On Tue, Dec 13, 2022 at 03:01:34PM +0000, Biju Das wrote:
> Hi Rob,
>
> > Subject: Re: [PATCH 02/16] dt-bindings: usb: Add RZ/V2M USB3DRD binding
> >
> > On Mon, Dec 12, 2022 at 05:27:50PM +0000, Biju Das wrote:
> > > Add device tree bindings for the RZ/V2{M, MA} USB3DRD module.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > ---
> > > .../bindings/usb/renesas,rzv2m-usb3drd.yaml | 123 ++++++++++++++++++
> > > 1 file changed, 123 insertions(+)
> > > create mode 100644
> > > Documentation/devicetree/bindings/usb/renesas,rzv2m-usb3drd.yaml
> > >
> > > diff --git
> > > a/Documentation/devicetree/bindings/usb/renesas,rzv2m-usb3drd.yaml
> > > b/Documentation/devicetree/bindings/usb/renesas,rzv2m-usb3drd.yaml
> > > new file mode 100644
> > > index 000000000000..0c473c3398b3
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/usb/renesas,rzv2m-usb3drd.yaml
> > > @@ -0,0 +1,123 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) %YAML 1.2
> > > +---
> > > +
> > > +title: Renesas RZ/V2M USB 3.1 DRD controller
> > > +
> > > +maintainers:
> > > + - Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> > > +
> > > +description: |
> > > + The RZ/V2{M, MA} USB3.1 DRD module supports the following functions
> > > + * Role swapping function by the ID pin of the Micro-AB receptacle
> > > + * Battery Charging Specification Revision 1.2
> > > +
> > > +properties:
> > > + compatible:
> > > + items:
> > > + - enum:
> > > + - renesas,r9a09g011-usb3drd # RZ/V2M
> > > + - renesas,r9a09g055-usb3drd # RZ/V2MA
> > > + - const: renesas,rzv2m-usb3drd
> > > +
> > > + reg:
> > > + maxItems: 1
> > > +
> > > + clocks:
> > > + items:
> > > + - description: Peripheral AXI clock
> > > + - description: APB clock
> > > +
> > > + clock-names:
> > > + items:
> > > + - const: peri_axi
> > > + - const: apb
> > > +
> > > + power-domains:
> > > + maxItems: 1
> > > +
> > > + resets:
> > > + items:
> > > + - description: DRD reset
> > > + - description: Peripheral reset
> > > +
> > > + reset-names:
> > > + items:
> > > + - const: drd_reset
> > > + - const: aresetn_p
> > > +
> > > + ranges: true
> > > +
> > > + '#address-cells':
> > > + enum: [ 1, 2 ]
> > > +
> > > + '#size-cells':
> > > + enum: [ 1, 2 ]
> > > +
> > > + usb3peri:
> > > + $ref: /schemas/usb/renesas,usb3-peri.yaml
> > > +
> > > +patternProperties:
> > > + "^usb@[0-9a-f]+$":
> > > + type: object
> > > + $ref: renesas,usb-xhci.yaml#
> > > +
> > > +required:
> > > + - compatible
> > > + - reg
> > > + - clocks
> > > + - clock-names
> > > + - power-domains
> > > + - resets
> > > + - reset-names
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > + - |
> > > + #include <dt-bindings/clock/r9a09g011-cpg.h>
> > > + #include <dt-bindings/interrupt-controller/arm-gic.h>
> > > +
> > > + usb3drd: usb@85070000 {
> > > + compatible = "renesas,r9a09g011-usb3drd", "renesas,rzv2m-
> > usb3drd";
> > > + reg = <0x85070000 0x1000>;
> > > + clocks = <&cpg CPG_MOD R9A09G011_USB_ACLK_P>,
> > > + <&cpg CPG_MOD R9A09G011_USB_PCLK>;
> > > + clock-names = "peri_axi", "apb";
> > > + power-domains = <&cpg>;
> > > + resets = <&cpg R9A09G011_USB_DRD_RESET>,
> > > + <&cpg R9A09G011_USB_ARESETN_P>;
> > > + reset-names = "drd_reset", "aresetn_p";
> > > + ranges;
> > > + #address-cells = <1>;
> > > + #size-cells = <1>;
> > > +
> > > + usb3host: usb@85060000 {
> > > + compatible = "renesas,r9a09g011-xhci",
> > > + "renesas,rzv2m-xhci";
> > > + reg = <0x85060000 0x2000>;
> > > + interrupts = <GIC_SPI 245 IRQ_TYPE_LEVEL_HIGH>;
> > > + clocks = <&cpg CPG_MOD R9A09G011_USB_ACLK_H>,
> > > + <&cpg CPG_MOD R9A09G011_USB_PCLK>;
> > > + clock-names = "host_axi", "reg";
> > > + power-domains = <&cpg>;
> > > + resets = <&cpg R9A09G011_USB_ARESETN_H>;
> > > + };
> > > +
> > > + usb3peri: usb3peri {
> > > + compatible = "renesas,r9a09g011-usb3-peri",
> > > + "renesas,rzv2m-usb3-peri";
> > > + interrupts = <GIC_SPI 246 IRQ_TYPE_LEVEL_HIGH>,
> > > + <GIC_SPI 242 IRQ_TYPE_LEVEL_HIGH>,
> > > + <GIC_SPI 243 IRQ_TYPE_LEVEL_HIGH>,
> > > + <GIC_SPI 244 IRQ_TYPE_LEVEL_HIGH>;
> > > + interrupt-names = "all_p", "drd", "bc", "gpi";
> > > + clocks = <&cpg CPG_MOD R9A09G011_USB_ACLK_P>,
> > > + <&cpg CPG_MOD R9A09G011_USB_PCLK>;
> > > + clock-names = "aclk", "reg";
> > > + power-domains = <&cpg>;
> > > + resets = <&cpg R9A09G011_USB_ARESETN_P>;
> > > + };
> >
> > The USB device ctrlr doesn't have registers? It looks to me like you've
> > created 3 nodes for instantiating drivers rather that because you have 3
> > separate h/w blocks. Either you should split this to 2 independent nodes
> > or move usb3peri resources to the parent node. That would only be
> > interrupts because everything else is already there.
>
> Address map of USB device controller is 0x85070000-0x85070400
> Address map of USB3 DRD is 0x85070400-0x850704FF
Then your DT should reflect that with 'reg' in usb3peri.
Why does the device ctrlr have a DRD interrupt?
> The advantage of the current split is that,
>
> 1) With this model, I can use USB3 storage device for booting and mounting rootFS
> as XHCI driver is built-in and USB3 device ctrlr is usually module.
Sounds like a Linux problem. What does that have to do with the binding?
>
> 2) To reuse the usb device controller code as much as possible.
>
> If I create 2 independent nodes, then there will be more exported API's
> between USB3 peri and USB3 drd driver.
Why if that's a common split, then doesn't Linux have a defined
interface?
There is no reason you can spawn 2 drivers from 1 DT node if that's what
you need. Describe h/w blocks, not nodes for drivers. Sometimes the h/w
isn't partitioned just like Linux would like. That's a Linux problem,
not something to 'fix' in DT.
Rob
