This version (15 Oct 2018 16:25) was approved by Stefan Popa.The Previously approved version (13 Jun 2018 10:21) is available.
Table of Contents
AD5758 IIO DAC Linux Driver
Supported Devices
This driver supports the
Evaluation Boards
Description
This is a Linux industrial I/O (IIO) subsystem driver, targeting multi-channel serial interface DACs. The industrial I/O subsystem provides a unified framework for drivers for many different types of converters and sensors using a number of different physical interfaces (i2c, spi, etc). See IIO for more information.
Source Code
Status
Files
| Function | File |
|---|---|
| driver | drivers/iio/dac/ad5758.c |
Devicetree
Required properties for the AD5758:
- compatible: Must be “adi,ad5758”
- reg: SPI chip select number for the device
- spi-max-frequency: Max SPI frequency to use (< 50000000)
- spi-cpha: is the only mode that is supported
Optional properties:
- reset-gpios : GPIO spec for the RESET pin. If specified, it will be asserted during driver probe.
- adi,dc-dc-mode: Mode of operation of the dc-to-dc converter
- adi,dc-dc-ilim: The dc-to-dc converter current limit
- adi,slew: Array of slewrate settings should contain 3 fields:
- adi,range: The output range
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
ad5758@0 {
compatible = "adi,ad5758";
reg = <0>;
spi-max-frequency = <1000000>;
spi-cpha;
reset-gpios = <&gpio 22 0>; /* optional */
adi,dc-dc-mode = <2>;
adi,dc-dc-ilim = <200>;
adi,slew = <1 200000 12>;
adi,range = <1>;
Driver testing
This specifies any shell prompt running on the target
root:/> cd /sys/bus/iio/devices/ root:/sys/bus/iio/devices> ls iio:device0 root:/sys/bus/iio/devices> cd iio\:device0 root:/sys/bus/iio/devices/iio:device0> ls -l -r--r--r-- 1 root root 4096 May 23 09:14 dev -rw-r--r-- 1 root root 4096 May 23 09:14 out_voltage0_powerdown -rw-r--r-- 1 root root 4096 May 23 09:14 out_voltage0_raw -rw-r--r-- 1 root root 4096 May 23 09:14 out_voltage_scale -r--r--r-- 1 root root 4096 May 23 09:14 name drwxr-xr-x 2 root root 0 May 23 09:14 power lrwxrwxrwx 1 root root 0 May 23 09:14 subsystem -> ../../../../../../../../bus/iio -rw-r--r-- 1 root root 4096 May 23 09:14 uevent
Show device name
This specifies any shell prompt running on the target
root:/sys/bus/iio/devices/iio:device0> cat name ad5758
Show scale
Description:
scale to be applied to in_voltage0_raw in order to obtain the measured voltage in millivolts.
This specifies any shell prompt running on the target
root:/sys/bus/iio/devices/iio:device0> cat out_voltage_scale 0.152587890
Set channel 0 output voltage
Description:
/sys/bus/iio/devices/deviceX/out_voltage0_raw
Raw (unscaled, no bias etc.) output voltage for channel 0.
This specifies any shell prompt running on the target
root:/sys/bus/iio/devices/iio:device0> echo 32767 > out_voltage0_raw
U = out_voltage0_raw * out_voltage_scale = 32767 * 0.152587890 = 4999.84 mV
Enable power down mode on output 0
/sys/bus/iio/devices/deviceX/out_voltage0_powerdown
Description:
Writing 1 causes output 0 to enter the power down mode. Clearing returns to
normal operation.
This specifies any shell prompt running on the target
root:/sys/bus/iio/devices/iio:device0> echo 1 > out_voltage0_powerdown root:/sys/bus/iio/devices/iio:device0> cat out_voltage0_powerdown 1 root:/sys/bus/iio/devices/iio:device0> echo 0 > out_voltage0_powerdown root:/sys/bus/iio/devices/iio:device0> cat out_voltage0_powerdown 0
More Information
- IIO mailing list: linux [dash] iio [at] vger [dot] kernel [dot] org
resources/tools-software/linux-drivers/iio-dac/ad5758.txt · Last modified: 15 Oct 2018 16:25 by Stefan Popa