On Wed, 19 Jul 2017 10:59:34 +0200
Johan Hovold johan@xxxxxxxxxx wrote:
...
>> > +static const struct mfd_cell ftdi_cells[] = {
>> > + { .name = "ftdi-cbus-gpio", },
>> > + { .name = "ftdi-mpsse-i2c", },
>> > + { .name = "ftdi-mpsse-spi", },
>> > + { .name = "ftdi-fifo-fpp-mgr", },
>> > +};
>>
>> Correct me if I'm wrong, but aren't these modes really mutually
>> exclusive, possibly with exception of cbus-gpio (some pins are at least
>> available as GPIOs in MPSSE mode)? Then MFD is not is not the right fit
>> here either.
>
>You never replied to this, and I'm afraid there are more issue with this
>series.
Sorry, unfortunately I'm too busy with other stuff. Will try to find
time to rework.
>> And as David Laight already pointed out, your ftdi-fifo-fpp-mgr driver
>> seems too application specific for a generic chip like this.
>
>Of which this is one is one of the major.
Thanks all for feedback. I'm still pondering how to interface the
fpga manager driver to FTDI FIFO driver.
>In short, your driver is much to application specific and is probably
>something that needs to be implemented in userspace using libftdi.
I have a requirement to use the fpga manager framework, therefore the
kernel driver is needed. Our usage scenario is a multi stage fpga
configuration process, the first stage is a pre-configuration via
FTDI SPI/FIFO, all subsequent stages are also done by other fpga
manager drivers. libftdi based driver already existed for hardware
bring-up, now I need similar functionality as kernel fpga manager.
>Speaking of libftdi, you seem to have copied or borrowed a lot of code
>and protocol from libftdi and this should have been mentioned in commit
>messages and file headers (not just in a comment to one specific
>function).
I'll mention this in next patch series.
>These chips can be used for a many different applications (also in FIFO
>mode) so you cannot tie a driver to it exposing just a specific
>interface for programming a certain class of FPGAs.
Agreed.
Anatolij
--
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
