ZTE MC315 CDMA wireless PCMCIA data card on Linux

[Russell King]

On Mon, Dec 04, 2006 at 10:31:05PM -0500, Dominik Brodowski wrote:
> Hi,
> 
> On Thu, Nov 02, 2006 at 12:40:52PM +0530, Prof. Prabhat Ranjan wrote:
> > Basically it is based on Qualcomm 5105/6025 platform and seems to use Oxford 
> > Semiconductors OXCF950 Rev B. Here are the output from pccardctl :
> > 
> > $MANFID - 0279,950b
> > $FUNCID - 2
> > $PRODID_1 - CDMA1X
> > $PRODID_2 - CARD
> > 
> > In the file  "linux-2.6.18.1/drivers/serial/serial_cs.c" a number of 
> > workaround for OXCF950 Rev B have been added. In addition, I have also noted 
> > that in file 8250.c, 8250_pci.c and sunsu.c workarounds for this paricular 
> > chip. One of this seems to be related to Baudrate miscalculation. However, 
> > this workaround has not been done in serial_cs.c.
> > 
> > I am wondering whether the card is not responding due to one of these 
> > workarounds not being applied in serial_cs.c or any other pointers one may 
> > have.
> 
> Actually, these workarounds are already executed, else the code wouldn't
> reach the line stating the addition of ttyS3. Russell, do you have any ideas
> on what's going wrong here? Or someone (i.e. new linux-serial maintainer)
> who might be interested in this?

Not sure.  Wild stab in the dark time.

The 950 has a set of registers which select a clock divisor.  It appears
that on some bluetooth cards, these registers are set at power up to be
compatible with standard 16550A baud rate divisor numbers.

However, we reset the chip, which resets the clock divisor registers
back to zero.

What Prof. Prabhat could try is communicating with the card after
selecting a slow baud rate, and see whether that gets anywhere.

Because of this clock divisor register setup, all 950 seem to require
quite a bit of black art to get them working.  I would have dearly liked
to have a 950 card to be used for experimenting with, but I tried for
_years_ (literally) and never got anywhere...

Consequently, I do not have any enthusiasm for 950 support.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of: