From: Thierry Reding <treding@xxxxxxxxxx>
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.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
Changes in v2:
- add note about the corrected example to commit message
- collate all single entry compatibles into an enum
.../bindings/serial/nvidia,tegra20-hsuart.txt | 73 ----------
.../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.
- <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..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 <thierry.reding@xxxxxxxxx>
+ - Jon Hunter <jonathanh@xxxxxxxxxx>
+
+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 <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
