[flashrom] Can ft2232_spi mode give access to GPIO bits?

Antony Pavlov antonynpavlov at gmail.com
Sun Feb 8 13:38:39 CET 2015


On Sun, 8 Feb 2015 10:22:40 +0100
Stefan Tauner <stefan.tauner at alumni.tuwien.ac.at> wrote:

> On Thu, 29 Jan 2015 00:41:21 +0000
> Phillip Vallejo <pvallejo at pacificbiosciences.com> wrote:
> 
> > In using the FT2232H chip in MPSSE with SPI there are many GPIO bits on other pins. I have 2 questions about flashrom with ft2232_spi mode:
> > 
> > 1.       Is there access through flashrom to those GPIO bits? (if so, where is the description?)
> > 
> > 2.       If not, If I use a different program before flashrom to set GPIO bits, will flashrom reset GPIO bits to a particular state?
> 
> Hi,
> 
> the ft2232_spi.c driver sets some non-SPI GPIO pins for some programmer
> models that require it. That's what the cs_bits and pindir variables
> are for. Check out the comments at the declaration and around accesses
> of those variables. I guess your programmer needs something similar
> too? Can you please explain why? There is no way to apply these
> settings from the command line (so far), and I am not sure if that
> would be a good idea either...
> 

Please see how openocd handles this task. Here is tcl description
for Flyswatter2 jtag dongle (https://gitorious.org/jtag-tools/openocd/source/9064fa9081d14eab30f7886dfa5655ba0537d017:tcl/interface/ftdi/flyswatter2.cfg):

    interface ftdi
    ftdi_device_desc "Flyswatter2"
    ftdi_vid_pid 0x0403 0x6010
    ftdi_layout_init 0x0538 0x057b
    ftdi_layout_signal nTRST -data 0x0010
    ftdi_layout_signal nSRST -data 0x0020 -noe 0x0100

E.g. the 'ftdi_layout_init 0x0538 0x057b' directive sets necessary output and directions init values
for both high and low ft2232's ports (at the moment flashrom's ft2232_spi works only with low ft2232 port values).

I suppose it's possible to add similar options to flashrom's ft2232_spi.

-- 
Best regards,
  Antony Pavlov




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