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

[Stefan Tauner]

On Thu, 29 Jan 2015 00:41:21 +0000
Phillip Vallejo  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:
>   Is there access through flashrom to those GPIO bits? (if so, where is the description?)
>
>   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...

Can ft2232_spi mode give access to GPIO bits?

[Antony Pavlov]

On Sun, 8 Feb 2015 10:22:40 +0100
Stefan Tauner  wrote:
> On Thu, 29 Jan 2015 00:41:21 +0000
> Phillip Vallejo  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:
> >   Is there access through flashrom to those GPIO bits? (if so, where is the description?)
> >
> >   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/9064fa9081d14eab30f7886dfa56...):

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

Can ft2232_spi mode give access to GPIO bits?

[Phillip Vallejo]

Thanks! This is a custom design that uses GPIO for other functions in conjunction with flashing a rom. I think I have a working model to go forward. 
Thanks again,
-Phil

-----Original Message-----
From: Antony Pavlov [mailto:[e-mail]] 
Sent: Sunday, February 08, 2015 4:39 AM
To: [e-mail]
Cc: Stefan Tauner; Phillip Vallejo
Subject: Re: [flashrom] Can ft2232_spi mode give access to GPIO bits?

On Sun, 8 Feb 2015 10:22:40 +0100
Stefan Tauner  wrote:
> On Thu, 29 Jan 2015 00:41:21 +0000
> Phillip Vallejo  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:
> >   Is there access through flashrom to those GPIO bits? (if so, where is the description?)
> >
> >   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/9064fa9081d14eab30f7886dfa56...):

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.