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

[Sascha Hauer]

On Fri, Jan 19, 2018 at 12:29:01PM +0300, Antony Pavlov wrote:
> 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.

How would you handle multiple FTDI chips then if you want to make use
of more than one at a time?

Sascha


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