[PATCH] dt-bindings: serial: tegra-hsuart: Convert to json-schema

* [PATCH] dt-bindings: serial: tegra-hsuart: Convert to json-schema
@ 2023-06-30 13:58 Thierry Reding
  2023-06-30 16:54 ` Rob Herring
  0 siblings, 1 reply; 2+ messages in thread
From: Thierry Reding @ 2023-06-30 13:58 UTC (permalink / raw)
  To: Rob Herring, Krzysztof Kozlowski, Conor Dooley
  Cc: Jon Hunter, devicetree, linux-serial, linux-tegra

From: Thierry Reding <treding@nvidia.com>

Convert the Tegra High-Speed UART bindings from the free-form text
format to json-schema.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 .../bindings/serial/nvidia,tegra20-hsuart.txt |  73 -----------
 .../serial/nvidia,tegra20-hsuart.yaml         | 124 ++++++++++++++++++
 2 files changed, 124 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.
-  <range_low range_high 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..247ee33f8a01
--- /dev/null
+++ b/Documentation/devicetree/bindings/serial/nvidia,tegra20-hsuart.yaml
@@ -0,0 +1,124 @@
+# 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 <thierry.reding@gmail.com>
+  - Jon Hunter <jonathanh@nvidia.com>
+
+properties:
+  compatible:
+    oneOf:
+      - const: nvidia,tegra20-hsuart
+      - const: nvidia,tegra30-hsuart
+      - items:
+          - const: nvidia,tegra124-hsuart
+          - const: nvidia,tegra30-hsuart
+      - const: nvidia,tegra186-hsuart
+      - const: nvidia,tegra194-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 <dt-bindings/clock/tegra30-car.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    serial@70006000 {
+        compatible = "nvidia,tegra30-hsuart";
+        reg = <0x70006000 0x40>;
+        interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
+        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 */
+    };
-- 
2.41.0


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