| SCMD(4) | Device Drivers Manual | SCMD(4) | 
scmd —
scmd* at iic? ...
scmd* at spi? ...
scmd driver provides the common framework to the
  Sparkfun SCMD board. The SCMD board is a Cypress core ARM SOC in front of a
  DRV8835 motor driver chip. There are a number of ways to talk to the board and
  scmdi2c(4) and
  scmdspi(4) should be consulted
  for the I2C and SPI frontend drivers. The board is fully documented in the
  datasheet for at Sparkfun.
The board provides a register address space of 126 registers which control the various behaviors of the motors attached to the board. Each SCMD board can handle two motors, and up to 16 SCMD boards may be chained together allowing for 34 motors to be controlled from a single master instance. The secondary boards are accessed by set of view port registers from the main board. The scmd(4) driver and its associated frontends flatten the main SCMD board and all chained boards into a linear register space that can be opened, seeked, read from and written to like any other file or device without having to worry about the view port.
A command line utility scmdctl(1) is provided that allows convient command line commands for most of the functions provided by the SCMD board.
hw.scmd0.debugSCMD_DEBUG, this
      node will appear and can be used to set the debugging level.scmd driver first appeared in
  NetBSD 10.0.
scmd driver was written by Brad
  Spencer
  <brad@anduin.eldar.org>.
| January 1, 2022 | NetBSD 10.1 |