Re: [PATCH 3/3] devicetree: bindings: pinctrl: Add bindings doc for Sunplus SP7021.

Linus Walleij
2021-11-09T04:00:04Z

Hi Wells Lu,

thanks for your patch!

On Wed, Oct 27, 2021 at 10:55 AM Wells Lu <wellslutw@gmail.com> wrote:

> + properties:
> + pins:
> + description: |
> + Define pins which are used by pinctrl node's client device.
> +
> + It consists of one or more integers which represents the config
> + setting for corresponding pin. Please use macro SPPCTL_IOPAD to
> + define the integers for pins.
> +
> + The first argument of the macro is pin number, the second is pin
> + type, the third is type of GPIO, the last is default output state
> + of GPIO.
> + $ref: /schemas/types.yaml#/definitions/uint32-array
> +
> + function:
> + description: |
> + Define pin-function which is used by pinctrl node's client device.
> + The name should be one of string in the following enumeration.
> + $ref: "/schemas/types.yaml#/definitions/string"
> + enum: [ SPI_FLASH, SPI_FLASH_4BIT, SPI_NAND, CARD0_EMMC, SD_CARD,
> + UA0, FPGA_IFX, HDMI_TX, LCDIF, USB0_OTG, USB1_OTG ]
> +
> + groups:
> + description: |
> + Define pin-group in a specified pin-function.
> + The name should be one of string in the following enumeration.
> + $ref: "/schemas/types.yaml#/definitions/string"
> + enum: [ SPI_FLASH1, SPI_FLASH2, SPI_FLASH_4BIT1, SPI_FLASH_4BIT2,
> + SPI_NAND, CARD0_EMMC, SD_CARD, UA0, FPGA_IFX, HDMI_TX1,
> + HDMI_TX2, HDMI_TX3, LCDIF, USB0_OTG, USB1_OTG ]

Is it possible to use
Documentation/devicetree/bindings/pinctrl/pinmux-node.yaml
for this like other drivers do?

> + zero_func:
> + description: |
> + Disabled pins which are not used by pinctrl node's client device.
> + $ref: /schemas/types.yaml#/definitions/uint32-array

I have never seen this before. Can't you just use pin control hogs
for this so the pin controller just take care of these pins?

> + allOf:
> + - if:
> + properties:
> + function:
> + enum:
> + - SPI_FLASH
> + then:
> + properties:
> + groups:
> + enum:
> + - SPI_FLASH1
> + - SPI_FLASH2
> + - if:
> + properties:
> + function:
> + enum:
> + - SPI_FLASH_4BIT
> + then:
> + properties:
> + groups:
> + enum:
> + - SPI_FLASH_4BIT1
> + - SPI_FLASH_4BIT2
> + - if:
> + properties:
> + function:
> + enum:
> + - SPI_NAND
> + then:
> + properties:
> + groups:
> + enum:
> + - SPI_NAND
> + - if:
> + properties:
> + function:
> + enum:
> + - CARD0_EMMC
> + then:
> + properties:
> + groups:
> + enum:
> + - CARD0_EMMC
> + - if:
> + properties:
> + function:
> + enum:
> + - SD_CARD
> + then:
> + properties:
> + groups:
> + enum:
> + - SD_CARD
> + - if:
> + properties:
> + function:
> + enum:
> + - UA0
> + then:
> + properties:
> + groups:
> + enum:
> + - UA0
> + - if:
> + properties:
> + function:
> + enum:
> + - FPGA_IFX
> + then:
> + properties:
> + groups:
> + enum:
> + - FPGA_IFX
> + - if:
> + properties:
> + function:
> + enum:
> + - HDMI_TX
> + then:
> + properties:
> + groups:
> + enum:
> + - HDMI_TX1
> + - HDMI_TX2
> + - HDMI_TX3
> + - if:
> + properties:
> + function:
> + enum:
> + - LCDIF
> + then:
> + properties:
> + groups:
> + enum:
> + - LCDIF
> + - if:
> + properties:
> + function:
> + enum:
> + - USB0_OTG
> + then:
> + properties:
> + groups:
> + enum:
> + - USB0_OTG
> + - if:
> + properties:
> + function:
> + enum:
> + - USB1_OTG
> + then:
> + properties:
> + groups:
> + enum:
> + - USB1_OTG

This looks complex to me, I need feedback from bindings people
on this.

> + pins_uart0: pins_uart0 {
> + function = "UA0";
> + groups = "UA0";
> + };
> +
> + pins_uart1: pins_uart1 {
> + pins = <
> + SPPCTL_IOPAD(11,SPPCTL_PCTL_G_PMUX,MUXF_UA1_TX,0)
> + SPPCTL_IOPAD(10,SPPCTL_PCTL_G_PMUX,MUXF_UA1_RX,0)
> + SPPCTL_IOPAD(7,SPPCTL_PCTL_G_GPIO,0,SPPCTL_PCTL_L_OUT)
> + >;
> + };

This first looks like two ways to do the same thing?
UART0 uses strings for group + function and uart1 control
individual pins.

Is it possible to just do it one way?

I think the pins = <...> scheme includes also multiplexing settings
and then it should be named pinmux = <...>:

Please read
Documentation/devicetree/bindings/pinctrl/pinmux-node.yaml
closely.

Yours,
Linus Walleij