[PATCH v1 12/12] Documentation: fpga: add description of fpgahp driver

[Tianfei Zhang <tianfei.zhang@intel.com>]

Add the description of fpgahp driver.

Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
---
 Documentation/fpga/fpgahp.rst | 29 +++++++++++++++++++++++++++++
 Documentation/fpga/index.rst  |  1 +
 MAINTAINERS                   |  1 +
 3 files changed, 31 insertions(+)
 create mode 100644 Documentation/fpga/fpgahp.rst

diff --git a/Documentation/fpga/fpgahp.rst b/Documentation/fpga/fpgahp.rst
new file mode 100644
index 000000000000..3ec34bbffde1
--- /dev/null
+++ b/Documentation/fpga/fpgahp.rst
@@ -0,0 +1,29 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+FPGA Hotplug Manager Driver
+===========================
+
+Authors:
+
+- Tianfei Zhang <tianfei.zhang@intel.com>
+
+There are some board managements for PCIe-based FPGA card like burning the entire
+image, loading a new FPGA image or BMC firmware in FPGA deployment of data center
+or cloud. For example, loading a new FPGA image, the driver needs to remove all of
+PCI devices like PFs/VFs and as well as any other types of devices (platform, etc.)
+defined within the FPGA. After triggering the image load of the FPGA card via BMC,
+the driver reconfigures the PCI bus. The FPGA Hotplug Manager (fpgahp) driver manages
+those devices and functions leveraging the PCI hotplug framework to deal with the
+reconfiguration of the PCI bus and removal/probe of PCI devices below the FPGA card.
+
+This fpgahp driver adds 2 new callbacks to extend the hotplug mechanism to
+allow selecting and loading a new FPGA image.
+
+ - available_images: Optional: called to return the available images of a FPGA card.
+ - image_load: Optional: called to load a new image for a FPGA card.
+
+In general, the fpgahp driver provides some sysfs files::
+
+        /sys/bus/pci/slots/<X-X>/available_images
+        /sys/bus/pci/slots/<X-X>/image_load
diff --git a/Documentation/fpga/index.rst b/Documentation/fpga/index.rst
index f80f95667ca2..8973a8a3f066 100644
--- a/Documentation/fpga/index.rst
+++ b/Documentation/fpga/index.rst
@@ -8,6 +8,7 @@ fpga
     :maxdepth: 1
 
     dfl
+    fpgahp
 
 .. only::  subproject and html
 
diff --git a/MAINTAINERS b/MAINTAINERS
index 85d4e3a0e986..569c7f680229 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8169,6 +8169,7 @@ L:	linux-fpga@vger.kernel.org
 L:	linux-pci@vger.kernel.org
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-driver-fpgahp
+F:	Documentation/fpga/fpgahp.rst
 F:	drivers/pci/hotplug/fpgahp.c
 F:	include/linux/fpga/fpgahp_manager.h
 
-- 
2.38.1