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

From: Alain Volmat
Date: Thu Nov 21 2019 - 08:25:38 EST


On Wed, Nov 20, 2019 at 05:53:37PM +0000, Rob Herring wrote:
> 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.

Pull-request on the dt-schema git sent in order to add those two properties
into the i2c-controller.yaml

Patch v2 to come regarding other points.

>
> > + 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
> >