
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u32 offset, val;
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int ret;
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offset = xhci_find_next_ext_cap(base, 0, 0);
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while (offset) {
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val = readl(base + offset);
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switch (XHCI_EXT_CAPS_ID(val)) {
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case XHCI_EXT_CAPS_VENDOR_INTEL:
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if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
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ret = xhci_create_intel_xhci_sw_pdev(xhci,
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offset);
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if (ret)
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return ret;
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}
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break;
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}
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offset = xhci_find_next_ext_cap(base, offset, 0);
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(xhci_ext_cap_init);
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