On Thu, Dec 7, 2017 at 8:31 AM, Anatolij Gustschin <agust@xxxxxxx> wrote: > Hi, > > I have to rework drivers for custom FT232H based FPGA configuration > adapters to make them suitable for including in mainline kernel. These > adapters should be usable via low-level drivers for FPGA Manager > framework. Two required low-level FPGA Manager drivers (for PS-SPI and > CvP configurations) are already in mainline. The missing parts are the > MPSSE SPI master driver (for attaching altera-ps-spi SPI devices) and > the FTDI FIFO FPP interface driver for FPGA Manager. I'm CCing the > relevant subsystem mailing lists and would like to get feedback to the > draft below before rewriting the missing driver parts. > > A few words about our FPGA and FPGA configuration adapter hardware. We > have FPGA PCIe boards with two different FT232H based configuration > adapters. The first adapter type utilizes FT232H chip in MPSSE mode to > connect ADBUS SPI/GPIO pins to Stratix-V PS-SPI interface. Another > adapter type connects FT232H ADBUS (in FT245 FIFO mode) and two ACBUS > GPIOs to a CPLD, the CPLD is connected to the Arria-10 FPP interface. > Both FPGA boards are connected to the host via PCIe and USB (FT232H). > > Below simplified diagram shows the drivers relationship used in the > first patch series [1] submitted to the FPGA and USB lists before > (this series didn't yet include the MPSSE SPI master driver). > > +-------------+ > | | > | STRATIX V |PS-SPI FT245 FIFO & GPIO > | +-----+ +-------------------+ > | on Board 1 | | | | > | | +----+---+ > | PCIe | ADBUS&ACBUS | CPLD | > +---+---------+ Connection Options +----+---+ > ^ (MPSSE or FIFO&GPIO) | > | | +------+-------+ > altera-cvp +-----------+----------+ | FPP | > | | | | > | FT232H 0x0403:0x6014 | | ARRIA 10 | > | | | | > +----------+-----------+ | on Board 2 | > | | | > MFD drv +----------+-----------+ | PCIe | > creates | ftdi-ft232h MFD drv | +----------+---+ > platform | USB bulk/ctrl xfer | ^ > devices +---+------+-------+---+ | > below | | | | > +-----+ | +-------------+ +--------+ > | | | | > +------+-------+ +--+-----------+ +-------+---------+ | > |ftdi-mpsse-spi| |ftdi-cbus-gpio| |ftdi-fifo-fpp-mgr| | > | platform dev | | platform dev | | platform dev | | > +-------+------+ +------+-------+ +---------+-------+ | > platform ^ ^ ^ | > drivers: + + | | > MPSSE SPI master ACBUS GPIO Ctrl +-----+ +--+ > ^ ^ | | > | | + + > altera-ps-spi \uses ftdi-fifo-fpp altera-cvp > FPGA Manager ------+ FPGA Manager FPGA Manager > ^ ^ ^ > | | | > +-------------------------+ + +------------+ > fpga-mgr > > The first FTDI FPP adapter driver patch series has some fundamental > issues as discussed on the lists and I plan to rework the FT232H > specific parts to prepare a new patch series. We have already > reserved custom PIDs for both adapter types and can use them in > adapter EEPROMs to ensure binding to the vendor specific drivers > for SPI and FIFO FPP types. > > Instead of MFD part as in previous version I intend to add an USB misc > driver for our FPGA configuration adapters under drivers/usb/misc. > When probing for VID/PID assigned to FIFO-FPP adapter type, this > driver will register CBUS GPIO controller, GPIO lookup tables for I'm not clear how these lookup tables will be specified. Is this platform using device tree? > FIFO FPP device and will create a platform device for attaching the > low-level FPGA manager driver for FIFO FPP interface. The attached > FPGA manager driver will be similar to the ftdi-fifo-fpp driver and > will reside in drivers/fpga. When probing for VID/PID assigned to > MPSSE SPI adapter type, the USB misc driver will register MPSSE GPIO > controller, GPIO lookup tables for altera-ps-spi control/status GPIOs > and will create platform device for attaching MPSSE SPI master > controller driver. The SPI master controller platform driver will > register MPSSE SPI bus with SPI slave device from spi_board_info > struct in its platform data (in our case altera-ps-spi SPI slave > device for attaching altera-ps-spi driver). The intended location > of this custom SPI master controller driver is drivers/spi. > > Below simplified diagram shows the intended device and drivers > relationship for reworking the adapter drivers. > > +-------------+ > | | > | STRATIX V |PS-SPI FT245 FIFO & GPIO > | +-----+ +-------------------+ > | on Board 1 | + + | > | | +----+---+ > | PCIe | ADBUS&ACBUS | CPLD | > +---+---------+ Connection Options +----+---+ > ^ (MPSSE or FIFO&GPIO) | > + + +------+-------+ > altera-cvp +-----------+----------+ | FPP | > | FT232H | | | > | 0x0403:0x7148 | | ARRIA 10 | > | 0x0403:0x7149 | | | > +----------+-----------+ | on Board 2 | > | | | > +-----------+------------+ | PCIe | > USB misc | fpga-cfg-intf USB misc | +----------+---+ > drv creates| bulk/ctrl xfer | ^ > platform |ACBUS GPIO Ctrl (0x7148)| | > devices |MPSSE GPIO Ctrl (0x7149)| | > below +-------+-------+--------+ | > | | | > for +----+ +------+ for | > PID 0x7149 | | PID 0x7148 | > +---------+--------+ +-------+---------+ | > | ftdi-mpsse-spi + | | | | > | altera-ps-spi in | |ftdi-fifo-fpp-mgr| | > | spi_board_info | | platform device | | > +---------+--------+ +--------+--------+ | > ^ ^ | > drivers: | | | > + | | > MPSSE SPI master | | > ^ | | > | + + > altera-ps-spi ftdi-fifo-fpp altera-cvp > FPGA Manager FPGA Manager FPGA Manager > ^ ^ ^ > | | | > +---------------+ + +---------+ > fpga-mgr > Just to be clear, this is several solutions that are being superimposed in one diagram, depending on which platform you are on, right? Alan > It would be worthwhile to concentrate the common USB transfer related > functions (bulk, control and FTDI mode setting code used in previous > ftdi-ft232h driver part) in a single file and reuse them in MPSSE SPI > master and FIFO FPP drivers to avoid code duplication. I plan to add > these functions in USB misc adapter driver and it could pass them to > platform drivers as callbacks in an ops struct via platform data. > > Before reworking the adapter drivers I'd like to get comments to this > draft, especially when there are design issues that will cause driver > rejection in the appropriate subsystem. > > Thanks! > > Anatolij > > [1] https://lkml.org/lkml/2017/7/6/710 > -- > To unsubscribe from this list: send the line "unsubscribe linux-fpga" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
