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====== AD5360 IIO Multi-Channel DAC Linux Driver ======

===== Supported Devices =====

  * [[adi>AD5360]]
  * [[adi>AD5361]]
  * [[adi>AD5362]]
  * [[adi>AD5363]]
  * [[adi>AD5370]]
  * [[adi>AD5371]]
  * [[adi>AD5372]]
  * [[adi>AD5373]]

===== Evaluation Boards =====

  * [[adi>EVAL-AD5360EBZ]]
  * [[adi>EVAL-AD5361EBZ]]
  * [[adi>EVAL-AD5362EBZ]]
  * [[adi>EVAL-AD5363EBZ]]
  * [[adi>EVAL-AD5370EBZ]]
  * [[adi>EVAL-AD5371EBZ]]
  * [[adi>EVAL-AD5372EBZ]]
  * [[adi>EVAL-AD5373EBZ]]
===== Description =====

This is a Linux industrial I/O ([[software:linux:docs:iio:iio|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 [[software:linux:docs:iio:iio|IIO]] for more information.

====== Source Code ======

===== Status =====

^ Source ^ Mainlined? ^
| [[git.linux.org>drivers/iio/dac/ad5360.c|git]] | [[git.linux.org>drivers/iio/dac/ad5360.c|Yes]] |
===== Files =====

^ Function ^ File ^
| driver  | [[git.linux.org>drivers/iio/dac/ad5360.c]] |

====== Example device tree ======
<code c>
	fragment@0 {
		target-path = "/";
		__overlay__ {
			vref0: fixedregulator@0 {
				compatible = "regulator-fixed";
				regulator-name = "fixed-supply0";
				regulator-min-microvolt = <3000000>;
				regulator-max-microvolt = <3000000>;
				regulator-boot-on;
			};
			vref1: fixedregulator@1 {
				compatible = "regulator-fixed";
				regulator-name = "fixed-supply1";
				regulator-min-microvolt = <3000000>;
				regulator-max-microvolt = <3000000>;
				regulator-boot-on;
			};
		};
	};

	fragment@1 {
		target = <&spi0>;
		__overlay__ {
			#address-cells = <1>;
			#size-cells = <0>;
			status = "okay";

			ad5370@0{
				compatible = "adi,ad5370";
				reg = <0>;
				spi-max-frequency = <1000000>;
				spi-cpha;
				vref0-supply = <&vref0>;
				vref1-supply = <&vref1>;
			};
		};
	};
};
</code>

====== Example platform device initialization ======

===== Specifying reference voltage via the regulator framework =====

Below example specifies a 2.5 Volt reference for the SPI device 3 on SPI-Bus 0. (**spi0.3**)
In this example all 4 reference voltage are supplied by the same regulator.

Except for the AD5371 devices expect two supplies named "vref0" and "vref1". The AD5371 expects a third supply named "vref2".

<code c>
#if defined(CONFIG_REGULATOR_FIXED_VOLTAGE) || defined(CONFIG_REGULATOR_FIXED_VOLTAGE_MODULE)
static struct regulator_consumer_supply ad5360_consumer_supplies[] = {
	REGULATOR_SUPPLY("vref0", "spi0.3"),
	REGULATOR_SUPPLY("vref1", "spi0.3"),
	REGULATOR_SUPPLY("vref2", "spi0.3"),
};

static struct regulator_init_data stamp_avdd_reg_init_data = {
	.constraints	= {
		.name	= "2V5",
		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
	},
	.consumer_supplies = ad5360_consumer_supplies,
	.num_consumer_supplies = ARRAY_SIZE(ad5360_consumer_supplies),
};

static struct fixed_voltage_config stamp_vdd_pdata = {
	.supply_name	= "board-2V5",
	.microvolts	= 2500000,
	.gpio		= -EINVAL,
	.enabled_at_boot = 0,
	.init_data	= &stamp_avdd_reg_init_data,
};
static struct platform_device brd_voltage_regulator = {
	.name		= "reg-fixed-voltage",
	.id		= -1,
	.num_resources	= 0,
	.dev		= {
		.platform_data	= &stamp_vdd_pdata,
	},
};
#endif
</code>

<code c>
static struct platform_device *board_devices[] __initdata = {
#if defined(CONFIG_REGULATOR_FIXED_VOLTAGE) || defined(CONFIG_REGULATOR_FIXED_VOLTAGE_MODULE)
	&brd_voltage_regulator
#endif
};
</code>


<code c>
static int __init board_init(void)
{
	[--snip--]

	platform_add_devices(board_devices, ARRAY_SIZE(board_devices));

	[--snip--]

	return 0;
}
arch_initcall(board_init);
</code>

{{page>software/linux/docs/platform_and_bus_model#Declaring SPI slave devices&firstseconly&noeditbtn}}

Depending on the converter IC used, you may need to set the modalias accordingly, matching your part name.
It may also required to adjust max_speed_hz. Please consult the datasheet, for maximum spi clock supported by the device in question.

<code c>
static struct spi_board_info board_spi_board_info[] __initdata = {
#if defined(CONFIG_AD5360_SPI) || \
 	defined(CONFIG_AD5360_SPI_MODULE)
	{
		/* the modalias must be the same as spi device driver name */
		.modalias = "ad5360", /* Name of spi_driver for this device */
		.max_speed_hz = 1000000,     /* max spi clock (SCK) speed in HZ */
		.bus_num = 0, /* Framework bus number */
		.chip_select = 3, /* Framework chip select */
		.mode = SPI_MODE_1,
	},
#endif
};
</code>

<code c>
static int __init board_init(void)
{
	[--snip--]

	spi_register_board_info(board_spi_board_info, ARRAY_SIZE(board_spi_board_info));

	[--snip--]

	return 0;
}
arch_initcall(board_init);
</code>

====== Adding Linux driver support ======

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

<WRAP round help>
The AD5360 Driver depends on **CONFIG_SPI**
</WRAP>

<code>
Linux Kernel Configuration
    Device Drivers  --->
        ...
        <*>     Industrial I/O support --->
            --- Industrial I/O support
            ...
            Digital to analog converters  ---> 
                ...
                <*>  Analog Devices Analog Devices AD5360/61/62/63/70/71/73 DAC driver
                ...
            ...
        ...
</code>
====== Hardware configuration ======


====== Driver testing ======

{{page>software:linux:docs:iio:iio_snippets#iio device files&noheader&firstseconly&noeditbtn}}

<WRAP box bggreen><wrap info>This specifies any shell prompt running on the target</wrap>
<xterm>
root:/> **cd /sys/bus/iio/devices/**
root:/sys/bus/iio/devices> ls
iio:device0

root:/sys/bus/iio/devices> **cd iio:device0**

root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **ls -l**
-r--r--r--    1 root     root          4096 Jan  2 21:54 dev
-r--r--r--    1 root     root          4096 Jan  2 21:54 name
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage0_calibbias
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage0_calibscale
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage0_offset
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage0_raw
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage0_scale
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage10_calibbias
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage10_calibscale
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage10_offset
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage10_raw
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage10_scale
...
-rw-r--r--    1 root     root          4096 Jan  2 21:54 out_voltage_powerdown
drwxr-xr-x    2 root     root             0 Jan  2 21:54 power
lrwxrwxrwx    1 root     root             0 Jan  2 21:54 subsystem -> ../../../../../bus/iio
-rw-r--r--    1 root     root          4096 Jan  2 21:54 uevent
</xterm></WRAP>

=== Show device name ===

<WRAP box bggreen><wrap info>This specifies any shell prompt running on the target</wrap>
<xterm>
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **cat name**
ad5360
</xterm></WRAP>

=== Show scale ===

**Description:**\\ /sys/bus/iio/devices/iio:deviceX/out_voltageY_scale \\

scale to be applied to out_voltage0_raw in order to obtain the measured voltage in millivolts.

<WRAP box bggreen><wrap info>This specifies any shell prompt running on the target</wrap>
<xterm>
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **cat out_voltage0_scale**
0.038140
</xterm></WRAP>

=== Set channel Y output voltage ===

**Description:**\\
/sys/bus/iio/devices/iio:deviceX/out_voltageY_raw\\

Raw (unscaled, no bias etc.) output voltage for
channel Y.

<WRAP box bggreen><wrap info>This specifies any shell prompt running on the target</wrap>
<xterm>
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **echo 10000 > out_voltage0_raw**
</xterm></WRAP>

**U** = //out_voltage0_raw * out_voltage0_scale// = 10000 * 0,038140 //mV// = **381,14 //mV//**

=== Calibrate channel Y gain ===

**Description:**\\
/sys/bus/iio/devices/iio:deviceX/out_voltageY_calibscale\\

Each channel has an adjustable gain which can be used to calibrate the channel's scale and compensate for full-scale errors. The default value is 65535.

If scale calibration is used the following formula can be used calculate the output voltage:
**U** = //( ( out_voltageY_raw * ( out_voltageY_calibscale + 1 ) ) / 2^16 - out_voltageY_calibbias ) *  out_voltageY_scale//

=== Calibrate channel Y offset ===

**Description:**\\
/sys/bus/iio/devices/iio:deviceX/out_voltageY_calibbias\\

Each channel has an adjustable offset which can be used to calibrate the channel's offset and compensate for zero-scale errors. The default value is 0.

If offset calibration is used the following formula can be used calculate the output voltage:
**U** = //( ( out_voltageY_raw * ( out_voltageY_calibscale + 1 ) ) / 2^16 - out_voltageY_calibbias ) *  out_voltageY_scale//

=== Enable power down mode for the device ===

/sys/bus/iio/devices/iio:deviceX/out_voltage_powerdown

**Description:**\\
Writing 1 causes the device to enter power down mode. Clearing returns to
normal operation.

<WRAP box bggreen><wrap info>This specifies any shell prompt running on the target</wrap>
<xterm>
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **echo 1 > out_voltage_powerdown**
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **cat out_voltage_powerdown**
1
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **echo 0 > out_voltage_powerdown**
root:/sys/devices/platform/bfin-spi.0/spi0.3/iio:device0> **cat out_voltage_powerdown**
0
</xterm></WRAP>

====== More Information ======

{{page>software:linux:docs:iio:iio_snippets#iio pointers&noheader&firstseconly&noeditbtn}}
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