Re: [PATCH 1/1] Add c2 port support.

[Rodolfo Giometti <giometti@enneenne.com>]

On Fri, Oct 03, 2008 at 02:59:23PM -0700, Greg KH wrote:
> On Fri, Oct 03, 2008 at 04:36:29PM +0200, Rodolfo Giometti wrote:
> > C2port implements a two wire serial communication protocol (bit
> > banging) designed to enable in-system programming, debugging, and
> > boundary-scan testing on low pin-count Silicon Labs devices.
> > 
> > Currently this code supports only flash programming through sysfs
> > interface but extensions shoud be easy to add.
> > 
> > Signed-off-by: Rodolfo Giometti <giometti@linux.it>
> > ---
> >  drivers/misc/Kconfig       |   13 +
> >  drivers/misc/Makefile      |    1 +
> >  drivers/misc/c2port_core.c |  996 ++++++++++++++++++++++++++++++++++++++++++++
> >  include/linux/c2port.h     |   65 +++
> 
> Why does this file have to be in include/linux?  I don't think this
> exports any structures to userspace, and no other code calls this
> driver, so it should all fit into the .c file just fine.

The inlcude file is needed because you have to define a clients for
each c2 port implementations, see here for further info:

   http://wiki.enneenne.com/index.php/Silicon_C2_Interface

The file c2port_core.c implements the core, a client implements the
low level functions.

> Also, please create the needed Documentation/ABI/ files for these new
> sysfs entries, describing how they are used, and what the format of them
> are.

Ok.

> Is there any way to detect automatically if this hardware is present in
> the system or not?

I don't think so. The C2 port is usually implemented with two generic
GPIOs.

> Otherwise, how will it be loaded by a distro automatically?

The C2 port client is usually defined into platform machine data file,
for example I defined my client into linux/arch/arm/mach-pxa/wr1100.c
(wr1100.c is not in a vanilla tree, refere to mainstone.c for similar
code). In this manner the driver is autoloaded at boot time.

I posted the code in order to get some feedbacks and then repropose
something suitable for inclusion. So I'd like to know if I should make
a separate subdir into linux/drivers/misc/ to hold possible clients
(i.e. linux/drivers/misc/c2port/).

Thanks for your suggestions,

Rodolfo

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