documentation: fpga: move fpga-region.txt to driver-api

[linux-block.git] / Documentation / fpga / fpga-region.txt

diff --git a/Documentation/fpga/fpga-region.txt b/Documentation/fpga/fpga-region.txt
deleted file mode 100644 (file)
index d38fa3b..0000000
--- a/Documentation/fpga/fpga-region.txt
+++ /dev/null
@@ -1,94 +0,0 @@
-FPGA Regions
-
-Alan Tull 2017
-
-CONTENTS
- - Introduction
- - The FPGA region API
- - Usage example
-
-Introduction
-============
-
-This document is meant to be an brief overview of the FPGA region API usage.  A
-more conceptual look at regions can be found in [1].
-
-For the purposes of this API document, let's just say that a region associates
-an FPGA Manager and a bridge (or bridges) with a reprogrammable region of an
-FPGA or the whole FPGA.  The API provides a way to register a region and to
-program a region.
-
-Currently the only layer above fpga-region.c in the kernel is the Device Tree
-support (of-fpga-region.c) described in [1].  The DT support layer uses regions
-to program the FPGA and then DT to handle enumeration.  The common region code
-is intended to be used by other schemes that have other ways of accomplishing
-enumeration after programming.
-
-An fpga-region can be set up to know the following things:
-* which FPGA manager to use to do the programming
-* which bridges to disable before programming and enable afterwards.
-
-Additional info needed to program the FPGA image is passed in the struct
-fpga_image_info [2] including:
-* pointers to the image as either a scatter-gather buffer, a contiguous
-  buffer, or the name of firmware file
-* flags indicating specifics such as whether the image if for partial
-  reconfiguration.
-
-===================
-The FPGA region API
-===================
-
-To register or unregister a region:
------------------------------------
-
-       int fpga_region_register(struct fpga_region *region);
-       int fpga_region_unregister(struct fpga_region *region);
-
-An example of usage can be seen in the probe function of [3]
-
-To program an FPGA:
--------------------
-       int fpga_region_program_fpga(struct fpga_region *region);
-
-This function operates on info passed in the fpga_image_info
-(region->info).
-
-This function will attempt to:
- * lock the region's mutex
- * lock the region's FPGA manager
- * build a list of FPGA bridges if a method has been specified to do so
- * disable the bridges
- * program the FPGA
- * re-enable the bridges
- * release the locks
-
-=============
-Usage example
-=============
-
-First, allocate the info struct:
-
-       info = fpga_image_info_alloc(dev);
-       if (!info)
-               return -ENOMEM;
-
-Set flags as needed, i.e.
-
-       info->flags |= FPGA_MGR_PARTIAL_RECONFIG;
-
-Point to your FPGA image, such as:
-
-       info->sgt = &sgt;
-
-Add info to region and do the programming:
-
-       region->info = info;
-       ret = fpga_region_program_fpga(region);
-
-Then enumerate whatever hardware has appeared in the FPGA.
-
---
-[1] ../devicetree/bindings/fpga/fpga-region.txt
-[2] ./fpga-mgr.txt
-[3] ../../drivers/fpga/of-fpga-region.c