Document newly introduced fpga_manager_ops callback parse_header() along with header_size and data_size fields of struct fpga_image_info. Signed-off-by: Ivan Bornyakov <i.bornyakov@xxxxxxxxxxx> --- Documentation/driver-api/fpga/fpga-mgr.rst | 31 ++++++++++++++++------ 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst index 42c01f396dce..f1e106c3194c 100644 --- a/Documentation/driver-api/fpga/fpga-mgr.rst +++ b/Documentation/driver-api/fpga/fpga-mgr.rst @@ -79,14 +79,29 @@ 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. + 1. .parse_header (optional, may be called once or multiple times) + 2. .write_init + 3. .write or .write_sg (may be called once or multiple times) + 4. .write_complete + +The .parse_header function will set header_size and data_size to +struct fpga_image_info. If header_size is set, .write function will get image +buffer starting at header_size offset from the beginning. If data_size is set, +.write function will get data_size bytes of the image buffer, otherwise .write +will get data up to the end of image buffer. This will not affect .write_sg, +.write_sg will still get whole image in sg_table form. If FPGA image is +already mapped as a single contiguous buffer, whole buffer will be passed into +.parse_header. If image is in scatter-gather form, core code will buffer up at +least .initial_header_size before the first call of .parse_header, if it is +not enough, .parse_header should set desired size into info->header_size and +return -EAGAIN, then it will be called again with greater part of image buffer +on the input. + +The .write_init function will prepare the FPGA to receive the image data. The +buffer passed into .write_init will be at least info->header_size bytes long, +if it's defined, otherwise .initial_header_size; 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 -- 2.35.1
