Re: [PATCH 08/12] xhci: Add Intel extended cap / otg phy mux handling

Hans de Goede
2018-02-25T13:01:12Z

Hi,

On 16-02-18 14:53, Andy Shevchenko wrote:
> On Fri, Feb 16, 2018 at 12:47 PM, Hans de Goede <hdegoede@redhat.com> wrote:
>> 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.
>
> SPDX?

Ack, fixed for v2.

>> +/*
>> + * XHCI extended capability handling
>> + *
>> + * Copyright (c) 2017 Hans de Goede <hdegoede@redhat.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>
>> + pdev = platform_device_alloc("intel_xhci_usb_sw", PLATFORM_DEVID_NONE);
>
> Perhaps,
>
> #define USB_SW_DRV_NAME "..."

Ack, fixed for v2.

>> + if (!pdev) {
>> + xhci_err(xhci, "couldn't allocate intel_xhci_usb_sw pdev\n");
>
> ...and re-use it everywhere here.
>
> pdev -> platform device.
>
>> + return -ENOMEM;
>> + }
>> +
>> + res.start = hcd->rsrc_start + cap_offset;
>> + res.end = res.start + 0x3ff;
>
> Is this magic always the same? Where its value comes from?
> At least define with comment.

Ack, I've added a USB_SW_RESOURCE_SIZE #define for this for v2.

>> +int xhci_ext_cap_init(struct xhci_hcd *xhci)
>> +{
>> + void __iomem *base = &xhci->cap_regs->hc_capbase;
>> + u32 cap_offset, val;
>> + int ret;
>> +
>> + cap_offset = xhci_find_next_ext_cap(base, 0, 0);
>> +
>> + while (cap_offset) {
>> + val = readl(base + cap_offset);
>> +
>> + switch (XHCI_EXT_CAPS_ID(val)) {
>> + case XHCI_EXT_CAPS_VENDOR_INTEL:
>> + if (xhci->quirks & XHCI_INTEL_USB_ROLE_SW) {
>
>> + ret = xhci_create_intel_xhci_sw_pdev(
>> + xhci, cap_offset);
>
> Can we leave xhci on previous line?

Fixed for v2.

>> + if (ret)
>> + return ret;
>> + }
>> + break;
>> + }
>> + cap_offset = xhci_find_next_ext_cap(base, cap_offset, 0);
>> + }
>> +
>> + return 0;
>> +}
>
>

Regards,

Hans