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

Move Documentation/fpga/fpga-mgr.txt to driver-api/fpga/fpga-mgr.rst
and:
 - Add to driver-api/fpga/index.rst
 - Format changes so documentation builds cleanly.
 - Minor rewrites that make the doc flow better as ReST documentation.
   - Such as moving API reference to end of doc
 - Change API reference section to refer to kernel-doc documentation in
   fpga-mgr.c driver code rather than statically defining each function.

Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/driver-api/fpga/fpga-mgr.rst

@@ -0,0 +1,220 @@
+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 atmost .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 read the hardware FPGA manager and
+return a code of type enum fpga_mgr_states.  It doesn't result in a change in
+hardware 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 a FPGA
+--------------------------
+
+.. 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

Documentation/driver-api/fpga/index.rst

@@ -8,3 +8,4 @@ FPGA Subsystem
    :maxdepth: 2
 
    intro
+   fpga-mgr

Documentation/fpga/fpga-mgr.txt

@@ -1,218 +0,0 @@
-FPGA Manager Core
-
-Alan Tull 2015
-
-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.
-
-API Functions:
-==============
-
-To program the FPGA:
---------------------
-
-	int fpga_mgr_load(struct fpga_manager *mgr,
-			  struct fpga_image_info *info);
-
-Load the FPGA from an image which is indicated in the info.  If successful,
-the FPGA ends up in operating mode.  Return 0 on success or a negative error
-code.
-
-To allocate or free a struct fpga_image_info:
----------------------------------------------
-
-	struct fpga_image_info *fpga_image_info_alloc(struct device *dev);
-
-	void fpga_image_info_free(struct fpga_image_info *info);
-
-To get/put a reference to a FPGA manager:
------------------------------------------
-
-	struct fpga_manager *of_fpga_mgr_get(struct device_node *node);
-	struct fpga_manager *fpga_mgr_get(struct device *dev);
-	void fpga_mgr_put(struct fpga_manager *mgr);
-
-Given a DT node or device, get a reference to a FPGA manager.  This pointer
-can be saved until you are ready to program the FPGA.  fpga_mgr_put releases
-the reference.
-
-
-To get exclusive control of a FPGA manager:
--------------------------------------------
-
-	int fpga_mgr_lock(struct fpga_manager *mgr);
-	void fpga_mgr_unlock(struct fpga_manager *mgr);
-
-The user should call fpga_mgr_lock and verify that it returns 0 before
-attempting to program the FPGA.  Likewise, the user should call
-fpga_mgr_unlock when done programming the FPGA.
-
-To alloc/free a FPGA manager struct:
-------------------------------------
-
-	struct fpga_manager *fpga_mgr_create(struct device *dev,
-					     const char *name,
-					     const struct fpga_manager_ops *mops,
-					     void *priv);
-	void fpga_mgr_free(struct fpga_manager *mgr);
-
-To register or unregister the low level FPGA-specific driver:
--------------------------------------------------------------
-
-	int fpga_mgr_register(struct fpga_manager *mgr);
-
-	void fpga_mgr_unregister(struct fpga_manager *mgr);
-
-Use of these functions is described below in "How To Support a new FPGA
-device."
-
-
-How to write an image buffer to a supported FPGA
-================================================
-#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);
-
-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 atmost .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 read the hardware FPGA manager and
-return a code of type enum fpga_mgr_states.  It doesn't result in a change in
-hardware state.