Support two-wire cJTAG OSCAN1 and JScan3 using FTDI adapters

cJTAG OSCAN1, in lieu of 4-wire JTAG, is starting to be a configuration
option for some SiFive hardware. An FTDI-based adapter that can be
configured to drive the bidirectional pin TMSC is assumed for this
topology. Specifically, the Olimex ARM-USB-TINY-H with the ARM-JTAG-SWD
adapter, connected to a SiFive cJTAG-enabled target board is the only
known concrete topology, currently. But in theory, other FTDI based
devices that can drive a two-wire bidirectional signaling pattern could
be made to work in this scheme in the future.

These code changes are offered as a way to drive that topology. It's
translating IR/DR and JTAG traversal commands to the two-wire clocking
and signaling.

See:
- https://github.com/riscv-collab/riscv-openocd/pull/320
- https://github.com/riscv-collab/riscv-openocd/pull/736

Signed-off-by: Greg Savin <greg.savin@sifive.com>
Signed-off-by: mrv96 <mrv96@users.noreply.github.com>
Signed-off-by: Tim Newsome <tim@sifive.com>
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Change-Id: Ia1daa2c01227c4b0005be947b2bb0de81a800874
Reviewed-on: https://review.openocd.org/c/openocd/+/6981
Tested-by: jenkins

tcl/interface/ftdi/olimex-arm-jtag-cjtag.cfg

@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+#
+# Olimex ARM JTAG SWD adapter
+# https://www.olimex.com/Products/ARM/JTAG/ARM-JTAG-SWD/
+#
+
+#
+# Olimex ARM-USB-TINY-H
+#
+# http://www.olimex.com/dev/arm-usb-tiny-h.html
+#
+
+interface ftdi
+ftdi oscan1_mode on
+ftdi device_desc "Olimex OpenOCD JTAG ARM-USB-TINY-H"
+ftdi vid_pid 0x15ba 0x002a
+
+ftdi layout_init 0x0808 0x0a1b
+ftdi layout_signal nSRST -oe 0x0200
+# oscan1_ftdi_layout_signal nTRST -data 0x0100 -oe 0x0100
+ftdi layout_signal LED -data 0x0800
+
+# These signals are used for cJTAG escape sequence on initialization only
+ftdi layout_signal TCK -data 0x0001
+ftdi layout_signal TDI -data 0x0002
+ftdi layout_signal TDO -input 0x0004
+ftdi layout_signal TMS -data 0x0008
+ftdi layout_signal JTAG_SEL -data 0x0100 -oe 0x0100

tcl/interface/ftdi/olimex-arm-usb-ocd-h-cjtag.cfg

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+#
+# Olimex ARM-USB-OCD-H (using cJTAG)
+#
+# http://www.olimex.com/dev/arm-usb-ocd-h.html
+#
+
+interface ftdi
+ftdi oscan1_mode on
+ftdi device_desc "Olimex OpenOCD JTAG ARM-USB-OCD-H"
+ftdi vid_pid 0x15ba 0x002b
+
+ftdi layout_init 0x0808 0x0a1b
+ftdi layout_signal nSRST -oe 0x0200
+# oscan1_ftdi_layout_signal nTRST -data 0x0100 -oe 0x0100
+ftdi layout_signal LED -data 0x0800
+
+# These signals are used for cJTAG escape sequence on initialization only
+ftdi layout_signal TCK -data 0x0001
+ftdi layout_signal TDI -data 0x0002
+ftdi layout_signal TDO -input 0x0004
+ftdi layout_signal TMS -data 0x0008
+ftdi layout_signal JTAG_SEL -data 0x0100 -oe 0x0100

tcl/interface/ftdi/olimex-arm-usb-tiny-h-cjtag.cfg

@@ -0,0 +1,29 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+#
+# Olimex ARM JTAG SWD adapter
+# https://www.olimex.com/Products/ARM/JTAG/ARM-JTAG-SWD/
+#
+
+#
+# Olimex ARM-USB-TINY-H (using cJTAG)
+#
+# http://www.olimex.com/dev/arm-usb-tiny-h.html
+#
+
+interface ftdi
+ftdi oscan1_mode on
+ftdi device_desc "Olimex OpenOCD JTAG ARM-USB-TINY-H"
+ftdi vid_pid 0x15ba 0x002a
+
+ftdi layout_init 0x0808 0x0a1b
+ftdi layout_signal nSRST -oe 0x0200
+# oscan1_ftdi_layout_signal nTRST -data 0x0100 -oe 0x0100
+ftdi layout_signal LED -data 0x0800
+
+# These signals are used for cJTAG escape sequence on initialization only
+ftdi layout_signal TCK -data 0x0001
+ftdi layout_signal TDI -data 0x0002
+ftdi layout_signal TDO -input 0x0004
+ftdi layout_signal TMS -data 0x0008
+ftdi layout_signal JTAG_SEL -data 0x0100 -oe 0x0100