From: thierry.reding@avionic-design•de (Thierry Reding)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support
Date: Tue, 12 Jun 2012 19:20:41 +0200 [thread overview]
Message-ID: <20120612172041.GA28010@avionic-0098.adnet.avionic-design.de> (raw)
In-Reply-To: <4FD763C5.3090500@wwwdotorg.org>
* Stephen Warren wrote:
> On 06/12/2012 12:21 AM, Thierry Reding wrote:
> > * Stephen Warren wrote:
> >> On 06/11/2012 09:05 AM, Thierry Reding wrote:
> >>> This commit adds support for instantiating the Tegra PCIe
> >>> controller from a device tree.
> >>
> >>> +++ b/Documentation/devicetree/bindings/pci/tegra-pcie.txt
> >>
> >> Can we please name this nvidia,tegra20-pcie.txt to match the
> >> naming of all the other Tegra bindings.
> >
> > Yes, will do.
> >
> >>> +Required properties: +- compatible: "nvidia,tegra20-pcie" +-
> >>> reg: physical base address and length of the controller's
> >>> registers
> >>
> >> Since there's more than one range now, that should specify how
> >> many entries are required and what they represent.
> >
> > Okay.
> >
> >>> +Optional properties: +- pex-clk-supply: supply voltage for
> >>> internal reference clock +- vdd-supply: power supply for
> >>> controller (1.05V)
> >>
> >> Those shouldn't be optional. If the board has no regulator, the
> >> board's .dts should provide a fixed always-on regulator that
> >> those properties can refer to, so that the driver can always
> >> get() those regulators.
> >
> > That'll add more dummy regulators and I don't think sprinkling them
> > across the DTS is going to work very well. Maybe collecting them
> > under a top-level "regulators" node is a good option. If you have a
> > better alternative, I'm all open for it.
> >
> >>> diff --git a/arch/arm/boot/dts/tegra20.dtsi
> >>> b/arch/arm/boot/dts/tegra20.dtsi
> >>
> >>> + pci {
> >> ...
> >>> + status = "disable";
> >>
> >> That should be "disabled"; sorry for providing a bad example.
> >
> > Yes.
> >
> >>> diff --git a/arch/arm/mach-tegra/pcie.c
> >>> b/arch/arm/mach-tegra/pcie.c
> >>
> >>> +static struct tegra_pcie_pdata *tegra_pcie_parse_dt(struct
> >>> platform_device *pdev)
> >>
> >>> + if (of_find_property(node, "vdd-supply", NULL)) {
> >>
> >> As mentioned above, that if statement should be removed, since
> >> the regulators shouldn't be optional.
> >
> > Okay.
> >
> >>> + pcie->vdd_supply = regulator_get(&pdev->dev, "vdd");
> >>
> >> Those could be devm_regulator_get(). Then tegra_pcie_remove()
> >> wouldn't have to put() them.
> >
> > Okay.
> >
> >>> + for (i = 0; i < TEGRA_PCIE_MAX_PORTS; i++) +
> >>> pdata->enable_ports[i] = true;
> >>
> >> Shouldn't the DT indicate which ports are used? I assume there's
> >> some reason that the existing driver allows that to be
> >> configured, rather than always enabling all ports. At least,
> >> enumeration time wasted on non-existent ports springs to mind,
> >> and perhaps attempting to enable port 1 when port 0 is x4 and
> >> using all the lanes would cause errors in port 0?
> >
> > Yes, that's been on my mind as well. I'm not sure about the best
> > binding for this. Perhaps something like:
> >
> > pci { enable-ports = <0 1 2>; };
> >
> > Would do?
>
> That seems reasonable, although since the property is presumably
> something specific to the Tegra PCIe binding, not generic, I think it
> should be nvidia,enable-ports.
I came up with the following alternative:
pci {
compatible = "nvidia,tegra20-pcie";
reg = <0x80003000 0x00000800 /* PADS registers */
0x80003800 0x00000200 /* AFI registers */
0x80004000 0x00100000 /* configuration space */
0x80104000 0x00100000 /* extended configuration space */
0x80400000 0x00010000 /* downstream I/O */
0x90000000 0x10000000 /* non-prefetchable memory */
0xa0000000 0x10000000>; /* prefetchable memory */
interrupts = <0 98 0x04 /* controller interrupt */
0 99 0x04>; /* MSI interrupt */
status = "disabled";
ranges = <0x80000000 0x80000000 0x00002000 /* 2 root ports */
0x80004000 0x80004000 0x00100000 /* configuration space */
0x80104000 0x80104000 0x00100000 /* extended configuration space */
0x80400000 0x80400000 0x00010000 /* downstream I/O */
0x90000000 0x90000000 0x10000000 /* non-prefetchable memory */
0xa0000000 0xa0000000 0x10000000>; /* prefetchable memory */
#address-cells = <1>;
#size-cells = <1>;
port at 80000000 {
reg = <0x80000000 0x00001000>;
status = "disabled";
};
port at 80001000 {
reg = <0x80001000 0x00001000>;
status = "disabled";
};
};
The "ranges" property can probably be cleaned up a bit, but the most
interesting part is the port@ children, which can simply be enabled in board
DTS files by setting the status property to "okay". I find that somewhat more
intuitive to the variant with an "enable-ports" property.
What do you think of this?
Thierry
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next prev parent reply other threads:[~2012-06-12 17:20 UTC|newest]
Thread overview: 96+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-11 15:05 [PATCH v2 00/10] ARM: tegra: Add PCIe device tree support Thierry Reding
2012-06-11 15:05 ` [PATCH v2 01/10] PCI: Keep pci_fixup_irqs() around after init Thierry Reding
2012-06-11 15:05 ` [PATCH v2 02/10] ARM: pci: Keep pci_common_init() " Thierry Reding
2012-06-11 15:05 ` [PATCH v2 03/10] ARM: pci: Allow passing per-controller private data Thierry Reding
2012-06-11 15:05 ` [PATCH v2 04/10] ARM: tegra: Move tegra_pcie_xclk_clamp() to PMC Thierry Reding
2012-06-11 15:05 ` [PATCH v2 05/10] ARM: tegra: Rewrite PCIe support as a driver Thierry Reding
2012-06-11 21:09 ` Stephen Warren
2012-06-12 6:41 ` Thierry Reding
2012-06-12 7:24 ` Thierry Reding
2012-06-12 16:00 ` Stephen Warren
2012-06-13 8:12 ` Thierry Reding
2012-06-11 21:22 ` Stephen Warren
2012-06-12 4:59 ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 06/10] ARM: tegra: pcie: Add MSI support Thierry Reding
2012-06-11 21:19 ` Stephen Warren
2012-06-12 5:07 ` Thierry Reding
2012-06-12 5:33 ` Stephen Warren
2012-06-12 5:41 ` Thierry Reding
2012-06-12 6:10 ` Thierry Reding
2012-06-12 15:40 ` Stephen Warren
2012-06-12 17:23 ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 07/10] ARM: tegra: pcie: Add device tree support Thierry Reding
2012-06-11 21:33 ` Stephen Warren
2012-06-12 6:21 ` Thierry Reding
2012-06-12 15:44 ` Stephen Warren
2012-06-12 17:20 ` Thierry Reding [this message]
2012-06-12 19:10 ` Mitch Bradley
2012-06-12 19:46 ` Stephen Warren
2012-06-12 19:52 ` Mitch Bradley
2012-06-13 5:54 ` Thierry Reding
2012-06-13 7:04 ` Mitch Bradley
2012-06-12 20:15 ` Stephen Warren
2012-06-12 21:11 ` Mitch Bradley
2012-06-13 6:45 ` Thierry Reding
2012-06-13 7:28 ` Mitch Bradley
2012-06-13 7:52 ` Thierry Reding
2012-06-13 8:05 ` Mitch Bradley
2012-06-13 8:19 ` Thierry Reding
2012-06-13 8:36 ` Mitch Bradley
2012-06-13 8:42 ` Thierry Reding
2012-06-14 9:19 ` Thierry Reding
2012-06-14 18:30 ` Stephen Warren
2012-06-14 19:29 ` Thierry Reding
2012-06-14 19:50 ` Stephen Warren
2012-06-15 6:12 ` Thierry Reding
2012-06-19 13:30 ` Thierry Reding
2012-06-19 16:40 ` Stephen Warren
2012-06-19 21:31 ` Mitch Bradley
2012-06-20 16:32 ` Stephen Warren
2012-06-20 17:41 ` Mitch Bradley
2012-06-20 17:47 ` Stephen Warren
2012-06-20 19:57 ` Arnd Bergmann
2012-06-20 20:19 ` Mitch Bradley
2012-06-21 6:47 ` Thierry Reding
2012-06-22 10:18 ` Bjorn Helgaas
2012-06-22 11:00 ` Thierry Reding
2012-06-22 11:46 ` Bjorn Helgaas
2012-06-22 12:43 ` Thierry Reding
2012-06-22 13:03 ` Arnd Bergmann
2012-06-22 16:49 ` Bjorn Helgaas
2012-06-22 16:53 ` Arnd Bergmann
2012-06-22 17:13 ` Bjorn Helgaas
2012-06-22 21:08 ` Arnd Bergmann
2012-06-22 17:14 ` Arnd Bergmann
2012-06-22 17:00 ` Stephen Warren
2012-06-22 17:28 ` Stephen Warren
2012-06-23 21:35 ` Bjorn Helgaas
2012-06-25 6:34 ` Thierry Reding
2012-06-26 17:22 ` Stephen Warren
2012-06-27 6:19 ` Thierry Reding
2012-06-22 16:20 ` Stephen Warren
2012-06-22 17:09 ` Mitch Bradley
2012-06-22 11:04 ` Thierry Reding
2012-06-22 13:22 ` Thierry Reding
2012-06-22 13:48 ` Arnd Bergmann
2012-06-22 14:02 ` Thierry Reding
2012-06-22 16:40 ` Arnd Bergmann
2012-06-13 20:21 ` Arnd Bergmann
2012-06-14 8:37 ` Thierry Reding
2012-06-14 10:25 ` Arnd Bergmann
2012-06-14 10:31 ` Thierry Reding
2012-06-14 11:06 ` Arnd Bergmann
2012-06-14 11:58 ` Thierry Reding
2012-06-13 6:34 ` Thierry Reding
2012-06-13 16:20 ` Stephen Warren
2012-06-13 17:03 ` Stephen Warren
2012-06-11 15:05 ` [PATCH v2 08/10] ARM: tegra: harmony: Initialize regulators from DT Thierry Reding
2012-06-11 21:36 ` Stephen Warren
2012-06-12 6:13 ` Thierry Reding
2012-06-21 20:17 ` Stephen Warren
2012-06-22 6:06 ` Thierry Reding
2012-06-11 15:05 ` [PATCH v2 09/10] ARM: tegra: harmony: Initialize PCIe " Thierry Reding
2012-06-11 21:41 ` Stephen Warren
2012-06-12 5:48 ` Thierry Reding
2012-06-12 15:38 ` Stephen Warren
2012-06-11 15:05 ` [PATCH v2 10/10] ARM: tegra: trimslice: " Thierry Reding
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