[PATCH 10/14] documentation: fpga: move fpga-mgr.txt to driver-api

From: Alan Tull
Date: Wed May 16 2018 - 19:19:19 EST


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@xxxxxxxxxx>
---
Documentation/driver-api/fpga/fpga-mgr.rst | 220 +++++++++++++++++++++++++++++
Documentation/driver-api/fpga/index.rst | 1 +
Documentation/fpga/fpga-mgr.txt | 218 ----------------------------
3 files changed, 221 insertions(+), 218 deletions(-)
create mode 100644 Documentation/driver-api/fpga/fpga-mgr.rst
delete mode 100644 Documentation/fpga/fpga-mgr.txt

diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst
new file mode 100644
index 0000000..bcf2dd2
--- /dev/null
+++ b/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
diff --git a/Documentation/driver-api/fpga/index.rst b/Documentation/driver-api/fpga/index.rst
index 71e568a..34b2075 100644
--- a/Documentation/driver-api/fpga/index.rst
+++ b/Documentation/driver-api/fpga/index.rst
@@ -8,3 +8,4 @@ FPGA Subsystem
:maxdepth: 2

intro
+ fpga-mgr
diff --git a/Documentation/fpga/fpga-mgr.txt b/Documentation/fpga/fpga-mgr.txt
deleted file mode 100644
index 86b6df6..0000000
--- a/Documentation/fpga/fpga-mgr.txt
+++ /dev/null
@@ -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.
--
2.7.4