From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH v0 06/10] arm: orion5x: Add DT-based support for Netgear WNR854T Date: Mon, 18 Jul 2016 12:06:26 +0200 Message-ID: <1792384.6N9lHjmBFc@wuerfel> References: <1468679348-10522-1-git-send-email-jm@lentin.co.uk> <6404488.GyOP57DJrV@wuerfel> <20160718114424.14a28889@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160718114424.14a28889@free-electrons.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Thomas Petazzoni Cc: Andrew Lunn , Florian Fainelli , Jason Cooper , devicetree@vger.kernel.org, netdev@vger.kernel.org, Jamie Lentin , linux-kernel@vger.kernel.org, Gregory Clement , Imre Kaloz , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth List-Id: devicetree@vger.kernel.org On Monday, July 18, 2016 11:44:24 AM CEST Thomas Petazzoni wrote: > > On Sun, 17 Jul 2016 22:41:35 +0200, Arnd Bergmann wrote: > > > I would assume that the PCIe port should work out of the box with the driver > > Unfortunately, no. The PCIe on Orion5x requires a workaround for > reading/writing the PCI configuration space. Instead of doing MMIO > accesses to PCIE_CONF_ADDR_OFF / PCIE_CONF_DATA_OFF, you must map a > MBus window, which provides a memory-mapped view of the PCI > configuration space. > > Definitely not impossible to implement, but the driver doesn't work > as-is. Ok. > > We also don't seem to need any MBUS window setup for the I/O and > > memory spaces, which greatly simplifies the driver compared to the > > pci-mvebu one, it would be a fairly straightforward implementation > > based on pci-host-generic.c (which unfortunately just got way > > more complicated and might need to go on a diet). > > MBus windows are needed. See: > > mvebu_mbus_add_window_remap_by_id(ORION_MBUS_PCI_IO_TARGET, > ORION_MBUS_PCI_IO_ATTR, > ORION5X_PCI_IO_PHYS_BASE, > ORION5X_PCI_IO_SIZE, > ORION5X_PCI_IO_BUS_BASE); > mvebu_mbus_add_window_by_id(ORION_MBUS_PCI_MEM_TARGET, > ORION_MBUS_PCI_MEM_ATTR, > ORION5X_PCI_MEM_PHYS_BASE, > ORION5X_PCI_MEM_SIZE); > > in orion5x_setup_wins(). Ok, I was just looking at the wrong file, as they are set up from common.c, not pci.c. > Note that we already have some Orion5x converted to DT, and that use > PCI: board-rd88f5182.c is an example. So we could very well take Jamie > patches as-is, and move later to a DT-representation for PCI/PCIe. Ah, I thought all the DT users were moved to mach-mvebu. I agree this new patch isn't introducing anything we don't already have then, so we can just take it, but the conversion will not be nice when we do that. I was also hoping that we could get to the point where pci_common_init() is only used for legacy machines without DT and without multiplatform, it seems I missed a couple of users here. Arnd