chore(docs): move deprecated platforms information around

We used to have a dedicated page for deprecated platforms information.
This document contained 2 pieces of information:

 a) the process for deprecating a platform port;
 b) the list of deprecated platforms to this day.

I think it makes more sense to move b) to the platforms ports landing
page, such that it is more visible.

This also has the nice effect to move the 'Deprecated platforms' title
as the last entry of the 'Platform ports' table of contents, like so:

 - Platform ports
   - 1. Allwinner ARMv8 SoCs
   - 2. Arm Development Platforms
     ...
   - 39. Broadcom Stingray
   - Deprecated platforms

instead of it being lost in the middle of supported platform ports.

Regarding a), this gets moved under the "Processes & Policies" section.
More specifically, it gets clubbed with the existing platform
compatibility policy. The combined document gets renamed into a
"Platforms Ports Policy" document.

Change-Id: I6e9ce2abc68b8a8ac88e7bd5f21749c14c9a2af6
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

docs/about/release-information.rst

@@ -56,9 +56,9 @@ depending on project requirement and partner feedback.
 Removal of Deprecated Interfaces
 --------------------------------
 
-As mentioned in the :ref:`Platform Compatibility Policy`, this is a live
+As mentioned in the :ref:`Platform Ports Policy`, this is a live document
-document cataloging all the deprecated interfaces in TF-A project and the
+cataloging all the deprecated interfaces in TF-A project and the Release version
-Release version after which it will be removed.
+after which it will be removed.
 
 +--------------------------------+-------------+---------+---------------------------------------------------------+
 | Interface                      | Deprecation | Removed | Comments                                                |
@@ -70,4 +70,4 @@ Release version after which it will be removed.
 
 --------------
 
-*Copyright (c) 2018-2021, Arm Limited and Contributors. All rights reserved.*
+*Copyright (c) 2018-2022, Arm Limited and Contributors. All rights reserved.*

docs/getting_started/porting-guide.rst

@@ -23,8 +23,8 @@ Some modifications are common to all Boot Loader (BL) stages. Section 2
 discusses these in detail. The subsequent sections discuss the remaining
 modifications for each BL stage in detail.
 
-Please refer to the :ref:`Platform Compatibility Policy` for the policy
+Please refer to the :ref:`Platform Ports Policy` for the policy regarding
-regarding compatibility and deprecation of these porting interfaces.
+compatibility and deprecation of these porting interfaces.
 
 Only Arm development platforms (such as FVP and Juno) may use the
 functions/definitions in ``include/plat/arm/common/`` and the corresponding

docs/plat/deprecated.rst

@@ -1,24 +0,0 @@
-Deprecated platforms
-====================
-
-Process of deprecating a platform
----------------------------------
-
-Platform can be deprecated and its source can be kept in repository for a cooling
-off period before deleting it or it can be deleted straight away. For later types
-Deprecated/Deleted version would be same.
-
-List of deprecated platforms
-----------------------------
-
-+----------------+----------------+--------------------+--------------------+
-|    Platform    |     Vendor     | Deprecated version |  Deleted version   |
-+================+================+====================+====================+
-|    sgm775      |      Arm       |        2.5         |       2.7          |
-+----------------+----------------+--------------------+--------------------+
-|    mt6795      |      MTK       |        2.5         |       2.7          |
-+----------------+----------------+--------------------+--------------------+
-|    sgi575      |      Arm       |        2.8         |       3.0          |
-+----------------+----------------+--------------------+--------------------+
-|    rdn1edge    |      Arm       |        2.8         |       3.0          |
-+----------------+----------------+--------------------+--------------------+

docs/plat/index.rst

@@ -9,7 +9,6 @@ Platform Ports
 
    allwinner
    arm/index
-   deprecated
    meson-axg
    meson-gxbb
    meson-gxl
@@ -62,6 +61,21 @@ documentation associated with them.
    - Arm SGI-575
    - MediaTek MT8173 SoCs
 
+Deprecated platforms
+--------------------
+
++----------------+----------------+--------------------+--------------------+
+|    Platform    |     Vendor     | Deprecated version |  Deleted version   |
++================+================+====================+====================+
+|    sgm775      |      Arm       |        2.5         |       2.7          |
++----------------+----------------+--------------------+--------------------+
+|    mt6795      |      MTK       |        2.5         |       2.7          |
++----------------+----------------+--------------------+--------------------+
+|    sgi575      |      Arm       |        2.8         |       3.0          |
++----------------+----------------+--------------------+--------------------+
+|    rdn1edge    |      Arm       |        2.8         |       3.0          |
++----------------+----------------+--------------------+--------------------+
+
 --------------
 
 *Copyright (c) 2019-2022, Arm Limited. All rights reserved.*

docs/process/index.rst

@@ -7,7 +7,7 @@ Processes & Policies
    :numbered:
 
    security
-   platform-compatibility-policy
+   platform-ports-policy
    commit-style
    coding-style
    coding-guidelines

docs/process/platform-compatibility-policy.rst → docs/process/platform-ports-policy.rst

@@ -1,11 +1,8 @@
-Platform Compatibility Policy
+Platform Ports Policy
-=============================
+=====================
 
-Introduction
+This document clarifies a couple of policy points around platform ports
-------------
+management.
-
-This document clarifies the project's policy around compatibility for upstream
-platforms.
 
 Platform compatibility policy
 -----------------------------
@@ -29,6 +26,24 @@ public mailing list`_ to notify platforms that they should migrate away from the
 deprecated interfaces. Platforms are expected to migrate before the removal of
 the deprecated interface.
 
+Platform deprecation policy
+---------------------------
+
+If a platform is no longer maintained, it is best to deprecate it to keep the
+projects' source tree clean and healthy. Deprecation can be a 1-stage or 2-stage
+process (up to the platform maintainers).
+
+ - *2-stage*: The platform's source code can be kept in the repository for a
+   cooling off period before deleting it (typically 2 release cycles). In this
+   case, we keep track ot the *Deprecated* version separately from the *Deleted*
+   version.
+
+ - *1-stage*: The platform's source code can be deleted straight away. In this
+   case, both versions are the same.
+
+The :ref:`Platform Ports` page provides a list of all deprecated/deleted
+platform ports (or soon to be) to this day.
+
 --------------
 
 *Copyright (c) 2018-2022, Arm Limited and Contributors. All rights reserved.*