Re: [PATCH v4] pci-rcar-gen2: add device tree support

[Bjorn Helgaas <bhelgaas@google.com>]

[+cc Arnd]

On Tue, May 20, 2014 at 01:10:20AM +0400, Sergei Shtylyov wrote:
> From: Ben Dooks <ben.dooks@codethink.co.uk>
> 
> Add device tree probing support to the 'pci-rcar-gen2' driver.
> 
> Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
> [Sergei: numerous fixes/cleanups/additions]
> Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>

I'd like to see an ack from Simon (since it changes pci-rcar-gen2.c) and
Arnd (since he pointed out some issues with the devicetree binding).

Bjorn

> ---
> The patch is against the 'next' branch of Bjorn Helgaas' 'pci.git' repo.
> 
> Changes in version 4:
> - added the descriptions for the #{address|size|interrupt}-cells and
>   #interrupt-map[-mask] properties to the binding document;
> - added the interrupt-related properties to the example;
> - refreshed the patch.
> 
> Changes in version 3:
> - added "renesas,pci-r8a7791" to the possible "compatible" property values;
> - removed '#ifdef CONFIG_OF' around rcar_pci_of_match[] and hence of_match_ptr()
>   invocation too;
> - fixed trailing whitespace in the DT parsing code;
> - removed the wrong "renessas," prefix from the binding document's file name;
> - moved the PCI device sub-nodes from the board example to the SoC example;
> - fixed labels in the board example;
> - fixed grammar and punctuation in the binding document;
> - reworded the changelog, fixed the subject.
> 
> Changes in version 2:
> - merged the binding document from a separate patch;
> - moved to the "bus-range" property parsing;
> - added example to the binding document.
> 
>  Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt |   66 ++++++++++++++++
>  drivers/pci/host/pci-rcar-gen2.c                        |   31 +++++++
>  2 files changed, 95 insertions(+), 2 deletions(-)
> 
> Index: pci/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
> ===================================================================
> --- /dev/null
> +++ pci/Documentation/devicetree/bindings/pci/pci-rcar-gen2.txt
> @@ -0,0 +1,66 @@
> +Renesas AHB to PCI bridge
> +-------------------------
> +
> +This is the bridge used internally to connect the USB controllers to the
> +AHB. There is one bridge instance per USB port connected to the internal
> +OHCI and EHCI controllers.
> +
> +Required properties:
> +- compatible: "renesas,pci-r8a7790" for the R8A7790 SoC;
> +	      "renesas,pci-r8a7791" for the R8A7791 SoC.
> +- reg:	A list of physical regions to access the device: the first is
> +	the operational registers for the OHCI/EHCI controllers and the
> +	second is for the bridge configuration and control registers.
> +- interrupts: interrupt for the device.
> +- clocks: The reference to the device clock.
> +- bus-range: The PCI bus number range; as this is a single bus, the range
> +	     should be specified as the same value twice.
> +- #address-cells: must be 3.
> +- #size-cells: must be 2.
> +- #interrupt-cells: must be 1.
> +- interrupt-map: standard property used to define the mapping of the PCI
> +  interrupts to the GIC interrupts.
> +- interrupt-map-mask: standard property that helps to define the interrupt
> +  mapping.
> +
> +Example SoC configuration:
> +
> +	pci0: pci@ee090000  {
> +		compatible = "renesas,pci-r8a7790";
> +		clocks = <&mstp7_clks R8A7790_CLK_EHCI>;
> +		reg = <0x0 0xee090000 0x0 0xc00>,
> +		      <0x0 0xee080000 0x0 0x1100>;
> +		interrupts = <0 108 IRQ_TYPE_LEVEL_HIGH>;
> +		status = "disabled";
> +
> +		bus-range = <0 0>;
> +		#address-cells = <3>;
> +		#size-cells = <2>;
> +		#interrupt-cells = <1>;
> +		interrupt-map-mask = <0xff00 0 0 0x7>;
> +		interrupt-map = <0x0000 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
> +			      	 0x0800 0 0 1 &gic 0 108 IRQ_TYPE_LEVEL_HIGH
> +			      	 0x1000 0 0 2 &gic 0 108 IRQ_TYPE_LEVEL_HIGH>;
> +
> +		pci@0,1 {
> +			reg = <0x800 0 0 0 0>;
> +			device_type = "pci";
> +			phys = <&usbphy 0 0>;
> +			phy-names = "usb";
> +		};
> +
> +		pci@0,2 {
> +			reg = <0x1000 0 0 0 0>;
> +			device_type = "pci";
> +			phys = <&usbphy 0 0>;
> +			phy-names = "usb";
> +		};
> +	};
> +
> +Example board setup:
> +
> +&pci0 {
> +	status = "okay";
> +	pinctrl-0 = <&usb0_pins>;
> +	pinctrl-names = "default";
> +};
> Index: pci/drivers/pci/host/pci-rcar-gen2.c
> ===================================================================
> --- pci.orig/drivers/pci/host/pci-rcar-gen2.c
> +++ pci/drivers/pci/host/pci-rcar-gen2.c
> @@ -98,6 +98,7 @@ struct rcar_pci_priv {
>  	struct resource io_res;
>  	struct resource mem_res;
>  	struct resource *cfg_res;
> +	unsigned busnr;
>  	int irq;
>  	unsigned long window_size;
>  };
> @@ -312,8 +313,8 @@ static int rcar_pci_setup(int nr, struct
>  	pci_add_resource(&sys->resources, &priv->io_res);
>  	pci_add_resource(&sys->resources, &priv->mem_res);
>  
> -	/* Setup bus number based on platform device id */
> -	sys->busnr = to_platform_device(priv->dev)->id;
> +	/* Setup bus number based on platform device id / of bus-range */
> +	sys->busnr = priv->busnr;
>  	return 1;
>  }
>  
> @@ -366,6 +367,23 @@ static int rcar_pci_probe(struct platfor
>  
>  	priv->window_size = SZ_1G;
>  
> +	if (pdev->dev.of_node) {
> +		struct resource busnr;
> +		int ret;
> +
> +		ret = of_pci_parse_bus_range(pdev->dev.of_node, &busnr);
> +		if (ret < 0) {
> +			dev_err(&pdev->dev, "failed to parse bus-range\n");
> +			return ret;
> +		}
> +
> +		priv->busnr = busnr.start;
> +		if (busnr.end != busnr.start)
> +			dev_warn(&pdev->dev, "only one bus number supported\n");
> +	} else {
> +		priv->busnr = pdev->id;
> +	}
> +
>  	hw_private[0] = priv;
>  	memset(&hw, 0, sizeof(hw));
>  	hw.nr_controllers = ARRAY_SIZE(hw_private);
> @@ -377,11 +395,20 @@ static int rcar_pci_probe(struct platfor
>  	return 0;
>  }
>  
> +static struct of_device_id rcar_pci_of_match[] = {
> +	{ .compatible = "renesas,pci-r8a7790", },
> +	{ .compatible = "renesas,pci-r8a7791", },
> +	{ },
> +};
> +
> +MODULE_DEVICE_TABLE(of, rcar_pci_of_match);
> +
>  static struct platform_driver rcar_pci_driver = {
>  	.driver = {
>  		.name = "pci-rcar-gen2",
>  		.owner = THIS_MODULE,
>  		.suppress_bind_attrs = true,
> +		.of_match_table = rcar_pci_of_match,
>  	},
>  	.probe = rcar_pci_probe,
>  };