[PATCH v6 0/3] Add AD74413R driver

[PATCH v6 0/3] Add AD74413R driver

[Cosmin Tanislav]

The AD74412R and AD74413R are quad-channel software configurable input/output
solutions for building and process control applications. They contain
functionality for analog output, analog input, digital input, resistance
temperature detector, and thermocouple measurements integrated
into a single chip solution with an SPI interface.
The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
four configurable input/output channels and a suite of diagnostic functions.
The AD74413R differentiates itself from the AD74412R by being HART-compatible.

V1 -> V2
 * sign off using company email

V2 -> V3
 * replace gpo config firmware flag with one flag specifying whether gpo is in
   comparator mode
 * create two separate gpiochips, one output-only for GPO pins not in
   comparator mode and one input-only for the value of digital input channels
 * wire up all gpo functionalities using pinconf
 * keep number of characters per line under 80
 * rework locking
 * do not invalidate other chip revisions
 * do not set indio device parent
 * print probe error for refin regulator
 * move conversion from range register value to range / offset / raw offset
   into separate function
 * module.h -> mod_devicetable.h
 * use generic firmware interface functions
 * add comment regarding cache alignment
 * add comment regarding ADC channels buffered read setup
 * un-inline comment regarding 100us delay for conversion start
 * inline return statements
 * remove assignments to val2 where not necessary
 * local_channels -> chans
 * index -> i
 * channel_config -> config
 * IIO_ALTVOLTAGE -> IIO_VOLTAGE
 * .info_mask_shared_by_type_available -> .info_mask_separate_available
 * remove unlikely probe error messages
 * use an array indexed by channel function for retrieving iio channels
 * count iio channels while parsing
 * move HART rate rejection outside of setter
 * move channel function validation outside of setter
 * use SPI messages for read and write
 * validate DAC code earlier
 * simplify switches to only handle existing iio channels
 * pass indio_dev into functions needing access to it
 * pass spi into devm_regmap_init
 * dt-bindings: sort compatibles
 * dt-bindings: remove driver word from description
 * dt-bindings: remove refin supply description
 * dt-bindings: specify channel function default value
 * dt-bindings: remove maxItems from scalar value

V3 -> v4
 * remove double gpo from macro name
 * reset at probe
 * config -> chip_info and store chip name inside chip info
 * cacheline align every DMA buffer
 * simplify generation of adc samples message by caching xfer, tx_buf and rx_buf
 * use mask itself for writing the value of channel enable and gpo data
 * move reg read and write transfers to the same buffers and use local
   variables for transfers
 * merge the two for loops handling gpio configuration
 * let firmware decide irq edge
 * remove INDIO_BUFFER_SOFTWARE already set by iio framwork
 * do not set trigger device parent
 * return dev_err_probe for regulator error case
 * do not set cs_change to 0 when not needed
 * do not set spi device drvdata as it is not needed
 * fix bug regarding wrong channels being created for resistance input,
   digital input, and current input with hart
 * use voltage input channels spec for high impedance mode
 * put () around macro parameters
 * merge AD74413R_CHANNEL macro into its uses
 * remove unused switch case scope
 * inline return IIO_VAL_INT
 * use {get,put}_unaligned_be16
 * use proper types for reg and val
 * move default case handling into switch statements
 * pass driver state into regmap functions
 * use genmask for generating a 16bit max value
 * alphanumeric order for part numbers
 * dt-bindings: remove $ref from ohms value

V4 -> V5
 * dt-bindings: include headers necessary
 * dt-bindings: add IRQ_TYPE_EDGE_FALLING to interrupt flags
 * dt-bindings: ohm -> ohms
 * dt-bindings: spi0 -> spi

V5 -> V6
 * fix warnings regarding overflows

Cosmin Tanislav (3):
  iio: add adddac subdirectory
  dt-bindings: iio: add AD74413R
  iio: addac: add AD74413R driver

 .../bindings/iio/addac/adi,ad74413r.yaml      |  157 ++
 MAINTAINERS                                   |    9 +
 drivers/iio/Kconfig                           |    1 +
 drivers/iio/Makefile                          |    1 +
 drivers/iio/addac/Kconfig                     |   20 +
 drivers/iio/addac/Makefile                    |    7 +
 drivers/iio/addac/ad74413r.c                  | 1473 +++++++++++++++++
 include/dt-bindings/iio/addac/adi,ad74413r.h  |   21 +
 8 files changed, 1689 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
 create mode 100644 drivers/iio/addac/Kconfig
 create mode 100644 drivers/iio/addac/Makefile
 create mode 100644 drivers/iio/addac/ad74413r.c
 create mode 100644 include/dt-bindings/iio/addac/adi,ad74413r.h

-- 
2.34.1

[PATCH v6 1/3] iio: add adddac subdirectory

[Cosmin Tanislav]

From: Cosmin Tanislav <cosmin.tanislav@analog.com>

For IIO devices that expose both ADC and DAC functionality.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 drivers/iio/Kconfig        | 1 +
 drivers/iio/Makefile       | 1 +
 drivers/iio/addac/Kconfig  | 8 ++++++++
 drivers/iio/addac/Makefile | 6 ++++++
 4 files changed, 16 insertions(+)
 create mode 100644 drivers/iio/addac/Kconfig
 create mode 100644 drivers/iio/addac/Makefile

diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 2334ad249b46..4fb4321a72cb 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -70,6 +70,7 @@ config IIO_TRIGGERED_EVENT
 
 source "drivers/iio/accel/Kconfig"
 source "drivers/iio/adc/Kconfig"
+source "drivers/iio/addac/Kconfig"
 source "drivers/iio/afe/Kconfig"
 source "drivers/iio/amplifiers/Kconfig"
 source "drivers/iio/cdc/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 65e39bd4f934..8d48c70fee4d 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o
 
 obj-y += accel/
 obj-y += adc/
+obj-y += addac/
 obj-y += afe/
 obj-y += amplifiers/
 obj-y += buffer/
diff --git a/drivers/iio/addac/Kconfig b/drivers/iio/addac/Kconfig
new file mode 100644
index 000000000000..2e64d7755d5e
--- /dev/null
+++ b/drivers/iio/addac/Kconfig
@@ -0,0 +1,8 @@
+#
+# ADC DAC drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Analog to digital and digital to analog converters"
+
+endmenu
diff --git a/drivers/iio/addac/Makefile b/drivers/iio/addac/Makefile
new file mode 100644
index 000000000000..b888b9ee12da
--- /dev/null
+++ b/drivers/iio/addac/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for industrial I/O ADDAC drivers
+#
+
+# When adding new entries keep the list in alphabetical order
-- 
2.34.1

[PATCH v6 2/3] dt-bindings: iio: add AD74413R

[Cosmin Tanislav]

The AD74412R and AD74413R are quad-channel software configurable input/output
solutions for building and process control applications. They contain
functionality for analog output, analog input, digital input, resistance
temperature detector, and thermocouple measurements integrated
into a single chip solution with an SPI interface.
The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
four configurable input/output channels and a suite of diagnostic functions.
The AD74413R differentiates itself from the AD74412R by being HART-compatible.

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 .../bindings/iio/addac/adi,ad74413r.yaml      | 157 ++++++++++++++++++
 include/dt-bindings/iio/addac/adi,ad74413r.h  |  21 +++
 2 files changed, 178 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
 create mode 100644 include/dt-bindings/iio/addac/adi,ad74413r.h

diff --git a/Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml b/Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
new file mode 100644
index 000000000000..a6d6b5ef13b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
@@ -0,0 +1,157 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/addac/adi,ad74413r.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD74412R/AD74413R device
+
+maintainers:
+  - Cosmin Tanislav <cosmin.tanislav@analog.com>
+
+description: |
+  The AD74412R and AD74413R are quad-channel software configurable input/output
+  solutions for building and process control applications. They contain
+  functionality for analog output, analog input, digital input, resistance
+  temperature detector, and thermocouple measurements integrated
+  into a single chip solution with an SPI interface.
+  The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
+  four configurable input/output channels and a suite of diagnostic functions.
+  The AD74413R differentiates itself from the AD74412R by being HART-compatible.
+
+properties:
+  compatible:
+    enum:
+      - adi,ad74412r
+      - adi,ad74413r
+
+  reg:
+    maxItems: 1
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+  spi-max-frequency:
+    maximum: 1000000
+
+  spi-cpol: true
+
+  interrupts:
+    maxItems: 1
+
+  refin-supply: true
+
+  adi,rsense-resistance-ohms:
+    description:
+      RSense resistance values in Ohms.
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+  - spi-cpol
+  - refin-supply
+  - adi,rsense-resistance-ohms
+
+additionalProperties: false
+
+patternProperties:
+  "^channel@[0-3]$":
+    type: object
+    description: Represents the external channels which are connected to the device.
+
+    properties:
+      reg:
+        description: |
+          The channel number. It can have up to 4 channels numbered from 0 to 3.
+        minimum: 0
+        maximum: 3
+
+      adi,ch-func:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description: |
+          Channel function.
+          HART functions are not supported on AD74412R.
+          0 - CH_FUNC_HIGH_IMPEDANCE
+          1 - CH_FUNC_VOLTAGE_OUTPUT
+          2 - CH_FUNC_CURRENT_OUTPUT
+          3 - CH_FUNC_VOLTAGE_INPUT
+          4 - CH_FUNC_CURRENT_INPUT_EXT_POWER
+          5 - CH_FUNC_CURRENT_INPUT_LOOP_POWER
+          6 - CH_FUNC_RESISTANCE_INPUT
+          7 - CH_FUNC_DIGITAL_INPUT_LOGIC
+          8 - CH_FUNC_DIGITAL_INPUT_LOOP_POWER
+          9 - CH_FUNC_CURRENT_INPUT_EXT_POWER_HART
+          10 - CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART
+        minimum: 0
+        maximum: 10
+        default: 0
+
+      adi,gpo-comparator:
+        type: boolean
+        description: |
+          Whether to configure GPO as a comparator or not.
+          When not configured as a comparator, the GPO will be treated as an
+          output-only GPIO.
+
+    required:
+      - reg
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+    #include <dt-bindings/iio/addac/adi,ad74413r.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      cs-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
+      status = "okay";
+
+      ad74413r@0 {
+        compatible = "adi,ad74413r";
+        reg = <0>;
+        spi-max-frequency = <1000000>;
+        spi-cpol;
+
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        interrupt-parent = <&gpio>;
+        interrupts = <26 IRQ_TYPE_EDGE_FALLING>;
+
+        refin-supply = <&ad74413r_refin>;
+        adi,rsense-resistance-ohms = <100>;
+
+        channel@0 {
+          reg = <0>;
+
+          adi,ch-func = <CH_FUNC_VOLTAGE_OUTPUT>;
+        };
+
+        channel@1 {
+          reg = <1>;
+
+          adi,ch-func = <CH_FUNC_CURRENT_OUTPUT>;
+        };
+
+        channel@2 {
+          reg = <2>;
+
+          adi,ch-func = <CH_FUNC_DIGITAL_INPUT_LOGIC>;
+          adi,gpo-comparator;
+        };
+
+        channel@3 {
+          reg = <3>;
+
+          adi,ch-func = <CH_FUNC_CURRENT_INPUT_EXT_POWER>;
+        };
+      };
+    };
+...
diff --git a/include/dt-bindings/iio/addac/adi,ad74413r.h b/include/dt-bindings/iio/addac/adi,ad74413r.h
new file mode 100644
index 000000000000..a43b010f974f
--- /dev/null
+++ b/include/dt-bindings/iio/addac/adi,ad74413r.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _DT_BINDINGS_ADI_AD74413R_H
+#define _DT_BINDINGS_ADI_AD74413R_H
+
+#define CH_FUNC_HIGH_IMPEDANCE					0x0
+#define CH_FUNC_VOLTAGE_OUTPUT					0x1
+#define CH_FUNC_CURRENT_OUTPUT					0x2
+#define CH_FUNC_VOLTAGE_INPUT					0x3
+#define CH_FUNC_CURRENT_INPUT_EXT_POWER			0x4
+#define CH_FUNC_CURRENT_INPUT_LOOP_POWER		0x5
+#define CH_FUNC_RESISTANCE_INPUT				0x6
+#define CH_FUNC_DIGITAL_INPUT_LOGIC				0x7
+#define CH_FUNC_DIGITAL_INPUT_LOOP_POWER		0x8
+#define CH_FUNC_CURRENT_INPUT_EXT_POWER_HART	0x9
+#define CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART	0xA
+
+#define CH_FUNC_MIN		CH_FUNC_HIGH_IMPEDANCE
+#define CH_FUNC_MAX		CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART
+
+#endif /* _DT_BINDINGS_ADI_AD74413R_H */
-- 
2.34.1

[PATCH v6 3/3] iio: addac: add AD74413R driver

[Cosmin Tanislav]

The AD74412R and AD74413R are quad-channel software configurable input/output
solutions for building and process control applications. They contain
functionality for analog output, analog input, digital input, resistance
temperature detector, and thermocouple measurements integrated
into a single chip solution with an SPI interface.
The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
four configurable input/output channels and a suite of diagnostic functions.
The AD74413R differentiates itself from the AD74412R by being HART-compatible.

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.

.
├── in_current0_offset
├── in_current0_raw
├── in_current0_sampling_frequency
├── in_current0_sampling_frequency_available
├── in_current0_scale
├── in_voltage1_offset
├── in_voltage1_raw
├── in_voltage1_sampling_frequency
├── in_voltage1_sampling_frequency_available
├── in_voltage1_scale
├── in_voltage2_offset
├── in_voltage2_raw
├── in_voltage2_sampling_frequency
├── in_voltage2_sampling_frequency_available
├── in_voltage2_scale
├── in_current3_offset
├── in_current3_raw
├── in_current3_sampling_frequency
├── in_current3_sampling_frequency_available
├── in_current3_scale
├── out_voltage0_raw
├── out_voltage0_scale
├── out_current1_raw
├── out_current1_scale
├── name
├── buffer
│   ├── data_available
│   ├── enable
│   ├── length
│   └── watermark
└── scan_elements
    ├── in_current0_en
    ├── in_current0_index
    ├── in_current0_type
    ├── in_voltage1_en
    ├── in_voltage1_index
    ├── in_voltage1_type
    ├── in_voltage2_en
    ├── in_voltage2_index
    ├── in_voltage2_type
    ├── in_current3_en
    ├── in_current3_index
    └── in_current3_type

Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>
---
 MAINTAINERS                  |    9 +
 drivers/iio/addac/Kconfig    |   12 +
 drivers/iio/addac/Makefile   |    1 +
 drivers/iio/addac/ad74413r.c | 1473 ++++++++++++++++++++++++++++++++++
 4 files changed, 1495 insertions(+)
 create mode 100644 drivers/iio/addac/ad74413r.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 7a2345ce8521..ed13c5efeb4f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1069,6 +1069,15 @@ W:	http://ez.analog.com/community/linux-device-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad7780.yaml
 F:	drivers/iio/adc/ad7780.c
 
+ANALOG DEVICES INC AD74413R DRIVER
+M:	Cosmin Tanislav <cosmin.tanislav@analog.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+W:	http://ez.analog.com/community/linux-device-drivers
+F:	Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
+F:	drivers/iio/addac/ad74413r.c
+F:	include/dt-bindings/iio/addac/adi,ad74413r.h
+
 ANALOG DEVICES INC AD9389B DRIVER
 M:	Hans Verkuil <hverkuil-cisco@xs4all.nl>
 L:	linux-media@vger.kernel.org
diff --git a/drivers/iio/addac/Kconfig b/drivers/iio/addac/Kconfig
index 2e64d7755d5e..138492362f20 100644
--- a/drivers/iio/addac/Kconfig
+++ b/drivers/iio/addac/Kconfig
@@ -5,4 +5,16 @@
 
 menu "Analog to digital and digital to analog converters"
 
+config AD74413R
+	tristate "Analog Devices AD74412R/AD74413R driver"
+	depends on GPIOLIB && SPI
+	select REGMAP_SPI
+	select CRC8
+	help
+	  Say yes here to build support for Analog Devices AD74412R/AD74413R
+	  quad-channel software configurable input/output solution.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad74413r.
+
 endmenu
diff --git a/drivers/iio/addac/Makefile b/drivers/iio/addac/Makefile
index b888b9ee12da..cfd4bbe64ad3 100644
--- a/drivers/iio/addac/Makefile
+++ b/drivers/iio/addac/Makefile
@@ -4,3 +4,4 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD74413R) += ad74413r.o
diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
new file mode 100644
index 000000000000..d4071e0165dd
--- /dev/null
+++ b/drivers/iio/addac/ad74413r.c
@@ -0,0 +1,1473 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Analog Devices, Inc.
+ * Author: Cosmin Tanislav <cosmin.tanislav@analog.com>
+ */
+
+#include <asm/unaligned.h>
+#include <linux/bitfield.h>
+#include <linux/crc8.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/interrupt.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <dt-bindings/iio/addac/adi,ad74413r.h>
+
+#define AD74413R_CRC_POLYNOMIAL	0x7
+DECLARE_CRC8_TABLE(ad74413r_crc8_table);
+
+#define AD74413R_CHANNEL_MAX	4
+
+#define AD74413R_FRAME_SIZE	4
+
+struct ad74413r_chip_info {
+	const char	*name;
+	bool		hart_support;
+};
+
+struct ad74413r_channel_config {
+	u32		func;
+	bool		gpo_comparator;
+	bool		initialized;
+};
+
+struct ad74413r_channels {
+	struct iio_chan_spec	*channels;
+	unsigned int		num_channels;
+};
+
+struct ad74413r_state {
+	struct ad74413r_channel_config	channel_configs[AD74413R_CHANNEL_MAX];
+	unsigned int			gpo_gpio_offsets[AD74413R_CHANNEL_MAX];
+	unsigned int			comp_gpio_offsets[AD74413R_CHANNEL_MAX];
+	struct gpio_chip		gpo_gpiochip;
+	struct gpio_chip		comp_gpiochip;
+	struct mutex			lock;
+	struct completion		adc_data_completion;
+	unsigned int			num_gpo_gpios;
+	unsigned int			num_comparator_gpios;
+	u32				rsense_resistance_ohms;
+
+	const struct ad74413r_chip_info	*chip_info;
+	struct spi_device		*spi;
+	struct regulator		*refin_reg;
+	struct regmap			*regmap;
+	struct device			*dev;
+	struct iio_trigger		*trig;
+
+	size_t			adc_active_channels;
+	struct spi_message	adc_samples_msg;
+	struct spi_transfer	adc_samples_xfer[AD74413R_CHANNEL_MAX + 1];
+
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 */
+	struct {
+		u8 rx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX];
+		s64 timestamp;
+	} adc_samples_buf ____cacheline_aligned;
+
+	u8	adc_samples_tx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX]
+			____cacheline_aligned;
+	u8	reg_tx_buf[AD74413R_FRAME_SIZE] ____cacheline_aligned;
+	u8	reg_rx_buf[AD74413R_FRAME_SIZE] ____cacheline_aligned;
+};
+
+#define AD74413R_REG_NOP		0x00
+
+#define AD74413R_REG_CH_FUNC_SETUP_X(x)	(0x01 + (x))
+#define AD74413R_CH_FUNC_SETUP_MASK	GENMASK(3, 0)
+
+#define AD74413R_REG_ADC_CONFIG_X(x)		(0x05 + (x))
+#define AD74413R_ADC_CONFIG_RANGE_MASK		GENMASK(7, 5)
+#define AD74413R_ADC_CONFIG_REJECTION_MASK	GENMASK(4, 3)
+#define AD74413R_ADC_RANGE_10V			0b000
+#define AD74413R_ADC_RANGE_2P5V_EXT_POW		0b001
+#define AD74413R_ADC_RANGE_2P5V_INT_POW		0b010
+#define AD74413R_ADC_RANGE_5V_BI_DIR		0b011
+#define AD74413R_ADC_REJECTION_50_60		0b00
+#define AD74413R_ADC_REJECTION_NONE		0b01
+#define AD74413R_ADC_REJECTION_50_60_HART	0b10
+#define AD74413R_ADC_REJECTION_HART		0b11
+
+#define AD74413R_REG_DIN_CONFIG_X(x)	(0x09 + (x))
+#define AD74413R_DIN_DEBOUNCE_MASK	GENMASK(4, 0)
+#define AD74413R_DIN_DEBOUNCE_LEN	(1 << 5)
+
+#define AD74413R_REG_DAC_CODE_X(x)	(0x16 + (x))
+#define AD74413R_DAC_CODE_MAX		((1 << 13) - 1)
+#define AD74413R_DAC_VOLTAGE_MAX	11000
+
+#define AD74413R_REG_GPO_PAR_DATA		0x0d
+#define AD74413R_REG_GPO_CONFIG_X(x)		(0x0e + (x))
+#define AD74413R_GPO_CONFIG_DATA_MASK	BIT(3)
+#define AD74413R_GPO_CONFIG_SELECT_MASK		GENMASK(2, 0)
+#define AD74413R_GPO_CONFIG_100K_PULL_DOWN	0b000
+#define AD74413R_GPO_CONFIG_LOGIC		0b001
+#define AD74413R_GPO_CONFIG_LOGIC_PARALLEL	0b010
+#define AD74413R_GPO_CONFIG_COMPARATOR		0b011
+#define AD74413R_GPO_CONFIG_HIGH_IMPEDANCE	0b100
+
+#define AD74413R_REG_ADC_CONV_CTRL	0x23
+#define AD74413R_CONV_SEQ_MASK		GENMASK(9, 8)
+#define AD74413R_CONV_SEQ_ON		0b00
+#define AD74413R_CONV_SEQ_SINGLE	0b01
+#define AD74413R_CONV_SEQ_CONTINUOUS	0b10
+#define AD74413R_CONV_SEQ_OFF		0b11
+#define AD74413R_CH_EN_MASK(x)		BIT(x)
+
+#define AD74413R_REG_DIN_COMP_OUT		0x25
+#define AD74413R_DIN_COMP_OUT_SHIFT_X(x)	x
+
+#define AD74413R_REG_ADC_RESULT_X(x)	(0x26 + (x))
+#define AD74413R_ADC_RESULT_MAX		GENMASK(15, 0)
+
+#define AD74413R_REG_READ_SELECT	0x41
+
+#define AD74413R_REG_CMD_KEY		0x44
+#define AD74413R_CMD_KEY_LDAC		0x953a
+#define AD74413R_CMD_KEY_RESET1		0x15fa
+#define AD74413R_CMD_KEY_RESET2		0xaf51
+
+static const int ad74413r_adc_sampling_rates[] = {
+	20, 4800,
+};
+
+static const int ad74413r_adc_sampling_rates_hart[] = {
+	10, 20, 1200, 4800,
+};
+
+static int ad74413r_crc(u8 *buf)
+{
+	return crc8(ad74413r_crc8_table, buf, 3, 0);
+}
+
+static void ad74413r_format_reg_write(u8 reg, u16 val, u8 *buf)
+{
+	buf[0] = reg;
+	put_unaligned_be16(val, &buf[1]);
+	buf[3] = ad74413r_crc(buf);
+}
+
+static int ad74413r_reg_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct ad74413r_state *st = context;
+
+	ad74413r_format_reg_write(reg, val, st->reg_tx_buf);
+
+	return spi_write(st->spi, st->reg_tx_buf, AD74413R_FRAME_SIZE);
+}
+
+static int ad74413r_crc_check(struct ad74413r_state *st, u8 *buf)
+{
+	u8 expected_crc = ad74413r_crc(buf);
+
+	if (buf[3] != expected_crc) {
+		dev_err(st->dev, "Bad CRC %02x for %02x%02x%02x\n",
+			buf[3], buf[0], buf[1], buf[2]);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ad74413r_reg_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct ad74413r_state *st = context;
+	struct spi_transfer reg_read_xfer[] = {
+		{
+			.tx_buf = st->reg_tx_buf,
+			.len = AD74413R_FRAME_SIZE,
+			.cs_change = 1,
+		},
+		{
+			.rx_buf = st->reg_rx_buf,
+			.len = AD74413R_FRAME_SIZE,
+		},
+	};
+	int ret;
+
+	ad74413r_format_reg_write(AD74413R_REG_READ_SELECT, reg,
+				  st->reg_tx_buf);
+
+	ret = spi_sync_transfer(st->spi, reg_read_xfer,
+				ARRAY_SIZE(reg_read_xfer));
+	if (ret)
+		return ret;
+
+	ret = ad74413r_crc_check(st, st->reg_rx_buf);
+	if (ret)
+		return ret;
+
+	*val = get_unaligned_be16(&st->reg_rx_buf[1]);
+
+	return 0;
+}
+
+const struct regmap_config ad74413r_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 16,
+	.reg_read = ad74413r_reg_read,
+	.reg_write = ad74413r_reg_write,
+};
+
+static int ad74413r_set_gpo_config(struct ad74413r_state *st,
+				   unsigned int offset, u8 mode)
+{
+	return regmap_update_bits(st->regmap, AD74413R_REG_GPO_CONFIG_X(offset),
+				  AD74413R_GPO_CONFIG_SELECT_MASK, mode);
+}
+
+static const unsigned int ad74413r_debounce_map[AD74413R_DIN_DEBOUNCE_LEN] = {
+	0,     13,    18,    24,    32,    42,    56,    75,
+	100,   130,   180,   240,   320,   420,   560,   750,
+	1000,  1300,  1800,  2400,  3200,  4200,  5600,  7500,
+	10000, 13000, 18000, 24000, 32000, 42000, 56000, 75000,
+};
+
+static int ad74413r_set_comp_debounce(struct ad74413r_state *st,
+				      unsigned int offset,
+				      unsigned int debounce)
+{
+	unsigned int val = AD74413R_DIN_DEBOUNCE_LEN - 1;
+	unsigned int i;
+
+	for (i = 0; i < AD74413R_DIN_DEBOUNCE_LEN; i++)
+		if (debounce <= ad74413r_debounce_map[i]) {
+			val = i;
+			break;
+		}
+
+	return regmap_update_bits(st->regmap,
+				  AD74413R_REG_DIN_CONFIG_X(offset),
+				  AD74413R_DIN_DEBOUNCE_MASK,
+				  val);
+}
+
+static void ad74413r_gpio_set(struct gpio_chip *chip,
+			      unsigned int offset, int val)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned int real_offset = st->gpo_gpio_offsets[offset];
+	int ret;
+
+	ret = ad74413r_set_gpo_config(st, real_offset,
+				      AD74413R_GPO_CONFIG_LOGIC);
+	if (ret)
+		return;
+
+	regmap_update_bits(st->regmap, AD74413R_REG_GPO_CONFIG_X(real_offset),
+			   AD74413R_GPO_CONFIG_DATA_MASK,
+			   val ? AD74413R_GPO_CONFIG_DATA_MASK : 0);
+}
+
+static void ad74413r_gpio_set_multiple(struct gpio_chip *chip,
+				       unsigned long *mask,
+				       unsigned long *bits)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned long real_mask = 0;
+	unsigned long real_bits = 0;
+	unsigned int offset = 0;
+	int ret;
+
+	for_each_set_bit_from(offset, mask, AD74413R_CHANNEL_MAX) {
+		unsigned int real_offset = st->gpo_gpio_offsets[offset];
+
+		ret = ad74413r_set_gpo_config(st, real_offset,
+			AD74413R_GPO_CONFIG_LOGIC_PARALLEL);
+		if (ret)
+			return;
+
+		real_mask |= BIT(real_offset);
+		if (*bits & offset)
+			real_bits |= BIT(real_offset);
+	}
+
+	regmap_update_bits(st->regmap, AD74413R_REG_GPO_PAR_DATA,
+			   real_mask, real_bits);
+}
+
+static int ad74413r_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned int real_offset = st->comp_gpio_offsets[offset];
+	unsigned int status;
+	int ret;
+
+	ret = regmap_read(st->regmap, AD74413R_REG_DIN_COMP_OUT, &status);
+	if (ret)
+		return ret;
+
+	status &= AD74413R_DIN_COMP_OUT_SHIFT_X(real_offset);
+
+	return status ? 1 : 0;
+}
+
+static int ad74413r_gpio_get_multiple(struct gpio_chip *chip,
+				      unsigned long *mask,
+				      unsigned long *bits)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned int offset = 0;
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(st->regmap, AD74413R_REG_DIN_COMP_OUT, &val);
+	if (ret)
+		return ret;
+
+	for_each_set_bit_from(offset, mask, AD74413R_CHANNEL_MAX) {
+		unsigned int real_offset = st->comp_gpio_offsets[offset];
+
+		if (val & BIT(real_offset))
+			*bits |= offset;
+	}
+
+	return ret;
+}
+
+static int ad74413r_gpio_get_gpo_direction(struct gpio_chip *chip,
+					   unsigned int offset)
+{
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int ad74413r_gpio_get_comp_direction(struct gpio_chip *chip,
+					    unsigned int offset)
+{
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int ad74413r_gpio_set_gpo_config(struct gpio_chip *chip,
+					unsigned int offset,
+					unsigned long config)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned int real_offset = st->gpo_gpio_offsets[offset];
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_BIAS_PULL_DOWN:
+		return ad74413r_set_gpo_config(st, real_offset,
+			AD74413R_GPO_CONFIG_100K_PULL_DOWN);
+	case PIN_CONFIG_BIAS_HIGH_IMPEDANCE:
+		return ad74413r_set_gpo_config(st, real_offset,
+			AD74413R_GPO_CONFIG_HIGH_IMPEDANCE);
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int ad74413r_gpio_set_comp_config(struct gpio_chip *chip,
+					 unsigned int offset,
+					 unsigned long config)
+{
+	struct ad74413r_state *st = gpiochip_get_data(chip);
+	unsigned int real_offset = st->comp_gpio_offsets[offset];
+
+	switch (pinconf_to_config_param(config)) {
+	case PIN_CONFIG_INPUT_DEBOUNCE:
+		return ad74413r_set_comp_debounce(st, real_offset,
+			pinconf_to_config_argument(config));
+	default:
+		return -ENOTSUPP;
+	}
+}
+
+static int ad74413r_reset(struct ad74413r_state *st)
+{
+	int ret;
+
+	ret = regmap_write(st->regmap, AD74413R_REG_CMD_KEY,
+			   AD74413R_CMD_KEY_RESET1);
+	if (ret)
+		return ret;
+
+	return regmap_write(st->regmap, AD74413R_REG_CMD_KEY,
+			    AD74413R_CMD_KEY_RESET2);
+}
+
+static int ad74413r_set_channel_dac_code(struct ad74413r_state *st,
+					 unsigned int channel, int dac_code)
+{
+	struct reg_sequence reg_seq[2] = {
+		{ AD74413R_REG_DAC_CODE_X(channel), dac_code },
+		{ AD74413R_REG_CMD_KEY, AD74413R_CMD_KEY_LDAC },
+	};
+
+	return regmap_multi_reg_write(st->regmap, reg_seq, 2);
+}
+
+static int ad74413r_set_channel_function(struct ad74413r_state *st,
+					 unsigned int channel, u8 func)
+{
+	return regmap_update_bits(st->regmap,
+				  AD74413R_REG_CH_FUNC_SETUP_X(channel),
+				  AD74413R_CH_FUNC_SETUP_MASK, func);
+}
+
+static int ad74413r_set_adc_conv_seq(struct ad74413r_state *st,
+				     unsigned int status)
+{
+	int ret;
+
+	/*
+	 * These bits do not clear when a conversion completes.
+	 * To enable a subsequent conversion, repeat the write.
+	 */
+	ret = regmap_write_bits(st->regmap, AD74413R_REG_ADC_CONV_CTRL,
+				AD74413R_CONV_SEQ_MASK,
+				FIELD_PREP(AD74413R_CONV_SEQ_MASK, status));
+	if (ret)
+		return ret;
+
+	/*
+	 * Wait 100us before starting conversions.
+	 */
+	usleep_range(100, 120);
+
+	return 0;
+}
+
+static int ad74413r_set_adc_channel_enable(struct ad74413r_state *st,
+					   unsigned int channel,
+					   bool status)
+{
+	return regmap_update_bits(st->regmap, AD74413R_REG_ADC_CONV_CTRL,
+				  AD74413R_CH_EN_MASK(channel),
+				  status ? AD74413R_CH_EN_MASK(channel) : 0);
+}
+
+static int ad74413r_get_adc_range(struct ad74413r_state *st,
+				  unsigned int channel,
+				  unsigned int *val)
+{
+	int ret;
+
+	ret = regmap_read(st->regmap, AD74413R_REG_ADC_CONFIG_X(channel), val);
+	if (ret)
+		return ret;
+
+	*val = FIELD_GET(AD74413R_ADC_CONFIG_RANGE_MASK, *val);
+
+	return 0;
+}
+
+static int ad74413r_get_adc_rejection(struct ad74413r_state *st,
+				      unsigned int channel,
+				      unsigned int *val)
+{
+	int ret;
+
+	ret = regmap_read(st->regmap, AD74413R_REG_ADC_CONFIG_X(channel), val);
+	if (ret)
+		return ret;
+
+	*val = FIELD_GET(AD74413R_ADC_CONFIG_REJECTION_MASK, *val);
+
+	return 0;
+}
+
+static int ad74413r_set_adc_rejection(struct ad74413r_state *st,
+				      unsigned int channel,
+				      unsigned int val)
+{
+	return regmap_update_bits(st->regmap,
+				  AD74413R_REG_ADC_CONFIG_X(channel),
+				  AD74413R_ADC_CONFIG_REJECTION_MASK,
+				  FIELD_PREP(AD74413R_ADC_CONFIG_REJECTION_MASK,
+				  val));
+}
+
+static int ad74413r_rejection_to_rate(struct ad74413r_state *st,
+				      unsigned int rej, int *val)
+{
+	switch (rej) {
+	case AD74413R_ADC_REJECTION_50_60:
+		*val = 20;
+		return 0;
+	case AD74413R_ADC_REJECTION_NONE:
+		*val = 4800;
+		return 0;
+	case AD74413R_ADC_REJECTION_50_60_HART:
+		*val = 10;
+		return 0;
+	case AD74413R_ADC_REJECTION_HART:
+		*val = 1200;
+		return 0;
+	default:
+		dev_err(st->dev, "ADC rejection invalid\n");
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_rate_to_rejection(struct ad74413r_state *st,
+				      int rate, unsigned int *val)
+{
+	switch (rate) {
+	case 20:
+		*val = AD74413R_ADC_REJECTION_50_60;
+		return 0;
+	case 4800:
+		*val = AD74413R_ADC_REJECTION_NONE;
+		return 0;
+	case 10:
+		*val = AD74413R_ADC_REJECTION_50_60_HART;
+		return 0;
+	case 1200:
+		*val = AD74413R_ADC_REJECTION_HART;
+		return 0;
+	default:
+		dev_err(st->dev, "ADC rate invalid\n");
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_range_to_voltage_range(struct ad74413r_state *st,
+					   unsigned int range, int *val)
+{
+	switch (range) {
+	case AD74413R_ADC_RANGE_10V:
+		*val = 10000;
+		return 0;
+	case AD74413R_ADC_RANGE_2P5V_EXT_POW:
+	case AD74413R_ADC_RANGE_2P5V_INT_POW:
+		*val = 2500;
+		return 0;
+	case AD74413R_ADC_RANGE_5V_BI_DIR:
+		*val = 5000;
+		return 0;
+	default:
+		dev_err(st->dev, "ADC range invalid\n");
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_range_to_voltage_offset(struct ad74413r_state *st,
+					    unsigned int range, int *val)
+{
+	switch (range) {
+	case AD74413R_ADC_RANGE_10V:
+	case AD74413R_ADC_RANGE_2P5V_EXT_POW:
+		*val = 0;
+		return 0;
+	case AD74413R_ADC_RANGE_2P5V_INT_POW:
+	case AD74413R_ADC_RANGE_5V_BI_DIR:
+		*val = -2500;
+		return 0;
+	default:
+		dev_err(st->dev, "ADC range invalid\n");
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_range_to_voltage_offset_raw(struct ad74413r_state *st,
+						unsigned int range, int *val)
+{
+	switch (range) {
+	case AD74413R_ADC_RANGE_10V:
+	case AD74413R_ADC_RANGE_2P5V_EXT_POW:
+		*val = 0;
+		return 0;
+	case AD74413R_ADC_RANGE_2P5V_INT_POW:
+		*val = -((int) AD74413R_ADC_RESULT_MAX);
+		return 0;
+	case AD74413R_ADC_RANGE_5V_BI_DIR:
+		*val = -((int) AD74413R_ADC_RESULT_MAX / 2);
+		return 0;
+	default:
+		dev_err(st->dev, "ADC range invalid\n");
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_get_output_voltage_scale(struct ad74413r_state *st,
+					     int *val, int *val2)
+{
+	*val = AD74413R_DAC_VOLTAGE_MAX;
+	*val2 = AD74413R_DAC_CODE_MAX;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int ad74413r_get_output_current_scale(struct ad74413r_state *st,
+					     int *val, int *val2)
+{
+	*val = regulator_get_voltage(st->refin_reg);
+	*val2 = st->rsense_resistance_ohms * AD74413R_DAC_CODE_MAX * 1000;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int ad74413r_get_input_voltage_scale(struct ad74413r_state *st,
+					    unsigned int channel,
+					    int *val, int *val2)
+{
+	unsigned int range;
+	int ret;
+
+	ret = ad74413r_get_adc_range(st, channel, &range);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_range_to_voltage_range(st, range, val);
+	if (ret)
+		return ret;
+
+	*val2 = AD74413R_ADC_RESULT_MAX;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+
+static int ad74413r_get_input_voltage_offset(struct ad74413r_state *st,
+					     unsigned int channel, int *val)
+{
+	unsigned int range;
+	int ret;
+
+	ret = ad74413r_get_adc_range(st, channel, &range);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_range_to_voltage_offset_raw(st, range, val);
+	if (ret)
+		return ret;
+
+	return IIO_VAL_INT;
+}
+
+static int ad74413r_get_input_current_scale(struct ad74413r_state *st,
+					    unsigned int channel, int *val,
+					    int *val2)
+{
+	unsigned int range;
+	int ret;
+
+	ret = ad74413r_get_adc_range(st, channel, &range);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_range_to_voltage_range(st, range, val);
+	if (ret)
+		return ret;
+
+	*val2 = AD74413R_ADC_RESULT_MAX * st->rsense_resistance_ohms;
+
+	return IIO_VAL_FRACTIONAL;
+}
+
+static int ad74413_get_input_current_offset(struct ad74413r_state *st,
+					    unsigned int channel, int *val)
+{
+	unsigned int range;
+	int voltage_range;
+	int voltage_offset;
+	int ret;
+
+	ret = ad74413r_get_adc_range(st, channel, &range);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_range_to_voltage_range(st, range, &voltage_range);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_range_to_voltage_offset(st, range, &voltage_offset);
+	if (ret)
+		return ret;
+
+	*val = voltage_offset * AD74413R_ADC_RESULT_MAX / voltage_range;
+
+	return IIO_VAL_INT;
+}
+
+static int ad74413r_get_adc_rate(struct ad74413r_state *st,
+				 unsigned int channel, int *val)
+{
+	unsigned int rejection;
+	int ret;
+
+	ret = ad74413r_get_adc_rejection(st, channel, &rejection);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_rejection_to_rate(st, rejection, val);
+	if (ret)
+		return ret;
+
+	return IIO_VAL_INT;
+}
+
+static int ad74413r_set_adc_rate(struct ad74413r_state *st,
+				 unsigned int channel, int val)
+{
+	unsigned int rejection;
+	int ret;
+
+	ret = ad74413r_rate_to_rejection(st, val, &rejection);
+	if (ret)
+		return ret;
+
+	return ad74413r_set_adc_rejection(st, channel, rejection);
+}
+
+static irqreturn_t ad74413r_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	u8 *rx_buf = st->adc_samples_buf.rx_buf;
+	unsigned int i;
+	int ret;
+
+	ret = spi_sync(st->spi, &st->adc_samples_msg);
+	if (ret)
+		goto out;
+
+	for (i = 0; i < st->adc_active_channels; i++)
+		ad74413r_crc_check(st, &rx_buf[i * AD74413R_FRAME_SIZE]);
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &st->adc_samples_buf,
+					   iio_get_time_ns(indio_dev));
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ad74413r_adc_data_interrupt(int irq, void *data)
+{
+	struct iio_dev *indio_dev = data;
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	if (iio_buffer_enabled(indio_dev))
+		iio_trigger_poll(st->trig);
+	else
+		complete(&st->adc_data_completion);
+
+	return IRQ_HANDLED;
+}
+
+static int _ad74413r_get_single_adc_result(struct ad74413r_state *st,
+					   unsigned int channel, int *val)
+{
+	unsigned int uval;
+	int ret;
+
+	reinit_completion(&st->adc_data_completion);
+
+	ret = ad74413r_set_adc_channel_enable(st, channel, true);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_SINGLE);
+	if (ret)
+		return ret;
+
+	ret = wait_for_completion_timeout(&st->adc_data_completion,
+					  msecs_to_jiffies(1000));
+	if (!ret) {
+		ret = -ETIMEDOUT;
+		return ret;
+	}
+
+	ret = regmap_read(st->regmap, AD74413R_REG_ADC_RESULT_X(channel),
+			  &uval);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_set_adc_channel_enable(st, channel, false);
+	if (ret)
+		return ret;
+
+	*val = uval;
+
+	return IIO_VAL_INT;
+}
+
+static int ad74413r_get_single_adc_result(struct iio_dev *indio_dev,
+					  unsigned int channel, int *val)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	int ret;
+
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
+
+	mutex_lock(&st->lock);
+	ret = _ad74413r_get_single_adc_result(st, channel, val);
+	mutex_unlock(&st->lock);
+
+	iio_device_release_direct_mode(indio_dev);
+
+	return ret;
+}
+
+static int ad74413r_adc_to_resistance_result(int adc_result, int *val)
+{
+	if (adc_result == AD74413R_ADC_RESULT_MAX)
+		return -EINVAL;
+
+	*val = DIV_ROUND_CLOSEST(adc_result * 2100,
+				 AD74413R_ADC_RESULT_MAX - adc_result);
+	return 0;
+}
+
+static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
+				     const unsigned long *active_scan_mask)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	struct spi_transfer *xfer = st->adc_samples_xfer;
+	u8 *rx_buf = &st->adc_samples_buf.rx_buf[-1 * AD74413R_FRAME_SIZE];
+	u8 *tx_buf = st->adc_samples_tx_buf;
+	unsigned int channel;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	spi_message_init(&st->adc_samples_msg);
+	st->adc_active_channels = 0;
+
+	for_each_clear_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
+		ret = ad74413r_set_adc_channel_enable(st, channel, false);
+		if (ret)
+			goto out;
+	}
+
+	if (*active_scan_mask == 0)
+		goto out;
+
+	/*
+	 * The read select register is used to select which register's value
+	 * will be sent by the slave on the next SPI frame.
+	 *
+	 * Create an SPI message that, on each step, writes to the read select
+	 * register to select the ADC result of the next enabled channel, and
+	 * reads the ADC result of the previous enabled channel.
+	 *
+	 * Example:
+	 * W: [WCH1] [WCH2] [WCH2] [WCH3] [    ]
+	 * R: [    ] [RCH1] [RCH2] [RCH3] [RCH4]
+	 */
+
+	for_each_set_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
+		ret = ad74413r_set_adc_channel_enable(st, channel, true);
+		if (ret)
+			goto out;
+
+		st->adc_active_channels++;
+
+		if (xfer == st->adc_samples_xfer)
+			xfer->rx_buf = NULL;
+		else
+			xfer->rx_buf = rx_buf;
+
+		xfer->tx_buf = tx_buf;
+		xfer->len = AD74413R_FRAME_SIZE;
+		xfer->cs_change = 1;
+
+		ad74413r_format_reg_write(AD74413R_REG_READ_SELECT,
+					  AD74413R_REG_ADC_RESULT_X(channel),
+					  tx_buf);
+
+		spi_message_add_tail(xfer, &st->adc_samples_msg);
+
+		xfer++;
+		tx_buf += AD74413R_FRAME_SIZE;
+		rx_buf += AD74413R_FRAME_SIZE;
+	}
+
+	xfer->rx_buf = rx_buf;
+	xfer->tx_buf = NULL;
+	xfer->len = AD74413R_FRAME_SIZE;
+	xfer->cs_change = 0;
+
+	spi_message_add_tail(xfer, &st->adc_samples_msg);
+
+out:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad74413r_buffer_postenable(struct iio_dev *indio_dev)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	return ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_CONTINUOUS);
+}
+
+static int ad74413r_buffer_predisable(struct iio_dev *indio_dev)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	return ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
+}
+
+static int ad74413r_read_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int *val, int *val2, long info)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output)
+				return ad74413r_get_output_voltage_scale(st,
+					val, val2);
+			else
+				return ad74413r_get_input_voltage_scale(st,
+					chan->channel, val, val2);
+		case IIO_CURRENT:
+			if (chan->output)
+				return ad74413r_get_output_current_scale(st,
+					val, val2);
+			else
+				return ad74413r_get_input_current_scale(st,
+					chan->channel, val, val2);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			return ad74413r_get_input_voltage_offset(st,
+				chan->channel, val);
+		case IIO_CURRENT:
+			return ad74413_get_input_current_offset(st,
+				chan->channel, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_RAW:
+		if (chan->output)
+			return -EINVAL;
+
+		return ad74413r_get_single_adc_result(indio_dev, chan->channel,
+						      val);
+	case IIO_CHAN_INFO_PROCESSED: {
+		int ret;
+
+		ret = ad74413r_get_single_adc_result(indio_dev, chan->channel,
+						     val);
+		if (ret < 0)
+			return ret;
+
+		ad74413r_adc_to_resistance_result(*val, val);
+
+		return ret;
+	}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return ad74413r_get_adc_rate(st, chan->channel, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long info)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		if (!chan->output)
+			return -EINVAL;
+
+		if (val > AD74413R_DAC_CODE_MAX) {
+			dev_err(st->dev, "Invalid DAC code\n");
+			return -EINVAL;
+		}
+
+		return ad74413r_set_channel_dac_code(st, chan->channel, val);
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		return ad74413r_set_adc_rate(st, chan->channel, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad74413r_read_avail(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       const int **vals, int *type, int *length,
+			       long info)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (st->chip_info->hart_support) {
+			*vals = ad74413r_adc_sampling_rates_hart;
+			*length = ARRAY_SIZE(ad74413r_adc_sampling_rates_hart);
+		} else {
+			*vals = ad74413r_adc_sampling_rates;
+			*length = ARRAY_SIZE(ad74413r_adc_sampling_rates);
+		}
+		*type = IIO_VAL_INT;
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_buffer_setup_ops ad74413r_buffer_ops = {
+	.postenable = &ad74413r_buffer_postenable,
+	.predisable = &ad74413r_buffer_predisable,
+};
+
+static const struct iio_trigger_ops ad74413r_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+};
+
+static const struct iio_info ad74413r_info = {
+	.read_raw = &ad74413r_read_raw,
+	.write_raw = &ad74413r_write_raw,
+	.read_avail = &ad74413r_read_avail,
+	.update_scan_mode = &ad74413r_update_scan_mode,
+};
+
+#define AD74413R_DAC_CHANNEL(_type, extra_mask_separate)		\
+	{								\
+		.type = (_type),					\
+		.indexed = 1,						\
+		.output = 1,						\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)		\
+				      | (extra_mask_separate),		\
+	}
+
+#define AD74413R_ADC_CHANNEL(_type, extra_mask_separate)		\
+	{								\
+		.type = (_type),					\
+		.indexed = 1,						\
+		.output = 0,						\
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)		\
+				      | BIT(IIO_CHAN_INFO_SAMP_FREQ)	\
+				      | (extra_mask_separate),		\
+		.info_mask_separate_available =				\
+					BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
+		.scan_type = {						\
+			.sign = 'u',					\
+			.realbits = 16,					\
+			.storagebits = 32,				\
+			.shift = 8,					\
+			.endianness = IIO_BE,				\
+		},							\
+	}
+
+#define AD74413R_ADC_VOLTAGE_CHANNEL					\
+	AD74413R_ADC_CHANNEL(IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE)	\
+			     | BIT(IIO_CHAN_INFO_OFFSET))
+
+#define AD74413R_ADC_CURRENT_CHANNEL					\
+	AD74413R_ADC_CHANNEL(IIO_CURRENT,  BIT(IIO_CHAN_INFO_SCALE)	\
+			     | BIT(IIO_CHAN_INFO_OFFSET))
+
+static struct iio_chan_spec ad74413r_voltage_output_channels[] = {
+	AD74413R_DAC_CHANNEL(IIO_VOLTAGE, BIT(IIO_CHAN_INFO_SCALE)),
+	AD74413R_ADC_CURRENT_CHANNEL,
+};
+
+static struct iio_chan_spec ad74413r_current_output_channels[] = {
+	AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
+	AD74413R_ADC_VOLTAGE_CHANNEL,
+};
+
+static struct iio_chan_spec ad74413r_voltage_input_channels[] = {
+	AD74413R_ADC_VOLTAGE_CHANNEL,
+};
+
+static struct iio_chan_spec ad74413r_current_input_channels[] = {
+	AD74413R_ADC_CURRENT_CHANNEL,
+};
+
+static struct iio_chan_spec ad74413r_resistance_input_channels[] = {
+	AD74413R_ADC_CHANNEL(IIO_RESISTANCE, BIT(IIO_CHAN_INFO_PROCESSED)),
+};
+
+static struct iio_chan_spec ad74413r_digital_input_channels[] = {
+	AD74413R_ADC_VOLTAGE_CHANNEL,
+};
+
+#define _AD74413R_CHANNELS(_channels)			\
+	{						\
+		.channels = _channels,			\
+		.num_channels = ARRAY_SIZE(_channels),	\
+	}
+
+#define AD74413R_CHANNELS(name) \
+	_AD74413R_CHANNELS(ad74413r_ ## name ## _channels)
+
+static const struct ad74413r_channels ad74413r_channels_map[] = {
+	[CH_FUNC_HIGH_IMPEDANCE] = AD74413R_CHANNELS(voltage_input),
+	[CH_FUNC_VOLTAGE_OUTPUT] = AD74413R_CHANNELS(voltage_output),
+	[CH_FUNC_CURRENT_OUTPUT] = AD74413R_CHANNELS(current_output),
+	[CH_FUNC_VOLTAGE_INPUT] = AD74413R_CHANNELS(voltage_input),
+	[CH_FUNC_CURRENT_INPUT_EXT_POWER] = AD74413R_CHANNELS(current_input),
+	[CH_FUNC_CURRENT_INPUT_LOOP_POWER] = AD74413R_CHANNELS(current_input),
+	[CH_FUNC_RESISTANCE_INPUT] = AD74413R_CHANNELS(resistance_input),
+	[CH_FUNC_DIGITAL_INPUT_LOGIC] = AD74413R_CHANNELS(digital_input),
+	[CH_FUNC_DIGITAL_INPUT_LOOP_POWER] = AD74413R_CHANNELS(digital_input),
+	[CH_FUNC_CURRENT_INPUT_EXT_POWER_HART] = AD74413R_CHANNELS(current_input),
+	[CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART] = AD74413R_CHANNELS(current_input),
+};
+
+static int ad74413r_parse_channel_config(struct iio_dev *indio_dev,
+					 struct fwnode_handle *channel_node)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	struct ad74413r_channel_config *config;
+	u32 index;
+	int ret;
+
+	ret = fwnode_property_read_u32(channel_node, "reg", &index);
+	if (ret) {
+		dev_err(st->dev, "Failed to read channel reg: %d\n", ret);
+		return ret;
+	}
+
+	if (index > AD74413R_CHANNEL_MAX) {
+		dev_err(st->dev, "Channel index %u is too large\n", index);
+		return -EINVAL;
+	}
+
+	config = &st->channel_configs[index];
+	if (config->initialized) {
+		dev_err(st->dev, "Channel %u already initialized\n", index);
+		return -EINVAL;
+	}
+
+	config->func = CH_FUNC_HIGH_IMPEDANCE;
+	fwnode_property_read_u32(channel_node, "adi,ch-func", &config->func);
+
+	if (config->func < CH_FUNC_MIN || config->func > CH_FUNC_MAX) {
+		dev_err(st->dev, "Invalid channel function %u\n", config->func);
+		return -EINVAL;
+	}
+
+	if (!st->chip_info->hart_support
+		&& (config->func == CH_FUNC_CURRENT_INPUT_EXT_POWER_HART
+		    || config->func == CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART)) {
+		dev_err(st->dev, "Unsupported HART function %u\n", config->func);
+		return -EINVAL;
+	}
+
+	if (config->func == CH_FUNC_DIGITAL_INPUT_LOGIC
+		|| config->func == CH_FUNC_DIGITAL_INPUT_LOOP_POWER)
+		st->num_comparator_gpios++;
+
+	config->gpo_comparator = fwnode_property_read_bool(channel_node,
+		"adi,gpo-comparator");
+
+	if (!config->gpo_comparator)
+		st->num_gpo_gpios++;
+
+	indio_dev->num_channels += ad74413r_channels_map[config->func].num_channels;
+
+	config->initialized = true;
+
+	return 0;
+}
+
+static int ad74413r_parse_channel_configs(struct iio_dev *indio_dev)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	struct fwnode_handle *channel_node = NULL;
+	int ret;
+
+	fwnode_for_each_available_child_node(dev_fwnode(st->dev), channel_node) {
+		ret = ad74413r_parse_channel_config(indio_dev, channel_node);
+		if (ret)
+			goto put_channel_node;
+	}
+
+	return 0;
+
+put_channel_node:
+	fwnode_handle_put(channel_node);
+
+	return ret;
+}
+
+static int ad74413r_setup_channels(struct iio_dev *indio_dev)
+{
+	struct ad74413r_state *st = iio_priv(indio_dev);
+	struct ad74413r_channel_config *config;
+	struct iio_chan_spec *channels, *chans;
+	unsigned int i, num_chans, chan_i;
+	int ret;
+
+	channels = devm_kcalloc(st->dev, sizeof(*channels),
+				indio_dev->num_channels, GFP_KERNEL);
+	if (!channels)
+		return -ENOMEM;
+
+	indio_dev->channels = channels;
+
+	for (i = 0; i < AD74413R_CHANNEL_MAX; i++) {
+		config = &st->channel_configs[i];
+		chans = ad74413r_channels_map[config->func].channels;
+		num_chans = ad74413r_channels_map[config->func].num_channels;
+
+		memcpy(channels, chans, num_chans * sizeof(*chans));
+
+		for (chan_i = 0; chan_i < num_chans; chan_i++) {
+			struct iio_chan_spec *chan = &channels[chan_i];
+
+			chan->channel = i;
+			if (chan->output)
+				chan->scan_index = -1;
+			else
+				chan->scan_index = i;
+
+		}
+
+		ret = ad74413r_set_channel_function(st, i, config->func);
+		if (ret)
+			return ret;
+
+		channels += num_chans;
+	}
+
+	return 0;
+}
+
+static int ad74413r_setup_gpios(struct ad74413r_state *st)
+{
+	struct ad74413r_channel_config *config;
+	unsigned int comp_gpio_i = 0;
+	unsigned int gpo_gpio_i = 0;
+	unsigned int i;
+	u8 gpo_config;
+	int ret;
+
+	for (i = 0; i < AD74413R_CHANNEL_MAX; i++) {
+		config = &st->channel_configs[i];
+
+		if (config->gpo_comparator) {
+			gpo_config = AD74413R_GPO_CONFIG_COMPARATOR;
+		} else {
+			gpo_config = AD74413R_GPO_CONFIG_LOGIC;
+			st->gpo_gpio_offsets[gpo_gpio_i++] = i;
+		}
+
+		if (config->func == CH_FUNC_DIGITAL_INPUT_LOGIC
+			|| config->func == CH_FUNC_DIGITAL_INPUT_LOOP_POWER)
+			st->comp_gpio_offsets[comp_gpio_i++] = i;
+
+		ret = ad74413r_set_gpo_config(st, i, gpo_config);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void ad74413r_regulator_disable(void *regulator)
+{
+	regulator_disable(regulator);
+}
+
+static int ad74413r_probe(struct spi_device *spi)
+{
+	struct ad74413r_state *st;
+	struct iio_dev *indio_dev;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (indio_dev == NULL)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	st->spi = spi;
+	st->dev = &spi->dev;
+	st->chip_info = device_get_match_data(&spi->dev);
+	mutex_init(&st->lock);
+	init_completion(&st->adc_data_completion);
+
+	st->regmap = devm_regmap_init(st->dev, NULL, st,
+				      &ad74413r_regmap_config);
+	if (IS_ERR(st->regmap))
+		return PTR_ERR(st->regmap);
+
+	st->refin_reg = devm_regulator_get(st->dev, "refin");
+	if (IS_ERR(st->refin_reg))
+		return dev_err_probe(st->dev, PTR_ERR(st->refin_reg),
+				     "Failed to get refin regulator\n");
+
+	ret = regulator_enable(st->refin_reg);
+	if (ret)
+		return ret;
+
+	ret = devm_add_action_or_reset(st->dev, ad74413r_regulator_disable,
+				       st->refin_reg);
+	if (ret)
+		return ret;
+
+	st->rsense_resistance_ohms = 100;
+	device_property_read_u32(st->dev, "adi,rsense-resistance-ohms",
+				 &st->rsense_resistance_ohms);
+
+	st->trig = devm_iio_trigger_alloc(st->dev, "%s-dev%d",
+					  st->chip_info->name, iio_device_id(indio_dev));
+	if (!st->trig)
+		return -ENOMEM;
+
+	st->trig->ops = &ad74413r_trigger_ops;
+	iio_trigger_set_drvdata(st->trig, st);
+
+	ret = devm_iio_trigger_register(st->dev, st->trig);
+	if (ret)
+		return ret;
+
+	indio_dev->name = st->chip_info->name;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->info = &ad74413r_info;
+	indio_dev->trig = iio_trigger_get(st->trig);
+
+	ret = ad74413r_reset(st);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_parse_channel_configs(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_setup_channels(indio_dev);
+	if (ret)
+		return ret;
+
+	ret = ad74413r_setup_gpios(st);
+	if (ret)
+		return ret;
+
+	if (st->num_gpo_gpios) {
+		st->gpo_gpiochip.owner = THIS_MODULE;
+		st->gpo_gpiochip.label = st->chip_info->name;
+		st->gpo_gpiochip.base = -1;
+		st->gpo_gpiochip.ngpio = st->num_gpo_gpios;
+		st->gpo_gpiochip.parent = st->dev;
+		st->gpo_gpiochip.can_sleep = true;
+		st->gpo_gpiochip.set = ad74413r_gpio_set;
+		st->gpo_gpiochip.set_multiple = ad74413r_gpio_set_multiple;
+		st->gpo_gpiochip.set_config = ad74413r_gpio_set_gpo_config;
+		st->gpo_gpiochip.get_direction =
+			ad74413r_gpio_get_gpo_direction;
+
+		ret = devm_gpiochip_add_data(st->dev, &st->gpo_gpiochip, st);
+		if (ret)
+			return ret;
+	}
+
+	if (st->num_comparator_gpios) {
+		st->comp_gpiochip.owner = THIS_MODULE;
+		st->comp_gpiochip.label = st->chip_info->name;
+		st->comp_gpiochip.base = -1;
+		st->comp_gpiochip.ngpio = st->num_comparator_gpios;
+		st->comp_gpiochip.parent = st->dev;
+		st->comp_gpiochip.can_sleep = true;
+		st->comp_gpiochip.get = ad74413r_gpio_get;
+		st->comp_gpiochip.get_multiple = ad74413r_gpio_get_multiple;
+		st->comp_gpiochip.set_config = ad74413r_gpio_set_comp_config;
+		st->comp_gpiochip.get_direction =
+			ad74413r_gpio_get_comp_direction;
+
+		ret = devm_gpiochip_add_data(st->dev, &st->comp_gpiochip, st);
+		if (ret)
+			return ret;
+	}
+
+	ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
+	if (ret)
+		return ret;
+
+	ret = devm_request_irq(st->dev, spi->irq, ad74413r_adc_data_interrupt,
+			       0, st->chip_info->name, indio_dev);
+	if (ret)
+		return ret;
+
+	ret = devm_iio_triggered_buffer_setup(st->dev, indio_dev,
+					      &iio_pollfunc_store_time,
+					      &ad74413r_trigger_handler,
+					      &ad74413r_buffer_ops);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(st->dev, indio_dev);
+}
+
+static int ad74413r_unregister_driver(struct spi_driver *spi)
+{
+	spi_unregister_driver(spi);
+
+	return 0;
+}
+
+static int __init ad74413r_register_driver(struct spi_driver *spi)
+{
+	crc8_populate_msb(ad74413r_crc8_table, AD74413R_CRC_POLYNOMIAL);
+
+	return spi_register_driver(spi);
+}
+
+static const struct ad74413r_chip_info ad74412r_chip_info_data = {
+	.hart_support = false,
+	.name = "ad74412r",
+};
+
+static const struct ad74413r_chip_info ad74413r_chip_info_data = {
+	.hart_support = true,
+	.name = "ad74413r",
+};
+
+static const struct of_device_id ad74413r_dt_id[] = {
+	{
+		.compatible = "adi,ad74412r",
+		.data = &ad74412r_chip_info_data,
+	},
+	{
+		.compatible = "adi,ad74413r",
+		.data = &ad74413r_chip_info_data,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, ad74413r_dt_id);
+
+static struct spi_driver ad74413r_driver = {
+	.driver = {
+		   .name = "ad74413r",
+		   .of_match_table = ad74413r_dt_id,
+	},
+	.probe = ad74413r_probe,
+};
+
+module_driver(ad74413r_driver,
+	      ad74413r_register_driver,
+	      ad74413r_unregister_driver);
+
+MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD74413R ADDAC");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1

Re: [PATCH v6 2/3] dt-bindings: iio: add AD74413R

[Linus Walleij]

On Fri, Nov 26, 2021 at 5:03 PM Cosmin Tanislav <demonsingur@gmail.com> wrote:

> +  adi,rsense-resistance-ohms:
> +    description:
> +      RSense resistance values in Ohms.

This description is very terse. If it is existing for the same purpose as
shunt-resistor-micro-ohms in
Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml
then you should just recycle the standard binding
shunt-resistor-micro-ohms instead of inventing this custom one.

Yours,
Linus Walleij

Re: [PATCH v6 3/3] iio: addac: add AD74413R driver

[Linus Walleij]

Hi Cosmin,

thanks for your patch!

I noticed this has a GPIO chip inside of it :)

On Fri, Nov 26, 2021 at 5:03 PM Cosmin Tanislav <demonsingur@gmail.com> wrote:

These:

> +static void ad74413r_gpio_set(struct gpio_chip *chip,
> +                             unsigned int offset, int val)
> +static void ad74413r_gpio_set_multiple(struct gpio_chip *chip,
> +                                      unsigned long *mask,
> +                                      unsigned long *bits)
> +static int ad74413r_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +static int ad74413r_gpio_get_multiple(struct gpio_chip *chip,
> +                                     unsigned long *mask,
> +                                     unsigned long *bits)

(...)
> +       if (st->num_gpo_gpios) {
> +               st->gpo_gpiochip.owner = THIS_MODULE;
> +               st->gpo_gpiochip.label = st->chip_info->name;
> +               st->gpo_gpiochip.base = -1;
> +               st->gpo_gpiochip.ngpio = st->num_gpo_gpios;
> +               st->gpo_gpiochip.parent = st->dev;
> +               st->gpo_gpiochip.can_sleep = true;
> +               st->gpo_gpiochip.set = ad74413r_gpio_set;
> +               st->gpo_gpiochip.set_multiple = ad74413r_gpio_set_multiple;
> +               st->gpo_gpiochip.set_config = ad74413r_gpio_set_gpo_config;
> +               st->gpo_gpiochip.get_direction =
> +                       ad74413r_gpio_get_gpo_direction;
> +
> +               ret = devm_gpiochip_add_data(st->dev, &st->gpo_gpiochip, st);
> +               if (ret)
> +                       return ret;
> +       }
> +
> +       if (st->num_comparator_gpios) {
> +               st->comp_gpiochip.owner = THIS_MODULE;
> +               st->comp_gpiochip.label = st->chip_info->name;
> +               st->comp_gpiochip.base = -1;
> +               st->comp_gpiochip.ngpio = st->num_comparator_gpios;
> +               st->comp_gpiochip.parent = st->dev;
> +               st->comp_gpiochip.can_sleep = true;
> +               st->comp_gpiochip.get = ad74413r_gpio_get;
> +               st->comp_gpiochip.get_multiple = ad74413r_gpio_get_multiple;
> +               st->comp_gpiochip.set_config = ad74413r_gpio_set_comp_config;
> +               st->comp_gpiochip.get_direction =
> +                       ad74413r_gpio_get_comp_direction;

Look a bit like the generic drivers/gpio/gpio-regmap.c
GPIO_REGMAP.

Example:
drivers/gpio/gpio-sl28cpld.c
drivers/pinctrl/bcm/pinctrl-bcm63xx.c

Or is it too particular for this?

I don't know if the regmap gpio can deal with adding a few functions
like a custom .set_config() on top of the templates to be honest, maybe
that is something we can fix in that case?

Cc:ing Michael Walle so he can pitch in if I'm onto something here or not.

Anyways the GPIO portions look good otherwise.

Yours,
Linus Walleij

Re: [PATCH v6 3/3] iio: addac: add AD74413R driver

[Jonathan Cameron]

On Fri, 26 Nov 2021 18:02:19 +0200
Cosmin Tanislav <demonsingur@gmail.com> wrote:

> The AD74412R and AD74413R are quad-channel software configurable input/output
> solutions for building and process control applications. They contain
> functionality for analog output, analog input, digital input, resistance
> temperature detector, and thermocouple measurements integrated
> into a single chip solution with an SPI interface.
> The devices feature a 16-bit ADC and four configurable 13-bit DACs to provide
> four configurable input/output channels and a suite of diagnostic functions.
> The AD74413R differentiates itself from the AD74412R by being HART-compatible.
> 
> 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.

Thanks for the example. This definitely helps.  

> 
> .
> ├── in_current0_offset
> ├── in_current0_raw
> ├── in_current0_sampling_frequency

The sampling frequency per channel is a bit unusual, but oddly enough that
is how it is documented even when in sequence mode.  So I guess we should
just live with it being strange...  Obviously the actual sampling frequency
will be lower because we'll be measuring other things between each reading
of this channel. Oh well. odd :)

> ├── in_current0_sampling_frequency_available
> ├── in_current0_scale
> ├── in_voltage1_offset
> ├── in_voltage1_raw
> ├── in_voltage1_sampling_frequency
> ├── in_voltage1_sampling_frequency_available
> ├── in_voltage1_scale
> ├── in_voltage2_offset
> ├── in_voltage2_raw
> ├── in_voltage2_sampling_frequency
> ├── in_voltage2_sampling_frequency_available
> ├── in_voltage2_scale
> ├── in_current3_offset
> ├── in_current3_raw
> ├── in_current3_sampling_frequency
> ├── in_current3_sampling_frequency_available
> ├── in_current3_scale
> ├── out_voltage0_raw
> ├── out_voltage0_scale
> ├── out_current1_raw
> ├── out_current1_scale
> ├── name
> ├── buffer
> │   ├── data_available
> │   ├── enable
> │   ├── length
> │   └── watermark
> └── scan_elements
>     ├── in_current0_en
>     ├── in_current0_index
>     ├── in_current0_type
>     ├── in_voltage1_en
>     ├── in_voltage1_index
>     ├── in_voltage1_type
>     ├── in_voltage2_en
>     ├── in_voltage2_index
>     ├── in_voltage2_type
>     ├── in_current3_en
>     ├── in_current3_index
>     └── in_current3_type
> 
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@analog.com>

Unless I'm missing something, you are being overly cautious with the DMA
buffer alignments. Forcing that for the first one only should be enough.
> +};
> +
> +struct ad74413r_state {
> +	struct ad74413r_channel_config	channel_configs[AD74413R_CHANNEL_MAX];
> +	unsigned int			gpo_gpio_offsets[AD74413R_CHANNEL_MAX];
> +	unsigned int			comp_gpio_offsets[AD74413R_CHANNEL_MAX];
> +	struct gpio_chip		gpo_gpiochip;
> +	struct gpio_chip		comp_gpiochip;
> +	struct mutex			lock;
> +	struct completion		adc_data_completion;
> +	unsigned int			num_gpo_gpios;
> +	unsigned int			num_comparator_gpios;
> +	u32				rsense_resistance_ohms;
> +
> +	const struct ad74413r_chip_info	*chip_info;
> +	struct spi_device		*spi;
> +	struct regulator		*refin_reg;
> +	struct regmap			*regmap;
> +	struct device			*dev;
> +	struct iio_trigger		*trig;
> +
> +	size_t			adc_active_channels;
> +	struct spi_message	adc_samples_msg;
> +	struct spi_transfer	adc_samples_xfer[AD74413R_CHANNEL_MAX + 1];
> +
> +	/*
> +	 * DMA (thus cache coherency maintenance) requires the
> +	 * transfer buffers to live in their own cache lines.
> +	 */
> +	struct {
> +		u8 rx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX];
> +		s64 timestamp;
> +	} adc_samples_buf ____cacheline_aligned;
> +
> +	u8	adc_samples_tx_buf[AD74413R_FRAME_SIZE * AD74413R_CHANNEL_MAX]
> +			____cacheline_aligned;

I'm surprised I didn't mention this before but you only need to ensure that any
memory used for DMA is not in a cacheline with memory used for other things that
might change concurrently.

I'm assuming there is only one DMA transaction going on to one piece of hardwre
here so you should be fine with just forcing the alignment of adc_samples_buf
to be ____cacheline_aligned.  That will ensure non of these DMA buffers share
a line with anything other than each other.

To give the short explanation of why we jump through these hoops.

1) DMA transfer started - it grabs a whole cacheline because that is how this
   particular platform works (even if it is doing DMA to just one byte)
2) A flag or similar is updated in the same cacheline.
3) The DMA transfer ends and the cacheline is entirely overwritten with
   the data from the DAM and whatever was grabbed in step 1.

So as long as we are only dealing with buffers in the same DMA transaction
it will be safe for them to share cachelines.

Note that we play games with the alignment of iio_priv() region at allocation
to ensure that is appropriately aligned, such that when we align an element
within it the alignment ends up right as well.  This case was so common
it was worth the 'magic' handling to ensure we could embed DMA buffers.


> +	u8	reg_tx_buf[AD74413R_FRAME_SIZE] ____cacheline_aligned;
> +	u8	reg_rx_buf[AD74413R_FRAME_SIZE] ____cacheline_aligned;
> +};

Re: [PATCH v6 2/3] dt-bindings: iio: add AD74413R

[Jonathan Cameron]

On Sat, 27 Nov 2021 02:23:26 +0100
Linus Walleij <linus.walleij@linaro.org> wrote:

> On Fri, Nov 26, 2021 at 5:03 PM Cosmin Tanislav <demonsingur@gmail.com> wrote:
> 
> > +  adi,rsense-resistance-ohms:
> > +    description:
> > +      RSense resistance values in Ohms.  
> 
> This description is very terse. If it is existing for the same purpose as
> shunt-resistor-micro-ohms in
> Documentation/devicetree/bindings/iio/afe/current-sense-shunt.yaml
> then you should just recycle the standard binding
> shunt-resistor-micro-ohms instead of inventing this custom one.

Good point.  I'd forgotten about that one.  We had to make that generic
as a current sense shunt inherently doesn't have a vendor :)

Thanks Linus!

Jonathan
> 
> Yours,
> Linus Walleij