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

[Qu Wenruo]

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?

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.
>>   */
>>
>