[PATCH V4 4/6] arm64/ls1043a: add DTS for Freescale LS1043A SoC
Hou Zhiqiang
B48286 at freescale.com
Fri Oct 16 02:58:48 PDT 2015
> -----Original Message-----
> From: Sharma Bhupesh-B45370
> Sent: 2015年10月16日 13:12
> To: Hou Zhiqiang-B48286; Wood Scott-B07421
> Cc: linux-arm-kernel at lists.infradead.org; catalin.marinas at arm.com;
> will.deacon at arm.com; linux-i2c at vger.kernel.org; linux-
> watchdog at vger.kernel.org; linux-doc at vger.kernel.org; linux-
> clk at vger.kernel.org; mark.rutland at arm.com; linux at roeck-us.net; wsa at the-
> dreams.de; wim at iguana.be; corbet at lwn.net; mturquette at baylibre.com;
> sboyd at codeaurora.org; Hu Mingkai-B21284; Xie Shaohui-B21989; Song Wenbin-
> B53747; Li Yang-Leo-R58472
> Subject: RE: [PATCH V4 4/6] arm64/ls1043a: add DTS for Freescale LS1043A
> SoC
>
> > From: Hou Zhiqiang-B48286
> > Sent: Friday, October 16, 2015 9:07 AM
> >
> >
> > > -----Original Message-----
> > > From: Wood Scott-B07421
> > > Sent: 2015年10月16日 4:46
> > > To: Hou Zhiqiang-B48286
> > > Cc: linux-arm-kernel at lists.infradead.org; catalin.marinas at arm.com;
> > > will.deacon at arm.com; linux-i2c at vger.kernel.org; linux-
> > > watchdog at vger.kernel.org; linux-doc at vger.kernel.org; linux-
> > > clk at vger.kernel.org; mark.rutland at arm.com; linux at roeck-us.net;
> > > wsa at the- dreams.de; wim at iguana.be; corbet at lwn.net;
> > > mturquette at baylibre.com; sboyd at codeaurora.org; Hu Mingkai-B21284;
> > > Xie Shaohui-B21989; Sharma Bhupesh-B45370; Song Wenbin-B53747; Li
> > > Yang-Leo-R58472; Sharma Bhupesh-
> > > B45370
> > > Subject: Re: [PATCH V4 4/6] arm64/ls1043a: add DTS for Freescale
> > > LS1043A SoC
> > >
> > > On Thu, 2015-10-15 at 20:12 +0800, Zhiqiang Hou wrote:
> > > > From: Mingkai Hu <Mingkai.Hu at freescale.com>
> > > >
> > > > LS1043a is an SoC with 4 ARMv8 A53 cores and most other IP blocks
> > > > similar to LS1021a which complies to Chassis 2.1 spec.
> > > >
> > > > Following levels of DTSI/DTS files have been created for the
> > > > LS1043A SoC family:
> > > >
> > > > - fsl-ls1043a.dtsi:
> > > > DTS-Include file for FSL LS1043A SoC.
> > > >
> > > > Signed-off-by: Li Yang <leoli at freescale.com>
> > > > Signed-off-by: Hou Zhiqiang <B48286 at freescale.com>
> > > > Signed-off-by: Mingkai Hu <Mingkai.Hu at freescale.com>
> > > > Signed-off-by: Wenbin Song <Wenbin.Song at freescale.com>
> > > > ---
> > > > V4:
> > > > - Add soc node with simple-bus compatible.
> > > > - Add property interrupt-affinity for armv8 pmuv3 node.
> > > >
> > > > V3:
> > > > - Add device tree node for SATA.
> > > > - Remove properity enable-method for all cpu node.
> > > > Remove reserved memory region for spin-table.
> > > >
> > > > V2:
> > > > - Add secondary core boot method.
> > > > - Move out the sysclk node from the clockgen node.
> > > > - Correct the reg size of GICC.
> > > >
> > > > arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi | 525
> > > > +++++++++++++++++++++++++
> > > > 1 file changed, 525 insertions(+) create mode 100644
> > > > arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
> > > >
> > > > diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
> > > > b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
> > > > new file mode 100644
> > > > index 0000000..1a5bf79
> > > > --- /dev/null
> > > > +++ b/arch/arm64/boot/dts/freescale/fsl-ls1043a.dtsi
> > > > @@ -0,0 +1,525 @@
> > > > +/*
> > > > + * Device Tree Include file for Freescale Layerscape-1043A family
> > SoC.
> > > > + *
> > > > + * Copyright 2014-2015, Freescale Semiconductor
> > > > + *
> > > > + * Mingkai Hu <Mingkai.hu at freescale.com>
> > > > + *
> > > > + * This file is dual-licensed: you can use it either under the
> > > > +terms
> > > > + * of the GPLv2 or the X11 license, at your option. Note that
> > > > +this dual
> > > > + * licensing only applies to this file, and not this project as a
> > > > + * whole.
> > > > + *
> > > > + * a) This library is free software; you can redistribute it
> and/or
> > > > + * modify it under the terms of the GNU General Public License
> > as
> > > > + * published by the Free Software Foundation; either version 2
> > of
> > > the
> > > > + * License, or (at your option) any later version.
> > > > + *
> > > > + * This library is distributed in the hope that it will be
> > useful,
> > > > + * but WITHOUT ANY WARRANTY; without even the implied warranty
> > of
> > > > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
> the
> > > > + * GNU General Public License for more details.
> > > > + *
> > > > + * Or, alternatively,
> > > > + *
> > > > + * b) Permission is hereby granted, free of charge, to any person
> > > > + * obtaining a copy of this software and associated
> > documentation
> > > > + * files (the "Software"), to deal in the Software without
> > > > + * restriction, including without limitation the rights to use,
> > > > + * copy, modify, merge, publish, distribute, sublicense,
> and/or
> > > > + * sell copies of the Software, and to permit persons to whom
> > the
> > > > + * Software is furnished to do so, subject to the following
> > > > + * conditions:
> > > > + *
> > > > + * The above copyright notice and this permission notice shall
> > be
> > > > + * included in all copies or substantial portions of the
> > Software.
> > > > + *
> > > > + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
> > KIND,
> > > > + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
> > WARRANTIES
> > > > + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
> > > > + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
> > > > + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
> > > > + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
> ARISING
> > > > + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE
> OR
> > > > + * OTHER DEALINGS IN THE SOFTWARE.
> > > > + */
> > > > +
> > > > +/ {
> > > > + compatible = "fsl,ls1043a";
> > > > + interrupt-parent = <&gic>;
> > > > + #address-cells = <2>;
> > > > + #size-cells = <2>;
> > > > +
> > > > + cpus {
> > > > + #address-cells = <2>;
> > > > + #size-cells = <0>;
> > > > +
> > > > + /*
> > > > + * We expect the enable-method for cpu's to be
> > > > + "psci",
> > > but this
> > > > + * is dependent on the SoC FW, which will fill this
> in.
> > > > + *
> > > > + * Currently supported enable-method is psci v0.2
> > > > + */
> > > > + cpu0: cpu at 0{
> > > > + device_type = "cpu";
> > > > + compatible = "arm,cortex-a53";
> > > > + reg = <0x0 0x0>;
> > > > + clocks = <&clockgen 1 0>;
> > > > + };
> > > > +
> > > > + cpu1: cpu at 1{
> > > > + device_type = "cpu";
> > > > + compatible = "arm,cortex-a53";
> > > > + reg = <0x0 0x1>;
> > > > + clocks = <&clockgen 1 0>;
> > > > + };
> > > > +
> > > > + cpu2: cpu at 2{
> > > > + device_type = "cpu";
> > > > + compatible = "arm,cortex-a53";
> > > > + reg = <0x0 0x2>;
> > > > + clocks = <&clockgen 1 0>;
> > > > + };
> > > > +
> > > > + cpu3: cpu at 3{
> > > > + device_type = "cpu";
> > > > + compatible = "arm,cortex-a53";
> > > > + reg = <0x0 0x3>;
> > > > + clocks = <&clockgen 1 0>;
> > > > + };
> > > > + };
> > > > +
> > > > + memory at 80000000{
> > > > + device_type = "memory";
> > > > + reg = <0x0 0x80000000 0 0x80000000>;
> > > > + /* DRAM space 1, size: 2GiB DRAM */
> > > > + };
> > > > +
> > > > + sysclk: sysclk {
> > > > + compatible = "fixed-clock";
> > > > + #clock-cells = <0>;
> > > > + clock-frequency = <100000000>;
> > > > + clock-output-names = "sysclk";
> > > > + };
> > > > +
> > > > + soc {
> > > > + compatible = "simple-bus";
> > > > + #address-cells = <2>;
> > > > + #size-cells = <2>;
> > > > + ranges;
> > > > +
> > > > + clockgen: clocking at 1ee1000{
> > > > + compatible = "fsl,ls1043a-clockgen";
> > > > + reg = <0x0 0x1ee1000 0x0 0x1000>;
> > > > + #clock-cells = <2>;
> > > > + clocks = <&sysclk>;
> > > > + };
> > > > +
> > > > + timer {
> > > > + compatible = "arm,armv8-timer";
> > > > + interrupts = <1 13 0x1>, /* Physical Secure
> > > > + PPI
> > > */
> > > > + <1 14 0x1>, /* Physical
> > > > + Non-Secure
> > > PPI */
> > > > + <1 11 0x1>, /* Virtual PPI */
> > > > + <1 10 0x1>; /* Hypervisor PPI */
> > > > + };
> > > > +
> > > > + pmu {
> > > > + compatible = "arm,armv8-pmuv3";
> > > > + interrupts = <0 106 0x4>,
> > > > + <0 107 0x4>,
> > > > + <0 95 0x4>,
> > > > + <0 97 0x4>;
> > > > + interrupt-affinity = <&cpu0>,
> > > > + <&cpu1>,
> > > > + <&cpu2>,
> > > > + <&cpu3>;
> > > > + };
> > > > +
> > > > + gic: interrupt-controller at 1400000{
> > > > + compatible = "arm,gic-400";
> > > > + #interrupt-cells = <3>;
> > > > + interrupt-controller;
> > > > + reg = <0x0 0x1401000 0 0x1000>, /* GICD */
> > > > + <0x0 0x1402000 0 0x2000>, /* GICC */
> > > > + <0x0 0x1404000 0 0x2000>, /* GICH */
> > > > + <0x0 0x1406000 0 0x2000>; /* GICV */
> > > > + interrupts = <1 9 0xf08>;
> > > > + };
> > >
> > > The recently posted ls2080 device tree patch puts pmu, gic, etc.
> > > under the root node rather than the soc node. Where should they go?
> > > At least it should be consistent...
> >
> > Why treat pmu, gic and timer as special? Who can explain it?
> > I find some venders put the gic and/or timer node under the soc node,
> > such as arch/arm64/boot/dts/marvell/berlin4ct.dtsi,
> > arch/arm64/boot/dts/mediatek/mt8173.dtsi and
> > arch/arm64/boot/dts/qcom/msm8916.dtsi.
> > So I put them underneath the soc node.
>
> As you said it depends on your SOC architecture and bus layout.
>
> 1. ARMv8 timer is a per-core timer with a global timebase, so it doesn't
> make much sense to place it under /soc node as we don't keep /cpus under
> the /soc node as well
>
> 2. Similarly for GIC and Timer.
>
> However, your SoC bus layout might be different. So if you have exact
> idea of the bus layout for your SoC, better to use exact names like AHB,
> APB and AXI.
>
Thanks for your clarify.
> Refer to IMX28 bus organization example (slide 24/45) in 'device-tree for
> dummies pdf' [1]
>
> [1]
> https://events.linuxfoundation.org/sites/events/files/slides/petazzoni-
> device-tree-dummies.pdf
Thanks,
Zhiqiang
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