as we introduce swd and jtag as two transports, we want
to start up with a new transport folder to organize the
code a bit.

Signed-off-by: Spencer Oliver <ntfreak@users.sourceforge.net>

* Bugfix and simplify legacy jtag-only defaulting
* Make "dummy" declare its jtag-only nature
* likewise update ft2232
* warn if selection is _required_ (multi-transport adapters),

fixes the "only ft2232 works" bug for at least dummy, with
other drivers going the "legacy" path (submit patches).

Signed-off-by: David Brownell <db@helium.(none)>

Classic manifestation of weakness of dangling {
formatting :-) Hard to spot these sort of mistakes visually.

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

This adds the guts of a transport framework with initialization,
which should work with current JTAG-only configurations (tested
with FT2232).

Each debug adapter can declare the transports it supports, and
exactly one transport is initialized.  (with its commands) in
any given OpenOCD session.

  * Define a new "struct transport with init hooks and a few
 "transport"  subcommands to support it:

     "list" ... list the transports configured (just "jtag" for now)
     "select" ... makes the debug session use that transport
     "init" ... initializes the selected transport (internal)

  * "interface_transports" ... declares transports the current interface
    can support.  (Some will do this from C code instead, when there are
    no hardware versioning (or other) issues to prevent it.

Plus some FT2232 tweaks, including a few to streamline upcoming
support for an SWD transport (initially for Luminary adapters).

Eventually src/jtag should probably become src/transport, moving
jtag-specific stuff  to transport/jtag.

Signed-off-by: David Brownell <db@helium.(none)>

Signed-off-by: Øyvind Harboe <oyvind.harboe@zylin.com>

Clean up the jtag/tcl.c file, which was one of the biggest and
messiest ones in that directory.  Do it by splitting out all the
generic adapter commands to a separate "adapter.c" file (leaving
the "tcl.c" file holding only JTAG utilities).

Also rename the little-used "jtag interface" to "adapter_name", which
should have been at least re-categorized earlier (it's not jtag-only).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>