docs: fpga: document programming fpgas using regions

Clarify the intention that interfaces and upper layers use
regions rather than managers directly.

Rearrange API documentation to better group the API functions
used to create FPGA mgr/bridge/regions and the API used for
programming FPGAs.

Signed-off-by: Alan Tull <atull@kernel.org>
Suggested-by: Federico Vaga <federico.vaga@cern.ch>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 45 insertions, 47 deletions

diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
index dc9f75cc3352..0529b2d2231a 100644
--- a/Documentation/driver-api/fpga/fpga-region.rst
+++ b/Documentation/driver-api/fpga/fpga-region.rst
@@ -34,41 +34,6 @@ fpga_image_info including:
  * flags indicating specifics such as whether the image is for partial
    reconfiguration.
 
-How to program an FPGA using a region
--------------------------------------
-
-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);
-
-:c:func:`fpga_region_program_fpga()` 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
-
-Then you will want to enumerate whatever hardware has appeared in the FPGA.
-
 How to add a new FPGA region
 ----------------------------
 
@@ -77,15 +42,36 @@ An example of usage can be seen in the probe function of [#f2]_.
 .. [#f1] ../devicetree/bindings/fpga/fpga-region.txt
 .. [#f2] ../../drivers/fpga/of-fpga-region.c
 
-API to program an FPGA
-----------------------
-
-.. kernel-doc:: drivers/fpga/fpga-region.c
-   :functions: fpga_region_program_fpga
-
 API to add a new FPGA region
 ----------------------------
 
+* struct :c:type:`fpga_region` — The FPGA region struct
+* :c:func:`devm_fpga_region_create` — Allocate and init a region struct
+* :c:func:`fpga_region_register` —  Register an FPGA region
+* :c:func:`fpga_region_unregister` —  Unregister an FPGA region
+
+The FPGA region's probe function will need to get a reference to the FPGA
+Manager it will be using to do the programming.  This usually would happen
+during the region's probe function.
+
+* :c:func:`fpga_mgr_get` — Get a reference to an FPGA manager, raise ref count
+* :c:func:`of_fpga_mgr_get` —  Get a reference to an FPGA manager, raise ref count,
+  given a device node.
+* :c:func:`fpga_mgr_put` — Put an FPGA manager
+
+The FPGA region will need to specify which bridges to control while programming
+the FPGA.  The region driver can build a list of bridges during probe time
+(:c:member:`fpga_region->bridge_list`) or it can have a function that creates
+the list of bridges to program just before programming
+(:c:member:`fpga_region->get_bridges`).  The FPGA bridge framework supplies the
+following APIs to handle building or tearing down that list.
+
+* :c:func:`fpga_bridge_get_to_list` — Get a ref of an FPGA bridge, add it to a
+  list
+* :c:func:`of_fpga_bridge_get_to_list` — Get a ref of an FPGA bridge, add it to a
+  list, given a device node
+* :c:func:`fpga_bridges_put` — Given a list of bridges, put them
+
 .. kernel-doc:: include/linux/fpga/fpga-region.h
    :functions: fpga_region
 
@@ -93,13 +79,25 @@ API to add a new FPGA region
    :functions: devm_fpga_region_create
 
 .. kernel-doc:: drivers/fpga/fpga-region.c
-   :functions: fpga_region_create
-
-.. kernel-doc:: drivers/fpga/fpga-region.c
-   :functions: fpga_region_free
-
-.. kernel-doc:: drivers/fpga/fpga-region.c
    :functions: fpga_region_register
 
 .. kernel-doc:: drivers/fpga/fpga-region.c
    :functions: fpga_region_unregister
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: of_fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+   :functions: fpga_mgr_put
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridge_get_to_list
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: of_fpga_bridge_get_to_list
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+   :functions: fpga_bridges_put