Re: [PATCH v2 02/14] dt-bindings: pinctrl: Add RaspberryPi RP1 gpio/pinctrl/pinmux bindings

Andrea della Porta
2024-10-21T17:41:24Z

Hi Krzysztof,

On 08:29 Tue 08 Oct , Krzysztof Kozlowski wrote:
> On Mon, Oct 07, 2024 at 02:39:45PM +0200, Andrea della Porta wrote:
> > Add device tree bindings for the gpio/pin/mux controller that is part of
> > the RP1 multi function device, and relative entries in MAINTAINERS file.
> >
> > Signed-off-by: Andrea della Porta <andrea.porta@suse.com>
> > ---
> > .../pinctrl/raspberrypi,rp1-gpio.yaml | 169 ++++++++++++++++++
> > MAINTAINERS | 2 +
> > 2 files changed, 171 insertions(+)
> > create mode 100644 Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml
> >
> > diff --git a/Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml b/Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml
> > new file mode 100644
> > index 000000000000..46e071ec6251
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/raspberrypi,rp1-gpio.yaml
> > @@ -0,0 +1,169 @@
> > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > +%YAML 1.2
> > +---
> > +$id: http://devicetree.org/schemas/pinctrl/raspberrypi,rp1-gpio.yaml#
> > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > +
> > +title: RaspberryPi RP1 GPIO/Pinconf/Pinmux Controller submodule
> > +
> > +maintainers:
> > + - Andrea della Porta <andrea.porta@suse.com>
> > +
> > +description:
> > + The RP1 chipset is a Multi Function Device containing, among other sub-peripherals,
> > + a gpio/pinconf/mux controller whose 54 pins are grouped into 3 banks. It works also
> > + as an interrupt controller for those gpios.
> > +
> > + Each pin configuration node lists the pin(s) to which it applies, and one or
> > + more of the mux function to select on those pin(s), and their configuration.
> > + The pin configuration and multiplexing supports the generic bindings.
> > + For details on each properties (including the meaning of "pin configuration node"),
> > + you can refer to ./pinctrl-bindings.txt.
>
> Drop the sentence. pinctrl.yaml defines this already.

Just to be sure, by 'sentence' I assume you mean the entire paragraph from
"Each pin configuration..." to "...refer to ./pinctrl-bindings.txt.", right?

>
> > +
> > +properties:
> > + compatible:
> > + const: raspberrypi,rp1-gpio
> > +
> > + reg:
> > + maxItems: 3
> > + description: One reg specifier for each one of the 3 pin banks.
> > +
> > + '#gpio-cells':
> > + description: The first cell is the pin number and the second cell is used
> > + to specify the flags (see include/dt-bindings/gpio/gpio.h).
> > + const: 2
> > +
> > + gpio-controller: true
> > +
> > + gpio-ranges:
> > + maxItems: 1
> > +
> > + gpio-line-names:
> > + maxItems: 54
> > +
> > + interrupts:
> > + maxItems: 3
> > + description: One interrupt specifier for each one of the 3 pin banks.
> > +
> > + '#interrupt-cells':
> > + description:
> > + Specifies the Bank number [0, 1, 2] and Flags as defined in
> > + include/dt-bindings/interrupt-controller/irq.h.
> > + const: 2
> > +
> > + interrupt-controller: true
> > +
> > +additionalProperties:
> > + anyOf:
>
> Uh, no, I think you got comments on this. You should be specific which
> nodes you expect, e.g. pins or groups. See other recent bindings for
> example.

Please see below.

>
> > + - type: object
> > + additionalProperties: false
> > + allOf:
> > + - $ref: pincfg-node.yaml#
> > + - $ref: pinmux-node.yaml#
> > +
> > + description:
> > + Pin controller client devices use pin configuration subnodes (children
> > + and grandchildren) for desired pin configuration.
> > + Client device subnodes use below standard properties.
> > +
> > + properties:
> > + pins:
> > + description:
> > + A string (or list of strings) adhering to the pattern "gpio[0-5][0-9]"
> > + function: true
> > + bias-disable: true
> > + bias-pull-down: true
> > + bias-pull-up: true
> > + slew-rate:
> > + description: 0 is slow slew rate, 1 is fast slew rate
> > + enum: [ 0, 1 ]
> > + drive-strength:
> > + enum: [ 2, 4, 8, 12 ]
> > +
> > + - type: object
> > + additionalProperties:
> > + $ref: "#/additionalProperties/anyOf/0"
>
> I don't quite get what you wanted to achieve here.

This should be a compact way to describe a schema that allows declarations like
the following:

rp1_gpio {
...

/* grouped gpios */
rp1_uart0_14_15: rp1_uart0_14_15 {
pin_txd {
function = "uart0";
pins = "gpio14";
bias-disable;
};

pin_rxd {
function = "uart0";
pins = "gpio15";
bias-pull-up;
};
};

/* standalone pins */
rp1_i2s0_18_21: rp1_i2s0_18_21 {
function = "i2s0";
pins = "gpio18", "gpio19", "gpio20", "gpio21";
bias-disable;
};

...
};

that is, both standalone and group pinctrl/pinmux node.

>
> > +
> > +allOf:
> > + - $ref: pinctrl.yaml#
> > +
> > +required:
> > + - reg
> > + - compatible
> > + - "#gpio-cells"
> > + - gpio-controller
> > + - interrupts
> > + - "#interrupt-cells"
> > + - interrupt-controller
> > +
> > +examples:
> > + - |
> > + #include <dt-bindings/interrupt-controller/irq.h>
> > +
> > + rp1 {
> > + #address-cells = <2>;
> > + #size-cells = <2>;
> > +
> > + rp1_gpio: pinctrl@c0400d0000 {
> > + reg = <0xc0 0x400d0000 0x0 0xc000>,
> > + <0xc0 0x400e0000 0x0 0xc000>,
> > + <0xc0 0x400f0000 0x0 0xc000>;
> > + compatible = "raspberrypi,rp1-gpio";
> > + gpio-controller;
> > + #gpio-cells = <2>;
> > + interrupt-controller;
> > + #interrupt-cells = <2>;
> > + interrupts = <0 IRQ_TYPE_LEVEL_HIGH>,
> > + <1 IRQ_TYPE_LEVEL_HIGH>,
> > + <2 IRQ_TYPE_LEVEL_HIGH>;
> > + gpio-line-names =
> > + "ID_SDA", // GPIO0
> > + "ID_SCL", // GPIO1
> > + "GPIO2", "GPIO3", "GPIO4", "GPIO5", "GPIO6",
> > + "GPIO7", "GPIO8", "GPIO9", "GPIO10", "GPIO11",
> > + "GPIO12", "GPIO13", "GPIO14", "GPIO15", "GPIO16",
> > + "GPIO17", "GPIO18", "GPIO19", "GPIO20", "GPIO21",
> > + "GPIO22", "GPIO23", "GPIO24", "GPIO25", "GPIO26",
> > + "GPIO27",
> > + "PCIE_RP1_WAKE", // GPIO28
> > + "FAN_TACH", // GPIO29
> > + "HOST_SDA", // GPIO30
> > + "HOST_SCL", // GPIO31
> > + "ETH_RST_N", // GPIO32
> > + "", // GPIO33
> > + "CD0_IO0_MICCLK", // GPIO34
> > + "CD0_IO0_MICDAT0", // GPIO35
> > + "RP1_PCIE_CLKREQ_N", // GPIO36
> > + "", // GPIO37
> > + "CD0_SDA", // GPIO38
> > + "CD0_SCL", // GPIO39
> > + "CD1_SDA", // GPIO40
> > + "CD1_SCL", // GPIO41
> > + "USB_VBUS_EN", // GPIO42
> > + "USB_OC_N", // GPIO43
> > + "RP1_STAT_LED", // GPIO44
> > + "FAN_PWM", // GPIO45
> > + "CD1_IO0_MICCLK", // GPIO46
> > + "2712_WAKE", // GPIO47
> > + "CD1_IO1_MICDAT1", // GPIO48
> > + "EN_MAX_USB_CUR", // GPIO49
> > + "", // GPIO50
> > + "", // GPIO51
> > + "", // GPIO52
> > + ""; // GPIO53
> > +
> > + rp1_uart0_14_15: rp1_uart0_14_15 {
>
> Underscores are not allowed in node names. Please read DTS coding style.
>
> Drop unused labels.

Ack.

Many thanks,
Andrea

>
> > + pin_txd {
> > + function = "uart0";
> > + pins = "gpio14";
> > + bias-disable;
> > + };
>
> Best regards,
> Krzysztof
>