[PATCH v2 01/10] dt-bindings: serial: snps-dw-apb-uart: Switch dma-names order

[Cristian Ciocaltea]

Commit 370f696e4474 ("dt-bindings: serial: snps-dw-apb-uart: add dma &
dma-names properties") documented dma-names property to handle Allwinner
D1 dtbs_check warnings, but relies on the rx->tx ordering, which is the
reverse of what a different board expects:

  rk3326-odroid-go2.dtb: serial at ff030000: dma-names:0: 'rx' was expected

A quick and incomplete check shows the inconsistency is present in many
other DTS files:

$ git grep -A10 snps,dw-apb-uart | grep dma-names | sort -u
arch/arm64/boot/dts/rockchip/px30.dtsi-         dma-names = "tx", "rx";
arch/arm64/boot/dts/rockchip/rk3328.dtsi-       dma-names = "tx", "rx";
arch/arm64/boot/dts/rockchip/rk3588s.dtsi-      dma-names = "tx", "rx";
arch/arm/boot/dts/rk3066a.dtsi-                 dma-names = "tx", "rx";
arch/arm/boot/dts/rk3128.dtsi-                  dma-names = "tx", "rx";
arch/arm/boot/dts/rk3288.dtsi-                  dma-names = "tx", "rx";
arch/arm/boot/dts/rv1126.dtsi-                  dma-names = "tx", "rx";
arch/arm/boot/dts/socfpga.dtsi-                 dma-names = "tx", "rx";
arch/arm/boot/dts/sun6i-a31.dtsi-               dma-names = "rx", "tx";
arch/arm/boot/dts/sun8i-a23-a33.dtsi-           dma-names = "rx", "tx";
arch/arm/boot/dts/sun8i-v3s.dtsi-               dma-names = "rx", "tx";
arch/arm/boot/dts/sunxi-h3-h5.dtsi-             dma-names = "rx", "tx";
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dma-names = "rx", "tx";

The initial proposed solution was to allow a flexible dma-names order in
the binding, due to potential ABI breakage concerns after fixing the DTS
files. But luckily the Allwinner boards are not really affected, since
all of them are using a shared DMA channel for rx and tx:

$ git grep -A10 snps,dw-apb-uart | grep 'sun.*dmas' | sort -u
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 10>, <&dma 10>;
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 22>, <&dma 22>;
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 6>, <&dma 6>;
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 7>, <&dma 7>;
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 8>, <&dma 8>;
arch/arm/boot/dts/sun6i-a31.dtsi-       dmas = <&dma 9>, <&dma 9>;
arch/arm/boot/dts/sun8i-a23-a33.dtsi-   dmas = <&dma 10>, <&dma 10>;
arch/arm/boot/dts/sun8i-a23-a33.dtsi-   dmas = <&dma 6>, <&dma 6>;
arch/arm/boot/dts/sun8i-a23-a33.dtsi-   dmas = <&dma 7>, <&dma 7>;
arch/arm/boot/dts/sun8i-a23-a33.dtsi-   dmas = <&dma 8>, <&dma 8>;
arch/arm/boot/dts/sun8i-a23-a33.dtsi-   dmas = <&dma 9>, <&dma 9>;
arch/arm/boot/dts/sun8i-v3s.dtsi-       dmas = <&dma 6>, <&dma 6>;
arch/arm/boot/dts/sun8i-v3s.dtsi-       dmas = <&dma 7>, <&dma 7>;
arch/arm/boot/dts/sun8i-v3s.dtsi-       dmas = <&dma 8>, <&dma 8>;
arch/arm/boot/dts/sunxi-h3-h5.dtsi-     dmas = <&dma 6>, <&dma 6>;
arch/arm/boot/dts/sunxi-h3-h5.dtsi-     dmas = <&dma 7>, <&dma 7>;
arch/arm/boot/dts/sunxi-h3-h5.dtsi-     dmas = <&dma 8>, <&dma 8>;
arch/arm/boot/dts/sunxi-h3-h5.dtsi-     dmas = <&dma 9>, <&dma 9>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 14>, <&dma 14>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 15>, <&dma 15>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 16>, <&dma 16>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 17>, <&dma 17>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 18>, <&dma 18>;
arch/riscv/boot/dts/allwinner/sunxi-d1s-t113.dtsi-  dmas = <&dma 19>, <&dma 19>;

Switch dma-names order to tx->rx as the first step in fixing the
inconsistency. The remaining DTS fixes will be handled by separate
patches.

Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea at collabora.com>
---
 Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
index 2becdfab4f15..d28cc96fa8e9 100644
--- a/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/snps-dw-apb-uart.yaml
@@ -72,8 +72,8 @@ properties:
 
   dma-names:
     items:
-      - const: rx
       - const: tx
+      - const: rx
 
   snps,uart-16550-compatible:
     description: reflects the value of UART_16550_COMPATIBLE configuration
-- 
2.40.0