[PATCH RFC] arm64: dts: Use separate dtb for Khadas vim3 usb3 and pcie controller

[Neil Armstrong]

On 16/11/2020 11:28, Qu Wenruo wrote:
> 
> 
> On 2020/11/16 下午4:33, Neil Armstrong wrote:
>> Hi,
>>
>> On 15/11/2020 04:39, Qu Wenruo wrote:
>>> Although the plan is to make the bootloader (U-boot) to load overlay for
>>> the device, but currently the board doesn't have the upstream support
>>> yet.
>>
>> No need for that, automatic PCIe enable is now support on upstream U-Boot
>> for VIM3 & VIM3L:
>> https://github.com/u-boot/u-boot/commit/adbff64af7b7cee3e0007b75df2644090edaafcb
> 
> Great.
> 
> BTW, the upstream U-boot is supposed to replace the factory Uboot
> compeletely, or just to be chainloaded from SDcard?

Both, but you should replace the factory u-boot.

You can easily boot to MaskROM by pressing the F button 3 times and boot from USB,
so you can't brick the device and recover to the factory image whatever the state
of the device.

Neil

> 
> Thanks,
> Qu
>>
>> Neil
>>
>>>
>>> This means even upstream kernel supports all the needed drivers, we still
>>> can't initialize the pcie controller.
>>>
>>> As a workaround, make seperate device trees for pcie controller and usb3
>>> controller.
>>>
>>> Now user still need to go into the factory bootloader to switch the mux,
>>> but they can easily boot the kernel with PCIE support by just swithcing
>>> to the pcie device tree.
>>>
>>> And since we didn't modify the original dtb, the future upstream uboot
>>> can still use overlay to switch mode using the same dtb file.
>>> The added new pcie dtb will just be a workaround.
>>>
>>> Tested on my VIM3 pro board, now I can boot the root fs on the NVME
>>> drive, with upstream kernel with the new pcie dtb.
>>>
>>> Signed-off-by: Qu Wenruo <wqu at suse.com>
>>> ---
>>>  arch/arm64/boot/dts/amlogic/Makefile          |  1 +
>>>  .../meson-g12b-a311d-khadas-vim3-pcie.dts     | 39 +++++++++++++++++++
>>>  .../amlogic/meson-g12b-a311d-khadas-vim3.dts  | 23 +----------
>>>  3 files changed, 41 insertions(+), 22 deletions(-)
>>>  create mode 100644 arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3-pcie.dts
>>>
>>> diff --git a/arch/arm64/boot/dts/amlogic/Makefile b/arch/arm64/boot/dts/amlogic/Makefile
>>> index ced03946314f..a0b8d30539e2 100644
>>> --- a/arch/arm64/boot/dts/amlogic/Makefile
>>> +++ b/arch/arm64/boot/dts/amlogic/Makefile
>>> @@ -6,6 +6,7 @@ dtb-$(CONFIG_ARCH_MESON) += meson-g12a-x96-max.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-gtking.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-gtking-pro.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-a311d-khadas-vim3.dtb
>>> +dtb-$(CONFIG_ARCH_MESON) += meson-g12b-a311d-khadas-vim3-pcie.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-s922x-khadas-vim3.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-odroid-n2.dtb
>>>  dtb-$(CONFIG_ARCH_MESON) += meson-g12b-odroid-n2-plus.dtb
>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3-pcie.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3-pcie.dts
>>> new file mode 100644
>>> index 000000000000..93641a32eeec
>>> --- /dev/null
>>> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3-pcie.dts
>>> @@ -0,0 +1,39 @@
>>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>>> +/*
>>> + * Copyright (c) 2019 BayLibre, SAS
>>> + * Author: Neil Armstrong <narmstrong at baylibre.com>
>>> + * Copyright (c) 2019 Christian Hewitt <christianshewitt at gmail.com>
>>> + */
>>> +
>>> +/dts-v1/;
>>> +
>>> +#include "meson-g12b-a311d.dtsi"
>>> +#include "meson-khadas-vim3.dtsi"
>>> +#include "meson-g12b-khadas-vim3.dtsi"
>>> +
>>> +/ {
>>> +	compatible = "khadas,vim3", "amlogic,a311d", "amlogic,g12b";
>>> +};
>>> +
>>> +/*
>>> + * The VIM3 on-board  MCU can mux the PCIe/USB3.0 shared differential
>>> + * lines using a FUSB340TMX USB 3.1 SuperSpeed Data Switch between
>>> + * an USB3.0 Type A connector and a M.2 Key M slot.
>>> + * The PHY driving these differential lines is shared between
>>> + * the USB3.0 controller and the PCIe Controller, thus only
>>> + * a single controller can use it.
>>> + *
>>> + * This is the PCIE device tree.
>>> + *
>>> + * Until upstream uboot can boot the board and modify the nodes before booting
>>> + * It's much easier to just choose this device tree file to use PCIE controller.
>>> + */
>>> +
>>> +&pcie {
>>> +	status = "okay";
>>> +};
>>> +
>>> +&usb {
>>> +	phys = <&usb2_phy0>, <&usb2_phy1>;
>>> +	phy-names = "usb2-phy0", "usb2-phy1";
>>> +};
>>> diff --git a/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
>>> index 124a80901084..9c111d76baec 100644
>>> --- a/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
>>> +++ b/arch/arm64/boot/dts/amlogic/meson-g12b-a311d-khadas-vim3.dts
>>> @@ -16,26 +16,5 @@ / {
>>>  };
>>>  
>>>  /*
>>> - * The VIM3 on-board  MCU can mux the PCIe/USB3.0 shared differential
>>> - * lines using a FUSB340TMX USB 3.1 SuperSpeed Data Switch between
>>> - * an USB3.0 Type A connector and a M.2 Key M slot.
>>> - * The PHY driving these differential lines is shared between
>>> - * the USB3.0 controller and the PCIe Controller, thus only
>>> - * a single controller can use it.
>>> - * If the MCU is configured to mux the PCIe/USB3.0 differential lines
>>> - * to the M.2 Key M slot, uncomment the following block to disable
>>> - * USB3.0 from the USB Complex and enable the PCIe controller.
>>> - * The End User is not expected to uncomment the following except for
>>> - * testing purposes, but instead rely on the firmware/bootloader to
>>> - * update these nodes accordingly if PCIe mode is selected by the MCU.
>>> - */
>>> -/*
>>> -&pcie {
>>> -	status = "okay";
>>> -};
>>> -
>>> -&usb {
>>> -	phys = <&usb2_phy0>, <&usb2_phy1>;
>>> -	phy-names = "usb2-phy0", "usb2-phy1";
>>> -};
>>> + * Vim3 default to USB3.0 instead of PCIE controller.
>>>   */
>>>
>>
>