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This version (23 Sep 2022 15:26) was approved by Ciprian Regus.

LTC2499 16-channel (eight differential, 24-bit ADC Linux Driver

Supported Devices

Evaluation Boards

Source Code

Status

Source Mainlined?
git Accepted, not upstream yet

Files

Function File
core driver ltc2497.c
Documentation lltc,ltc2497.yaml

Example device tree

Function File
dts rpi-ltc2499-overlay.dts

Driver testing

When configured with channel 0 as voltage output, channel 1 as current output, channel 2 as voltage input and channel 3 as current input, the following structure is created under the corresponding IIO device.

This specifies any shell prompt running on the target

root@analog:/sys/bus/iio/devices/iio:device0# ls -l
total 0
-r--r--r-- 1 root root 4096 Sep 22 15:17 dev
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage0_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage0-voltage1_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage10_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage10-voltage11_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage11_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage11-voltage10_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage12_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage12-voltage13_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage13_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage13-voltage12_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage14_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage14-voltage15_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage15_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage15-voltage14_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage1_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage1-voltage0_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage2_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage2-voltage3_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage3_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage3-voltage2_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage4_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage4-voltage5_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage5_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage5-voltage4_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage6_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage6-voltage7_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage7_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage7-voltage6_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage8_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage8-voltage9_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage9_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage9-voltage8_raw
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage_scale
-rw-r--r-- 1 root root 4096 Sep 22 15:17 in_voltage-voltage_scale
-r--r--r-- 1 root root 4096 Sep 22 15:17 name
lrwxrwxrwx 1 root root    0 Sep 22 15:17 of_node -> ../../../../../../../firmware/devicetree/base/soc/i2c@7e804000/ltc2499@76
drwxr-xr-x 2 root root    0 Sep 22 15:17 power
lrwxrwxrwx 1 root root    0 Sep 22 15:17 subsystem -> ../../../../../../../bus/iio
-rw-r--r-- 1 root root 4096 Sep 22 15:17 uevent

Show device name

This specifies any shell prompt running on the target

root@analog:/sys/bus/iio/devices/iio:device0# cat name
ltc2499

Show raw measurement

Description:
Raw measurement of current on channel 0.

This specifies any shell prompt running on the target

root@analog:/sys/bus/iio/devices/iio:device0# cat in_voltage0_raw
16777216

Show scale

Description:
Scale to be applied to the raw measurement of current on channel 0 in order to obtain the actual current.

This specifies any shell prompt running on the target

root@analog:/sys/bus/iio/devices/iio:device0# cat in_voltage_scale
0.000074505

More Information

resources/tools-software/linux-drivers/iio-adc/ltc2499.txt · Last modified: 23 Sep 2022 15:25 by Ciprian Regus