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

[Qu Wenruo <wqu@suse.com>]

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.

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@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@baylibre.com>
+ * Copyright (c) 2019 Christian Hewitt <christianshewitt@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.
  */
-- 
2.29.2