backport: jtag/drivers: add T-Head CK-Link JTAG adapter driver

Driver for T-Head CK-Link Lite V2 probes, including the Bouffalo Lab
BL616/BL702 CK-Link clones used as built-in debuggers on BL61x/BL70x
evaluation boards. The wire protocol is a framed command format over
USB bulk endpoints, reverse-engineered from T-Head's DebugServer.

Implements JTAG_SCAN via the probe's batch opcode, with IR caching
across execute_queue boundaries and end-of-queue flush so OpenOCD's
Capture-IR validation reads real hardware data. Speed is programmable
(freq_kHz = 48000 / (N+1), capped at the DebugServer-validated 2526
kHz). Probes are matched against a built-in VID/PID list and by
adapter serial.

Known protocol limitations, surfaced as one-time warnings:

  - Single batch entry encodes IR/DR bit-counts in single bytes;
    scans > 255 bits are clamped with TDI pass-through on the
    un-shifted portion.
  - The T-Head DTM's Capture-IR returns the current IR value rather
    than the IEEE 1149.1 'xxx01' pattern; init pre-loads IR = IDCODE.
  - No TMS-sequence opcode: JTAG_TMS and JTAG_PATHMOVE return
    ERROR_JTAG_NOT_IMPLEMENTED.
  - Multi-TAP chains are not supported.
  - RTCK is not supported.

Tested against BL618 and BL702 evaluation boards.

Adapted for the Zephyr OpenOCD fork: uses .transports string array
instead of .transport_ids, and the 4-argument jtag_libusb_open()
signature (serial matching handled internally by libusb_helper).

Backport of:
https://review.openocd.org/c/openocd/+/9586

Signed-off-by: William Markezana <william.markezana@gmail.com>

Author: will-tm

configure.ac

@@ -115,6 +115,7 @@ m4_define([ADAPTER_OPT], [m4_translit(ADAPTER_ARG($1), [_], [-])])
 
 m4_define([USB1_ADAPTERS],
 	[[[ftdi], [MPSSE mode of FTDI based devices], [FTDI]],
+	[[cklink], [T-Head CK-Link JTAG Probe], [CKLINK]],
 	[[stlink], [ST-Link Programmer], [HLADAPTER_STLINK]],
 	[[ti_icdi], [TI ICDI JTAG Programmer], [HLADAPTER_ICDI]],
 	[[ulink], [Keil ULINK JTAG Programmer], [ULINK]],

contrib/60-openocd.rules

@@ -226,6 +226,12 @@ ATTRS{idVendor}=="2aec", ATTRS{idProduct}=="1106", MODE="660", GROUP="plugdev",
 ATTRS{idVendor}=="303a", ATTRS{idProduct}=="1001", MODE="660", GROUP="plugdev", TAG+="uaccess"
 ATTRS{idVendor}=="303a", ATTRS{idProduct}=="1002", MODE="660", GROUP="plugdev", TAG+="uaccess"
 
+# T-Head CK-Link Lite (PingTouGe Semiconductor)
+ATTRS{idVendor}=="32bf", ATTRS{idProduct}=="b210", MODE="660", GROUP="plugdev", TAG+="uaccess"
+
+# Bouffalo Lab BL616/BL702 CK-Link clones
+ATTRS{idVendor}=="42bf", ATTRS{idProduct}=="b210", MODE="660", GROUP="plugdev", TAG+="uaccess"
+
 # Marvell Sheevaplug
 ATTRS{idVendor}=="9e88", ATTRS{idProduct}=="9e8f", MODE="660", GROUP="plugdev", TAG+="uaccess"
 

doc/openocd.texi

@@ -2523,6 +2523,22 @@ and a specific set of GPIOs is used.
 @c chooses among list of bit configs ... only one option
 @end deffn
 
+@deffn {Interface Driver} {cklink}
+Driver for the T-Head CK-Link Lite V2 JTAG probe and Bouffalo Lab
+BL616/BL702 clones, including the built-in debugger on Bouffalo BL618
+evaluation boards. Communication is over USB bulk endpoints using a
+T-Head DebugServer-compatible framed command protocol.
+
+The driver only supports JTAG transport and a single-TAP chain. The
+probe runs at a fixed clock; @command{adapter speed} requests are
+accepted but ignored (with a one-time warning). @command{JTAG_TMS} and
+@command{JTAG_PATHMOVE} are not supported by this probe's protocol.
+
+By default the driver matches 0x42bf/0xb210 (Bouffalo) and
+0x32bf/0xb210 (T-Head). The built-in list can be overridden via
+@command{adapter usb vid_pid}.
+@end deffn
+
 @deffn {Interface Driver} {cmsis-dap}
 ARM CMSIS-DAP compliant based adapter v1 (USB HID based)
 or v2 (USB bulk).

src/jtag/drivers/Makefile.am

@@ -165,6 +165,9 @@ endif
 if XLNX_PCIE_XVC
 DRIVERFILES += %D%/xlnx-pcie-xvc.c
 endif
+if CKLINK
+DRIVERFILES += %D%/cklink.c
+endif
 if BCM2835GPIO
 DRIVERFILES += %D%/bcm2835gpio.c
 endif