spidriver: Add support for the Excamera Labs SPIDriver programmer

This is a SPI hardware interface with a display (https://spidriver.com/),
connected as an FT230X USB serial device at a fixed baud rate of 460800.

Firmware: https://github.com/jamesbowman/spidriver
Protocol: https://github.com/jamesbowman/spidriver/blob/master/protocol.md

Most of the implementation is copied from the Bus Pirate programmer.

Tested with a SPIDriver v2 by reading FM25Q128A flash memory on Linux.

Change-Id: I07b23c1146d4ad3606b54a1e8dc8030cf4ebf57b
Signed-off-by: Simon Arlott <flashrom@octiron.net>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/86411
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Peter Marheine <pmarheine@chromium.org>
Reviewed-by: Anastasia Klimchuk <aklm@chromium.org>

doc/classic_cli_manpage.rst

@@ -356,6 +356,7 @@ All operations involving any chip access (probe/read/write/...) require the ``-p
         * ``mediatek_i2c_spi``    (for SPI flash ROMs attached to some Mediatek display devices accessible over I2C)
         * ``dirtyjtag_spi``       (for SPI flash ROMs attached to DirtyJTAG-compatible devices)
         * ``asm106x``             (for SPI flash ROMs attached to asm106x PCI SATA controllers)
+        * ``spidriver``           (for SPI flash ROMs attached to an Excamera Labs SPIDriver)
 
         Some programmers have optional or mandatory parameters which are described in detail in the
         **PROGRAMMER-SPECIFIC INFORMATION** section. Support for some programmers can be disabled at compile time.
@@ -1434,6 +1435,32 @@ and must explicitly be set to ``yes`` in order for the programmer to operate. Th
 mechanism in the driver to positively identify that a given I2C bus is actually connected to a supported device.
 
 
+spidriver programmer
+^^^^^^^^^^^^^^^^^^^^
+
+This is a SPI hardware interface with a display (https://spidriver.com/),
+connected as an FT230X USB serial device at a fixed baud rate of 460800.
+
+Firmware: https://github.com/jamesbowman/spidriver
+
+A required ``dev`` parameter specifies the Excamera Labs SPIDriver device node
+and an optional ``mode`` parameter specifies the mode of the SPI bus. The
+parameter delimiter is a comma. Syntax is::
+
+        flashrom -p spidriver:dev=/dev/device,mode=0
+
+where ``mode`` can be ``0``, ``1``, ``2`` or ``3``. The default is mode 0.
+Setting the SPI mode requires version 2 of the device firmware.
+
+An optional A and/or B parameter specifies the state of the SPIDriver A and B pins.
+This may be used to drive the A or B pins high or low before a transfer.
+Syntax is::
+
+        flashrom -p spidriver:a=state,b=state
+
+where ``state`` can be ``high`` or ``low``. The default ``state`` is ``high``.
+
+
 EXAMPLES
 --------
 
@@ -1512,7 +1539,7 @@ REQUIREMENTS
 
         * needs TCP access to the network or userspace access to a serial port
 
-* buspirate_spi
+* buspirate_spi, spidriver
 
         * needs userspace access to a serial port
 
@@ -1533,7 +1560,7 @@ REQUIREMENTS
         * have to be run as superuser/root
         * need raw access permission
 
-* serprog, buspirate_spi, dediprog, usbblaster_spi, ft2232_spi, pickit2_spi, ch341a_spi, digilent_spi, dirtyjtag_spi
+* serprog, buspirate_spi, dediprog, usbblaster_spi, ft2232_spi, pickit2_spi, ch341a_spi, digilent_spi, dirtyjtag_spi, spidriver
 
         * can be run as normal user on most operating systems if appropriate device permissions are set
 

doc/release_notes/devel.rst

@@ -64,3 +64,8 @@ should be used from now on.
 This new API fixes limitations with the old one where most users would need to
 define their own global state to track progress, and it was impossible to fix that
 issue while maintaining binary compatibility without adding a new API.
+
+Programmer updates
+------------------
+
+* spidriver: Add support for the Excamera Labs SPIDriver