[PATCH v2 3/5] doc: usage: cmd: Add documentation for fpga pr command

[Naresh Kumar Ravulapalli]

Documentation for FPGA partial reconfiguration (pr) command is added.

Signed-off-by: Naresh Kumar Ravulapalli <nareshkumar.ravulapalli at altera.com>
---
 doc/usage/cmd/fpga.rst | 65 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)
 create mode 100644 doc/usage/cmd/fpga.rst

diff --git a/doc/usage/cmd/fpga.rst b/doc/usage/cmd/fpga.rst
new file mode 100644
index 00000000000..5f0b6d0cea9
--- /dev/null
+++ b/doc/usage/cmd/fpga.rst
@@ -0,0 +1,65 @@
+.. SPDX-License-Identifier: GPL-2.0+:
+
+.. index::
+   single: fpga pr (command)
+
+fpga pr command
+===============
+
+Synopsis
+--------
+
+::
+
+    fpga pr <dev> <start|stop> <region>
+
+Description
+-----------
+
+The *fpga pr* command is used to support partial reconfiguration functionality
+on FPGA devices which support the same. General usage of the command would be
+*fpga pr <dev> start <region>* followed by *fpga load* command, where partial
+configuration image is loaded and stopping the operation with
+*fpga pr <dev> stop <region>*.
+
+dev
+    device number
+
+start
+    starts the partial reconfiguration (pr) operation on the specified **pr** region
+
+stop
+    stops the partial reconfiguration (pr) operation on the specified **pr** region
+
+region
+    region number to undergo the partial reconfiguration operation
+
+Return value
+------------
+
+The return value $? is set to 0 (true) if the operation is successful.
+
+Example
+-------
+
+::
+
+No console output is displayed when **pr** *start* and *stop* commands have been successful::
+
+    => fpga pr 0 start 0
+
+    => fpga pr 0 stop 0
+
+However, desired output can be added to specific **pr** implementation functions.
+For example, in case of Altera FPGA devices, following output is displayed. ::
+
+    => fpga pr 0 start 0
+    altera_freeze_br_req_ack request 1 acknowledged 1 ctrl 0
+
+    => fpga pr 0 stop 0
+    altera_freeze_br_req_ack request 2 acknowledged 2 ctrl 0
+
+Configuration
+-------------
+
+The *fpga pr* command is only available if **CONFIG_CMD_FPGA_PR=y**.
-- 
2.35.3