[PATCH v3 1/6] dt-bindings: remoteproc: k3-r5f: Add Jacinto LPM memory region

[Richard Genoud (TI)]

Declare a carveout memory region to store LPM metadata on Jacinto
devices.

For Jacinto devices, this memory region is needed for saving ATF context
and the certificate information of ATF and OPTEE and DM image. This LPM
metadata area is firewalled to be accessed only by TIFS.

U-Boot R5 SPL/TIFS will use this area to save and restore:
- ATF context
- ATF certificate information
- OPTEE certificate information
- DM image (which has been copied in memory at boot time by U-Boot
R5-SPL)

At resume, U-Boot R5 SPL is executed and detects that the board is
resuming (with a flag set in the PMIC), then it:
- brings out of retention the DDR
- retrieves the LPM memory region from DTS
- authenticates certificates from LPM memory region and applies firewalls
- asks TIFS to restore TFA and its own minimal context
- starts TFA on remote proc
- loads back DM image from memory and jumps to DM

https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/pm/lpm.html#lpm-msg-lpm-save-addr

NB: This memory region is not part of DM memory (which is not retained
at suspend)

Signed-off-by: Richard Genoud (TI) <richard.genoud at bootlin.com>
---
 .../bindings/remoteproc/ti,k3-r5f-rproc.yaml   | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
index 14e6b2f817b3..af2acd429974 100644
--- a/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/ti,k3-r5f-rproc.yaml
@@ -155,9 +155,10 @@ patternProperties:
         description: |
           phandle to the reserved memory nodes to be associated with the
           remoteproc device. There should be two reserved memory nodes defined
-          for the basic layout or 6 partitions for a detailed layout. The
-          reserved memory nodes should be carveout nodes, and should be defined
-          with a "no-map" property as per the bindings in
+          for the basic layout, three for the Jacinto layout or 6 partitions
+          for a detailed layout. The reserved memory nodes should be carveout
+          nodes, and should be defined with a "no-map" property as per the
+          bindings in
           Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt
         oneOf:
           - description: Basic layout
@@ -174,6 +175,12 @@ patternProperties:
               - description: LPM metadata
               - description: LPM FS context data and reserved sections
               - description: DM RM/PM trace and firmware code/data
+          - description: Jacinto layout
+            items:
+              - description: region used for dynamic DMA allocations like vrings and
+                             vring buffers
+              - description: region reserved for firmware image sections
+              - description: LPM metadata
 
       memory-region-names:
         description: |
@@ -192,6 +199,11 @@ patternProperties:
               - const: lpm-metadata
               - const: lpm-context
               - const: dm-firmware
+          - description: Jacinto layout
+            items:
+              - const: dma
+              - const: firmware
+              - const: lpm-metadata
 
 # Optional properties:
 # --------------------
-- 
2.47.3