Kernel driver max197

Author:

Supported chips:

Description

The A/D converters MAX197, and MAX199 are both 8-Channel, Multi-Range, 5V, 12-Bit DAS with 8+4 Bus Interface and Fault Protection.

The available ranges for the MAX197 are {0,-5V} to 5V, and {0,-10V} to 10V, while they are {0,-2V} to 2V, and {0,-4V} to 4V on the MAX199.

Platform data

The MAX197 platform data (defined in linux/platform_data/max197.h) should be filled with a pointer to a conversion function, defined like:

int convert(u8 ctrl);

ctrl is the control byte to write to start a new conversion. On success, the function must return the 12-bit raw value read from the chip, or a negative error code otherwise.

Control byte format:

Bit

Name

Description

7,6

PD1,PD0

Clock and Power-Down modes

5

ACQMOD

Internal or External Controlled Acquisition

4

RNG

Full-scale voltage magnitude at the input

3

BIP

Unipolar or Bipolar conversion mode

2,1,0

A2,A1,A0

Channel

Sysfs interface

in[0-7]_input

The conversion value for the corresponding channel. RO

in[0-7]_min

The lower limit (in mV) for the corresponding channel. For the MAX197, it will be adjusted to -10000, -5000, or 0. For the MAX199, it will be adjusted to -4000, -2000, or 0. RW

in[0-7]_max

The higher limit (in mV) for the corresponding channel. For the MAX197, it will be adjusted to 0, 5000, or 10000. For the MAX199, it will be adjusted to 0, 2000, or 4000. RW