Linux Serial subsystem development
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From: Johan Hovold <johan@kernel.org>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: Ryan Lovelett <ryan@lovelett.me>, linux-serial@vger.kernel.org
Subject: Re: FT232H user space GPIO device
Date: Tue, 24 Mar 2020 10:28:39 +0100	[thread overview]
Message-ID: <20200324092839.GC5810@localhost> (raw)
In-Reply-To: <20200323065211.GD129571@kroah.com>

On Mon, Mar 23, 2020 at 07:52:11AM +0100, Greg Kroah-Hartman wrote:
> On Sun, Mar 22, 2020 at 03:40:33PM -0400, Ryan Lovelett wrote:
> > I have been trying to find a way to get my Adafruit FT232H breakout
> > board [1] to appear as a user space GPIO device so I can use it with
> > libgpiod. As far as I can tell from reading table 3.5 from the
> > datasheet [2] ACBUS5, ACBUS6, ACBUS8 and ACBUS9 should all be usable
> > for this.
> > 
> > I found a patch that was submitted by Karoly Pados in 2018 [3] that
> > seemes to add support for that (though maybe only for a specific chip).
> > 
> > Through a little bit of ftrace and printk I realized that the switch
> > statement in ftdi_gpio_init was falling through to the default case for
> > the FT232H [4].
> 
> So it sounds like you have the wrong device type.  Can you make sure you
> use the latest kernel release (5.5) and if you have problems with this,
> email the linux-usb mailing list as the driver maintainers for that
> driver are there.

As Greg suggested you need to update your kernel as GPIO support for
FT232H went into 5.4.

Johan

  parent reply	other threads:[~2020-03-24  9:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-22 19:40 FT232H user space GPIO device Ryan Lovelett
2020-03-23  6:52 ` Greg KH
2020-03-23 13:00   ` Ryan Lovelett
2020-03-24  9:28   ` Johan Hovold [this message]
2020-03-24 12:38     ` Ryan Lovelett

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