[PATCH v2 0/7] sandbox: add gpio support with libftdi1

[Antony Pavlov]

On Wed, 17 Jan 2018 10:53:14 +0100
Sascha Hauer <s.hauer at pengutronix.de> wrote:

> Hi Antony,
> 
> On Mon, Jan 15, 2018 at 12:22:45AM +0300, Antony Pavlov wrote:
> > This patch series makes it possible to use FT2232H ACBUS[7:0]
> > pins as gpio pins from sandbox barebox.
> > 
> > There are ready-to-use FT2232H-based boards:
> > 
> >   * FT2232H-56Q Mini-Module (http://www.ftdichip.com/Products/Modules/DevelopmentModules.htm#FT2232H-56_Mini)
> >   * FT2232 breakout board (http://dangerousprototypes.com/docs/FT2232_breakout_board)
> > 
> > The main goal of adding gpio functionality to sandbox barebox
> > is using it for connecting real i2c and spi devices to sandbox barebox.
> 
> I applied the parseopt patches for now since they don't need any further
> discussions.
> 

There are three common parseopt-related patches:

  move parseopt to lib/
  include/parseopt.h: add guard macro
  parseopt: introduce parseopt_u16() and parseopt_str()

Please confirm that you have got all three patches.

> What puzzles me a bit is that the libftdi gpio controller is
> instantiated from the device tree but configured through the
> commandline. It probably has to be like this since we need the
> device tree for using the gpios.

Getting FTDI chip vendorID and deviceID from device tree is reasonable.
However hardcoding FTDI chip serialnumber into device tree is not so good idea.
In addition dropping cmdline FTDI options parsing makes parseopt_u16() and parseopt_str() unused.

I propose add FTDI chip vendorID, deviceID and serial options to device tree
and keep parsing the same options from cmdline so once can override FTDI chip
serial number from cmdline.

> Sascha
> 
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-- 
Best regards,
  Antony Pavlov