Arm Memory Map clarification

Arm Memory Map clarification

[sanjeev sharma]

Hello All,

I am working on 3.14 kernel for Nitrogen6x Board and during dealing
with IPU, I have realized that as per Table 2-1 (System memory map) of
the i.MX6 (Q) Reference Manual(Rev2,06/2014) IPU-1 base address is
0x0260_0000 but device Tree Node defined in imx6qdl.dtsi for IPU-1 i.e
alias of IPU0 is at @02400000 and for IPU-2
base address is defined at 0x02A0_0000 as per Table 2-1 (System memory
map) of the i.MX6 (Q) Reference Manual but device Tree Node defined in
imx6q.dtsi for IPU-2 i.e alias of IPU1 is at @02800000.

Why Device Tree node for the IPU starting before actual memory map
address. Is anyone know the reason behind it ?

Thanks in Advance !

Sanjeev Sharma

Arm Memory Map clarification

[Fabio Estevam]

On Wed, May 6, 2015 at 1:39 AM, sanjeev sharma
<sanjeevsharmaengg@gmail.com> wrote:
> Hello All,
>
> I am working on 3.14 kernel for Nitrogen6x Board and during dealing
> with IPU, I have realized that as per Table 2-1 (System memory map) of
> the i.MX6 (Q) Reference Manual(Rev2,06/2014) IPU-1 base address is
> 0x0260_0000 but device Tree Node defined in imx6qdl.dtsi for IPU-1 i.e
> alias of IPU0 is at @02400000 and for IPU-2
> base address is defined at 0x02A0_0000 as per Table 2-1 (System memory
> map) of the i.MX6 (Q) Reference Manual but device Tree Node defined in
> imx6q.dtsi for IPU-2 i.e alias of IPU1 is at @02800000.

Yes, this is a bit confusing.

imx6qdl.dsti says the ipu1 starts at 02400000. If you look at ipu-common.c:

static struct ipu_devtype ipu_type_imx6q = {
    .name = "IPUv3H",
    .cm_ofs = 0x00200000,

This .cm_ofs is used as the offset, which leads to 0x02600000 as
described in the Reference Manual.

Regards,

Fabio Estevam