ftdi-usb-sio-devel — FTDI USB Device Driver development discussion list

[Ftdi-usb-sio-devel] FT8U245AM

[Frederic <li...@gb...>]

Hello there,

I'm using a nice mp3 player called 'yampp3/usb'. You can find this project 
at :

   http://www.myplace.nu/mp3/index2.htm

This mp3 player uses a window front-end to download mp3 files (or new 
firmeware) through the ftdi FT8U245AM chip. I would like to develop tools 
to do that under Linux.

As a first step, I have to be able to read and write datas to the USB 
chip. I read that the 245 uses the same driver as the 232. But I don't 
understand how to use it. How can I read/write // datas ? Is it the same 
that writing serial datas ? But What to do with speed and all RS323 stuff? 
Can I skip it ?

Could someone help me a little bit, maybe just by pointing me to an 
example...

Regards,

-- 

   Frederic

   http://www.gbiloba.org

[Ftdi-usb-sio-devel] DLP-USB245M

[Per H. <per...@mv...>]

Hi folks,

I'm using a DLP-USB245M module which seems to be a nice little thing.
Under Windows I can use the VCP driver to read&write (still have a bit
problem with the direct driver to install properly)

Under Linux I can write to the device but the reads doesn't make it.
Anyone got an idea of what I'm doing wrong here?

Best regards,
Per

Bus 001 Device 012: ID 0403:6001 Future Technology Devices
Device Descriptor:
   bLength                18
   bDescriptorType         1
   bcdUSB               1.10
   bDeviceClass            0 Interface
   bDeviceSubClass         0
   bDeviceProtocol         0
   bMaxPacketSize0         8
   idVendor           0x0403 Future Technology Devices
   idProduct          0x6001
   bcdDevice            4.00
   iManufacturer           1 DLP Design
   iProduct                2 DLP-USB245M
   iSerial                 3 DPAOHY76
   bNumConfigurations      1
   Configuration Descriptor:
     bLength                 9
     bDescriptorType         2
     wTotalLength           32
     bNumInterfaces          1
     bConfigurationValue     1
     iConfiguration          0
     bmAttributes         0xa0
       Remote Wakeup
     MaxPower               44mA
     Interface Descriptor:
       bLength                 9
       bDescriptorType         4
       bInterfaceNumber        0
       bAlternateSetting       0
       bNumEndpoints           2
       bInterfaceClass       255 Vendor Specific Class
       bInterfaceSubClass    255 Vendor Specific Subclass
       bInterfaceProtocol    255 Vendor Specific Protocol
       iInterface              2 DLP-USB245M
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x81  EP 1 IN
         bmAttributes            2
           Transfer Type            Bulk
           Synch Type               none
         wMaxPacketSize         64
         bInterval               0
       Endpoint Descriptor:
         bLength                 7
         bDescriptorType         5
         bEndpointAddress     0x02  EP 2 OUT
         bmAttributes            2
           Transfer Type            Bulk
           Synch Type               none
         wMaxPacketSize         64
         bInterval               0
   Language IDs: (length=4)
      0409 English(US)
[root@perh root]#

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb (fwd)

[Mike R. <er...@es...>]

Looks like I need to patch usb-serial.h: struct usb_serial_port {
too.  I get the following error:

ftdi_sio.c:436: structure has no member named `sem'

from:   	down(&port->sem);

and looking at usb-serial.h it's obvious why I've got an error.
Source forge is down today for moving, when you get a chance can
you send me an updated usb-serial.h?  Thanks.

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb (fwd)

[Mike R. <er...@es...>]

On Mon, 18 Nov 2002, Bill Ryder wrote:

> On mandrake 9 with the 2.4.20-rc1 kernel  "/dev/usb/ttyUSB0" is a link
> to /dev/ttyUSB0.
>
> This is the device I use so the device should be OK. The major/minor
> numbers for /dev/ttyUSB0 and /dev/usb/ttyUSB0 should be the same.
>
> I use /dev/ttyUSB0 for everything I ever do with the device.

OK, so it shouldn't make any difference.  (I did create all those,
and it didn't change anything).

> You should definitely turn on the full usb serial debugging to get some
> more info from the driver methinks.

I just copied the bryder_20011111_2.4.15-pre2_ftdi_sio.patch into
my kernel source.  Next step is to compile it and try testing
things.  I've never dived this deep into things before, but that's
the point of linux.  What's the easy way to set CONFIG_USB_SERIAL_DEBUG?

My main purpose is to make hardware work, I don't think anyone else
should need a back port.

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb (fwd)

[Bill R. <br...@pa...>]

HI there,


Mike Rosing wrote:

>I was just going to sleep when the below output came back to me:
>
>  
>
>>Nov 14 21:23:07 localhost kernel: usbserial.c: FTDI 8U232AM converter now
>>attached to ttyUSB0 (or usb/tts/0 for devfs)
>>
>>and dmesg returns:
>>
>>usbserial.c: FTDI 8U232AM converter now attached to ttyUSB0 (or usb/tts/0
>>for devfs)
>>
>>So I'm doing something stupid in my calls to the driver.  Here's what I
>>do:
>>	portname == "/dev/usb/ttyUSB0"
>>

On mandrake 9 with the 2.4.20-rc1 kernel  "/dev/usb/ttyUSB0" is a link 
to /dev/ttyUSB0.

This is the device I use so the device should be OK. The major/minor 
numbers for /dev/ttyUSB0 and /dev/usb/ttyUSB0 should be the same.

I use /dev/ttyUSB0 for everything I ever do with the device.

You should definitely turn on the full usb serial debugging to get some 
more info from the driver methinks.

---
Bill

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb (fwd)

[Mike R. <er...@es...>]

I was just going to sleep when the below output came back to me:

>Nov 14 21:23:07 localhost kernel: usbserial.c: FTDI 8U232AM converter now
>attached to ttyUSB0 (or usb/tts/0 for devfs)
>
>and dmesg returns:
>
>usbserial.c: FTDI 8U232AM converter now attached to ttyUSB0 (or usb/tts/0
>for devfs)
>
>So I'm doing something stupid in my calls to the driver.  Here's what I
>do:
>	portname == "/dev/usb/ttyUSB0"
>
>	serial = open( portname, O_RDWR | O_NOCTTY | O_NONBLOCK);

The attachment may not be quite right.  usbserial wants the device to
be in a sub-directory of /dev, but the actuall serial driver does not.
I'll try moving my device files up one directory and see if that helps.

Otherwise, I get to learn about usb calls directly (I did a "man devfs"
and "man -K devfs" and got nothing on my machine, so it's gonna take
a while :-)

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Mike R. <er...@es...>]

On Thu, 14 Nov 2002, Bill Ryder wrote:

> Does it write into /var/log/messages saying a FTDI device was detected?
> /proc doesn't tell the whole story - it will take you a usb device was
> detected.

Yeah, baby, this looks really good:

Nov 14 21:23:07 localhost kernel: hub.c: USB new device connect on bus1/1,
assigned device number 2
Nov 14 21:23:07 localhost kernel: usb.c: USB new device connect, assigned
device number 2
Nov 14 21:23:07 localhost kernel: Manufacturer: FTDI
Nov 14 21:23:07 localhost kernel: Product: USB <-> Serial
Nov 14 21:23:07 localhost kernel: usbserial.c: FTDI 8U232AM converter
detected
Nov 14 21:23:07 localhost kernel: usbserial.c: FTDI 8U232AM converter now
attached to ttyUSB0 (or usb/tts/0 for devfs)

and dmesg returns:

hub.c: port 1 connection change
hub.c: port 1, portstatus 101, change 1, 12 Mb/s
hub.c: port 1, portstatus 103, change 10, 12 Mb/s
hub.c: USB new device connect on bus1/1, assigned device number 2
usb.c: USB new device connect, assigned device number 2
usb.c: kmalloc IF d18c5900, numif 1
usb.c: new device strings: Mfr=1, Product=2, SerialNumber=0
usb.c: USB device number 2 default language ID 0x409
Manufacturer: FTDI
Product: USB <-> Serial
usbserial.c: Looking at FTDI 8U232AM Vendor id=0403 Product id=6001
usbserial.c: descriptor matches
usbserial.c: found bulk in
usbserial.c: found bulk out
usbserial.c: FTDI 8U232AM converter detected
usbserial.c: get_free_serial 1
usbserial.c: get_free_serial - minor base = 0
usbserial.c: usb_serial_probe - setting up 1 port structures for this
device
usbserial.c: FTDI 8U232AM converter now attached to ttyUSB0 (or usb/tts/0
for devfs)
usb.c: serial driver claimed interface d18c5900

So I'm doing something stupid in my calls to the driver.  Here's what I
do:

	serial = open( portname, O_RDWR | O_NOCTTY | O_NONBLOCK);
  [..error check on serial ok..]
	tcgetattr( serial, &tio);
	printf("tio.c_cc[vmin] = %d, [vtime] = %d\n", tio.c_cc[VMIN],
tio.c_cc[VTIME]);
	tio.c_iflag = 0;
	tio.c_oflag = 0;
	tio.c_cflag = CREAD | CRTSCTS | CS8 | B38400 | CLOCAL;
	tio.c_lflag = 0;

/*  use time instead of data.  If no response, something wrong.
	If there is  a response, deal with as much as possible.
*/
	tio.c_cc[VMIN] = 0;
	tio.c_cc[VTIME] = 1;
	tcflush( serial, TCIOFLUSH);
	tcsetattr( serial, TCSANOW, &tio);

   [...other stuff for me ...]
	i = ioctl( serial, TIOCMGET, &arg);
	printf("error = %d  iniitial bits are %x\n", i, arg);
	outmsg[0] = 'A';
	outmsg[1] = 'B';
	outmsg[2] = 'C';
	num = write( serial, outmsg, 3);
	if(num<0) perror("write didn't work");
	j = 0;
	while( j<10)
	{
		num = read( serial, inmsg, 63);
		if (num < 0) perror("first read didn't work");
	:
	:

and here's what I get:

tio.c_cc[vmin] = 0, [vtime] = 1
error = 0  iniitial bits are 120
Initializing com link to jtag interface

first read didn't work: Resource temporarily unavailable
number of bytes from 0x81 command -1
number of bytes from 0x81 command 3
received A@A
init_stream returns 4

>  I am making an *assumption* (possibly unwarranted) that it won't work
> because I am not aware of anyone backporting the current drivers - and
> the early versions had plenty of bugs and they only supported the
> original SIO.

Yeah, it seems like I should be able to fake my way past it tho.
I just gotta make the driver think it's doing something useful,
even tho there are no serial lines out there.

> ftdi_sio_write
>
> The trick with the devices is the original device (the SIO)  required a
> byte count on the front of the output packet, the newer devices (ie the
> 232AM and 232BM, 245 don't.
>
> So your choices are to backport the current driver, or compare the
> current driver to the driver in 2.2 and fix it manually. Certainly not
> impossible.

Oh I see, that extra byte is being sent to the device, and it's not
really needed.  Maybe I can fake that out too, but I guess talking to
the usb device directly rather than to the serial device might be simpler.

Thanks, I think it's getting closer.  Yesterday I didn't even get the "A"
back, just pure garbage.  If all I have to do is change the open() line
and it makes the driver happy, I may be in the clear.

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] easy questions

[Bill R. <br...@pa...>]

Hi there,


Alberto Mainoni wrote:

>I have a too easy questions!
>How can I compile the 1.2.1 driver.
>I have used gcc -c ftdi_sio.c, I have a lot of errors in file
>included.
>Can I have an exactly procedure to do it please.
>I am use e Mandrake 9 with kernel 2.4.19!
>

This is the place to go for how to build a kernel.

http://www.tldp.org/HOWTO/Kernel-HOWTO.html

And here's some general kernel info

http://www.tldp.org/HOWTO/KernelAnalysis-HOWTO.html

You will need to put the driver files in the directory
   <kernel_source_root_whereever>/drivers/usb/serial

and then do your:
   make modules
   make modules_install

assuming it is configured as a loadable module.

---
Bill

[Ftdi-usb-sio-devel] easy questions

[Alberto M. <ma...@ti...>]

I have a too easy questions!
How can I compile the 1.2.1 driver.
I have used gcc -c ftdi_sio.c, I have a lot of errors in file
included.
Can I have an exactly procedure to do it please.
I am use e Mandrake 9 with kernel 2.4.19!

Thanks for responses
Regards,

Albert

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Mike R. <er...@es...>]

Thanks!  I'll be digging into it later this evening (morning my
time now :-)

Since I've got more time than money, hacking is the way to go...

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Bill R. <br...@pa...>]

Mike Rosing wrote:

>On Thu, 14 Nov 2002, Bill Ryder wrote:
>
>  
>
>>As far as I know the device is not supported in the 2.2 kernels - just
>>the 2.4 kernels.
>>    
>>
>
>Bummer.  It said on the kernel page that 2.2.20 has the driver (which
>is obvious since it sees the device).
>

Does it write into /var/log/messages saying a FTDI device was detected? 
/proc doesn't tell the whole story - it will take you a usb device was 
detected.

>>It is possible that the usb-serial default driver is picking up the
>>device but there is no way that will work properly.
>>
>>So you'll need to move to a 2.4.18 kernel or above.
>>    
>>
>
>Any particular reason why? 
>
The main reason the device is 'not supported' in the 2.2 kernels is 
because I don't run the 2.2.x kernels :-)

 I am making an *assumption* (possibly unwarranted) that it won't work 
because I am not aware of anyone backporting the current drivers - and 
the early versions had plenty of bugs and they only supported the 
original SIO.

> I've got the sources, maybe I can hack
>something and fix my problem?  When I do a write() to the /dev/ttyUSB0,
>which routine in ftdi_sio.c actually gets it?
>
ftdi_sio_write

The trick with the devices is the original device (the SIO)  required a 
byte count on the front of the output packet, the newer devices (ie the 
232AM and 232BM, 245 don't.

So your choices are to backport the current driver, or compare the 
current driver to the driver in 2.2 and fix it manually. Certainly not 
impossible.


Good luck!

Bill

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Mike R. <er...@es...>]

On Thu, 14 Nov 2002, Bill Ryder wrote:

>
> As far as I know the device is not supported in the 2.2 kernels - just
> the 2.4 kernels.

Bummer.  It said on the kernel page that 2.2.20 has the driver (which
is obvious since it sees the device).

> It is possible that the usb-serial default driver is picking up the
> device but there is no way that will work properly.
>
> So you'll need to move to a 2.4.18 kernel or above.

Any particular reason why?  I've got the sources, maybe I can hack
something and fix my problem?  When I do a write() to the /dev/ttyUSB0,
which routine in ftdi_sio.c actually gets it?

I've got a lot of stuff that will probably break if I go from 2.2.x to
2.4.x, and since usb is already broken it's easier to just fix that!

If it's hopeless, and I'm screwed, I won't have much choice.  But I'd like
to know why.  Thanks!!

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Bill R. <br...@pa...>]

Hi there,

As far as I know the device is not supported in the 2.2 kernels - just 
the 2.4 kernels.

It is possible that the usb-serial default driver is picking up the 
device but there is no way that will work properly.

So you'll need to move to a 2.4.18 kernel or above.

Mike Rosing wrote:

>Howdy,
>
>I have attached a 245 "B" to a usb cable on a 2.2.20
>linux kernel.  When I cat /proc/bus/usb/devices it shows
>up just fine.  When I open /dev/usb/ttyUSB0 I have no
>errors, but when I try to send data to the chip, I get no
>RFX response.  I assume I've got something wrong in the
>set up call to the driver.  What are the correct serial
>parameters the driver wants to see?
>
>It seems like the serial parameters don't matter, but
>I bet they have to be what the driver likes.  Any
>hints appreciated!
>
>Patience, persistence, truth,
>Dr. mike
>
>
>
>
>-------------------------------------------------------
>This sf.net email is sponsored by: Are you worried about 
>your web server security? Click here for a FREE Thawte 
>Apache SSL Guide and answer your Apache SSL security 
>needs: http://www.gothawte.com/rd523.html
>_______________________________________________
>Ftdi-usb-sio-devel mailing list
>Ftd...@li...
>https://lists.sourceforge.net/lists/listinfo/ftdi-usb-sio-devel
>
>
>  
>

[Ftdi-usb-sio-devel] howto: setting up driver to ftdi usb

[Mike R. <er...@es...>]

Howdy,

I have attached a 245 "B" to a usb cable on a 2.2.20
linux kernel.  When I cat /proc/bus/usb/devices it shows
up just fine.  When I open /dev/usb/ttyUSB0 I have no
errors, but when I try to send data to the chip, I get no
RFX response.  I assume I've got something wrong in the
set up call to the driver.  What are the correct serial
parameters the driver wants to see?

It seems like the serial parameters don't matter, but
I bet they have to be what the driver likes.  Any
hints appreciated!

Patience, persistence, truth,
Dr. mike

Re: [Ftdi-usb-sio-devel] Question on FTDI driver

[Bill R. <br...@pa...>]

  Hi,

There is no correspondence between the serial number of the device and 
the /dev/ttyUSB number.

The first device enumerated gets USB0, then next USB1 and so on.

You are correct about the usb-serial layer needing to be changed A lot 
of work would be required to make this work through to the usb-serial 
infrastructure (at least last time I looked at it anyway) which is not 
something I am interested in doing.

If you want to work on a solution the other person to liase with would 
be Greg since he  owns the usb-serial layer but this topic has been 
broached before and there isn't much interest in the current developers.

Bill


Serge Manigault wrote:

>Hello,
>I would like to know were are stored the informations about the link
>between the FTDI chip (serial number) and the linux device /dev/ttyUSB?
>I didn't find any tools related to such information.
>I try to use several FTDI chip connected (hotpluged) on a HUB.
>I had a look at the sources and may be it's more an usb-serial upper
>layer,
>may be someone here will have a link...
>Thanks for any responses,
>Regards,
>
>Serge
>
>
>
>  
>

[Ftdi-usb-sio-devel] Question on FTDI driver

[Serge M. <Ser...@as...>]

Hello,
I would like to know were are stored the informations about the link
between the FTDI chip (serial number) and the linux device /dev/ttyUSB?
I didn't find any tools related to such information.
I try to use several FTDI chip connected (hotpluged) on a HUB.
I had a look at the sources and may be it's more an usb-serial upper
layer,
may be someone here will have a link...
Thanks for any responses,
Regards,

Serge

[Ftdi-usb-sio-devel] Info on USB serial converter device side firmware

[Rupesh S <ru...@my...>]

Hi,
I'm planning to develop a console support through USB, with a Motorola =
coldfire processor integrated USB controller.console support on the host =
will be making use of a dumb terminal on a virtual serial port(USB).
Any body can help me get some sample source code on the device firmware ??
Rupesh

Re: [Ftdi-usb-sio-devel] FT232BM & Linux support

[Bill R. <br...@pa...>]

The BM samples I recently received from FTDI (thanx FTDI :-) work fine 
with the stock driver.

The only changes you might have to make is add a new VID/PID so the 
driver reconises them (but my samples didn't need this)

The BM's do have some new features  which I am working on supporting in 
the driver. (namely the programmable latency).

---
Bill



Rolf Brudeseth wrote:

>Is the FT232BM chip also supported in the 2.4.20 kernel?
>                                                                            
>                                                                            
> The 'http://ftdi-usb-sio.sourceforge.net/' web site only makes reference   
> to the FT8U232AM chip.                                                     
>                                                                            
> However, the data-sheet indicates support:                                 
> http://ftdichip.com/Documents/ds232b11.pdf                                 
>                                                                            
> Thanks,                                                                    
>                                                                            
> Rolf                                                                       
>                                                                            
>                                                                            
>                                                                            
>                                                                            
>
>--
>Rolf Brudeseth
>ro...@us...
>pSeries System Engineering & Integration, IBM Enterprise Systems Group
>Austin, TX
>
>
>
>
>
>-------------------------------------------------------
>This sf.net email is sponsored by: Influence the future 
>of Java(TM) technology. Join the Java Community 
>Process(SM) (JCP(SM)) program now. 
>http://ads.sourceforge.net/cgi-bin/redirect.pl?sunm0003en
>_______________________________________________
>Ftdi-usb-sio-devel mailing list
>Ftd...@li...
>https://lists.sourceforge.net/lists/listinfo/ftdi-usb-sio-devel
>
>
>  
>

[Ftdi-usb-sio-devel] FT232BM & Linux support

[Rolf B. <ro...@us...>]

Is the FT232BM chip also supported in the 2.4.20 kernel?
                                                                            
                                                                            
 The 'http://ftdi-usb-sio.sourceforge.net/' web site only makes reference   
 to the FT8U232AM chip.                                                     
                                                                            
 However, the data-sheet indicates support:                                 
 http://ftdichip.com/Documents/ds232b11.pdf                                 
                                                                            
 Thanks,                                                                    
                                                                            
 Rolf                                                                       
                                                                            
                                                                            
                                                                            
                                                                            

--
Rolf Brudeseth
ro...@us...
pSeries System Engineering & Integration, IBM Enterprise Systems Group
Austin, TX

Re: [Ftdi-usb-sio-devel] (no subject)

[Bill R. <br...@pa...>]

I was thinking about using the POSIX VTIME/VMIN stuff  to do this.

The baudrate could be used to figure out the minimum latency is someone 
uses the VMIN value, and VTIME will almost translate directly at least 
up to 16ms anyway.

I have sent off an email to FTDI today to get more info on the BM.



Ian Abbott wrote:

>On Monday 14 October 2002 12:39, Gilles GRENIER wrote:
>  
>
>>is it possible to set the latency timer different to 16ms (for
>>FT232BM device with the actual (kernel 2.4.20) driver)? best regards
>>Gilles GRENIER
>>    
>>
>
>No, the current driver doesn't support this yet, mainly because the 
>FT232BM  hasn't been around very long!
>
>I'm not sure where such a mechanism would fit into the driver - Perhaps 
>the Hayes ESP ioctls, TIOCGHAYESESP and TIOCSHAYESESP could be borrowed 
>so that setserial's 'rx_timeout' parameter could be used to set the 
>latency, but this would be a bit of a kludge.  The legitimate values 
>for the 'rx_timeout' parameter (0 to 255) do correspond quite nicely 
>with the latency times that the FT232BM can be set to though (1 to 255 
>ms)!
>
>Another possibility may be to make the latency depend on the baud rate 
>in some way, though that would be odd for the FT245BM USB FIFO device, 
>as it doesn't really have a baud rate.
>  
>

Re: [Ftdi-usb-sio-devel] (no subject)

[Ian A. <ab...@me...>]

On Monday 14 October 2002 12:39, Gilles GRENIER wrote:
> is it possible to set the latency timer different to 16ms (for
> FT232BM device with the actual (kernel 2.4.20) driver)? best regards
> Gilles GRENIER

No, the current driver doesn't support this yet, mainly because the 
FT232BM  hasn't been around very long!

I'm not sure where such a mechanism would fit into the driver - Perhaps 
the Hayes ESP ioctls, TIOCGHAYESESP and TIOCSHAYESESP could be borrowed 
so that setserial's 'rx_timeout' parameter could be used to set the 
latency, but this would be a bit of a kludge.  The legitimate values 
for the 'rx_timeout' parameter (0 to 255) do correspond quite nicely 
with the latency times that the FT232BM can be set to though (1 to 255 
ms)!

Another possibility may be to make the latency depend on the baud rate 
in some way, though that would be odd for the FT245BM USB FIFO device, 
as it doesn't really have a baud rate.
-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <ab...@me...>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-

[Ftdi-usb-sio-devel] (no subject)

[Gilles G. <ggr...@mi...>]

Hi,
is it possible to set the latency timer different to 16ms (for FT232BM =
device with the actual (kernel 2.4.20) driver)?
best regards
Gilles GRENIER
ggr...@mi...
MIDI SYSTEM
FRANCE
(+33)4 92 92 59 08

[Ftdi-usb-sio-devel] sample application needed

[Gilles G. <ggr...@mi...>]

Hi,
i'm trying to use ftdi drivers i have some questions...
i open the device (/dev/ttyUSB0) at 115200bps and when i receive a =
special character(0xf) is send 64 bytes over the device.
but the delay beetwen receiving character and transfert data is too long =
(16ms).
my question is: how to reduce the transfert time?

may be i have badly initialized the device?
regards

Gilles GRENIER
ggr...@mi...
MIDI SYSTEM
FRANCE
(+33)4 92 92 59 08

Re: [Ftdi-usb-sio-devel] 62 bytes... comes from where?

[Bill R. <br...@pa...>]

Hi there,

I've been off air for a while (leaving SGI) hence the late reply.


Kentaro Fukuchi wrote:

>Our question is
>
>1) why read() returns 62 bytes at once?
>

The device returns 64 bytes in one read at the moment - two of which are 
status bytes -  which gives you 62 bytes.

The longer you wait the larger the buffer should get.

As to your second question sounds like you just had a bug with the 
controller driver.

>2) who drops rest 79 bytes? FTDI or the driver?
>
>We uses the latest driver (version 1.2.1).
>
>Thanks in advance.
>
>Kentaro Fukuchi
>  
>

---
Bill Ryder

>  
>

[Ftdi-usb-sio-devel] Re: Support of USB to FIFO parallel device

[Ian A. <ab...@me...>]

[sorry for lack of threading - I'm cut'n'pasting from the archives!]

Bill Ryder wrote:
>Stephen Noftall wrote:
>>I am using FTDI's FT245BM chip with Linux on an embedded board I am
>>designing.
>>
>>I was wondering if anyone has used this chip before? Is there any gotchas
>>with it?

>I have only tested with the 245AM so far so I am not sure what issues 
>you might have. Assuming the protocol to talk to the device is the same 
>at the most you should just need to change the vendor/product id.

It ought to be noted that FTDI can issue a USB PID for your design, using 
FTDI's VID. See the FTDI's FAQ at <http://www.ftdichip.com/FTSupport.htm>.

The "BM" chips (FT232BM UART and FT245BM FIFO) seem to be similar to the "AM" 
parts. The data sheets don't go down to the register level (they seem to be 
aimed more towards hardware engineers rather than programmers!), but as far 
as drivers are concerned, the following differences are of note:

* The BM chips support an isosynchronous transfer mode in addition to the
  "bulk" transfer mode.  This is selected by an option bit in the EEPROM.

* The FT232BM chip has a programmable read buffer timeout (1ms to 255ms)
  rather than a fixed 16ms timeout.

* The FT245BM chip has a programmable FIFO TX buffer timeout (1ms to 255ms)
  rather than a fixed 16ms timeout.

* The fractional part of the FT232BM's divisor has an extra bit so it now does
  all the eighths, rather than just n+0, n+0.125, n+0.25 and n+0.5.  I guess
  this means the divisor register is now 17 bits long, but the divisor bits
  are still mixed up.

* The BM chips support a "bit bang" mode for switching the 8 UART interface
  control signals between UART interface mode and an 8-bit parallel IO port.
  It's meant for programming FPGAs and suchlike.

* The FT232BM supports a baud rate of 2000000 baud (3000000 divided by
  1.5).  This did not work on the FT8U232AM.  However, baud rates of 2666666,
  2400000, 2181818, 1846153, 1714285 and 1600000 (3000000 divided by 1.125,
  1.25, 1.375, 1.625, 1.75 and 1.875) do not appear to be supported.

* The BM chips have an option bit in the EEPROM to return a USB 2.0 descriptor
  rather than a USB 1.1 descriptor.  The USB 2.0 descriptor identifies it as a
  "Full Speed" (12 Mb/s) device.

I'm thinking of implementing the extra baud rates for the FT232BM (unless 
someone else has already done it!) and adding the default USB PIDs for the 
FT232BM and FT245BM.  I'm not sure where the other stuff such as programmable 
timeouts and isosynchronous transfer support fits into the scheme of things 
yet, driver-wise.  The company I work for is planning to replace a FT8U232AM 
in an existing design with the FT232BM and may be using the FT245BM in some 
other designs.

-- 
-=( Ian Abbott @ MEV Ltd.    E-mail: <ab...@me...>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-