v4.19.13 snapshot.
diff --git a/Documentation/driver-api/fpga/fpga-bridge.rst b/Documentation/driver-api/fpga/fpga-bridge.rst
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+FPGA Bridge
+===========
+
+API to implement a new FPGA bridge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. kernel-doc:: include/linux/fpga/fpga-bridge.h
+ :functions: fpga_bridge
+
+.. kernel-doc:: include/linux/fpga/fpga-bridge.h
+ :functions: fpga_bridge_ops
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_create
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_free
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_register
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_unregister
+
+API to control an FPGA bridge
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+You probably won't need these directly. FPGA regions should handle this.
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: of_fpga_bridge_get
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_get
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_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_bridge_enable
+
+.. kernel-doc:: drivers/fpga/fpga-bridge.c
+ :functions: fpga_bridge_disable
diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
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+FPGA Manager
+============
+
+Overview
+--------
+
+The FPGA manager core exports a set of functions for programming an FPGA with
+an image. The API is manufacturer agnostic. All manufacturer specifics are
+hidden away in a low level driver which registers a set of ops with the core.
+The FPGA image data itself is very manufacturer specific, but for our purposes
+it's just binary data. The FPGA manager core won't parse it.
+
+The FPGA image to be programmed can be in a scatter gather list, a single
+contiguous buffer, or a firmware file. Because allocating contiguous kernel
+memory for the buffer should be avoided, users are encouraged to use a scatter
+gather list instead if possible.
+
+The particulars for programming the image are presented in a structure (struct
+fpga_image_info). This struct contains parameters such as pointers to the
+FPGA image as well as image-specific particulars such as whether the image was
+built for full or partial reconfiguration.
+
+How to support a new FPGA device
+--------------------------------
+
+To add another FPGA manager, write a driver that implements a set of ops. The
+probe function calls fpga_mgr_register(), such as::
+
+ static const struct fpga_manager_ops socfpga_fpga_ops = {
+ .write_init = socfpga_fpga_ops_configure_init,
+ .write = socfpga_fpga_ops_configure_write,
+ .write_complete = socfpga_fpga_ops_configure_complete,
+ .state = socfpga_fpga_ops_state,
+ };
+
+ static int socfpga_fpga_probe(struct platform_device *pdev)
+ {
+ struct device *dev = &pdev->dev;
+ struct socfpga_fpga_priv *priv;
+ struct fpga_manager *mgr;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ /*
+ * do ioremaps, get interrupts, etc. and save
+ * them in priv
+ */
+
+ mgr = fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager",
+ &socfpga_fpga_ops, priv);
+ if (!mgr)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, mgr);
+
+ ret = fpga_mgr_register(mgr);
+ if (ret)
+ fpga_mgr_free(mgr);
+
+ return ret;
+ }
+
+ static int socfpga_fpga_remove(struct platform_device *pdev)
+ {
+ struct fpga_manager *mgr = platform_get_drvdata(pdev);
+
+ fpga_mgr_unregister(mgr);
+
+ return 0;
+ }
+
+
+The ops will implement whatever device specific register writes are needed to
+do the programming sequence for this particular FPGA. These ops return 0 for
+success or negative error codes otherwise.
+
+The programming sequence is::
+ 1. .write_init
+ 2. .write or .write_sg (may be called once or multiple times)
+ 3. .write_complete
+
+The .write_init function will prepare the FPGA to receive the image data. The
+buffer passed into .write_init will be at most .initial_header_size bytes long;
+if the whole bitstream is not immediately available then the core code will
+buffer up at least this much before starting.
+
+The .write function writes a buffer to the FPGA. The buffer may be contain the
+whole FPGA image or may be a smaller chunk of an FPGA image. In the latter
+case, this function is called multiple times for successive chunks. This interface
+is suitable for drivers which use PIO.
+
+The .write_sg version behaves the same as .write except the input is a sg_table
+scatter list. This interface is suitable for drivers which use DMA.
+
+The .write_complete function is called after all the image has been written
+to put the FPGA into operating mode.
+
+The ops include a .state function which will determine the state the FPGA is in
+and return a code of type enum fpga_mgr_states. It doesn't result in a change
+in state.
+
+How to write an image buffer to a supported FPGA
+------------------------------------------------
+
+Some sample code::
+
+ #include <linux/fpga/fpga-mgr.h>
+
+ struct fpga_manager *mgr;
+ struct fpga_image_info *info;
+ int ret;
+
+ /*
+ * Get a reference to FPGA manager. The manager is not locked, so you can
+ * hold onto this reference without it preventing programming.
+ *
+ * This example uses the device node of the manager. Alternatively, use
+ * fpga_mgr_get(dev) instead if you have the device.
+ */
+ mgr = of_fpga_mgr_get(mgr_node);
+
+ /* struct with information about the FPGA image to program. */
+ info = fpga_image_info_alloc(dev);
+
+ /* flags indicates whether to do full or partial reconfiguration */
+ info->flags = FPGA_MGR_PARTIAL_RECONFIG;
+
+ /*
+ * At this point, indicate where the image is. This is pseudo-code; you're
+ * going to use one of these three.
+ */
+ if (image is in a scatter gather table) {
+
+ info->sgt = [your scatter gather table]
+
+ } else if (image is in a buffer) {
+
+ info->buf = [your image buffer]
+ info->count = [image buffer size]
+
+ } else if (image is in a firmware file) {
+
+ info->firmware_name = devm_kstrdup(dev, firmware_name, GFP_KERNEL);
+
+ }
+
+ /* Get exclusive control of FPGA manager */
+ ret = fpga_mgr_lock(mgr);
+
+ /* Load the buffer to the FPGA */
+ ret = fpga_mgr_buf_load(mgr, &info, buf, count);
+
+ /* Release the FPGA manager */
+ fpga_mgr_unlock(mgr);
+ fpga_mgr_put(mgr);
+
+ /* Deallocate the image info if you're done with it */
+ fpga_image_info_free(info);
+
+API for implementing a new FPGA Manager driver
+----------------------------------------------
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :functions: fpga_manager
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :functions: fpga_manager_ops
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_create
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_free
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_register
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_unregister
+
+API for programming an FPGA
+---------------------------
+
+FPGA Manager flags
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :doc: FPGA Manager flags
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :functions: fpga_image_info
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :functions: fpga_mgr_states
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_image_info_alloc
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_image_info_free
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: of_fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_get
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_put
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_lock
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_unlock
+
+.. kernel-doc:: include/linux/fpga/fpga-mgr.h
+ :functions: fpga_mgr_states
+
+Note - use :c:func:`fpga_region_program_fpga()` instead of :c:func:`fpga_mgr_load()`
+
+.. kernel-doc:: drivers/fpga/fpga-mgr.c
+ :functions: fpga_mgr_load
diff --git a/Documentation/driver-api/fpga/fpga-region.rst b/Documentation/driver-api/fpga/fpga-region.rst
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+FPGA Region
+===========
+
+Overview
+--------
+
+This document is meant to be a brief overview of the FPGA region API usage. A
+more conceptual look at regions can be found in the Device Tree binding
+document [#f1]_.
+
+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 [#f1]_. 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 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 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
+----------------------------
+
+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
+----------------------------
+
+.. kernel-doc:: include/linux/fpga/fpga-region.h
+ :functions: fpga_region
+
+.. 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
diff --git a/Documentation/driver-api/fpga/index.rst b/Documentation/driver-api/fpga/index.rst
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+==============
+FPGA Subsystem
+==============
+
+:Author: Alan Tull
+
+.. toctree::
+ :maxdepth: 2
+
+ intro
+ fpga-mgr
+ fpga-bridge
+ fpga-region
diff --git a/Documentation/driver-api/fpga/intro.rst b/Documentation/driver-api/fpga/intro.rst
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+Introduction
+============
+
+The FPGA subsystem supports reprogramming FPGAs dynamically under
+Linux. Some of the core intentions of the FPGA subsystems are:
+
+* The FPGA subsystem is vendor agnostic.
+
+* The FPGA subsystem separates upper layers (userspace interfaces and
+ enumeration) from lower layers that know how to program a specific
+ FPGA.
+
+* Code should not be shared between upper and lower layers. This
+ should go without saying. If that seems necessary, there's probably
+ framework functionality that can be added that will benefit
+ other users. Write the linux-fpga mailing list and maintainers and
+ seek out a solution that expands the framework for broad reuse.
+
+* Generally, when adding code, think of the future. Plan for reuse.
+
+The framework in the kernel is divided into:
+
+FPGA Manager
+------------
+
+If you are adding a new FPGA or a new method of programming an FPGA,
+this is the subsystem for you. Low level FPGA manager drivers contain
+the knowledge of how to program a specific device. This subsystem
+includes the framework in fpga-mgr.c and the low level drivers that
+are registered with it.
+
+FPGA Bridge
+-----------
+
+FPGA Bridges prevent spurious signals from going out of an FPGA or a
+region of an FPGA during programming. They are disabled before
+programming begins and re-enabled afterwards. An FPGA bridge may be
+actual hard hardware that gates a bus to a CPU or a soft ("freeze")
+bridge in FPGA fabric that surrounds a partial reconfiguration region
+of an FPGA. This subsystem includes fpga-bridge.c and the low level
+drivers that are registered with it.
+
+FPGA Region
+-----------
+
+If you are adding a new interface to the FPGA framework, add it on top
+of an FPGA region to allow the most reuse of your interface.
+
+The FPGA Region framework (fpga-region.c) associates managers and
+bridges as reconfigurable regions. A region may refer to the whole
+FPGA in full reconfiguration or to a partial reconfiguration region.
+
+The Device Tree FPGA Region support (of-fpga-region.c) handles
+reprogramming FPGAs when device tree overlays are applied.