diff options
Diffstat (limited to 'Documentation/fpga/fpga-mgr.txt')
| -rw-r--r-- | Documentation/fpga/fpga-mgr.txt | 62 |
1 files changed, 45 insertions, 17 deletions
diff --git a/Documentation/fpga/fpga-mgr.txt b/Documentation/fpga/fpga-mgr.txt index ce3e84fa9023..78f197fadfd1 100644 --- a/Documentation/fpga/fpga-mgr.txt +++ b/Documentation/fpga/fpga-mgr.txt @@ -18,31 +18,46 @@ API Functions: To program the FPGA from a file or from a buffer: ------------------------------------------------- - int fpga_mgr_buf_load(struct fpga_manager *mgr, u32 flags, + int fpga_mgr_buf_load(struct fpga_manager *mgr, + struct fpga_image_info *info, const char *buf, size_t count); -Load the FPGA from an image which exists as a buffer in memory. +Load the FPGA from an image which exists as a contiguous buffer in +memory. Allocating contiguous kernel memory for the buffer should be avoided, +users are encouraged to use the _sg interface instead of this. - int fpga_mgr_firmware_load(struct fpga_manager *mgr, u32 flags, + int fpga_mgr_buf_load_sg(struct fpga_manager *mgr, + struct fpga_image_info *info, + struct sg_table *sgt); + +Load the FPGA from an image from non-contiguous in memory. Callers can +construct a sg_table using alloc_page backed memory. + + int fpga_mgr_firmware_load(struct fpga_manager *mgr, + struct fpga_image_info *info, const char *image_name); Load the FPGA from an image which exists as a file. The image file must be on -the firmware search path (see the firmware class documentation). - -For both these functions, flags == 0 for normal full reconfiguration or -FPGA_MGR_PARTIAL_RECONFIG for partial reconfiguration. If successful, the FPGA -ends up in operating mode. Return 0 on success or a negative error code. +the firmware search path (see the firmware class documentation). If successful, +the FPGA ends up in operating mode. Return 0 on success or a negative error +code. +A FPGA design contained in a FPGA image file will likely have particulars that +affect how the image is programmed to the FPGA. These are contained in struct +fpga_image_info. Currently the only such particular is a single flag bit +indicating whether the image is for full or partial reconfiguration. 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); + +Given a DT node or device, get an exclusive reference to a FPGA manager. void fpga_mgr_put(struct fpga_manager *mgr); -Given a DT node, get an exclusive reference to a FPGA manager or release -the reference. +Release the reference. To register or unregister the low level FPGA-specific driver: @@ -70,8 +85,11 @@ struct device_node *mgr_node = ... char *buf = ... int count = ... +/* struct with information about the FPGA image to program. */ +struct fpga_image_info info; + /* flags indicates whether to do full or partial reconfiguration */ -int flags = 0; +info.flags = 0; int ret; @@ -79,7 +97,7 @@ int ret; struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node); /* Load the buffer to the FPGA */ -ret = fpga_mgr_buf_load(mgr, flags, buf, count); +ret = fpga_mgr_buf_load(mgr, &info, buf, count); /* Release the FPGA manager */ fpga_mgr_put(mgr); @@ -96,8 +114,11 @@ struct device_node *mgr_node = ... /* FPGA image is in this file which is in the firmware search path */ const char *path = "fpga-image-9.rbf" +/* struct with information about the FPGA image to program. */ +struct fpga_image_info info; + /* flags indicates whether to do full or partial reconfiguration */ -int flags = 0; +info.flags = 0; int ret; @@ -105,7 +126,7 @@ int ret; struct fpga_manager *mgr = of_fpga_mgr_get(mgr_node); /* Get the firmware image (path) and load it to the FPGA */ -ret = fpga_mgr_firmware_load(mgr, flags, path); +ret = fpga_mgr_firmware_load(mgr, &info, path); /* Release the FPGA manager */ fpga_mgr_put(mgr); @@ -154,14 +175,21 @@ success or negative error codes otherwise. The programming sequence is: 1. .write_init - 2. .write (may be called once or multiple times) + 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 .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. +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. |