Hi all,

The notes and recording link from the 4/26 System Device Tree call are posted at https://github.com/OpenAMP/open-amp/wiki/System-Device-Tree-Meeting-Notes-2022#20220426

Below is the example shared by Oleksii.

The next System DT call in the first half of May will be focused on Lopper – calendar invitation coming soon.  I will work on scheduling a call in 2^nd half of May/early June for the traditional System DT topics.

Have a great weekend,

Nathalie

=====

From: Oleksii Moisieiev
Sent: Tuesday, April 26, 2022 10:54 AM
To: Nathalie Chan King Choy; Stefano Stabellini
Cc: Tomas Evensen
Subject: Re: [PATCH v2 2/2] dt-bindings: xen: Add xen,scmi-devid property description for SCMI (fwd)

Hi Nathalie,

Sure.

I've demonstrated the part of my device-tree file for r8a77951 kingfisher board.

It has scmi node implemented as scmi-smc driver node:

/ {

    firmware {

scmi {

  compatible = "arm,scmi-smc";

  arm,smc-id = <0x82000002>;

  shmem = <&cpu_scp_shm>;

  /* .... */

        };

     };

};

And nodes with the resource domains, controlled by scmi:

&usb_dmac0 /* dma-controller@e65a0000*/

{

arm,scmi-devid = <13>;

clocks = <&scmi_clock 5>;

resets = <&scmi_reset 12>;

power-domains = <&scmi_power 0>;

};

&usb_dmac1 /* dma-controller@e65b0000*/

{

arm,scmi-devid = <14>;

clocks = <&scmi_clock 6>;

resets = <&scmi_reset 13>;

power-domains = <&scmi_power 0>;

};

&hsusb /* usb@e6590000*/

{

arm,scmi-devid = <19>;

clocks = <&scmi_clock 3>, <&scmi_clock 2>;

resets = <&scmi_reset 10>, <&scmi_reset 9>;

power-domains = <&scmi_power 0>;

};

Where - clocks/resets/power-domains are the links to the scmi resources with the resource-id, used by this control.

arm,scmi-devid (which is old naming and used only in this example) is the id of the device which should match the device-id mapping inside the firmware.

Trusted agent, which is Xen in our case will send 

BASE_SET_DEVICE_PERMISSIONS message to the firmware, with agent_id and device_id as paramters (see 4.2.2.10 of DEN0056C for details). Both parameters are uint32_t.

OLEKSII MOISIEIEV 

Senior Software Engineer 

Office:  +380 44 390 5457x68833

Email:  Oleksii_Moisieiev@epam.com 

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