| From 8315e661b3bcf4055c7f1cf2bf2e23dfdefb0844 Mon Sep 17 00:00:00 2001 |
| From: Alan Tull <atull@kernel.org> |
| Date: Wed, 16 May 2018 18:50:03 -0500 |
| Subject: [PATCH 1696/1795] 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> |
| (cherry picked from commit 547b822c22b18e346ee1d562d1787486e5c88c3c) |
| Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> |
| --- |
| 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 000000000000..bcf2dd24e179 |
| --- /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 71e568aea6cd..34b20754517f 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 86b6df66a905..000000000000 |
| --- 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. |
| -- |
| 2.19.0 |
| |