Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices

From	Johan Hovold <johan@kernel.org>
Newsgroups	linux.kernel
Subject	Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices
Date	2017-07-10 14:40 +0200
Message-ID	<u1G8O-53s-33@gated-at.bofh.it> (permalink)
References	<u0lSN-2dT-1@gated-at.bofh.it> <u0lSO-2dT-19@gated-at.bofh.it> <u0wbw-Lh-19@gated-at.bofh.it> <u0ydj-2cj-3@gated-at.bofh.it>
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On Fri, Jul 07, 2017 at 11:53:29AM +0200, Anatolij Gustschin wrote:
> On Fri, 07 Jul 2017 09:48:48 +0200
> Bjørn Mork bjorn@mork.no wrote:
> 
> >[adding Johan on the CC list]
> >
> >Anatolij Gustschin <agust@denx.de> writes:
> >
> >> +static struct usb_device_id ftdi_mfd_table[] = {
> >> +	{ USB_DEVICE(0x0403, 0x6014) },
> >> +	{}
> >> +};
> >> +MODULE_DEVICE_TABLE(usb, ftdi_mfd_table);  
> >
> >This device ID is currently handled by the ftdi_sio driver, so I believe
> >you at least have to explain how you intend these two drivers to
> >cooperate...
> 
> these drivers cannot cooperate, the different ftdi function modes
> use same device pins as in UART mode. So, you either can use the
> device in UART interface mode or in some different mode. I do not
> load the ftdi_sio module or do unbind the USB device from the
> ftdio_sio driver and bind it to the mfd driver, e.g.:
> 
>   sh -c "echo -n "3-2:1.0" > /sys/bus/usb/drivers/ftdi_sio/unbind"
>   sh -c "echo -n "3-2:1.0" > /sys/bus/usb/drivers/ftdi-mfd/bind"

I'm afraid that's not good enough. If we're going to support a non-UART
mode through a separate driver, we need to have all drivers for these
devices be able to retrieve the current mode during probe and only bind
when the mode matches.

Johan

Thread

[PATCH 0/3] FPGA Manager support for FPP via FT232H FT245-FIFO Anatolij Gustschin <agust@denx.de> - 2017-07-06 22:50 +0200
  [PATCH 1/3] mfd: Add support for FTDI FT232H devices Anatolij Gustschin <agust@denx.de> - 2017-07-06 22:50 +0200
    Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Bjørn Mork <bjorn@mork.no> - 2017-07-07 09:50 +0200
      Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Anatolij Gustschin <agust@denx.de> - 2017-07-07 12:00 +0200
        Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Johan Hovold <johan@kernel.org> - 2017-07-10 14:40 +0200
          Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Anatolij Gustschin <agust@denx.de> - 2017-07-11 09:00 +0200
            Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Johan Hovold <johan@kernel.org> - 2017-07-12 11:00 +0200
              Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Bjørn Mork <bjorn@mork.no> - 2017-07-12 11:20 +0200
              Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Anatolij Gustschin <agust@denx.de> - 2017-07-13 18:40 +0200
    Re: [PATCH 1/3] mfd: Add support for FTDI FT232H devices Johan Hovold <johan@kernel.org> - 2017-07-10 15:00 +0200
  [PATCH 2/3] gpio: Add FT232H CBUS GPIO driver Anatolij Gustschin <agust@denx.de> - 2017-07-06 22:50 +0200
  [PATCH 3/3] fpga manager: Add FT232H driver for Altera FPP Anatolij Gustschin <agust@denx.de> - 2017-07-06 23:00 +0200
    RE: [PATCH 3/3] fpga manager: Add FT232H driver for Altera FPP David Laight <David.Laight@ACULAB.COM> - 2017-07-07 11:40 +0200

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