diff options
Diffstat (limited to 'Documentation/driver-api/fpga/fpga-mgr.rst')
| -rw-r--r-- | Documentation/driver-api/fpga/fpga-mgr.rst | 65 |
1 files changed, 50 insertions, 15 deletions
diff --git a/Documentation/driver-api/fpga/fpga-mgr.rst b/Documentation/driver-api/fpga/fpga-mgr.rst index 4d926b452cb3..49c0a9512653 100644 --- a/Documentation/driver-api/fpga/fpga-mgr.rst +++ b/Documentation/driver-api/fpga/fpga-mgr.rst @@ -24,7 +24,7 @@ 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:: +probe function calls fpga_mgr_register() or fpga_mgr_register_full(), such as:: static const struct fpga_manager_ops socfpga_fpga_ops = { .write_init = socfpga_fpga_ops_configure_init, @@ -49,14 +49,14 @@ probe function calls fpga_mgr_register(), such as:: * them in priv */ - mgr = devm_fpga_mgr_create(dev, "Altera SOCFPGA FPGA Manager", - &socfpga_fpga_ops, priv); - if (!mgr) - return -ENOMEM; + mgr = fpga_mgr_register(dev, "Altera SOCFPGA FPGA Manager", + &socfpga_fpga_ops, priv); + if (IS_ERR(mgr)) + return PTR_ERR(mgr); platform_set_drvdata(pdev, mgr); - return fpga_mgr_register(mgr); + return 0; } static int socfpga_fpga_remove(struct platform_device *pdev) @@ -68,18 +68,38 @@ probe function calls fpga_mgr_register(), such as:: return 0; } +Alternatively, the probe function could call one of the resource managed +register functions, devm_fpga_mgr_register() or devm_fpga_mgr_register_full(). +When these functions are used, the parameter syntax is the same, but the call +to fpga_mgr_unregister() should be removed. In the above example, the +socfpga_fpga_remove() function would not be required. 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 at most .initial_header_size bytes long; + 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. Before parse_header call, header_size is initialized +with initial_header_size. If flag skip_header of fpga_manager_ops is true, +.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 the whole bitstream is not immediately available then the core code will buffer up at least this much before starting. @@ -104,8 +124,14 @@ API for implementing a new FPGA Manager driver * ``fpga_mgr_states`` - Values for :c:expr:`fpga_manager->state`. * struct fpga_manager - the FPGA manager struct * struct fpga_manager_ops - Low level FPGA manager driver ops -* devm_fpga_mgr_create() - Allocate and init a manager struct -* fpga_mgr_register() - Register an FPGA manager +* struct fpga_manager_info - Parameter structure for fpga_mgr_register_full() +* fpga_mgr_register_full() - Create and register an FPGA manager using the + fpga_mgr_info structure to provide the full flexibility of options +* fpga_mgr_register() - Create and register an FPGA manager using standard + arguments +* devm_fpga_mgr_register_full() - Resource managed version of + fpga_mgr_register_full() +* devm_fpga_mgr_register() - Resource managed version of fpga_mgr_register() * fpga_mgr_unregister() - Unregister an FPGA manager .. kernel-doc:: include/linux/fpga/fpga-mgr.h @@ -117,11 +143,20 @@ API for implementing a new FPGA Manager driver .. kernel-doc:: include/linux/fpga/fpga-mgr.h :functions: fpga_manager_ops +.. kernel-doc:: include/linux/fpga/fpga-mgr.h + :functions: fpga_manager_info + .. kernel-doc:: drivers/fpga/fpga-mgr.c - :functions: devm_fpga_mgr_create + :functions: fpga_mgr_register_full .. kernel-doc:: drivers/fpga/fpga-mgr.c :functions: fpga_mgr_register .. kernel-doc:: drivers/fpga/fpga-mgr.c + :functions: devm_fpga_mgr_register_full + +.. kernel-doc:: drivers/fpga/fpga-mgr.c + :functions: devm_fpga_mgr_register + +.. kernel-doc:: drivers/fpga/fpga-mgr.c :functions: fpga_mgr_unregister |