[PATCH 0/3] ARM: dts: bcm2711-rpi-cm4-io: Enable xHCI host

[Stefan Wahren]

Hi Phil,

Am 27.11.23 um 12:22 schrieb Phil Elwell:
> On Mon, 27 Nov 2023 at 11:08, Stefan Wahren <wahrenst at gmx.net> wrote:
>> Hi Justin,
>>
>> [add Phil]
>>
>> Am 27.11.23 um 07:02 schrieb Justin Chen:
>>>
>>> On 11/25/23 6:56 PM, Stefan Wahren wrote:
>>>> In contrast to the Raspberry Pi 4, the Compute Module 4 or the IO board
>>>> does not have a VL805 USB 3.0 host controller, which is connected via
>>>> PCIe. Instead, the BCM2711 on the Compute Module provides the built-in
>>>> xHCI.
>>>>
>>> Does this work? I maintain this built-in xHCI controller internally. I
>>> wasn't aware the Compute Module uses this block.
>> i successful tested this with a CM4 (arm 32 bit,
>> multi_v7_lpae_defconfig) with eMMC. Before this series the USB devices
>> (mouse, keyboard) connected to the host interface didn't work. After
>> comparing vendor DTS with mainline i noticed the missing xHCI block [1].
>> Unfortunately i wasn't able to get further information from the public
>> datasheets. I don't know if the VideoCore does some magic tricks on the
>> xHCI or i missed some downstream xHCI changes.
>>
>>> This block is held in reset and needs a bit toggled to get things
>>> going. Florian, just to confirm, this is our "brcm,xhci-brcm-v2" block
>>> correct?
>>>
>>> Justin
>> [1]  -
>> https://github.com/raspberrypi/linux/blob/rpi-6.1.y/arch/arm/boot/dts/bcm2711-rpi-ds.dtsi#L119
> What's the question here? Does the XHCI block present in the
> raspberrypi/linux dtsi file really exist? Yes it does.
since i don't have any documentation about the xHCI block, i assumed the
compatible generic-xhci is correct. But Justin seems to suggest that the
xHCI block needs some special treatment and we need a specific compatible.

Did i missed some xHCI driver changes?
Does the VC firmware something to the xHCI especially on CM4?

Thanks
>
> Phil