[PATCH] serial: DCC(JTAG) serial and console emulation support
tony at atomide.com
Fri Oct 8 16:58:55 EDT 2010
* Tony Lindgren <tony at atomide.com> [101008 13:24]:
> * Nicolas Pitre <nico at fluxnic.net> [101007 18:16]:
> > On Thu, 7 Oct 2010, Tony Lindgren wrote:
> > >
> > > Can you please pass the read and write functions to the driver
> > > in platform_data? We are already booting kernels with both
> > > ARMv6 and 7 compiled in.
> > No. This has nothing to do with platform as this can be determined
> > within the driver itself. Would be much better to simply determine
> > which flavor to use at driver init time and assign two function pointers.
> In the long run some platform init code is needed for powering
> up the JTAG interface and take care of pin multiplexing etc.
> Also, isn't DCC (Debug Communications Channel) a JTAG standard? At least
> the following does not say anything about DCC being ARM specific:
> BTW, we already have ETM (Embedded Trace Module) in arch/arm/kernel/etm.c.
> That is set up as amba driver.
Hmm, then again it says this about the scan chains:
"SCAN_N ... ARM instruction to select the numbered scan chain used
with EXTEST or INTEST. There are six scan chains"
Which seems like these scan chains are ARM specific.
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