Platform data¶

The ads7828 driver accepts an optional ads7828_platform_data structure (definedin include/linux/platform_data/ads7828.h). The structure fields are:

• diff_input: (bool) Differential operation

  set to true for differential mode, false for default single ended mode.

• ext_vref: (bool) External reference

  set to true if it operates with an external reference, false for defaultinternal reference.

• vref_mv: (unsigned int) Voltage reference

  if using an external reference, set this to the reference voltage in mV,otherwise it will default to the internal value (2500mV). This value will bebounded with limits accepted by the chip, described in the datasheet.

If no structure is provided, the configuration defaults to single endedoperation and internal voltage reference (2.5V).

Description¶

This driver implements support for the Texas Instruments ADS7828 and ADS7830.

The ADS7828 device is a 12-bit 8-channel A/D converter, while the ADS7830 does8-bit sampling.

It can operate in single ended mode (8 +ve inputs) or in differential mode,where 4 differential pairs can be measured.

The chip also has the facility to use an external voltage reference. Thismay be required if your hardware supplies the ADS7828 from a 5V supply, seethe datasheet for more details.

There is no reliable way to identify this chip, so the driver will not scansome addresses to try to auto-detect it. That means that you will have tostatically declare the device in the platform support code.