ADMV1013

ADMV1013 24 GHz to 44 GHz, Wideband, Microwave Upconverter Linux Driver.

Supported Devices

Evaluation Boards

Description

This is a Linux industrial I/O (Linux Industrial I/O Subsystem) subsystem driver, targeting serial interface Microwave converters. 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 Linux Industrial I/O Subsystem for more information.

Source Code

Status

Source

Mainlined?

ADI tree

Yes

Files

Function

File

driver

admv1013.c

Documentation

Documentation/ABI/testing/sysfs-bus-iio

Unlike PCI or USB devices, SPI devices are not enumerated at the hardware level. Instead, the software must know which devices are connected on each SPI bus segment, and what slave selects these devices are using. For this reason, the kernel code must instantiate SPI devices explicitly. The most common method is to declare the SPI devices by bus number.

This method is appropriate when the SPI bus is a system bus, as in many embedded systems, wherein each SPI bus has a number which is known in advance. It is thus possible to pre-declare the SPI devices that inhabit this bus. This is done with an array of struct spi_board_info, which is registered by calling spi_register_board_info().

For more information see: Overview of Linux kernel SPI support

Hardware configuration

Use the device and evaluation-board documentation for physical wiring, power supplies and the LO connection.

Adding Linux driver support

Kernel configuration

Configure kernel with make menuconfig (alternatively use make xconfig or make qconfig)

Note

The ADMV1013 Driver depends on CONFIG_SPI

Linux Kernel Configuration
    Device Drivers  --->
        <*>     Industrial I/O support --->
            --- Industrial I/O support
                Frequency  --->
                    <*> Analog Devices ADMV1013 Microwave Upconverter

Devicetree configuration

Properties

Required properties:

  • compatible = "adi,admv1013".

  • reg: SPI chip-select number.

  • clocks and clock-names = "lo_in": The LO input clock.

  • Supply references:

    • vcm-supply.

    • vcc-drv-supply.

    • vcc2-drv-supply.

    • vcc-vva-supply.

    • vcc-amp1-supply.

    • vcc-amp2-supply.

    • vcc-env-supply.

    • vcc-bg-supply.

    • vcc-bg2-supply.

    • vcc-mixer-supply.

    • vcc-quad-supply.

Mode-selection properties:

  • adi,input-mode: String iq or if.

  • adi,quad-se-mode: String diff, se-pos or se-neg.

  • adi,detector-enable: Boolean enabling the detector.

Example

This example selects IF input mode and differential quadrature mode. The LO clock provider supplies the input frequency.

&spi0 {
  #address-cells = <1>;
  #size-cells = <0>;
  admv1013@0{
    compatible = "adi,admv1013";
    reg = <0>;
    spi-max-frequency = <1000000>;
    clocks = <&admv1013_lo>;
    clock-names = "lo_in";
    vcm-supply = <&vcm>;
    vcc-drv-supply = <&vcc_drv>;
    vcc2-drv-supply = <&vcc2_drv>;
    vcc-vva-supply = <&vcc_vva>;
    vcc-amp1-supply = <&vcc_amp1>;
    vcc-amp2-supply = <&vcc_amp2>;
    vcc-env-supply = <&vcc_env>;
    vcc-bg-supply = <&vcc_bg>;
    vcc-bg2-supply = <&vcc_bg2>;
    vcc-mixer-supply = <&vcc_mixer>;
    vcc-quad-supply = <&vcc_quad>;
    adi,input-mode = "if";
    adi,quad-se-mode = "diff";
    adi,detector-enable;
  };
};

Driver testing

Identify the device

Each and every IIO device, typically a hardware chip, has a device folder under /sys/bus/iio/devices/iio:deviceX. Where X is the IIO index of the device. Under every of these directory folders reside a set of files, depending on the characteristics and features of the hardware device in question. These files are consistently generalized and documented in the IIO ABI documentation. In order to determine which IIO deviceX corresponds to which hardware device, the user can read the name file /sys/bus/iio/devices/iio:deviceX/name. In case the sequence in which the iio device drivers are loaded/registered is constant, the numbering is constant and may be known in advance.

Select the IIO device whose name attribute is admv1013.

cd /sys/bus/iio/devices/iio:device0
cat name
ls -l

root:/> cd /sys/bus/iio/devices/iio\:device0/
root:/> cat name
admv1013

Calibration bias

The in_altvoltageY_i_calibbias and in_altvoltageY_q_calibbias attributes control the I-path and Q-path mixer-offset calibration codes. Channel 0 selects the positive mixer output and channel 1 selects the negative mixer output. These are hardware calibration codes, not a decimal I/Q voltage pair. Read the channel’s current value before adjusting its calibration.

cat in_altvoltage0_i_calibbias
cat in_altvoltage0_q_calibbias
cat in_altvoltage1_i_calibbias
cat in_altvoltage1_q_calibbias

Calibrate I/Q phase

For a successfully registered device, set and read back the I-path phase code in the correct IIO device directory. The Q-path counterpart ends in q_calibphase.

set -eu
cat in_altvoltage0-altvoltage1_i_calibphase
echo 1 > in_altvoltage0-altvoltage1_i_calibphase
cat in_altvoltage0-altvoltage1_i_calibphase

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