From 1e218a91103f725bcf1c8788d272a7c213bce96a Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 5 Jul 2023 17:18:02 +0200 Subject: [PATCH] dt-bindings: serial: tegra-hsuart: Convert to json-schema Convert the Tegra High-Speed UART bindings from the free-form text format to json-schema. While at it, also fix fix the example to reflect the correct compatible string for Tegra30 chips. Reviewed-by: Rob Herring Signed-off-by: Thierry Reding --- .../bindings/serial/nvidia,tegra20-hsuart.txt | 73 ------------ .../bindings/serial/nvidia,tegra20-hsuart.yaml | 125 +++++++++++++++++++++ 2 files changed, 125 insertions(+), 73 deletions(-) delete mode 100644 Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt create mode 100644 Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.yaml diff --git a/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt deleted file mode 100644 index f709304036c2..000000000000 --- a/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.txt +++ /dev/null @@ -1,73 +0,0 @@ -NVIDIA Tegra20/Tegra30 high speed (DMA based) UART controller driver. - -Required properties: -- compatible : should be, - "nvidia,tegra20-hsuart" for Tegra20, - "nvidia,tegra30-hsuart" for Tegra30, - "nvidia,tegra186-hsuart" for Tegra186, - "nvidia,tegra194-hsuart" for Tegra194. - -- reg: Should contain UART controller registers location and length. -- interrupts: Should contain UART controller interrupts. -- clocks: Must contain one entry, for the module clock. - See ../clocks/clock-bindings.txt for details. -- resets : Must contain an entry for each entry in reset-names. - See ../reset/reset.txt for details. -- reset-names : Must include the following entries: - - serial -- dmas : Must contain an entry for each entry in dma-names. - See ../dma/dma.txt for details. -- dma-names : Must include the following entries: - - rx - - tx - -Optional properties: -- nvidia,enable-modem-interrupt: Enable modem interrupts. Should be enable - only if all 8 lines of UART controller are pinmuxed. -- nvidia,adjust-baud-rates: List of entries providing percentage of baud rate - adjustment within a range. - Each entry contains sets of 3 values. Range low/high and adjusted rate. - - When baud rate set on controller falls within the range mentioned in this - field, baud rate will be adjusted by percentage mentioned here. - Ex: <9600 115200 200> - Increase baud rate by 2% when set baud rate falls within range 9600 to 115200 - -Baud Rate tolerance: - Standard UART devices are expected to have tolerance for baud rate error by - -4 to +4 %. All Tegra devices till Tegra210 had this support. However, - Tegra186 chip has a known hardware issue. UART Rx baud rate tolerance level - is 0% to +4% in 1-stop config. Otherwise, the received data will have - corruption/invalid framing errors. Parker errata suggests adjusting baud - rate to be higher than the deviations observed in Tx. - - Tx deviation of connected device can be captured over scope (or noted from - its spec) for valid range and Tegra baud rate has to be set above actual - Tx baud rate observed. To do this we use nvidia,adjust-baud-rates - - As an example, consider there is deviation observed in Tx for baud rates as - listed below. - 0 to 9600 has 1% deviation - 9600 to 115200 2% deviation - This slight deviation is expcted and Tegra UART is expected to handle it. Due - to the issue stated above, baud rate on Tegra UART should be set equal to or - above deviation observed for avoiding frame errors. - Property should be set like this - nvidia,adjust-baud-rates = <0 9600 100>, - <9600 115200 200>; - -Example: - -serial@70006000 { - compatible = "nvidia,tegra30-hsuart", "nvidia,tegra20-hsuart"; - reg = <0x70006000 0x40>; - reg-shift = <2>; - interrupts = <0 36 0x04>; - nvidia,enable-modem-interrupt; - clocks = <&tegra_car 6>; - resets = <&tegra_car 6>; - reset-names = "serial"; - dmas = <&apbdma 8>, <&apbdma 8>; - dma-names = "rx", "tx"; - nvidia,adjust-baud-rates = <1000000 4000000 136>; /* 1.36% shift */ -}; diff --git a/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.yaml b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.yaml new file mode 100644 index 000000000000..04d55fecf47c --- /dev/null +++ b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.yaml @@ -0,0 +1,125 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/serial/nvidia,tegra20-hsuart.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: NVIDIA Tegra20/Tegra30 high speed (DMA based) UART controller driver + +maintainers: + - Thierry Reding + - Jon Hunter + +properties: + compatible: + oneOf: + - enum: + - nvidia,tegra20-hsuart + - nvidia,tegra30-hsuart + - nvidia,tegra186-hsuart + - nvidia,tegra194-hsuart + - items: + - const: nvidia,tegra124-hsuart + - const: nvidia,tegra30-hsuart + + reg: + maxItems: 1 + + interrupts: + maxItems: 1 + + clocks: + items: + - description: module clock + + resets: + items: + - description: module reset + + reset-names: + items: + - const: serial + + dmas: + items: + - description: DMA channel used for reception + - description: DMA channel used for transmission + + dma-names: + items: + - const: rx + - const: tx + + nvidia,enable-modem-interrupt: + $ref: /schemas/types.yaml#/definitions/flag + description: Enable modem interrupts. Should be enable only if all 8 lines of UART controller + are pinmuxed. + + nvidia,adjust-baud-rates: + $ref: /schemas/types.yaml#/definitions/uint32-matrix + description: | + List of entries providing percentage of baud rate adjustment within a range. Each entry + contains a set of 3 values: range low/high and adjusted rate. When the baud rate set on the + controller falls within the range mentioned in this field, the baud rate will be adjusted by + percentage mentioned here. + + Example: <9600 115200 200> + + Increase baud rate by 2% when set baud rate falls within range 9600 to 115200. + + Standard UART devices are expected to have tolerance for baud rate error by -4 to +4 %. All + Tegra devices till Tegra210 had this support. However, Tegra186 chip has a known hardware + issue. UART RX baud rate tolerance level is 0% to +4% in 1-stop config. Otherwise, the + received data will have corruption/invalid framing errors. Parker errata suggests adjusting + baud rate to be higher than the deviations observed in TX. + + TX deviation of connected device can be captured over scope (or noted from its spec) for + valid range and Tegra baud rate has to be set above actual TX baud rate observed. To do this + we use nvidia,adjust-baud-rates. + + As an example, consider there is deviation observed in TX for baud rates as listed below. 0 + to 9600 has 1% deviation 9600 to 115200 2% deviation. This slight deviation is expcted and + Tegra UART is expected to handle it. Due to the issue stated above, baud rate on Tegra UART + should be set equal to or above deviation observed for avoiding frame errors. Property + should be set like this: + + nvidia,adjust-baud-rates = <0 9600 100>, + <9600 115200 200>; + items: + items: + - description: range lower bound + - description: range upper bound + - description: adjustment (in permyriad, i.e. 0.01%) + +allOf: + - $ref: serial.yaml + +unevaluatedProperties: false + +required: + - compatible + - reg + - interrupts + - clocks + - resets + - reset-names + - dmas + - dma-names + +examples: + - | + #include + #include + + serial@70006000 { + compatible = "nvidia,tegra30-hsuart"; + reg = <0x70006000 0x40>; + interrupts = ; + nvidia,enable-modem-interrupt; + clocks = <&tegra_car TEGRA30_CLK_UARTA>; + resets = <&tegra_car 6>; + reset-names = "serial"; + dmas = <&apbdma 8>, <&apbdma 8>; + dma-names = "rx", "tx"; + nvidia,adjust-baud-rates = <1000000 4000000 136>; /* 1.36% shift */ + }; -- 2.11.0