Re: [PATCH] dt-bindings: i2c: stm32: Migrate i2c-stm32 documentation to yaml

From: Rob Herring
Date: Wed Nov 20 2019 - 12:53:53 EST


On Wed, Nov 20, 2019 at 7:43 AM Alain Volmat <alain.volmat@xxxxxx> wrote:
>
> The document was migrated to Yaml format and renamed st,stm32-i2c.yaml
>
> Signed-off-by: Alain Volmat <alain.volmat@xxxxxx>
> ---
> .../devicetree/bindings/i2c/i2c-stm32.txt | 65 ---------
> .../devicetree/bindings/i2c/st,stm32-i2c.yaml | 157 +++++++++++++++++++++
> 2 files changed, 157 insertions(+), 65 deletions(-)
> delete mode 100644 Documentation/devicetree/bindings/i2c/i2c-stm32.txt
> create mode 100644 Documentation/devicetree/bindings/i2c/st,stm32-i2c.yaml
>
> diff --git a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt b/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
> deleted file mode 100644
> index ce3df2fff6c8..000000000000
> --- a/Documentation/devicetree/bindings/i2c/i2c-stm32.txt
> +++ /dev/null
> @@ -1,65 +0,0 @@
> -* I2C controller embedded in STMicroelectronics STM32 I2C platform
> -
> -Required properties:
> -- compatible: Must be one of the following
> - - "st,stm32f4-i2c"
> - - "st,stm32f7-i2c"
> -- reg: Offset and length of the register set for the device
> -- interrupts: Must contain the interrupt id for I2C event and then the
> - interrupt id for I2C error.
> -- resets: Must contain the phandle to the reset controller.
> -- clocks: Must contain the input clock of the I2C instance.
> -- A pinctrl state named "default" must be defined to set pins in mode of
> - operation for I2C transfer
> -- #address-cells = <1>;
> -- #size-cells = <0>;
> -
> -Optional properties:
> -- clock-frequency: Desired I2C bus clock frequency in Hz. If not specified,
> - the default 100 kHz frequency will be used.
> - For STM32F4 SoC Standard-mode and Fast-mode are supported, possible values are
> - 100000 and 400000.
> - For STM32F7, STM32H7 and STM32MP1 SoCs, Standard-mode, Fast-mode and Fast-mode
> - Plus are supported, possible values are 100000, 400000 and 1000000.
> -- dmas: List of phandles to rx and tx DMA channels. Refer to stm32-dma.txt.
> -- dma-names: List of dma names. Valid names are: "rx" and "tx".
> -- i2c-scl-rising-time-ns: I2C SCL Rising time for the board (default: 25)
> - For STM32F7, STM32H7 and STM32MP1 only.
> -- i2c-scl-falling-time-ns: I2C SCL Falling time for the board (default: 10)
> - For STM32F7, STM32H7 and STM32MP1 only.
> - I2C Timings are derived from these 2 values
> -- st,syscfg-fmp: Use to set Fast Mode Plus bit within SYSCFG when Fast Mode
> - Plus speed is selected by slave.
> - 1st cell: phandle to syscfg
> - 2nd cell: register offset within SYSCFG
> - 3rd cell: register bitmask for FMP bit
> - For STM32F7, STM32H7 and STM32MP1 only.
> -
> -Example:
> -
> - i2c@40005400 {
> - compatible = "st,stm32f4-i2c";
> - #address-cells = <1>;
> - #size-cells = <0>;
> - reg = <0x40005400 0x400>;
> - interrupts = <31>,
> - <32>;
> - resets = <&rcc 277>;
> - clocks = <&rcc 0 149>;
> - pinctrl-0 = <&i2c1_sda_pin>, <&i2c1_scl_pin>;
> - pinctrl-names = "default";
> - };
> -
> - i2c@40005400 {
> - compatible = "st,stm32f7-i2c";
> - #address-cells = <1>;
> - #size-cells = <0>;
> - reg = <0x40005400 0x400>;
> - interrupts = <31>,
> - <32>;
> - resets = <&rcc STM32F7_APB1_RESET(I2C1)>;
> - clocks = <&rcc 1 CLK_I2C1>;
> - pinctrl-0 = <&i2c1_sda_pin>, <&i2c1_scl_pin>;
> - pinctrl-names = "default";
> - st,syscfg-fmp = <&syscfg 0x4 0x1>;
> - };
> diff --git a/Documentation/devicetree/bindings/i2c/st,stm32-i2c.yaml b/Documentation/devicetree/bindings/i2c/st,stm32-i2c.yaml
> new file mode 100644
> index 000000000000..0f51a6ed0e9b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i2c/st,stm32-i2c.yaml
> @@ -0,0 +1,157 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i2c/st,stm32-i2c.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: I2C controller embedded in STMicroelectronics STM32 I2C platform
> +
> +maintainers:
> + - Pierre-Yves MORDRET <pierre-yves.mordret@xxxxxx>
> +
> +allOf:
> + - $ref: /schemas/i2c/i2c-controller.yaml#
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - st,stm32f7-i2c
> + then:
> + properties:
> + i2c-scl-rising-time-ns:
> + description: I2C SCL Rising time for the board
> + $ref: /schemas/types.yaml#/definitions/uint32
> + default: 25
> +
> + i2c-scl-falling-time-ns:
> + description: I2C SCL Falling time for the board
> + $ref: /schemas/types.yaml#/definitions/uint32

These 2 should be added to i2c-controller.yaml and just the default
defined here.

> + default: 10
> +
> + - if:
> + properties:
> + compatible:
> + contains:
> + enum:
> + - st,stm32f4-i2c
> + then:
> + properties:
> + clock-frequency:
> + description: Desired I2C bus clock frequency in Hz. If not specified,
> + the default 100 kHz frequency will be used.
> + For STM32F4 SoC Standard-mode and Fast-mode are
> + supported, possible values are 100000 and 400000.
> + default: 100000
> + enum: [100000, 400000]
> + else:
> + properties:
> + clock-frequency:
> + description: Desired I2C bus clock frequency in Hz. If not specified,
> + the default 100 kHz frequency will be used.
> + For STM32F7, STM32H7 and STM32MP1 SoCs, Standard-mode,
> + Fast-mode and Fast-mode Plus are supported, possible
> + values are 100000, 400000 and 1000000.
> + default: 100000
> + enum: [100000, 400000, 1000000]

Move this to main 'properties'. Then the one in the 'then' clause just
needs the enum.

> +
> + st,syscfg-fmp:
> + $ref: "/schemas/types.yaml#/definitions/phandle-array"

Won't work. You have to do:

allOf:
- $ref: ...

> + description: Use to set Fast Mode Plus bit within SYSCFG when
> + Fast Mode Plus speed is selected by slave. Should be
> + phandle/offset/mask
> + items:
> + - description: phandle to syscfg
> + - description: register offset within syscfg
> + - description: register bitmask for FMP bit

Wouldn't this make more sense in the first if rather than the 'else' clause?

> +
> +properties:
> + compatible:
> + enum:
> + - st,stm32f4-i2c
> + - st,stm32f7-i2c
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + maxItems: 2

Implied by items length.

> + items:
> + - description: interrupt ID for I2C event
> + - description: interrupt ID for I2C error
> +
> + resets:
> + maxItems: 1
> +
> + clocks:
> + maxItems: 1
> +
> + dmas:
> + items:
> + - description: RX DMA Channel phandle
> + - description: TX DMA Channel phandle
> + minItems: 2
> + maxItems: 2

Implied by items length.

> +
> + dma-names:
> + items:
> + - const: rx
> + - const: tx
> + minItems: 2
> + maxItems: 2

Implied by items length.

> +
> +required:
> + - compatible

> + - '#address-cells'
> + - '#size-cells'

Can drop. i2c-controller.yaml makes them required.

> + - reg
> + - interrupts
> + - resets
> + - clocks
> +
> +examples:
> + - |
> + #include <dt-bindings/mfd/stm32f7-rcc.h>
> + #include <dt-bindings/clock/stm32fx-clock.h>
> + //Example 1 (with st,stm32f4-i2c compatible)
> + i2c@40005400 {
> + compatible = "st,stm32f4-i2c";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <0x40005400 0x400>;
> + interrupts = <31>,
> + <32>;
> + resets = <&rcc 277>;
> + clocks = <&rcc 0 149>;
> + };
> +
> + //Example 2 (with st,stm32f7-i2c compatible)
> + i2c@40005800 {
> + compatible = "st,stm32f7-i2c";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <0x40005800 0x400>;
> + interrupts = <31>,
> + <32>;
> + resets = <&rcc STM32F7_APB1_RESET(I2C1)>;
> + clocks = <&rcc 1 CLK_I2C1>;
> + };
> +
> + //Example 3 (with st,stm32f7-i2c compatible on stm32mp)
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/clock/stm32mp1-clks.h>
> + #include <dt-bindings/reset/stm32mp1-resets.h>
> + i2c@40013000 {
> + compatible = "st,stm32f7-i2c";
> + #address-cells = <1>;
> + #size-cells = <0>;
> + reg = <0x40013000 0x400>;
> + interrupts = <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>,
> + <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>;
> + clocks = <&rcc I2C2_K>;
> + resets = <&rcc I2C2_R>;
> + i2c-scl-rising-time-ns = <185>;
> + i2c-scl-falling-time-ns = <20>;
> + st,syscfg-fmp = <&syscfg 0x4 0x2>;
> + };
> +...
> --
> 2.7.4
>