Re: [PATCH] ARM: DT: stm32: move dma translation to board files

[Alexandre Torgue <alexandre.torgue@st.com>]

Hi Bruno,

On 10/27/2016 12:43 PM, Bruno Herrera wrote:
> Hi Alex,
>
> On Wed, Oct 26, 2016 at 7:09 AM, Alexandre Torgue
> <alexandre.torgue@st.com> wrote:
>> Hi Bruno,
>>
>> On 10/25/2016 11:06 PM, Bruno Herrera wrote:
>>>
>>> Hi Alexandre,
>>>
>>>>
>>>> stm32f469-disco and stm32f429-eval boards use SDRAM start address
>>>> remapping
>>>> (to @0) to boost performances. A DMA translation through "dma-ranges"
>>>> property was needed for other masters than the M4 CPU.
>>>> stm32f429-disco doesn't use remapping so doesn't need this DMA
>>>> translation.
>>>> This patches moves this DMA translation definition from stm32f429 soc
>>>> file
>>>> to board files.
>>>>
>>>> Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>
>>>>
>>>> diff --git a/arch/arm/boot/dts/stm32429i-eval.dts
>>>> b/arch/arm/boot/dts/stm32429i-eval.dts
>>>> index 13c7cd2..a763c15 100644
>>>> --- a/arch/arm/boot/dts/stm32429i-eval.dts
>>>> +++ b/arch/arm/boot/dts/stm32429i-eval.dts
>>>> @@ -82,6 +82,10 @@
>>>>                 };
>>>>         };
>>>>
>>>> +       soc {
>>>> +               dma-ranges = <0xc0000000 0x0 0x10000000>;
>>>> +       };
>>>> +
>>>>         usbotg_hs_phy: usbphy {
>>>>                 #phy-cells = <0>;
>>>>                 compatible = "usb-nop-xceiv";
>>>
>>>
>>> Shouldn't also the peripheral dma-ranges property move to board specific
>>> too?
>>> I  had this patch for while but I didn't had the time to submit:
>>
>>
>> Well spot I forgot it. Actually, discussing with Arnd ysterday on IIRC,
>> empty dma-ranges is not needed. Can you test on your side by removing
>> dma-ranges in usb node please ?
> Unfortunately will take a time for me to set up this environment on
> the STM32F4-EVAL board.
> And on the discovery boards we dont have this scenario. That was the
> main reason I did not submit the patch right away.
> My conclusion and I might be wrong but is based on the my tests with
> SDIO device at STM32F469I-DISCO board.
>
> I started this issue as discussion at ST Forum but Maxime gave me the hint.
>
> https://my.st.com/public/STe2ecommunities/mcu/Lists/cortex_mx_stm32/Flat.aspx?RootFolder=https%3a%2f%2fmy%2est%2ecom%2fpublic%2fSTe2ecommunities%2fmcu%2fLists%2fcortex_mx_stm32%2fDMA2%20and%20SYSCFG_MEMRMP%20relationship&FolderCTID=0x01200200770978C69A1141439FE559EB459D7580009C4E14902C3CDE46A77F0FFD06506F5B&currentviews=44
>
>> I will push a v2 by removing empty dma-ranges if tests are ok in your side.
>
> From my understating/conclusion is: when empty property(dma-ranges) is
> the device node, the mapping will be taken in consideration when using
> DMA otherwise the mapping is ignored.
> And in the SDIO case it is needed for DEV->MEM(SDRAM) and
> MEM(SDRAM)->DEV. If it is not the case for the devices in question so
> I suppose it can work without the property.

For sure translation has to be done but I'm not sure that an empty 
"dma-ranges" is needed in device node to activate it. For Ethernet empty 
"dma-ranges" is not needed. I will try with usb.

alex

>
>>
>> Thanks in advance
>> Alex
>>
>>
>>>
>>> Author: Bruno Herrera <bruherrera@gmail.com>
>>> Date:   Sun Oct 16 14:50:00 2016 -0200
>>>
>>>     ARM: DT: STM32: Use dma-ranges property per board not at dtsi file
>>>
>>> diff --git a/arch/arm/boot/dts/stm32429i-eval.dts
>>> b/arch/arm/boot/dts/stm32429i-eval.dts
>>> index 6bfc595..2a22a82 100644
>>> --- a/arch/arm/boot/dts/stm32429i-eval.dts
>>> +++ b/arch/arm/boot/dts/stm32429i-eval.dts
>>> @@ -52,6 +52,10 @@
>>>         model = "STMicroelectronics STM32429i-EVAL board";
>>>         compatible = "st,stm32429i-eval", "st,stm32f429";
>>>
>>> +       soc {
>>> +               dma-ranges = <0xC0000000 0x0 0x10000000>;
>>> +       };
>>> +
>>>         chosen {
>>>                 bootargs = "root=/dev/ram rdinit=/linuxrc";
>>>                 stdout-path = "serial0:115200n8";
>>> @@ -96,6 +100,7 @@
>>>
>>>  &ethernet0 {
>>>         status = "okay";
>>> +       dma-ranges;
>>>         pinctrl-0       = <&ethernet0_mii>;
>>>         pinctrl-names   = "default";
>>>         phy-mode        = "mii-id";
>>> @@ -116,6 +121,7 @@
>>>  };
>>>
>>>  &usbotg_hs {
>>> +       dma-ranges;
>>>         dr_mode = "host";
>>>         phys = <&usbotg_hs_phy>;
>>>         phy-names = "usb2-phy";
>>> diff --git a/arch/arm/boot/dts/stm32f429.dtsi
>>> b/arch/arm/boot/dts/stm32f429.dtsi
>>> index 7d624a2..697a133 100644
>>> --- a/arch/arm/boot/dts/stm32f429.dtsi
>>> +++ b/arch/arm/boot/dts/stm32f429.dtsi
>>> @@ -59,7 +59,6 @@
>>>         };
>>>
>>>         soc {
>>> -               dma-ranges = <0xc0000000 0x0 0x10000000>;
>>>
>>>                 timer2: timer@40000000 {
>>>                         compatible = "st,stm32-timer";
>>> @@ -472,13 +471,11 @@
>>>                         st,syscon = <&syscfg 0x4>;
>>>                         snps,pbl = <8>;
>>>                         snps,mixed-burst;
>>> -                       dma-ranges;
>>>                         status = "disabled";
>>>                 };
>>>
>>>                 usbotg_hs: usb@40040000 {
>>>                         compatible = "snps,dwc2";
>>> -                       dma-ranges;
>>>                         reg = <0x40040000 0x40000>;
>>>                         interrupts = <77>;
>>>                         clocks = <&rcc 0 29>;
>>>
>>>
>>>> diff --git a/arch/arm/boot/dts/stm32f429.dtsi
>>>> b/arch/arm/boot/dts/stm32f429.dtsi
>>>> index 0596d60..3a1cfdd 100644
>>>> --- a/arch/arm/boot/dts/stm32f429.dtsi
>>>> +++ b/arch/arm/boot/dts/stm32f429.dtsi
>>>> @@ -59,8 +59,6 @@
>>>>         };
>>>>
>>>>         soc {
>>>> -               dma-ranges = <0xc0000000 0x0 0x10000000>;
>>>> -
>>>>                 timer2: timer@40000000 {
>>>>                         compatible = "st,stm32-timer";
>>>>                         reg = <0x40000000 0x400>;
>>>> diff --git a/arch/arm/boot/dts/stm32f469-disco.dts
>>>> b/arch/arm/boot/dts/stm32f469-disco.dts
>>>> index 9e73656..c2213c0 100644
>>>> --- a/arch/arm/boot/dts/stm32f469-disco.dts
>>>> +++ b/arch/arm/boot/dts/stm32f469-disco.dts
>>>> @@ -64,6 +64,10 @@
>>>>         aliases {
>>>>                 serial0 = &usart3;
>>>>         };
>>>> +
>>>> +       soc {
>>>> +               dma-ranges = <0xc0000000 0x0 0x10000000>;
>>>> +       };
>>>>  };
>>>>
>>>>  &clk_hse {
>>>> --
>>>
>>>
>>>
>>> Br.,
>>> Bruno
>>>
>>