From: Aaron Sierra Date: Tue, 26 Aug 2014 21:46:11 +0000 (-0500) Subject: powerpc: fsl_pci: Add forced PCI Agent enumeration X-Git-Tag: v4.9.8~5473^2~44^2~19 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=00406e8772c61feb57c1baeb97531aa199614e65;p=platform%2Fkernel%2Flinux-rpi3.git powerpc: fsl_pci: Add forced PCI Agent enumeration The following commit prevents the MPC8548E on the XPedite5200 PrPMC module from enumerating its PCI/PCI-X bus: powerpc/fsl-pci: use 'Header Type' to identify PCIE mode The previous patch prevents any Freescale PCI-X bridge from enumerating the bus, if it is hardware strapped into Agent mode. In PCI-X, the Host is responsible for driving the PCI-X initialization pattern to devices on the bus, so that they know whether to operate in conventional PCI or PCI-X mode as well as what the bus timing will be. For a PCI-X PrPMC, the pattern is driven by the mezzanine carrier it is installed onto. Therefore, PrPMCs are PCI-X Agents, but one per system may still enumerate the bus. This patch causes the device node of any PCI/PCI-X bridge strapped into Agent mode to be checked for the fsl,pci-agent-force-enum property. If the property is present in the node, the bridge will be allowed to enumerate the bus. Cc: Minghuan Lian Signed-off-by: Aaron Sierra Signed-off-by: Scott Wood --- diff --git a/Documentation/devicetree/bindings/pci/fsl,pci.txt b/Documentation/devicetree/bindings/pci/fsl,pci.txt new file mode 100644 index 0000000..d8ac4a7 --- /dev/null +++ b/Documentation/devicetree/bindings/pci/fsl,pci.txt @@ -0,0 +1,27 @@ +* Bus Enumeration by Freescale PCI-X Agent + +Typically any Freescale PCI-X bridge hardware strapped into Agent mode +is prevented from enumerating the bus. The PrPMC form-factor requires +all mezzanines to be PCI-X Agents, but one per system may still +enumerate the bus. + +The property defined below will allow a PCI-X bridge to be used for bus +enumeration despite being strapped into Agent mode. + +Required properties: +- fsl,pci-agent-force-enum : There is no value associated with this + property. The property itself is treated as a boolean. + +Example: + + /* PCI-X bridge known to be PrPMC Monarch */ + pci0: pci@ef008000 { + fsl,pci-agent-force-enum; + #interrupt-cells = <1>; + #size-cells = <2>; + #address-cells = <3>; + compatible = "fsl,mpc8540-pcix", "fsl,mpc8540-pci"; + device_type = "pci"; + ... + ... + }; diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c index c507767..65d2ed4 100644 --- a/arch/powerpc/sysdev/fsl_pci.c +++ b/arch/powerpc/sysdev/fsl_pci.c @@ -522,7 +522,8 @@ int fsl_add_bridge(struct platform_device *pdev, int is_primary) } else { /* For PCI read PROG to identify controller mode */ early_read_config_byte(hose, 0, 0, PCI_CLASS_PROG, &progif); - if ((progif & 1) == 1) + if ((progif & 1) && + !of_property_read_bool(dev, "fsl,pci-agent-force-enum")) goto no_bridge; }