Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932799AbbENKJ4 (ORCPT ); Thu, 14 May 2015 06:09:56 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:19337 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932484AbbENKJy (ORCPT ); Thu, 14 May 2015 06:09:54 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 14 May 2015 03:07:25 -0700 Message-ID: <5554746A.4000608@nvidia.com> Date: Thu, 14 May 2015 11:09:46 +0100 From: Jon Hunter User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Lee Jones , Thierry Reding CC: Andrew Bresticker , Stephen Warren , Alexandre Courbot , , , , , , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Samuel Ortiz Subject: Re: [PATCH v8 4/9] mfd: Add binding document for NVIDIA Tegra XUSB References: <1430761002-9327-1-git-send-email-abrestic@chromium.org> <1430761002-9327-5-git-send-email-abrestic@chromium.org> <20150513143954.GA3394@x1> <55544CC5.9050001@nvidia.com> <20150514074058.GA22418@x1> <55546767.90501@nvidia.com> <20150514093042.GG22418@x1> In-Reply-To: <20150514093042.GG22418@x1> X-Originating-IP: [10.21.134.107] X-ClientProxiedBy: UKMAIL101.nvidia.com (10.26.138.13) To UKMAIL101.nvidia.com (10.26.138.13) Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6297 Lines: 165 On 14/05/15 10:30, Lee Jones wrote: > On Thu, 14 May 2015, Jon Hunter wrote: >> On 14/05/15 08:40, Lee Jones wrote: >>> On Thu, 14 May 2015, Jon Hunter wrote: >>>> On 13/05/15 15:39, Lee Jones wrote: >>>>> On Mon, 04 May 2015, Andrew Bresticker wrote: >>>>> >>>>>> Add a binding document for the XUSB host complex on NVIDIA Tegra124 >>>>>> and later SoCs. The XUSB host complex includes a mailbox for >>>>>> communication with the XUSB micro-controller and an xHCI host-controller. >>>>>> >>>>>> Signed-off-by: Andrew Bresticker >>>>>> Cc: Rob Herring >>>>>> Cc: Pawel Moll >>>>>> Cc: Mark Rutland >>>>>> Cc: Ian Campbell >>>>>> Cc: Kumar Gala >>>>>> Cc: Samuel Ortiz >>>>>> Cc: Lee Jones >>>>>> --- >>>>>> Changes from v7: >>>>>> - Move non-shared resources into child nodes. >>>>>> New for v7. >>>>>> --- >>>>>> .../bindings/mfd/nvidia,tegra124-xusb.txt | 37 ++++++++++++++++++++++ >>>>>> 1 file changed, 37 insertions(+) >>>>>> create mode 100644 Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt >>>>>> >>>>>> diff --git a/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt b/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt >>>>>> new file mode 100644 >>>>>> index 0000000..bc50110 >>>>>> --- /dev/null >>>>>> +++ b/Documentation/devicetree/bindings/mfd/nvidia,tegra124-xusb.txt >>>>>> @@ -0,0 +1,37 @@ >>>>>> +NVIDIA Tegra XUSB host copmlex >>>>>> +============================== >>>>>> + >>>>>> +The XUSB host complex on Tegra124 and later SoCs contains an xHCI host >>>>>> +controller and a mailbox for communication with the XUSB micro-controller. >>>>>> + >>>>>> +Required properties: >>>>>> +-------------------- >>>>>> + - compatible: For Tegra124, must contain "nvidia,tegra124-xusb". >>>>>> + Otherwise, must contain '"nvidia,-xusb", "nvidia,tegra124-xusb"' >>>>>> + where is tegra132. >>>>>> + - reg: Must contain the base and length of the XUSB FPCI registers. >>>>>> + - ranges: Bus address mapping for the XUSB block. Can be empty since the >>>>>> + mapping is 1:1. >>>>>> + - #address-cells: Must be 2. >>>>>> + - #size-cells: Must be 2. >>>>>> + >>>>>> +Example: >>>>>> +-------- >>>>>> + usb@0,70098000 { >>>>>> + compatible = "nvidia,tegra124-xusb"; >>>>>> + reg = <0x0 0x70098000 0x0 0x1000>; >>>>>> + ranges; >>>>>> + >>>>>> + #address-cells = <2>; >>>>>> + #size-cells = <2>; >>>>>> + >>>>>> + usb-host@0,70090000 { >>>>>> + compatible = "nvidia,tegra124-xhci"; >>>>>> + ... >>>>>> + }; >>>>>> + >>>>>> + mailbox { >>>>>> + compatible = "nvidia,tegra124-xusb-mbox"; >>>>>> + ... >>>>>> + }; >>>>> >>>>> This doesn't appear to be a proper MFD. I would have the USB and >>>>> Mailbox devices probe seperately and use a phandle to point the USB >>>>> device to its Mailbox. >>>>> >>>>> usb@xyz { >>>>> mboxes = <&xusb-mailbox, [chan]>; >>>>> }; >>>>> >>>> >>>> I am assuming that Andrew had laid it out like this to reflect the hw >>>> structure. The mailbox and xhci controller are part of the xusb >>>> sub-system and hence appear as child nodes. My understanding is that for >>>> device-tree we want the device-tree structure to reflect the actual hw. >>>> Is this not the case? >>> >>> Yes, the DT files should reflect h/w. I have requested to see what >>> the memory map looks like, so I might provide a more appropriate >>> solution to accepting a pretty pointless MFD. >> >> For the xusb-host has memory from 0x7009000 - 0x7009ffff. >> >> Within this range, we have this fpci range which is defined as 0x7009800 >> - 0x70098fff. This range is being shared between the mailbox and xhci >> drivers. Looking at the drivers, we have ... >> >> mailbox uses: 0x700980e0 - 0x700980f3 and 0x70098428 - 0x7009842b. >> xhci uses: 0x70098000 - 0x700980cf and 0x70098800 - 0x70098803. >> >> So it is a bit messy as they overlap. However, we could have ... >> >> xusb_mbox: mailbox { >> compatible = "nvidia,tegra124-xusb-mbox"; >> reg = <0x0 0x700980e0 0x0 0x14>, >> <0x0 0x70098428 0x0 0x4>; >> ... >> }; >> usb-host@0,70090000 { >> compatible = "nvidia,tegra124-xhci"; >> reg = <0x0 0x70090000 0x0 0x8000>, >> <0x0 0x70098000 0x0 0x00d0>; >> <0x0 0x70098800 0x0 0x0004>; >> <0x0 0x70099000 0x0 0x1000>; >> ... >> }; >> >> I believe that Thierry and Stephen said that they wished to avoid >> multiple devices sharing the same memory ranges, and so we would need to >> divvy up the memory map as above. However, I am not sure if this is an >> ok thing to do. >> >>> Two solutions spring to mind. You can either call >>> of_platform_populate() from the USB driver, as some already do: >>> >>> drivers/usb/dwc3/dwc3-exynos.c: >>> ret = of_platform_populate(node, NULL, NULL, dev); >>> drivers/usb/dwc3/dwc3-keystone.c: >>> error = of_platform_populate(node, NULL, NULL, dev); >>> drivers/usb/dwc3/dwc3-omap.c: >>> ret = of_platform_populate(node, NULL, NULL, dev); >>> drivers/usb/dwc3/dwc3-qcom.c: >>> ret = of_platform_populate(node, NULL, NULL, qdwc->dev); >>> drivers/usb/dwc3/dwc3-st.c: >>> ret = of_platform_populate(node, NULL, NULL, dev); >>> drivers/usb/musb/musb_am335x.c: >>> ret = of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev); >>> >>> Or use the "simple-mfd", which is currently in -next: >>> >>> git show next/master:Documentation/devicetree/bindings/mfd/mfd.txt >> >> That is nice. Sounds like the "simple-bus" style of device but for an > > That's precisely what it does. FYI: You 'can' use "simple-bus" and it > will do the right thing, but as an MFD isn't really a bus, it was > decided to create something a little more fitting. > >> mfd. Based upon the above, let me know if you think we could use the >> "simple-mfd"? > > I do. :) Thanks Lee. Thierry, any objections on the above mem-mapping? Cheers Jon -- 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/