Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758114AbaAKAMl (ORCPT ); Fri, 10 Jan 2014 19:12:41 -0500 Received: from exprod5og105.obsmtp.com ([64.18.0.180]:38464 "HELO exprod5og105.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753574AbaAKAMg (ORCPT ); Fri, 10 Jan 2014 19:12:36 -0500 MIME-Version: 1.0 In-Reply-To: <201401071635.02006.arnd@arndb.de> References: <1387785725-24262-1-git-send-email-tinamdar@apm.com> <201401031049.20932.arnd@arndb.de> <201401071635.02006.arnd@arndb.de> Date: Fri, 10 Jan 2014 16:12:34 -0800 Message-ID: Subject: Re: [RFC PATCH 3/3] dt-bindings: pci: xgene pcie device tree bindings From: Tanmay Inamdar To: Arnd Bergmann Cc: "linux-arm-kernel@lists.infradead.org" , Bjorn Helgaas , Grant Likely , Catalin Marinas , Rob Landley , devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-pci@vger.kernel.org, patches , "linux-kernel@vger.kernel.org" , Jon Masters Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 7, 2014 at 7:35 AM, Arnd Bergmann wrote: > On Tuesday 07 January 2014, Tanmay Inamdar wrote: >> On Fri, Jan 3, 2014 at 1:49 AM, Arnd Bergmann wrote: >> >> +Required properties: >> >> +- status: Either "ok" or "disabled". >> >> +- device_type: set to "pci" >> >> +- compatible: should contain "xgene,pcie" to identify the core. >> >> +- reg: base addresses and lengths of the pcie controller configuration >> >> + space register. >> >> +- #address-cells: set to <3> >> >> +- #size-cells: set to <2> >> >> +- ranges: ranges for the PCI memory, I/O regions, config and MSI regions >> >> +- #interrupt-cells: set to <1> >> >> +- interrupt-map-mask and interrupt-map: standard PCI properties >> >> + to define the mapping of the PCIe interface to interrupt >> >> + numbers. >> >> +- clocks: from common clock binding: handle to pci clock. >> >> +- clock-names: from common clock binding. Should be "pcieclk". >> >> + >> > >> > Better use an anonymous clock? >> >> Sorry. Can you please elaborate? > > I mean drop the "clock-names" property. > Did you mean clock-names in pcie-clock node or pcie node? I can drop clock-names from pcie clock node. However if I drop clock-names from pcie node, then clk_get call from pcie host driver would result in failure. Right? >> >> +SoC specific DT Entry: >> >> + pcie0: pcie@1f2b0000 { >> >> + status = "disabled"; >> >> + device_type = "pci"; >> >> + compatible = "xgene,pcie"; >> >> + #interrupt-cells = <1>; >> >> + #size-cells = <2>; >> >> + #address-cells = <3>; >> >> + reg = < 0x00 0x1f2b0000 0x0 0x00010000>; >> >> + ranges = <0x02000000 0x0 0x00000000 0xe0 0x00000000 0x0 0x10000000 /* mem*/ >> > >> > >> > Also, do you support no prefetchable memory? >> >> HW has either IO or Memory regions for mapping device's memory space. >> There is no separate prefetchable memory space. > > Are you sure the memory is non-prefetchable then? I would have expected > 0x42000000 rather than 0x02000000, but I could be misremembering it. > >> > >> >> + 0x00000000 0x0 0xd0000000 0xe0 0xd0000000 0x0 0x00200000 /* cfg */ >> > >> > config space is not normally in the ranges property, and I think you will need >> > it in the pcie node itself as a 'reg' property so the code can access it. >> >> pcie-designware.c does it that way. I just followed their implementation. > > I don't remember what led to that, it still seems wrong and I can't find anything > in the PCI binding for host bridges telling their config space this way. > >> >> + interrupt-map-mask = <0x0 0x0 0x0 0x7>; >> >> + interrupt-map = <0x0 0x0 0x0 0x1 &gic 0x0 0xc2 0x1>; >> > >> > Only one IRQ for all devices? >> >> The node represents a port. I believe that Linux framework uses only >> one of the legacy IRQs per port. Rest all remain unused. Hence I >> removed them. Please correct me if I am wrong. > > Any PCI device can normally have four interrupts (IntA through IntD), which are > traditionally separate pins on a PCI bus, but get emulated on PCIe. While it's > not common for any normal device to use more than one IRQ, a bridge device > will swizzle these (virtual) IRQ lines, so a device behind the bridge actually > gets a different host IRQ. > > Arnd -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/