doc: board: ti: add documenation for j7200

This patch adds documentation for j7200.

TRM link
https://www.ti.com/lit/pdf/spruiu1

Signed-off-by: Udit Kumar <u-kumar1@ti.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/doc/board/ti/j7200_evm.rst b/doc/board/ti/j7200_evm.rst
new file mode 100644
index 0000000..0d3a526
--- /dev/null
+++ b/doc/board/ti/j7200_evm.rst
@@ -0,0 +1,332 @@
+.. SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+.. sectionauthor:: Udit Kumar <u-kumar1@ti.com>
+
+J7200 Platforms
+===============
+
+Introduction:
+-------------
+The J7200 family of SoCs are part of K3 Multicore SoC architecture platform
+targeting automotive applications. They are designed as a low power, high
+performance and highly integrated device architecture, adding significant
+enhancement on processing power, graphics capability, video and imaging
+processing, virtualization and coherent memory support.
+
+The device is partitioned into three functional domains, each containing
+specific processing cores and peripherals:
+
+1. Wake-up (WKUP) domain:
+        * Device Management and Security Controller (DMSC)
+
+2. Microcontroller (MCU) domain:
+        * Dual Core ARM Cortex-R5F processor
+
+3. MAIN domain:
+        * Dual core 64-bit ARM Cortex-A72
+
+More info can be found in TRM: https://www.ti.com/lit/pdf/spruiu1
+
+Boot Flow:
+----------
+Below is the pictorial representation of boot flow:
+
+.. code-block:: text
+
+ +------------------------------------------------------------------------+-----------------------+
+ |        DMSC            |      MCU R5           |        A72            |  MAIN R5/C7x          |
+ +------------------------------------------------------------------------+-----------------------+
+ |    +--------+          |                       |                       |                       |
+ |    |  Reset |          |                       |                       |                       |
+ |    +--------+          |                       |                       |                       |
+ |         :              |                       |                       |                       |
+ |    +--------+          |   +-----------+       |                       |                       |
+ |    | *ROM*  |----------|-->| Reset rls |       |                       |                       |
+ |    +--------+          |   +-----------+       |                       |                       |
+ |    |        |          |         :             |                       |                       |
+ |    |  ROM   |          |         :             |                       |                       |
+ |    |services|          |         :             |                       |                       |
+ |    |        |          |   +-------------+     |                       |                       |
+ |    |        |          |   |  *R5 ROM*   |     |                       |                       |
+ |    |        |          |   +-------------+     |                       |                       |
+ |    |        |<---------|---|Load and auth|     |                       |                       |
+ |    |        |          |   | tiboot3.bin |     |                       |                       |
+ |    | Start  |          |   +-------------+     |                       |                       |
+ |    |  TIFS  |<---------|---|    Start    |     |                       |                       |
+ |    |        |          |   |    TIFS     |     |                       |                       |
+ |    +--------+          |   +-------------+     |                       |                       |
+ |        :               |   |             |     |                       |                       |
+ |    +---------+         |   |   Load      |     |                       |                       |
+ |    | *TIFS*  |         |   |   system    |     |                       |                       |
+ |    +---------+         |   | Config data |     |                       |                       |
+ |    |         |<--------|---|             |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |         :             |                       |                       |
+ |    |         |         |         :             |                       |                       |
+ |    |         |         |         :             |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |   |  *R5 SPL*   |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |   |    DDR      |     |                       |                       |
+ |    |         |         |   |   config    |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |   |    Load     |     |                       |                       |
+ |    |         |         |   |  tispl.bin  |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |   |   Load R5   |     |                       |                       |
+ |    |         |         |   |   firmware  |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |<--------|---| Start A72   |     |                       |                       |
+ |    |         |         |   | and jump to |     |                       |                       |
+ |    |         |         |   | DM fw image |     |                       |                       |
+ |    |         |         |   +-------------+     |                       |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |---------|-----------------------|---->| Reset rls |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |  TIFS   |         |                       |          :            |                       |
+ |    |Services |         |                       |     +-----------+     |                       |
+ |    |         |<--------|-----------------------|---->|*ATF/OPTEE*|     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |         |                       |          :            |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |<--------|-----------------------|---->| *A72 SPL* |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |         |                       |     |   Load    |     |                       |
+ |    |         |         |                       |     | u-boot.img|     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |         |                       |          :            |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |<--------|-----------------------|---->| *U-Boot*  |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |         |                       |     |  prompt   |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |         |                       |     |  Load R5  |     |                       |
+ |    |         |         |                       |     |  Firmware |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |<--------|-----------------------|-----|  Start R5 |     |      +-----------+    |
+ |    |         |---------|-----------------------|-----+-----------+-----|----->| R5 starts |    |
+ |    |         |         |                       |     |  Load C7  |     |      +-----------+    |
+ |    |         |         |                       |     |  Firmware |     |                       |
+ |    |         |         |                       |     +-----------+     |                       |
+ |    |         |<--------|-----------------------|-----|  Start C7 |     |      +-----------+    |
+ |    |         |---------|-----------------------|-----+-----------+-----|----->| C7 starts |    |
+ |    |         |         |                       |                       |      +-----------+    |
+ |    |         |         |                       |                       |                       |
+ |    +---------+         |                       |                       |                       |
+ |                        |                       |                       |                       |
+ +------------------------------------------------------------------------+-----------------------+
+
+- Here DMSC acts as master and provides all the critical services. R5/A72
+  requests DMSC to get these services done as shown in the above diagram.
+
+Sources:
+--------
+1. SYSFW:
+	Tree: git://git.ti.com/k3-image-gen/k3-image-gen.git
+	Branch: master
+
+2. ATF:
+	Tree: https://github.com/ARM-software/arm-trusted-firmware.git
+	Branch: master
+
+3. OPTEE:
+	Tree: https://github.com/OP-TEE/optee_os.git
+	Branch: master
+
+4. DM Firmware:
+	Tree: git://git.ti.com/processor-firmware/ti-linux-firmware.git
+	Branch: ti-linux-firmware
+
+5. U-Boot:
+	Tree: https://source.denx.de/u-boot/u-boot
+	Branch: master
+
+Build procedure:
+----------------
+1. SYSFW:
+
+.. code-block:: bash
+
+    make ARCH=arm CROSS_COMPILE=arm-none-linux-gnueabihf- SOC=j7200 SBL=u-boot-spl.bin SYSFW_PATH=<path to sysfw>/ti-fs-firmware-j7200-gp.bin
+    u-boot-spl.bin is generated at step 4.
+
+2. ATF:
+
+.. code-block:: bash
+
+    make CROSS_COMPILE=aarch64-linux-gnu- ARCH=aarch64 PLAT=k3 TARGET_BOARD=generic SPD=opteed
+
+3. OPTEE:
+
+.. code-block:: bash
+
+    make PLATFORM=k3-j7200 CFG_ARM64_core=y
+
+4. U-Boot:
+
+* 4.1 R5:
+
+.. code-block:: bash
+
+    make CROSS_COMPILE=arm-linux-gnueabihf- j7200_evm_r5_defconfig O=build/r5
+    make CROSS_COMPILE=arm-linux-gnueabihf- O=build/r5
+
+* 4.2 A72:
+
+.. code-block:: bash
+
+    make CROSS_COMPILE=aarch64-linux-gnu- j7200_evm_a72_defconfig O=build/a72
+    make CROSS_COMPILE=aarch64-linux-gnu- ATF=<ATF dir>/build/k3/generic/release/bl31.bin TEE=<OPTEE OS dir>/out/arm-plat-k3/core/tee-pager_v2.bin DM=<DM firmware>/ti-dm/j7200/ipc_echo_testb_mcu1_0_release_strip.xer5f O=build/a72
+
+Target Images
+--------------
+Copy the below images to an SD card and boot:
+ - tiboot3.bin from step 1
+ - tispl.bin, u-boot.img from 4.2
+
+Image formats:
+--------------
+
+- tiboot3.bin:
+
+.. code-block:: console
+
+ +-----------------------+
+ |        X.509          |
+ |      Certificate      |
+ | +-------------------+ |
+ | |                   | |
+ | |        R5         | |
+ | |   u-boot-spl.bin  | |
+ | |                   | |
+ | +-------------------+ |
+ | |                   | |
+ | |     FIT header    | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | |   DTB 1...N   | | |
+ | | +---------------+ | |
+ | +-------------------+ |
+ | |                   | |
+ | |      FIT HEADER   | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | |   sysfw.bin   | | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | |  board config | | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | |   PM config   | | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | |   RM config   | | |
+ | | +---------------+ | |
+ | | |               | | |
+ | | | Secure config | | |
+ | | +---------------+ | |
+ | +-------------------+ |
+ +-----------------------+
+
+- tispl.bin
+
+.. code-block:: console
+
+ +-----------------------+
+ |                       |
+ |       FIT HEADER      |
+ | +-------------------+ |
+ | |                   | |
+ | |      A72 ATF      | |
+ | +-------------------+ |
+ | |                   | |
+ | |     A72 OPTEE     | |
+ | +-------------------+ |
+ | |                   | |
+ | |      R5 DM FW     | |
+ | +-------------------+ |
+ | |                   | |
+ | |      A72 SPL      | |
+ | +-------------------+ |
+ | |                   | |
+ | |   SPL DTB 1...N   | |
+ | +-------------------+ |
+ +-----------------------+
+
+
+Switch Setting for Boot Mode
+----------------------------
+
+Boot Mode pins provide means to select the boot mode and options before the
+device is powered up. After every POR, they are the main source to populate
+the Boot Parameter Tables.
+
+The following table shows some common boot modes used on J7200 platform. More
+details can be found in the Technical Reference Manual:
+https://www.ti.com/lit/pdf/spruiu1 under the `Boot Mode Pins` section.
+
+
+*Boot Modes*
+
+============ ============= =============
+Switch Label SW9: 12345678 SW8: 12345678
+============ ============= =============
+SD           00000000      10000010
+EMMC         01000000      10000000
+OSPI         01000000      00000110
+UART         01110000      00000000
+USB DFU      00100000      10000000
+============ ============= =============
+
+For SW8 and SW9, the switch state in the "ON" position = 1.
+
+eMMC:
+-----
+ROM supports booting from eMMC raw read or UDA FS mode.
+
+Below is memory layout in case of booting from
+boot 0/1  partition in raw mode.
+
+Current allocated size for tiboot3 size is 1MB, tispl is 2MB.
+
+Size of u-boot.img is taken 4MB for refernece,
+But this is subject to change depending upon atf, optee size
+
+.. code-block:: console
+
+              boot0/1 partition (8 MB)                       user partition
+     0x0+----------------------------------+      0x0+------------------------+
+       |     tiboot3.bin (1 MB)           |         |                         |
+  0x800+----------------------------------+         |                         |
+       |       tispl.bin (2 MB)           |         |                         |
+ 0x1800+----------------------------------+         |                         |
+       |       u-boot.img (4MB)           |         |                         |
+ 0x3800+----------------------------------+         |                         |
+       |                                  |         |                         |
+ 0x3900+            environment           |         |                         |
+       |                                  |         |                         |
+ 0x3A00+----------------------------------+         +-------------------------+
+
+In case of UDA FS mode booting, following is layout.
+
+All boot images tiboot3.bin, tispl and u-boot should be written to
+fat formatted UDA FS as file.
+
+.. code-block:: console
+
+              boot0/1 partition (8 MB)                       user partition
+     0x0+---------------------------------+      0x0+-------------------------+
+       |                                  |         |       tiboot3.bin*      |
+  0x800+----------------------------------+         |                         |
+       |                                  |         |       tispl.bin         |
+ 0x1800+----------------------------------+         |                         |
+       |                                  |         |       u-boot.img        |
+ 0x3800+----------------------------------+         |                         |
+       |                                  |         |                         |
+ 0x3900+                                  |         |      environment        |
+       |                                  |         |                         |
+ 0x3A00+----------------------------------+         +-------------------------+
+
+
+
+In case of booting from eMMC, write above images into raw or UDA FS.
+and set mmc partconf accordingly.
diff --git a/doc/board/ti/k3.rst b/doc/board/ti/k3.rst
index b49a60c..2b2f4bb 100644
--- a/doc/board/ti/k3.rst
+++ b/doc/board/ti/k3.rst
@@ -31,6 +31,7 @@
    :maxdepth: 1
 
    j721e_evm
+   j7200_evm
    am62x_sk
 
 Boot Flow Overview