[2/2] dt-bindings: pinctrl: Add RZ/A2 pinctrl and GPIO

Message ID 20181005150951.22129-3-chris.brandt@renesas.com
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  • pinctrl: Add RZ/A2 pin and gpio driver
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Commit Message

Chris Brandt Oct. 5, 2018, 3:09 p.m.
Add device tree binding documentation and header file for Renesas R7S9210
(RZ/A2) SoCs.

Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
---
 .../bindings/pinctrl/renesas,rza2-pinctrl.txt      | 76 ++++++++++++++++++++++
 include/dt-bindings/pinctrl/r7s9210-pinctrl.h      | 47 +++++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
 create mode 100644 include/dt-bindings/pinctrl/r7s9210-pinctrl.h

Comments

Rob Herring Oct. 16, 2018, 10:47 p.m. | #1
On Fri, Oct 05, 2018 at 10:09:51AM -0500, Chris Brandt wrote:
> Add device tree binding documentation and header file for Renesas R7S9210
> (RZ/A2) SoCs.
> 
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> ---
>  .../bindings/pinctrl/renesas,rza2-pinctrl.txt      | 76 ++++++++++++++++++++++
>  include/dt-bindings/pinctrl/r7s9210-pinctrl.h      | 47 +++++++++++++
>  2 files changed, 123 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
>  create mode 100644 include/dt-bindings/pinctrl/r7s9210-pinctrl.h
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> new file mode 100644
> index 000000000000..5f338054f493
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> @@ -0,0 +1,76 @@
> +Renesas RZ/A2 combined Pin and GPIO controller
> +
> +The Renesas SoCs of the RZ/A2 series feature a combined Pin and GPIO controller.
> +Pin multiplexing and GPIO configuration is performed on a per-pin basis.
> +Each port features up to 8 pins, each of them configurable for GPIO
> +function (port mode) or in alternate function mode.
> +Up to 8 different alternate function modes exist for each single pin.
> +
> +Pin controller node
> +-------------------
> +
> +Required properties:
> +  - compatible: should be:
> +    - "renesas,r7s9210-pinctrl": for RZ/A2M
> +
> +  - reg
> +    address base and length of the memory area where the pin controller
> +    hardware is mapped to.
> +
> +Optional properties:
> +  - gpio-controller
> +    Include this in order to enable GPIO functionality. When included, both
> +    gpio_cells and gpio_ranges are then required.
> +  - #gpio-cells
> +    Must be 2
> +  - gpio-ranges
> +    Expresses the total number GPIO ports/pins in this SoC

Are these really optional? I guess in theory a board could use no GPIOs, 
but that seems unlikely. 

> +
> +
> +Example: Pin controller node for RZ/A2M SoC (r7s9210)
> +
> +	pinctrl: pin-controller@fcffe000 {
> +		compatible = "renesas,r7s9210-pinctrl";
> +		reg = <0xfcffe000 0x9D1>;
> +
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +		gpio-ranges = <&pinctrl 0 0 176>;
> +	};
> +
> +Sub-nodes
> +---------
> +
> +The child nodes of the pin controller node describe a pin multiplexing
> +function or a GPIO controller alternatively.

But the parent is already a GPIO controller. This needs to be fully 
defined.

> +
> +- Pin multiplexing sub-nodes:
> +  A pin multiplexing sub-node describes how to configure a set of
> +  (or a single) pin in some desired alternate function mode.
> +  The values for the pinmux properties are a combination of port name, pin
> +  number and the desired function index. Use the RZA2_PINMUX macro located
> +  in include/dt-bindings/pinctrl/r7s9210-pinctrl.h to easily define these.
> +  For assigning GPIO pins, use the macro RZA2_PIN_ID also in r7s9210-pinctrl.h
> +  to express the desired port pin.
> +
> +  Example: Board specific pins configuration
> +
> +	&pinctrl {
> +		/* Serial Console */
> +		scif4_pins: serial4 {
> +			pinmux = <RZA2_PINMUX(P9, 0, 4)>,	/* TxD4 */
> +				 <RZA2_PINMUX(P9, 1, 4)>;	/* RxD4 */
> +		};
> +	};
> +
> +  Example: Assigning a GPIO:
> +
> +	leds {
> +		status = "okay";
> +		compatible = "gpio-leds";
> +
> +		led0 {
> +			/* P6_0 */
> +			gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
> +		};
> +	};
Chris Brandt Oct. 17, 2018, 12:53 a.m. | #2
On Tuesday, October 16, 2018, Rob Herring wrote:
> > +Optional properties:
> > +  - gpio-controller
> > +    Include this in order to enable GPIO functionality. When included,
> both
> > +    gpio_cells and gpio_ranges are then required.
> > +  - #gpio-cells
> > +    Must be 2
> > +  - gpio-ranges
> > +    Expresses the total number GPIO ports/pins in this SoC
> 
> Are these really optional? I guess in theory a board could use no GPIOs,
> but that seems unlikely.

They are 'optional' in the sense that if you don't include them in the 
DT, the driver still loads (just without any GPIO, but pinctrl still 
works). So, I was just documenting that fact.

If you think I should just move these to required, let me know an I'm 
fine with that. (as in, DT documents HW, not software)


> > +Sub-nodes
> > +---------
> > +
> > +The child nodes of the pin controller node describe a pin multiplexing
> > +function or a GPIO controller alternatively.
> 
> But the parent is already a GPIO controller. This needs to be fully
> defined.

Now that I read this, I think my wording was off (I was borrowing text 
for other files).

How about this:

The child nodes of the pin controller designate pins to be used for
specific peripheral functions or as GPIO.


Chris
Rob Herring Oct. 18, 2018, 1:34 p.m. | #3
On Tue, Oct 16, 2018 at 7:53 PM Chris Brandt <Chris.Brandt@renesas.com> wrote:
>
> On Tuesday, October 16, 2018, Rob Herring wrote:
> > > +Optional properties:
> > > +  - gpio-controller
> > > +    Include this in order to enable GPIO functionality. When included,
> > both
> > > +    gpio_cells and gpio_ranges are then required.
> > > +  - #gpio-cells
> > > +    Must be 2
> > > +  - gpio-ranges
> > > +    Expresses the total number GPIO ports/pins in this SoC
> >
> > Are these really optional? I guess in theory a board could use no GPIOs,
> > but that seems unlikely.
>
> They are 'optional' in the sense that if you don't include them in the
> DT, the driver still loads (just without any GPIO, but pinctrl still
> works). So, I was just documenting that fact.
>
> If you think I should just move these to required, let me know an I'm
> fine with that. (as in, DT documents HW, not software)

I do. There's no implicit requirement that the s/w has to support it.

> > > +Sub-nodes
> > > +---------
> > > +
> > > +The child nodes of the pin controller node describe a pin multiplexing
> > > +function or a GPIO controller alternatively.
> >
> > But the parent is already a GPIO controller. This needs to be fully
> > defined.
>
> Now that I read this, I think my wording was off (I was borrowing text
> for other files).
>
> How about this:
>
> The child nodes of the pin controller designate pins to be used for
> specific peripheral functions or as GPIO.

Sure.
jacopo mondi Oct. 18, 2018, 8:51 p.m. | #4
Hi Chris,

On Fri, Oct 05, 2018 at 10:09:51AM -0500, Chris Brandt wrote:
> Add device tree binding documentation and header file for Renesas R7S9210
> (RZ/A2) SoCs.
>
> Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> ---
>  .../bindings/pinctrl/renesas,rza2-pinctrl.txt      | 76 ++++++++++++++++++++++
>  include/dt-bindings/pinctrl/r7s9210-pinctrl.h      | 47 +++++++++++++
>  2 files changed, 123 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
>  create mode 100644 include/dt-bindings/pinctrl/r7s9210-pinctrl.h
>
> diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> new file mode 100644
> index 000000000000..5f338054f493
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> @@ -0,0 +1,76 @@
> +Renesas RZ/A2 combined Pin and GPIO controller
> +
> +The Renesas SoCs of the RZ/A2 series feature a combined Pin and GPIO controller.
> +Pin multiplexing and GPIO configuration is performed on a per-pin basis.
> +Each port features up to 8 pins, each of them configurable for GPIO
> +function (port mode) or in alternate function mode.
> +Up to 8 different alternate function modes exist for each single pin.
> +
> +Pin controller node
> +-------------------
> +
> +Required properties:
> +  - compatible: should be:
> +    - "renesas,r7s9210-pinctrl": for RZ/A2M
> +
> +  - reg
> +    address base and length of the memory area where the pin controller
> +    hardware is mapped to.
> +
> +Optional properties:
> +  - gpio-controller
> +    Include this in order to enable GPIO functionality. When included, both
> +    gpio_cells and gpio_ranges are then required.
> +  - #gpio-cells
> +    Must be 2
> +  - gpio-ranges
> +    Expresses the total number GPIO ports/pins in this SoC

I have some concerns here, I'll reply to Rob on this
> +
> +
> +Example: Pin controller node for RZ/A2M SoC (r7s9210)
> +
> +	pinctrl: pin-controller@fcffe000 {
> +		compatible = "renesas,r7s9210-pinctrl";
> +		reg = <0xfcffe000 0x9D1>;
> +
> +		gpio-controller;
> +		#gpio-cells = <2>;
> +		gpio-ranges = <&pinctrl 0 0 176>;
> +	};
> +
> +Sub-nodes
> +---------
> +
> +The child nodes of the pin controller node describe a pin multiplexing
> +function or a GPIO controller alternatively.
> +
> +- Pin multiplexing sub-nodes:
> +  A pin multiplexing sub-node describes how to configure a set of
> +  (or a single) pin in some desired alternate function mode.
> +  The values for the pinmux properties are a combination of port name, pin
> +  number and the desired function index. Use the RZA2_PINMUX macro located
> +  in include/dt-bindings/pinctrl/r7s9210-pinctrl.h to easily define these.
> +  For assigning GPIO pins, use the macro RZA2_PIN_ID also in r7s9210-pinctrl.h
> +  to express the desired port pin.
> +
> +  Example: Board specific pins configuration
> +
> +	&pinctrl {
> +		/* Serial Console */
> +		scif4_pins: serial4 {
> +			pinmux = <RZA2_PINMUX(P9, 0, 4)>,	/* TxD4 */
> +				 <RZA2_PINMUX(P9, 1, 4)>;	/* RxD4 */
> +		};
> +	};
> +
> +  Example: Assigning a GPIO:
> +
> +	leds {
> +		status = "okay";
> +		compatible = "gpio-leds";
> +
> +		led0 {
> +			/* P6_0 */
> +			gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
> +		};
> +	};

I think you should list the required properties ('pinmux') and the pin
configuration flags the hardware supports. From a quick look to the
manual I only see a configurable drive strength, but I might have
missed something.

> diff --git a/include/dt-bindings/pinctrl/r7s9210-pinctrl.h b/include/dt-bindings/pinctrl/r7s9210-pinctrl.h
> new file mode 100644
> index 000000000000..39ac74ba520b
> --- /dev/null
> +++ b/include/dt-bindings/pinctrl/r7s9210-pinctrl.h
> @@ -0,0 +1,47 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Defines macros and constants for Renesas RZ/A2 pin controller pin
> + * muxing functions.
> + */
> +#ifndef __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H
> +#define __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H
> +
> +#define RZA2_PINS_PER_PORT	8
> +
> +/* Port names as labeled in the Hardware Manual */
> +#define P0 0
> +#define P1 1
> +#define P2 2
> +#define P3 3
> +#define P4 4
> +#define P5 5
> +#define P6 6
> +#define P7 7
> +#define P8 8
> +#define P9 9
> +#define PA 10
> +#define PB 11
> +#define PC 12
> +#define PD 13
> +#define PE 14
> +#define PF 15
> +#define PG 16
> +#define PH 17
> +/* No I */
> +#define PJ 18
> +#define PK 19
> +#define PL 20
> +#define PM 21
> +
> +/*
> + * Create the pin index from its bank and position numbers and store in
> + * the upper 8 bits the alternate function identifier
> + */
> +#define RZA2_PINMUX(b, p, f)	((b) * RZA2_PINS_PER_PORT + (p) | (f << 16))
> +
> +/*
> + * Convert a port and pin label to its global pin index
> + */
> + #define RZA2_PIN_ID(port, pin)	((port) * RZA2_PINS_PER_PORT + (pin))

Why not just RZA2_PIN() :) ?

Thanks
   j

> +
> +#endif /* __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H */
> --
> 2.16.1
>
jacopo mondi Oct. 18, 2018, 9:10 p.m. | #5
Hi Chris,

On Tue, Oct 16, 2018 at 05:47:00PM -0500, Rob Herring wrote:
> On Fri, Oct 05, 2018 at 10:09:51AM -0500, Chris Brandt wrote:
> > Add device tree binding documentation and header file for Renesas R7S9210
> > (RZ/A2) SoCs.
> >
> > Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
> > ---
> >  .../bindings/pinctrl/renesas,rza2-pinctrl.txt      | 76 ++++++++++++++++++++++
> >  include/dt-bindings/pinctrl/r7s9210-pinctrl.h      | 47 +++++++++++++
> >  2 files changed, 123 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> >  create mode 100644 include/dt-bindings/pinctrl/r7s9210-pinctrl.h
> >
> > diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> > new file mode 100644
> > index 000000000000..5f338054f493
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
> > @@ -0,0 +1,76 @@
> > +Renesas RZ/A2 combined Pin and GPIO controller
> > +
> > +The Renesas SoCs of the RZ/A2 series feature a combined Pin and GPIO controller.
> > +Pin multiplexing and GPIO configuration is performed on a per-pin basis.
> > +Each port features up to 8 pins, each of them configurable for GPIO
> > +function (port mode) or in alternate function mode.
> > +Up to 8 different alternate function modes exist for each single pin.
> > +
> > +Pin controller node
> > +-------------------
> > +
> > +Required properties:
> > +  - compatible: should be:
> > +    - "renesas,r7s9210-pinctrl": for RZ/A2M
> > +
> > +  - reg
> > +    address base and length of the memory area where the pin controller
> > +    hardware is mapped to.
> > +
> > +Optional properties:
> > +  - gpio-controller
> > +    Include this in order to enable GPIO functionality. When included, both
> > +    gpio_cells and gpio_ranges are then required.
> > +  - #gpio-cells
> > +    Must be 2
> > +  - gpio-ranges
> > +    Expresses the total number GPIO ports/pins in this SoC
>
> Are these really optional? I guess in theory a board could use no GPIOs,
> but that seems unlikely.

Here you define bindings that allows you to have only one
gpio-controller node for the whole system.
With RZ/A1 we have a gpio-controller sub-node for each port. It's
true though that you have a lot of ports and few pins per port, but
to refer to a gpio you have to index the gpio in the whole pin space
with RZA1_PIN_ID():

	gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;

While I think this is nicer:
        gpios = <&port6 0 GPIO_ACTIVE_HIGH>;

Having gpio-controller sub-nodes also allows you
to specify a 'ngpios' property for each port (or do all ports have 8
pins? If I read Table 51.1 right they don't..), and when RZ/A2x will
come and has different pins per port it's
easy for developers to identify the differences (but this
depends on the package too, so it's not that easy as I'm putting it
here probably)

What do you think?

Thanks
   j

> > +
> > +
> > +Example: Pin controller node for RZ/A2M SoC (r7s9210)
> > +
> > +	pinctrl: pin-controller@fcffe000 {
> > +		compatible = "renesas,r7s9210-pinctrl";
> > +		reg = <0xfcffe000 0x9D1>;
> > +
> > +		gpio-controller;
> > +		#gpio-cells = <2>;
> > +		gpio-ranges = <&pinctrl 0 0 176>;
> > +	};
> > +
> > +Sub-nodes
> > +---------
> > +
> > +The child nodes of the pin controller node describe a pin multiplexing
> > +function or a GPIO controller alternatively.
>
> But the parent is already a GPIO controller. This needs to be fully
> defined.
>
> > +
> > +- Pin multiplexing sub-nodes:
> > +  A pin multiplexing sub-node describes how to configure a set of
> > +  (or a single) pin in some desired alternate function mode.
> > +  The values for the pinmux properties are a combination of port name, pin
> > +  number and the desired function index. Use the RZA2_PINMUX macro located
> > +  in include/dt-bindings/pinctrl/r7s9210-pinctrl.h to easily define these.
> > +  For assigning GPIO pins, use the macro RZA2_PIN_ID also in r7s9210-pinctrl.h
> > +  to express the desired port pin.
> > +
> > +  Example: Board specific pins configuration
> > +
> > +	&pinctrl {
> > +		/* Serial Console */
> > +		scif4_pins: serial4 {
> > +			pinmux = <RZA2_PINMUX(P9, 0, 4)>,	/* TxD4 */
> > +				 <RZA2_PINMUX(P9, 1, 4)>;	/* RxD4 */
> > +		};
> > +	};
> > +
> > +  Example: Assigning a GPIO:
> > +
> > +	leds {
> > +		status = "okay";
> > +		compatible = "gpio-leds";
> > +
> > +		led0 {
> > +			/* P6_0 */
> > +			gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
> > +		};
> > +	};
Chris Brandt Oct. 19, 2018, 1:03 a.m. | #6
Hi Jacopo,

On Thursday, October 18, 2018, jacopo mondi wrote:
> > +  Example: Assigning a GPIO:
> > +
> > +	leds {
> > +		status = "okay";
> > +		compatible = "gpio-leds";
> > +
> > +		led0 {
> > +			/* P6_0 */
> > +			gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
> > +		};
> > +	};
> 
> I think you should list the required properties ('pinmux') and the pin
> configuration flags the hardware supports.

OK, I can list pinmux.

> From a quick look to the
> manual I only see a configurable drive strength, but I might have
> missed something.

Yes, some pin can have different drive strength, but not all pins. Also,
some part are not clear about the drive strength.
So for this initial release, I do not want to be trying to describe 
hardware that I don't completely understand yet.

> > +/*
> > + * Convert a port and pin label to its global pin index
> > + */
> > + #define RZA2_PIN_ID(port, pin)	((port) * RZA2_PINS_PER_PORT + (pin))
> 
> Why not just RZA2_PIN() :) ?

OK.
I don't mind a shorter name.


Chris
Chris Brandt Oct. 19, 2018, 1:47 a.m. | #7
Hi Jacopo,

On Thursday, October 18, 2018, jacopo mondi wrote:
> Here you define bindings that allows you to have only one
> gpio-controller node for the whole system.

Correct. Since DT describes HW, we do only have one gpio-controller for 
the entire chip. It is one piece of hardware, not many tiny pieces of 
hardware.

> With RZ/A1 we have a gpio-controller sub-node for each port.

As I started to write this driver, I think the RZ/A1 driver is a little 
bit strange. It is also one gpio-ctonroller HW. But, I'm not about to go
suggesting we change the RZ/A1 driver any time soon.


> It's
> true though that you have a lot of ports and few pins per port, but
> to refer to a gpio you have to index the gpio in the whole pin space
> with RZA1_PIN_ID():
> 
> 	gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
> 
> While I think this is nicer:
>         gpios = <&port6 0 GPIO_ACTIVE_HIGH>;
 
Both seem just as easy to use.
The difference is I don't want lots and lots of device tree sub nodes 
that are not really needed.

Technically, the GPIO controller is a single piece of HW that you index 
into it what pin you want to control. The 'indexing' is basically 
registers and bits addresses. But, it is still one big controller (not many 
smaller controllers like channels of SPI, UART or I2C).


> Having gpio-controller sub-nodes also allows you
> to specify a 'ngpios' property for each port (or do all ports have 8
> pins? If I read Table 51.1 right they don't..),

The "controller" (actual HW) controls 8-pins per port. In the RZ/A2M, 
not all pins are hooked up to actual pin pads. And that also change with 
different packages like you mentioned.

> and when RZ/A2x will
> come and has different pins per port it's
> easy for developers to identify the differences (but this
> depends on the package too, so it's not that easy as I'm putting it
> here probably)

Yes, as you start to guess about different packages, an RZ/A2x, or even 
a RZ/A3, and all the different combinations, it gets complicated.

However, what will always be true is that this pin controller HW, no
matter what SoC it is in, will always have the ability to control 8 pins
per port. So you just have to specify how many ports it has, and then
that will be a correct description of the hardware.

Chris

Patch

diff --git a/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
new file mode 100644
index 000000000000..5f338054f493
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/renesas,rza2-pinctrl.txt
@@ -0,0 +1,76 @@ 
+Renesas RZ/A2 combined Pin and GPIO controller
+
+The Renesas SoCs of the RZ/A2 series feature a combined Pin and GPIO controller.
+Pin multiplexing and GPIO configuration is performed on a per-pin basis.
+Each port features up to 8 pins, each of them configurable for GPIO
+function (port mode) or in alternate function mode.
+Up to 8 different alternate function modes exist for each single pin.
+
+Pin controller node
+-------------------
+
+Required properties:
+  - compatible: should be:
+    - "renesas,r7s9210-pinctrl": for RZ/A2M
+
+  - reg
+    address base and length of the memory area where the pin controller
+    hardware is mapped to.
+
+Optional properties:
+  - gpio-controller
+    Include this in order to enable GPIO functionality. When included, both
+    gpio_cells and gpio_ranges are then required.
+  - #gpio-cells
+    Must be 2
+  - gpio-ranges
+    Expresses the total number GPIO ports/pins in this SoC
+
+
+Example: Pin controller node for RZ/A2M SoC (r7s9210)
+
+	pinctrl: pin-controller@fcffe000 {
+		compatible = "renesas,r7s9210-pinctrl";
+		reg = <0xfcffe000 0x9D1>;
+
+		gpio-controller;
+		#gpio-cells = <2>;
+		gpio-ranges = <&pinctrl 0 0 176>;
+	};
+
+Sub-nodes
+---------
+
+The child nodes of the pin controller node describe a pin multiplexing
+function or a GPIO controller alternatively.
+
+- Pin multiplexing sub-nodes:
+  A pin multiplexing sub-node describes how to configure a set of
+  (or a single) pin in some desired alternate function mode.
+  The values for the pinmux properties are a combination of port name, pin
+  number and the desired function index. Use the RZA2_PINMUX macro located
+  in include/dt-bindings/pinctrl/r7s9210-pinctrl.h to easily define these.
+  For assigning GPIO pins, use the macro RZA2_PIN_ID also in r7s9210-pinctrl.h
+  to express the desired port pin.
+
+  Example: Board specific pins configuration
+
+	&pinctrl {
+		/* Serial Console */
+		scif4_pins: serial4 {
+			pinmux = <RZA2_PINMUX(P9, 0, 4)>,	/* TxD4 */
+				 <RZA2_PINMUX(P9, 1, 4)>;	/* RxD4 */
+		};
+	};
+
+  Example: Assigning a GPIO:
+
+	leds {
+		status = "okay";
+		compatible = "gpio-leds";
+
+		led0 {
+			/* P6_0 */
+			gpios = <&pinctrl RZA2_PIN_ID(P6, 0) GPIO_ACTIVE_HIGH>;
+		};
+	};
diff --git a/include/dt-bindings/pinctrl/r7s9210-pinctrl.h b/include/dt-bindings/pinctrl/r7s9210-pinctrl.h
new file mode 100644
index 000000000000..39ac74ba520b
--- /dev/null
+++ b/include/dt-bindings/pinctrl/r7s9210-pinctrl.h
@@ -0,0 +1,47 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Defines macros and constants for Renesas RZ/A2 pin controller pin
+ * muxing functions.
+ */
+#ifndef __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H
+#define __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H
+
+#define RZA2_PINS_PER_PORT	8
+
+/* Port names as labeled in the Hardware Manual */
+#define P0 0
+#define P1 1
+#define P2 2
+#define P3 3
+#define P4 4
+#define P5 5
+#define P6 6
+#define P7 7
+#define P8 8
+#define P9 9
+#define PA 10
+#define PB 11
+#define PC 12
+#define PD 13
+#define PE 14
+#define PF 15
+#define PG 16
+#define PH 17
+/* No I */
+#define PJ 18
+#define PK 19
+#define PL 20
+#define PM 21
+
+/*
+ * Create the pin index from its bank and position numbers and store in
+ * the upper 8 bits the alternate function identifier
+ */
+#define RZA2_PINMUX(b, p, f)	((b) * RZA2_PINS_PER_PORT + (p) | (f << 16))
+
+/*
+ * Convert a port and pin label to its global pin index
+ */
+ #define RZA2_PIN_ID(port, pin)	((port) * RZA2_PINS_PER_PORT + (pin))
+
+#endif /* __DT_BINDINGS_PINCTRL_RENESAS_RZA2_H */