Previously the ioctl-based configuration was not encoded properly.
It lacked the three command bits selecting the "set volatile
configuration" mode.
Thus, configuration the reference, power-down or gain resulted in no
change.
Now the configuration is properly applied.
The DAC value to be send is now combined with the proper command prefix
bits, too.
But this operation was already working, since the command prefix is zero.
Signed-off-by: Lars Kruse <devel@sumpfralle.de>
The MCP47X6 series consists of the following single channel DAC chips:
- MCP4706 (8 bit)
- MCP4716 (10 bit)
- MCP4726 (12 bit)
The driver supports the following configurations:
- gain
- power down
- voltage reference
Persistent configuration storage in the internal EEPROM is not
implemented.
Lars Kruse