stm32mp1: cosmetic: add comment on psci_migrate_info_type return value

Add explaination for the return value of psci_migrate_info_type:
  2 = Trusted OS.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>

diff --git a/arch/arm/mach-stm32mp/psci.c b/arch/arm/mach-stm32mp/psci.c
index 6ed2482080c1dcf578c1dc073388451c4151256f..c2dff38c368c9f6c540651157212015d14519cc9 100644 (file)
--- a/arch/arm/mach-stm32mp/psci.c
+++ b/arch/arm/mach-stm32mp/psci.c
@@ -103,7 +103,13 @@ int __secure psci_affinity_info(u32 function_id, u32 target_affinity,
 
 int __secure psci_migrate_info_type(u32 function_id)
 {
-       /* Trusted OS is either not present or does not require migration */
+       /*
+        * in Power_State_Coordination_Interface_PDD_v1_1_DEN0022D.pdf
+        * return 2 = Trusted OS is either not present or does not require
+        * migration, system of this type does not require the caller
+        * to use the MIGRATE function.
+        * MIGRATE function calls return NOT_SUPPORTED.
+        */
        return 2;
 }