This patchset supports some dfl device drivers written in userspace. In the patchset v1, the "driver_override" interface should be used to bind the DFL UIO driver to DFL devices. But there is concern that the "driver_override" interface is not OK itself.
In v2, we use a new matching algorithem. The "driver_override" interface is abandoned, the DFL UIO driver matches any DFL device which could not be handled by other DFL drivers. So the DFL UIO driver could be used for new DFL devices which are not supported by kernel. The concern is the UIO may not be suitable as a default/generic driver for all dfl features, such as features with multiple interrupts. In v4, we specify each matching device in the id_table of the UIO driver, just the same as other dfl drivers do. Now the UIO driver supports Ether Group feature. To support more DFL features, their feature ids should be added to the driver's id_table. Before v9, we create a "uio_pdrv_genirq" platform device using DFL devices' resources. Then we leverage the uio_pdrv_genirq driver for UIO support. It is suggested that we implement a driver in drivers/uio that directly calls UIO framework APIs. So we implement the uio_dfl driver in v9. The driver now only binds the ether group feature, which has no irq. So the irq support is not implemented yet. Main changes from v1: - switch to the new matching algorithem. It matches DFL devices which could not be handled by other DFL drivers. - refacor the code about device resources filling. - add the documentation. Main changes from v2: - split the match ops changes in dfl.c to an independent patch. - move the declarations needed for dfl-uio-pdev from include/linux/dfl.h to driver/fpga/dfl.h - some minor fixes. Main changes from v3: - switch to specifying each matching device in the driver's id_table. - refactor the irq handling code. Main changes from v4: - refactor the irq handling code. Main changes from v5: - fix the res[] zero initialization issue. - improve the return code for probe(). - some doc improvement. Main changes from v6: - use platform_device_register_resndata() for pdev creation. Main changes from v7: - some doc fixes. Main changes from v9: - switch to add a uio driver in drivers/uio Xu Yilun (2): uio: uio_dfl: add userspace i/o driver for DFL bus Documentation: fpga: dfl: Add description for DFL UIO support Documentation/fpga/dfl.rst | 23 ++++++++++++++++ drivers/uio/Kconfig | 13 +++++++++ drivers/uio/Makefile | 1 + drivers/uio/uio_dfl.c | 66 ++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 103 insertions(+) create mode 100644 drivers/uio/uio_dfl.c -- 2.7.4
