Re: [PATCH v3 1/2] dt-bindings: firmware: Add Open Profile for DICE

On Wed, Dec 15, 2021 at 3:08 PM David Brazdil [off-list ref] wrote:

Hi Rob,

quoted

quoted

+        dice_reserved: dice@12340000 {
+            reg = <0x00 0x12340000 0x2000>;
+            no-map;
+        };
+    };
+
+    dice {
+        compatible = "google,open-dice";
+        memory-region = <&dice_reserved>;

There's no need for this indirection. Just add the compatible to the
dice@12340000 node. You can bind drivers to /reserved-memory nodes.

I have not found a way to make that work for kernel modules. Built-in
drivers can bind with RESERVEDMEM_OF_DECLARE, which puts an entry in
__reservedmem_of_table and __reserved_mem_init_node() iterates find it
there. A good case study might be CONFIG_TEGRA210_EMC, where the driver
itself can be a module but the rmem parsing is always built-in under
CONFIG_TEGRA210_EMC_TABLE. I don't think that's worth the trouble with
this driver.

I forgot you have to add the compatible to reserved_mem_matches in
drivers/of/platform.c.

Rob