Re: [PATCH V4 2/5] arm/dt: add very basic dts file for babbage board

[Jason Hui <jason.hui-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>]

Hi, Shawn,

On Fri, Mar 11, 2011 at 2:56 PM, Shawn Guo <shawn.guo-KZfg59tc24xl57MIdRCFDg@public.gmane.org> wrote:
> Hi Jason,
>
> On Thu, Mar 10, 2011 at 12:59:42PM +0800, Jason Liu wrote:
>> Signed-off-by: Jason Liu <jason.hui-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>> Signed-off-by: Jason Liu <r64343-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
>> Singed-off-by: Rob Herring <robherring2-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
>> ---
>>  arch/arm/boot/dts/babbage.dts |  122 +++++++++++++++++++++++++++++++++++++++++
>>  1 files changed, 122 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/babbage.dts b/arch/arm/boot/dts/babbage.dts
>> new file mode 100644
>> index 0000000..ab87a1b
>> --- /dev/null
>> +++ b/arch/arm/boot/dts/babbage.dts
>> @@ -0,0 +1,122 @@
>> +/*
>> + * Copyright 2011 Linaro Ltd.
>> + * Copyright 2011 Freescale Semiconductor, Inc.
>> + *
>> + * The code contained herein is licensed under the GNU General Public
>> + * License. You may obtain a copy of the GNU General Public License
>> + * Version 2 or later at the following locations:
>> + *
>> + * http://www.opensource.org/licenses/gpl-license.html
>> + * http://www.gnu.org/copyleft/gpl.html
>> + */
>> +
>> +/dts-v1/;
>> +
>> +/ {
>> +     model = "Freescale i.MX51 Babbage";
>> +     compatible = "fsl,mx51-babbage";
>> +     #address-cells = <1>;
>> +     #size-cells = <1>;
>> +     #interrupt-cells = <1>;
>> +     interrupt-parent = <&tzic>;
>> +
>> +     memory {
>> +             reg = <0x90000000 0x20000000>;
>> +     };
>> +
>> +     chosen {
>> +             bootargs = "console=ttymxc0,115200n8 debug earlyprintk ip=dhcp";
>> +     };
>> +
>> +     soc {
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             compatible = "simple-bus";
>> +             ranges;
>> +
>> +             tzic: tz-interrupt-controller {
>> +                     #address-cells = <0>;
>> +                     #interrupt-cells = <1>;
>> +                     interrupt-controller;
>> +                     reg = <0xe0000000 0x1000>;
>> +                     compatible = "fsl,imx51-tzic";
>> +             };
>> +     };
>> +
>> +     clocks {
>> +             #address-cells = <1>;
>> +             #size-cells = <0>;
>> +
>> +             uart0_clk: uart0 {
>> +                     compatible = "clock";
>> +                     clock-outputs = "imx-uart.0";
>> +             };
>> +
>> +             uart1_clk: uart1 {
>> +                     compatible = "clock";
>> +                     clock-outputs = "imx-uart.1";
>> +             };
>> +
>> +             uart2_clk: uart2 {
>> +                     compatible = "clock";
>> +                     clock-outputs = "imx-uart.2";
>> +             };
>> +
>> +             fec_clk: fec {
>> +                     compatible = "clock";
>> +                     clock-outputs = "fec.0";
>> +             };
>> +     };
>> +
>> +     aips@73f00000 {
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             compatible = "simple-bus";
>> +             ranges = <0x0 0x73f00000 0x100000>;
>> +
>> +             imx-uart@bc000 {
>> +                     compatible = "fsl,imx51-uart";
>> +                     reg = <0xbc000 0x1000>;
>> +                     interrupts = <0x1f>;
>> +                     fsl,has-rts-cts;
>> +                     uart-clock = <&uart0_clk>, "uart";
>> +             };
>> +
>> +             imx-uart@c0000 {
>> +                     compatible = "fsl,imx51-uart";
>> +                     reg = <0xc0000 0x1000>;
>> +                     interrupts = <0x20>;
>> +                     fsl,has-rts-cts;
>> +                     uart-clock = <&uart1_clk>, "uart";
>> +             };
>> +     };
>> +
>> +     spba@70000000 {
>> +             #address-cells = <1>;
>> +             #size-cells = <1>;
>> +             compatible = "simple-bus";
>> +             ranges = <0x0 0x70000000 0x100000>;
>> +
>> +             imx-uart@c000 {
>> +                     compatible = "fsl,imx51-uart";
>> +                     reg = <0xc000 0x1000>;
>> +                     interrupts = <0x21>;
>> +                     fsl,has-rts-cts;
>> +                     uart-clock = <&uart2_clk>, "uart";
>> +             };
>> +     };
>> +
> Moving spba@70000000 section after aips@73f00000 seems a quick fix to
> get console=ttymxc0, but not a right fix to me.
>
> I do not find a real example on mx51, but let's make one, saying
> there are two instance of one IP block, xyz1 and xyz2, and xyz1 is on
> bus spba@70000000) while xyz2 is on bus apis@73f00000.  Your fix is
> broken here, as you need to put spba@70000000 after aips@73f00000 for
> uart driver, while xyz driver requires spba@70000000 stays before
> aips@73f00000.

No, I don't think so. Where the section is put is not one strict rule,
take a look at
powerpc dts file, you will see that.

>
> Also this quick fix is working for uart, but will not for some others,
> for example, eCSPI and SSI, which requires spba@70000000 even behind
> aips@83f00000 with your solution.

I don't see what's wrong with eCSPI and SSI when put spba behind aips
just like uart.
I will not take your comments.

BR,
Jason