Re: [PATCH v4 1/5] dt-bindings: PCI: add snps,dw-pcie.yaml

From: Mauro Carvalho Chehab
Date: Sun Jul 18 2021 - 06:55:23 EST


Em Sun, 18 Jul 2021 11:59:16 +0200
Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> escreveu:

> Em Thu, 15 Jul 2021 11:23:37 -0600
> Rob Herring <robh@xxxxxxxxxx> escreveu:
>
> > On Tue, Jul 13, 2021 at 01:17:51PM +0200, Mauro Carvalho Chehab wrote:
> > > Currently, the designware schema is defined on a text file:
> > > designware-pcie.txt
> > >
> > > Convert the pci-bus part into a schema.
> > >
> > > Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> > > ---
> > > .../devicetree/bindings/pci/snps,dw-pcie.yaml | 96 +++++++++++++++++++
> > > MAINTAINERS | 1 +
> > > 2 files changed, 97 insertions(+)
> > > create mode 100644 Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > >
> > > diff --git a/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > > new file mode 100644
> > > index 000000000000..fd372d715ab4
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/pci/snps,dw-pcie.yaml
> > > @@ -0,0 +1,96 @@
> > > +# SPDX-License-Identifier: GPL-2.0
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/pci/snps,dw-pcie.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: Synopsys DesignWare PCIe interface
> > > +
> > > +maintainers:
> > > + - Jingoo Han <jingoohan1@xxxxxxxxx>
> > > + - Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
> > > +
> > > +description: |
> > > + Synopsys DesignWare PCIe host controller
> > > +
> > > +allOf:
> > > + - $ref: /schemas/pci/pci-bus.yaml#
> > > +
> > > +properties:
> > > + compatible:
> > > + anyOf:
> > > + - {}
> > > + - const: snps,dw-pcie
> > > +
> > > + reg:
> > > + description: |
> > > + It should contain Data Bus Interface (dbi) and config registers for all
> > > + versions.
> > > + For designware core version >= 4.80, it may contain ATU address space.
> > > + minItems: 2
> > > + maxItems: 4
> > > +
> > > + reg-names:
> > > + minItems: 2
> > > + maxItems: 4
> > > + items:
> > > + enum: [dbi, dbi2, config, atu, addr_space, app, elbi, mgmt]
> >
> > Isn't 'config' only for host and 'addr_space' only for endpoint?
>
> The problem on enforcing an enum here is that severa *.dts files violate it.
> In the specific case of 'addr_space', there is (are?) place(s) where the wrong
> compatible was used, like on arch/arm/boot/dts/artpec6.dtsi:
>
> pcie: pcie@f8050000 {
> compatible = "axis,artpec6-pcie", "snps,dw-pcie";
> reg = <0xf8050000 0x2000
> 0xf8040000 0x1000
> 0xc0000000 0x2000>;
> reg-names = "dbi", "phy", "config";
> #address-cells = <3>;
> #size-cells = <2>;
> device_type = "pci";
> /* downstream I/O */
> ranges = <0x81000000 0 0 0xc0002000 0 0x00010000
> /* non-prefetchable memory */
> 0x82000000 0 0xc0012000 0xc0012000 0 0x1ffee000>;
> num-lanes = <2>;
> bus-range = <0x00 0xff>;
> interrupts = <GIC_SPI 148 IRQ_TYPE_LEVEL_HIGH>;
> interrupt-names = "msi";
> #interrupt-cells = <1>;
> interrupt-map-mask = <0 0 0 0x7>;
> interrupt-map = <0 0 0 1 &intc GIC_SPI 144 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 2 &intc GIC_SPI 145 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 3 &intc GIC_SPI 146 IRQ_TYPE_LEVEL_HIGH>,
> <0 0 0 4 &intc GIC_SPI 147 IRQ_TYPE_LEVEL_HIGH>;
> axis,syscon-pcie = <&syscon>;
> status = "disabled";
> };
>
> pcie_ep: pcie_ep@f8050000 {
> compatible = "axis,artpec6-pcie-ep", "snps,dw-pcie";
> reg = <0xf8050000 0x2000
> 0xf8051000 0x2000
> 0xf8040000 0x1000
> 0xc0000000 0x20000000>;
> reg-names = "dbi", "dbi2", "phy", "addr_space";
> num-ib-windows = <6>;
> num-ob-windows = <2>;
> num-lanes = <2>;
> axis,syscon-pcie = <&syscon>;
> status = "disabled";
> };
>
> (funny enough, this is not generating warnings here).
>
> Btw, besides the above, there are some DTS that use something different
> from what's there at the enum:
>
>
> $ make CROSS_COMPILE=aarch64-linux-gnu- ARCH=arm64 dtbs_check 2>&1 |tee dtbs_check.log
> $ grep "\['dbi', 'dbi2', 'config', 'atu', 'app', 'elbi', 'mgmt'\]" dtbs_check.log|sed "s,From schema:,,"|cut -d: -f 2-|cut -d' ' -f 4-|sort|uniq -c|sort -n -r
> 51 'ctrl' is not one of ['dbi', 'dbi2', 'config', 'atu', 'app', 'elbi', 'mgmt']
> 44 'parf' is not one of ['dbi', 'dbi2', 'config', 'atu', 'app', 'elbi', 'mgmt']
> 18 'cfg' is not one of ['dbi', 'dbi2', 'config', 'atu', 'app', 'elbi', 'mgmt']
> 4 'link' is not one of ['dbi', 'dbi2', 'config', 'atu', 'app', 'elbi', 'mgmt']
>
> In order to use an enum and not having warnings, the enum should be
> instead:
>
> reg-names:
> minItems: 2
> maxItems: 4
> items:
> enum: [dbi, dbi2, config, atu, app, elbi, mgmt, ctrl, parf, cfg, link]

Actually, some reg definitions have 5 items.

I'm sending an updated patch series.

Thanks,
Mauro