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resources:tools-software:linux-drivers:iio-dac:ad5593r [20 Nov 2015 15:11] – [Reference Circuits] Lars-Peter Clausen | resources:tools-software:linux-drivers:iio-dac:ad5593r [19 Jan 2018 10:12] (current) – rename xcomm_zynq -> master Alexandru Ardelean | ||
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The AD5593R have eight I/Ox pins (I/O0 to I/O7) that can be independently configured as digital-to-analog converter (DAC) outputs, analog-to-digital converter (ADC) inputs, digital outputs, or digital inputs. | The AD5593R have eight I/Ox pins (I/O0 to I/O7) that can be independently configured as digital-to-analog converter (DAC) outputs, analog-to-digital converter (ADC) inputs, digital outputs, or digital inputs. | ||
- | |||
When an I/Ox pin is configured as an analog output, it is driven by a 12-bit DAC. The output range of the DAC is 0 V to VREF or 0 V to 2 × VREF. | When an I/Ox pin is configured as an analog output, it is driven by a 12-bit DAC. The output range of the DAC is 0 V to VREF or 0 V to 2 × VREF. | ||
- | |||
When an I/Ox pin is configured as an analog input, it is connected to a 12-bit ADC via an analog multiplexer. The input range of the ADC is 0 V to VREF or 0 V to 2 × VREF. The ADC has a total throughput rate of 400 kSPS. | When an I/Ox pin is configured as an analog input, it is connected to a 12-bit ADC via an analog multiplexer. The input range of the ADC is 0 V to VREF or 0 V to 2 × VREF. The ADC has a total throughput rate of 400 kSPS. | ||
- | |||
The I/Ox pins can also be configured as digital, general-purpose input or output (GPIO) pins. The state of the GPIO pins can be set or read back by accessing the GPIO write data register or the GPIO read configuration register, respectively, | The I/Ox pins can also be configured as digital, general-purpose input or output (GPIO) pins. The state of the GPIO pins can be set or read back by accessing the GPIO write data register or the GPIO read configuration register, respectively, | ||
- | |||
The AD5593R have an integrated 2.5 V, 25 ppm/°C reference, which is turned off by default, and an integrated temperature indicator, which gives an indication of the die temperature. The temperature value is read back as part of an ADC read sequence. | The AD5593R have an integrated 2.5 V, 25 ppm/°C reference, which is turned off by default, and an integrated temperature indicator, which gives an indication of the die temperature. The temperature value is read back as part of an ADC read sequence. | ||
+ | |||
+ | ====== Source Code ====== | ||
+ | |||
+ | ===== Status ===== | ||
+ | |||
+ | ^ Source ^ Mainlined? ^ | ||
+ | | [[git.linux.org> | ||
+ | |||
+ | ===== Files ===== | ||
+ | |||
+ | ^ Function ^ File ^ | ||
+ | | driver | ||
+ | | include | ||
+ | | driver | ||
+ | | include | ||
+ | | Documentation | ||
====== Hardware configuration ====== | ====== Hardware configuration ====== | ||
Line 66: | Line 78: | ||
* " | * " | ||
* **reg**: I2C address of the chip (generally 0x10). | * **reg**: I2C address of the chip (generally 0x10). | ||
- | * **channel-modes**: An array of eight 8-bit values (one per channel) describing | + | * **#address-cells**: Should be 1. |
- | * 0 = unused (pulled down), | + | * **#size-cells**: Should be 0. |
- | * 1 = DAC, | + | * **channel nodes**: |
- | * 2 = ADC, | + | * Each child node represents |
- | * 6 = tri-state | + | * **Required properties**: |
+ | * **reg**: Pin on which this channel is connected to. | ||
+ | * **adi,mode**: Mode or function | ||
+ | | ||
+ | * CH_MODE_ADC | ||
+ | * CH_MODE_DAC (the pin is DAC output) | ||
+ | * CH_MODE_DAC_AND_ADC (the pin is DAC output but can be monitored by an ADC, since there is no disadvantage this this should be considered as the preferred DAC mode) | ||
+ | * CH_MODE_GPIO (the pin is registered with GPIOLIB) | ||
+ | * **Optional properties**: | ||
+ | * **adi, | ||
+ | * CH_OFFSTATE_PULLDOWN (the pin is pulled down) | ||
+ | * CH_OFFSTATE_OUT_LOW | ||
+ | * CH_OFFSTATE_OUT_HIGH (the pin is output high) | ||
+ | * CH_OFFSTATE_OUT_TRISTATE (the pin is tristated output) | ||
+ | |||
+ | ==== Optional properties ==== | ||
+ | * **vref-supply**: Phandle to the external reference voltage supply. This should only be set if there is an external reference voltage connected to the VREF pin. If the property is not set the internal 2.5V reference is used. | ||
+ | * **reset-gpios** : GPIO spec for the RESET pin. If specified, it will be asserted during driver probe. | ||
+ | * **gpio-controller**: | ||
+ | * **# | ||
+ | | ||
==== Device tree example ==== | ==== Device tree example ==== | ||
- | The following example instanciates the ad5593r driver for a AD5593R device connected on a I2C bus. It sets the I/O0 port as a DAC, the I/O1 and I/O2 ports as ADCs. The other I/O ports are connected to the ground with a pull-down resistor. | + | The following example instanciates the ad5593r driver for a AD5593R device connected on a I2C bus. It sets the I/O0 port as a DAC, the I/O1 port as ADC. I/O2 and I/O3 are configured for primary function DAC the additional ADC can measure the voltage being provided by the DAC. This feature can monitor the output voltage to detect short circuits or overload conditions. I/O4 is connected to the ground with a pull-down resistor. |
+ | |||
< | < | ||
- | ad5593r@0 { | + | #include < |
- | compatible = " | + | |
- | reg = < | + | vref: regulator-vref { |
- | channel-modes = /bits/ 8 <1 2 2 0 0 0 0 0>; | + | compatible = " |
+ | regulator-name = " | ||
+ | regulator-min-microvolt = < | ||
+ | regulator-max-microvolt = < | ||
+ | regulator-always-on; | ||
+ | }; | ||
+ | |||
+ | &i2c0 { | ||
+ | status = " | ||
+ | clock-frequency = < | ||
+ | ad5593r@10 { | ||
+ | # | ||
+ | # | ||
+ | # | ||
+ | compatible = " | ||
+ | reg = < | ||
+ | gpio-controller; | ||
+ | |||
+ | channel@0 { | ||
+ | reg = < | ||
+ | adi,mode = < | ||
+ | adi,off-state = <CH_OFFSTATE_PULLDOWN>; | ||
+ | }; | ||
+ | channel@1 { | ||
+ | reg = < | ||
+ | adi,mode = < | ||
+ | adi, | ||
+ | }; | ||
+ | channel@2 { | ||
+ | reg = <2>; | ||
+ | adi,mode = < | ||
+ | adi, | ||
+ | }; | ||
+ | channel@6 { | ||
+ | reg = < | ||
+ | adi,mode = < | ||
+ | adi, | ||
+ | }; | ||
+ | |||
+ | vref-supply = <& | ||
+ | reset-gpios = <& | ||
+ | |||
+ | }; | ||
}; | }; | ||
</ | </ | ||
- | ==== Driver testing ==== | + | ====== Driver testing ====== |
If the driver correctly detected the device, the " | If the driver correctly detected the device, the " | ||
Line 89: | Line 165: | ||
root@linaro-ubuntu-desktop: | root@linaro-ubuntu-desktop: | ||
IIO context created: local | IIO context created: local | ||
- | IIO context has 1 devices: | + | IIO context has 3 devices: |
- | iio:device1: ad5593r | + | iio:device2: ad5593r |
- | | + | |
voltage0: | voltage0: | ||
- | | + | |
attr 0: raw value: 0 | attr 0: raw value: 0 | ||
+ | attr 1: scale_available value: 0.732421875 1.464843750 | ||
+ | attr 2: scale value: 0.732421875 | ||
+ | voltage2: | ||
+ | 3 channel-specific attributes found: | ||
+ | attr 0: raw value: 0 | ||
+ | attr 1: scale_available value: 0.732421875 1.464843750 | ||
+ | attr 2: scale value: 0.732421875 | ||
+ | voltage3: | ||
+ | 3 channel-specific attributes found: | ||
+ | attr 0: raw value: 0 | ||
+ | attr 1: scale_available value: 0.732421875 1.464843750 | ||
+ | attr 2: scale value: 0.732421875 | ||
voltage1: | voltage1: | ||
- | | + | |
attr 0: raw value: 0 | attr 0: raw value: 0 | ||
+ | attr 1: scale value: 0.732421875 | ||
+ | attr 2: scale_available value: 0.732421875 1.464843750 | ||
voltage2: | voltage2: | ||
- | 1 channel-specific attributes found: | + | |
+ | attr 0: raw value: | ||
+ | attr 1: scale value: 0.732421875 | ||
+ | attr 2: scale_available value: 0.732421875 1.464843750 | ||
+ | voltage3: | ||
+ | 3 channel-specific attributes found: | ||
attr 0: raw value: 0 | attr 0: raw value: 0 | ||
+ | attr 1: scale value: 0.732421875 | ||
+ | attr 2: scale_available value: 0.732421875 1.464843750 | ||
+ | temp: (input) | ||
+ | 3 channel-specific attributes found: | ||
+ | attr 0: offset value: -628 | ||
+ | attr 1: raw value: 680 | ||
+ | attr 2: scale value: 452.147700000 | ||
+ | |||
+ | </ | ||
+ | ====== IIO sysfs interface ====== | ||
+ | |||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | total 0 | ||
+ | drwxr-xr-x 3 root root 0 Jan 1 1970 . | ||
+ | drwxr-xr-x 5 root root 0 Jan 1 1970 .. | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 dev | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_temp_offset | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_temp_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_temp_scale | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_voltage1_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_voltage2_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_voltage3_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_voltage_scale | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 in_voltage_scale_available | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 name | ||
+ | lrwxrwxrwx 1 root root 0 Jan 1 1970 of_node -> ../ | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 out_voltage0_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 out_voltage2_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 out_voltage3_raw | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 out_voltage_scale | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 out_voltage_scale_available | ||
+ | drwxrwxrwx 2 root root 0 Jan 1 1970 power | ||
+ | lrwxrwxrwx 1 root root 0 Jan 1 1970 subsystem -> ../ | ||
+ | -rw-rw-rw- 1 root root 4096 Jan 1 1970 uevent | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | </ | ||
+ | |||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | dev:252:2 | ||
+ | in_temp_offset: | ||
+ | in_temp_raw: | ||
+ | in_temp_scale: | ||
+ | in_voltage1_raw: | ||
+ | in_voltage2_raw: | ||
+ | in_voltage3_raw: | ||
+ | in_voltage_scale: | ||
+ | in_voltage_scale_available: | ||
+ | name: | ||
+ | out_voltage0_raw: | ||
+ | out_voltage2_raw: | ||
+ | out_voltage3_raw: | ||
+ | out_voltage_scale: | ||
+ | out_voltage_scale_available: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | uevent: | ||
+ | </ | ||
+ | |||
+ | |||
+ | ===== Show device name ===== | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | ad5593r | ||
+ | </ | ||
+ | |||
+ | |||
+ | ===== Scales ===== | ||
+ | |||
+ | The output range of the DAC is 0 V to VREF or 0 V to 2 × VREF. | ||
+ | **out_voltage_scale** is used to select the high or low range. | ||
+ | Without external reference the driver selects the internal 2500mV VREF reference. | ||
+ | So the scale computes as 2500mV/2^12 = 0.610351562 or 5000mV/2^12 = 1.220703124. | ||
+ | |||
+ | The input range of the ADC is 0 V to VREF or 0 V to 2 × VREF. | ||
+ | **in_voltage_scale** is used to select the high or low range. | ||
+ | Without external reference the driver selects the internal 2500mV VREF reference. | ||
+ | So the scale computes as 2500mV/2^12 = 0.610351562 or 5000mV/2^12 = 1.220703124. | ||
+ | |||
+ | ==== Show current scale ==== | ||
+ | |||
+ | **Description: | ||
+ | scale to be applied to out_voltageY_raw/ | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 0.610351562 | ||
+ | </ | ||
+ | |||
+ | ==== Show available scales ==== | ||
+ | |||
+ | **Description: | ||
+ | scale to be applied to out_voltageY_raw/ | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 0.610351562 1.220703124 | ||
+ | </ | ||
+ | |||
+ | ==== Change scales ==== | ||
+ | |||
+ | **Description: | ||
+ | scale to be applied to out_voltageY_raw/ | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 1.220703124 | ||
+ | </ | ||
+ | |||
+ | ===== Get channel Y input voltage ===== | ||
+ | |||
+ | Description: | ||
+ | Raw unscaled voltage measurement on channel Y | ||
+ | |||
+ | This specifies any shell prompt running on the target | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 1491 | ||
+ | </ | ||
+ | |||
+ | U = in_voltage3_raw * in_voltage_scale = 1491 * 0.610351562 = 910 mV | ||
+ | |||
+ | |||
+ | ===== Set channel Y output voltage ===== | ||
+ | |||
+ | **Description: | ||
+ | Raw (unscaled, no bias etc.) output voltage for channel Y. | ||
+ | |||
+ | <WRAP box bggreen>< | ||
+ | < | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | </ | ||
+ | |||
+ | **U** = // | ||
+ | |||
+ | ===== Example obtaining the temperature in °C ===== | ||
+ | |||
+ | |||
+ | T = ( in_temp_raw + in_temp_offset ) * in_temp_scale | ||
+ | |||
+ | T = ( 810 - 753 ) * 376.78975 = 21477 mdeg C = 21.5 °C | ||
+ | |||
+ | For more information see also here: [[git.linux.org> | ||
+ | |||
+ | ===== GPIO Testing | ||
+ | |||
+ | The GPIO sysfs interface allows users to manipulate any GPIO from userspace. Userspace utilizes a sysfs control interface to dynamically request and release individual GPIOs. Once a GPIO has been requested, writing to the newly created path allows you to control the direction and the data while reading from it returns the GPIO data (which usually corresponds to a 0 or 1 which represents the signal level). | ||
+ | |||
+ | For more information see also here: [[git.linux.org> | ||
+ | |||
+ | < | ||
+ | root@linaro-ubuntu-desktop: | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | export | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | total 0 | ||
+ | drwxr-xr-x 3 root root 0 Jan 1 1970 . | ||
+ | drwxr-xr-x 3 root root 0 Jan 1 1970 .. | ||
+ | -r--r--r-- 1 root root 4096 Feb 23 08:06 base | ||
+ | lrwxrwxrwx 1 root root 0 Feb 23 08:06 device -> ../ | ||
+ | -r--r--r-- 1 root root 4096 Feb 23 08:06 label | ||
+ | -r--r--r-- 1 root root 4096 Feb 23 08:06 ngpio | ||
+ | drwxr-xr-x 2 root root 0 Feb 23 08:06 power | ||
+ | lrwxrwxrwx 1 root root 0 Jan 1 1970 subsystem -> ../ | ||
+ | -rw-r--r-- 1 root root 4096 Jan 1 1970 uevent | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | base:890 | ||
+ | label: | ||
+ | ngpio:8 | ||
+ | |||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | total 0 | ||
+ | drwxr-xr-x 3 root root 0 Feb 23 08:06 . | ||
+ | drwxr-xr-x 4 root root 0 Feb 23 08:06 .. | ||
+ | -rw-r--r-- 1 root root 4096 Feb 23 08:06 active_low | ||
+ | lrwxrwxrwx 1 root root 0 Feb 23 08:06 device -> ../ | ||
+ | -rw-r--r-- 1 root root 4096 Feb 23 08:06 direction | ||
+ | drwxr-xr-x 2 root root 0 Feb 23 08:06 power | ||
+ | lrwxrwxrwx 1 root root 0 Feb 23 08:06 subsystem -> ../ | ||
+ | -rw-r--r-- 1 root root 4096 Feb 23 08:06 uevent | ||
+ | -rw-r--r-- 1 root root 4096 Feb 23 08:06 value | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | in | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 0 | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | out | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 0 | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | |||
+ | root@linaro-ubuntu-desktop:/ | ||
+ | 1 | ||
</ | </ |