RE: [PATCH 1/2] dt-bindings: PCI: Add Intel Keem Bay PCIe controller

["Wan Mohamad, Wan Ahmad Zainie" <wan.ahmad.zainie.wan.mohamad@intel.com>]

Hi Rob.

Thanks for the review.

> -----Original Message-----
> From: Rob Herring <robh@kernel.org>
> Sent: Wednesday, October 28, 2020 10:42 PM
> To: Wan Mohamad, Wan Ahmad Zainie
> <wan.ahmad.zainie.wan.mohamad@intel.com>
> Cc: bhelgaas@google.com; lorenzo.pieralisi@arm.com; linux-
> pci@vger.kernel.org; devicetree@vger.kernel.org;
> andriy.shevchenko@linux.intel.com; mgross@linux.intel.com; Raja
> Subramanian, Lakshmi Bai <lakshmi.bai.raja.subramanian@intel.com>
> Subject: Re: [PATCH 1/2] dt-bindings: PCI: Add Intel Keem Bay PCIe controller
> 
> On Tue, Oct 27, 2020 at 02:00:10PM +0800, Wan Ahmad Zainie wrote:
> > Document DT bindings for PCIe controller found on Intel Keem Bay SoC.
> >
> > Signed-off-by: Wan Ahmad Zainie
> > <wan.ahmad.zainie.wan.mohamad@intel.com>
> > ---
> >  .../bindings/pci/intel,keembay-pcie-ep.yaml   |  86 +++++++++++++
> >  .../bindings/pci/intel,keembay-pcie.yaml      | 120 ++++++++++++++++++
> >  2 files changed, 206 insertions(+)
> >  create mode 100644
> > Documentation/devicetree/bindings/pci/intel,keembay-pcie-ep.yaml
> >  create mode 100644
> > Documentation/devicetree/bindings/pci/intel,keembay-pcie.yaml
> >
> > diff --git
> > a/Documentation/devicetree/bindings/pci/intel,keembay-pcie-ep.yaml
> > b/Documentation/devicetree/bindings/pci/intel,keembay-pcie-ep.yaml
> > new file mode 100644
> > index 000000000000..11962c205744
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/intel,keembay-pcie-
> ep.yaml
> > @@ -0,0 +1,86 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: "http://devicetree.org/schemas/pci/intel,keembay-pcie-ep.yaml#"
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +
> > +title: Intel Keem Bay PCIe EP controller
> > +
> > +maintainers:
> > +  - Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
> > +
> > +properties:
> > +  compatible:
> > +      const: intel,keembay-pcie-ep

Fixed in v2, wrong indentation as per report.

> > +
> > +  reg:
> > +    items:
> > +      - description: DesignWare PCIe registers
> > +      - description: PCIe configuration space
> > +      - description: Keem Bay specific registers
> > +
> > +  reg-names:
> > +    items:
> > +      - const: dbi
> > +      - const: addr_space
> > +      - const: apb
> > +
> > +  interrupts:
> > +    items:
> > +      - description: PCIe interrupt
> > +      - description: PCIe event interrupt
> > +      - description: PCIe error interrupt
> > +      - description: PCIe memory access interrupt
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: intr
> > +      - const: ev_intr
> > +      - const: err_intr
> > +      - const: mem_access_intr
> 
> '_intr' is redundant. Drop it. You'll need a better name for the first one
> though.

I will drop _intr in v2.
I will send out once I get suitable name from Keem Bay data book.

> 
> > +
> > +  num-ib-windows:
> > +    description: Number of inbound address translation windows
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  num-ob-windows:
> > +    description: Number of outbound address translation windows
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +
> > +  num-lanes:
> > +    description: Number of lanes to use.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    enum: [ 1, 2, 4, 8 ]
> > +
> > +required:
> > +  - compatible
> > +  - reg
> > +  - reg-names
> > +  - interrupts
> > +  - interrupt-names
> > +  - num-ib-windows
> > +  - num-ob-windows
> > +
> > +additionalProperties: false
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +  - |
> > +    pcie-ep@37000000 {
> > +          compatible = "intel,keembay-pcie-ep";
> > +          reg = <0x37000000 0x00800000>,
> > +                <0x36000000 0x01000000>,
> > +                <0x37800000 0x00000200>;
> > +          reg-names = "dbi", "addr_space", "apb";
> > +          interrupts = <GIC_SPI 107 IRQ_TYPE_LEVEL_HIGH>,
> > +                       <GIC_SPI 108 IRQ_TYPE_EDGE_RISING>,
> > +                       <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>,
> > +                       <GIC_SPI 110 IRQ_TYPE_LEVEL_HIGH>;
> > +          interrupt-names = "intr", "ev_intr", "err_intr",
> > +                       "mem_access_intr";
> > +          num-ib-windows = <4>;
> > +          num-ob-windows = <4>;
> > +          num-lanes = <2>;
> > +    };
> > diff --git
> > a/Documentation/devicetree/bindings/pci/intel,keembay-pcie.yaml
> > b/Documentation/devicetree/bindings/pci/intel,keembay-pcie.yaml
> > new file mode 100644
> > index 000000000000..49e5d3d35bd4
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/pci/intel,keembay-pcie.yaml
> > @@ -0,0 +1,120 @@
> > +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) %YAML 1.2
> > +---
> > +$id: "http://devicetree.org/schemas/pci/intel,keembay-pcie.yaml#"
> > +$schema: "http://devicetree.org/meta-schemas/core.yaml#"
> > +
> > +title: Intel Keem Bay PCIe RC controller
> > +
> > +maintainers:
> > +  - Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
> > +
> > +allOf:
> > +  - $ref: /schemas/pci/pci-bus.yaml#
> > +
> > +properties:
> > +  compatible:
> > +      const: intel,keembay-pcie

Wrong indentation as per report.
I will fix in v2.

> 
> > +
> > +  device_type:
> > +    const: pci
> > +
> > +  "#address-cells":
> > +    const: 3
> > +
> > +  "#size-cells":
> > +    const: 2
> 
> Can drop these 3 as pci-bus.yaml defines them.

I will drop these 3 in v2.

> 
> > +
> > +  ranges:
> > +    maxItems: 1
> > +
> > +  reset-gpios:
> > +    maxItems: 1
> > +
> > +  reg:
> > +    items:
> > +      - description: DesignWare PCIe registers
> > +      - description: PCIe configuration space
> > +      - description: Keem Bay specific registers
> > +
> > +  reg-names:
> > +    items:
> > +      - const: dbi
> > +      - const: config
> > +      - const: apb
> > +
> > +  clocks:
> > +    items:
> > +      - description: bus clock
> > +      - description: auxiliary clock
> 
> The EP doesn't have clocks? You should have roughly the same resources for
> RC and EP modes.

For Keem Bay, EP mode link initialization is done in boot firmware.
This include setup the clocks.
That's why I do not include clocks for EP.

> 
> > +
> > +  clock-names:
> > +    items:
> > +      - const: master
> > +      - const: aux
> > +
> > +  interrupts:
> > +    items:
> > +      - description: PCIe interrupt
> > +      - description: PCIe event interrupt
> > +      - description: PCIe error interrupt
> > +
> > +  interrupt-names:
> > +    items:
> > +      - const: intr
> > +      - const: ev_intr
> > +      - const: err_intr
> > +
> > +  num-lanes:
> > +    description: Number of lanes to use.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    enum: [ 1, 2, 4, 8 ]
> > +
> > +  num-viewport:
> > +    description: Number of view ports configured in hardware.
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    default: 2
> 
> Pretty sure it's not 2 if num-ib-windows and num-ob-windows are 4.

As per pcie-designware-host.c, default value is 2, if it is not set.
My example and the DT in my system is 4.
I will fix in v2, by using const: 4.
Should I drop default?

> 
> > +
> > +required:
> > +  - compatible
> 
> > +  - device_type
> > +  - "#address-cells"
> > +  - "#size-cells"
> 
> Can drop these too.

I will drop them in v2.

> 
> > +  - reg
> > +  - reg-names
> > +  - ranges
> > +  - clocks
> > +  - interrupts
> > +  - interrupt-names
> > +  - reset-gpios
> > +
> > +additionalProperties: false
> 
> Use 'unevaluatedProperties: false' instead.

I will fix in v2.

> 
> > +
> > +examples:
> > +  - |
> > +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> > +    #include <dt-bindings/interrupt-controller/irq.h>
> > +    #include <dt-bindings/gpio/gpio.h>
> > +    #define KEEM_BAY_A53_PCIE
> > +    #define KEEM_BAY_A53_AUX_PCIE
> > +    pcie@37000000 {
> > +          compatible = "intel,keembay-pcie";
> > +          reg = <0x37000000 0x00800000>,
> > +                <0x36e00000 0x00200000>,
> > +                <0x37800000 0x00000200>;
> > +          reg-names = "dbi", "config", "apb";
> > +          #address-cells = <3>;
> > +          #size-cells = <2>;
> > +          device_type = "pci";
> > +          ranges = <0x02000000 0 0x36000000 0x36000000 0 0x00e00000>;
> > +          interrupts = <GIC_SPI 107 IRQ_TYPE_LEVEL_HIGH>,
> > +                       <GIC_SPI 108 IRQ_TYPE_LEVEL_HIGH>,
> > +                       <GIC_SPI 109 IRQ_TYPE_LEVEL_HIGH>;
> > +          interrupt-names = "intr", "ev_intr", "err_intr";
> > +          clocks = <&scmi_clk KEEM_BAY_A53_PCIE>,
> > +                   <&scmi_clk KEEM_BAY_A53_AUX_PCIE>;
> > +          clock-names = "master", "aux";
> > +          reset-gpios = <&pca2 9 GPIO_ACTIVE_LOW>;
> > +          num-viewport = <4>;
> > +          num-lanes = <2>;
> > +    };
> > --
> > 2.17.1
> >

Best regards,
Zainie