Re: [PATCH v4 1/2] staging: iio: ad7606: Move out of staging

From: Jonathan Cameron
Date: Mon Dec 10 2018 - 16:34:20 EST


On Mon, 10 Dec 2018 13:03:33 +0200
Stefan Popa <stefan.popa@xxxxxxxxxx> wrote:

> Move ad7606 ADC driver out of staging and into the mainline.
>
> Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>

Looks good to me. I'll let it sit for a few days though to give
time for a final review from anyone else who wants to and for
Rob to take a final look at the bindings if he wants to.

Thanks,

Jonathan

> ---
> Changes in v2:
> - Simplified the Kconfig menu.
> - Added SPDX-License-Identifier.
> - Ordered the includes alphabetically.
> - Used a threaded interrupt.
> - Replaced ad7606_poll_bh_to_ring() with ad7606_trigger_handler().
> - Used a trigger.
> - Replaced wait_event_interruptible() with wait_for_completion_timeout().
> - Replaced wake_up_interruptible() with complete().
> - Used devm_iio_triggered_buffer_setup().
> - Added buffer_ops.
> - Used single line comments where needed.
> - Removed the gap between docs and struct.
> - Added ad7606_of_match[].
> Changes in v3:
> - Added a comment which offers more information of the way the interrupt
> is triggered.
> - Fixed the way a new conversion is triggered.
> - endianness = IIO_CPU
> - Removed unnecessary mutex locks.
> - Removed the buffer_postdisable ops and replaced it with buffer_predisable.
> - Added a devm_add_action_or_reset() which deals with regulator_disable().
> - Misc style fixes.
> Changes in v4:
> - Removed unused fields from the ad7606_state struct.
> - Used the find_closest() macro when searching for the available scale
> and the oversampling ratios.
>
> MAINTAINERS | 7 +
> drivers/iio/adc/Kconfig | 28 ++
> drivers/iio/adc/Makefile | 3 +
> drivers/iio/adc/ad7606.c | 588 +++++++++++++++++++++++++++++++++++
> drivers/iio/adc/ad7606.h | 99 ++++++
> drivers/iio/adc/ad7606_par.c | 105 +++++++
> drivers/iio/adc/ad7606_spi.c | 82 +++++
> drivers/staging/iio/adc/Kconfig | 34 --
> drivers/staging/iio/adc/Makefile | 3 -
> drivers/staging/iio/adc/ad7606.c | 565 ---------------------------------
> drivers/staging/iio/adc/ad7606.h | 106 -------
> drivers/staging/iio/adc/ad7606_par.c | 113 -------
> drivers/staging/iio/adc/ad7606_spi.c | 79 -----
> 13 files changed, 912 insertions(+), 900 deletions(-)
> create mode 100644 drivers/iio/adc/ad7606.c
> create mode 100644 drivers/iio/adc/ad7606.h
> create mode 100644 drivers/iio/adc/ad7606_par.c
> create mode 100644 drivers/iio/adc/ad7606_spi.c
> delete mode 100644 drivers/staging/iio/adc/ad7606.c
> delete mode 100644 drivers/staging/iio/adc/ad7606.h
> delete mode 100644 drivers/staging/iio/adc/ad7606_par.c
> delete mode 100644 drivers/staging/iio/adc/ad7606_spi.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f642044..843545d 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -839,6 +839,13 @@ S: Supported
> F: drivers/iio/dac/ad5758.c
> F: Documentation/devicetree/bindings/iio/dac/ad5758.txt
>
> +ANALOG DEVICES INC AD7606 DRIVER
> +M: Stefan Popa <stefan.popa@xxxxxxxxxx>
> +L: linux-iio@xxxxxxxxxxxxxxx
> +W: http://ez.analog.com/community/linux-device-drivers
> +S: Supported
> +F: drivers/iio/adc/ad7606.c
> +
> ANALOG DEVICES INC AD9389B DRIVER
> M: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> L: linux-media@xxxxxxxxxxxxxxx
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index a52fea8..c3f61c9 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -58,6 +58,34 @@ config AD7476
> To compile this driver as a module, choose M here: the
> module will be called ad7476.
>
> +config AD7606
> + tristate
> + depends on GPIOLIB || COMPILE_TEST
> + depends on HAS_IOMEM
> + select IIO_BUFFER
> + select IIO_TRIGGERED_BUFFER
> +
> +config AD7606_IFACE_PARALLEL
> + tristate "Analog Devices AD7606 ADC driver with parallel interface support"
> + select AD7606
> + help
> + Say yes here to build parallel interface support for Analog Devices:
> + ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad7606_parallel.
> +
> +config AD7606_IFACE_SPI
> + tristate "Analog Devices AD7606 ADC driver with spi interface support"
> + depends on SPI
> + select AD7606
> + help
> + Say yes here to build spi interface support for Analog Devices:
> + ad7605-4, ad7606, ad7606-6, ad7606-4 analog to digital converters (ADC).
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad7606_spi.
> +
> config AD7766
> tristate "Analog Devices AD7766/AD7767 ADC driver"
> depends on SPI_MASTER
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index a6e6a0b..b734f4f 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -8,6 +8,9 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AD7291) += ad7291.o
> obj-$(CONFIG_AD7298) += ad7298.o
> +obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o
> +obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
> +obj-$(CONFIG_AD7606) += ad7606.o
> obj-$(CONFIG_AD7923) += ad7923.o
> obj-$(CONFIG_AD7476) += ad7476.o
> obj-$(CONFIG_AD7766) += ad7766.o
> diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> new file mode 100644
> index 0000000..fa3c8e0
> --- /dev/null
> +++ b/drivers/iio/adc/ad7606.c
> @@ -0,0 +1,588 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD7606 SPI ADC driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +#include <linux/util_macros.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/trigger_consumer.h>
> +
> +#include "ad7606.h"
> +
> +/*
> + * Scales are computed as 5000/32768 and 10000/32768 respectively,
> + * so that when applied to the raw values they provide mV values
> + */
> +static const unsigned int scale_avail[2] = {
> + 152588, 305176
> +};
> +
> +static const unsigned int ad7606_oversampling_avail[7] = {
> + 1, 2, 4, 8, 16, 32, 64,
> +};
> +
> +static int ad7606_reset(struct ad7606_state *st)
> +{
> + if (st->gpio_reset) {
> + gpiod_set_value(st->gpio_reset, 1);
> + ndelay(100); /* t_reset >= 100ns */
> + gpiod_set_value(st->gpio_reset, 0);
> + return 0;
> + }
> +
> + return -ENODEV;
> +}
> +
> +static int ad7606_read_samples(struct ad7606_state *st)
> +{
> + unsigned int num = st->chip_info->num_channels;
> + u16 *data = st->data;
> + int ret;
> +
> + /*
> + * The frstdata signal is set to high while and after reading the sample
> + * of the first channel and low for all other channels. This can be used
> + * to check that the incoming data is correctly aligned. During normal
> + * operation the data should never become unaligned, but some glitch or
> + * electrostatic discharge might cause an extra read or clock cycle.
> + * Monitoring the frstdata signal allows to recover from such failure
> + * situations.
> + */
> +
> + if (st->gpio_frstdata) {
> + ret = st->bops->read_block(st->dev, 1, data);
> + if (ret)
> + return ret;
> +
> + if (!gpiod_get_value(st->gpio_frstdata)) {
> + ad7606_reset(st);
> + return -EIO;
> + }
> +
> + data++;
> + num--;
> + }
> +
> + return st->bops->read_block(st->dev, num, data);
> +}
> +
> +static irqreturn_t ad7606_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct ad7606_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + mutex_lock(&st->lock);
> +
> + ret = ad7606_read_samples(st);
> + if (ret == 0)
> + iio_push_to_buffers_with_timestamp(indio_dev, st->data,
> + iio_get_time_ns(indio_dev));
> +
> + iio_trigger_notify_done(indio_dev->trig);
> + /* The rising edge of the CONVST signal starts a new conversion. */
> + gpiod_set_value(st->gpio_convst, 1);
> +
> + mutex_unlock(&st->lock);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + gpiod_set_value(st->gpio_convst, 1);
> + ret = wait_for_completion_timeout(&st->completion,
> + msecs_to_jiffies(1000));
> + if (!ret) {
> + ret = -ETIMEDOUT;
> + goto error_ret;
> + }
> +
> + ret = ad7606_read_samples(st);
> + if (ret == 0)
> + ret = st->data[ch];
> +
> +error_ret:
> + gpiod_set_value(st->gpio_convst, 0);
> +
> + return ret;
> +}
> +
> +static int ad7606_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int *val,
> + int *val2,
> + long m)
> +{
> + int ret;
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + switch (m) {
> + case IIO_CHAN_INFO_RAW:
> + ret = iio_device_claim_direct_mode(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = ad7606_scan_direct(indio_dev, chan->address);
> + iio_device_release_direct_mode(indio_dev);
> +
> + if (ret < 0)
> + return ret;
> + *val = (short)ret;
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + *val = 0;
> + *val2 = scale_avail[st->range];
> + return IIO_VAL_INT_PLUS_MICRO;
> + case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> + *val = st->oversampling;
> + return IIO_VAL_INT;
> + }
> + return -EINVAL;
> +}
> +
> +static ssize_t in_voltage_scale_available_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + int i, len = 0;
> +
> + for (i = 0; i < ARRAY_SIZE(scale_avail); i++)
> + len += scnprintf(buf + len, PAGE_SIZE - len, "0.%06u ",
> + scale_avail[i]);
> +
> + buf[len - 1] = '\n';
> +
> + return len;
> +}
> +
> +static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
> +
> +static int ad7606_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan,
> + int val,
> + int val2,
> + long mask)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + int values[3], i;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_SCALE:
> + mutex_lock(&st->lock);
> + i = find_closest(val2, scale_avail, ARRAY_SIZE(scale_avail));
> + gpiod_set_value(st->gpio_range, i);
> + st->range = i;
> + mutex_unlock(&st->lock);
> +
> + return 0;
> + case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> + if (val2)
> + return -EINVAL;
> + i = find_closest(val, ad7606_oversampling_avail,
> + ARRAY_SIZE(ad7606_oversampling_avail));
> +
> + values[0] = (i >> 0) & 1;
> + values[1] = (i >> 1) & 1;
> + values[2] = (i >> 2) & 1;
> +
> + mutex_lock(&st->lock);
> + gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
> + values);
> + st->oversampling = ad7606_oversampling_avail[i];
> + mutex_unlock(&st->lock);
> +
> + return 0;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static IIO_CONST_ATTR(oversampling_ratio_available, "1 2 4 8 16 32 64");
> +
> +static struct attribute *ad7606_attributes_os_and_range[] = {
> + &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
> + &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group ad7606_attribute_group_os_and_range = {
> + .attrs = ad7606_attributes_os_and_range,
> +};
> +
> +static struct attribute *ad7606_attributes_os[] = {
> + &iio_const_attr_oversampling_ratio_available.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group ad7606_attribute_group_os = {
> + .attrs = ad7606_attributes_os,
> +};
> +
> +static struct attribute *ad7606_attributes_range[] = {
> + &iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
> + NULL,
> +};
> +
> +static const struct attribute_group ad7606_attribute_group_range = {
> + .attrs = ad7606_attributes_range,
> +};
> +
> +#define AD760X_CHANNEL(num, mask) { \
> + .type = IIO_VOLTAGE, \
> + .indexed = 1, \
> + .channel = num, \
> + .address = num, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),\
> + .info_mask_shared_by_all = mask, \
> + .scan_index = num, \
> + .scan_type = { \
> + .sign = 's', \
> + .realbits = 16, \
> + .storagebits = 16, \
> + .endianness = IIO_CPU, \
> + }, \
> +}
> +
> +#define AD7605_CHANNEL(num) \
> + AD760X_CHANNEL(num, 0)
> +
> +#define AD7606_CHANNEL(num) \
> + AD760X_CHANNEL(num, BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO))
> +
> +static const struct iio_chan_spec ad7605_channels[] = {
> + IIO_CHAN_SOFT_TIMESTAMP(4),
> + AD7605_CHANNEL(0),
> + AD7605_CHANNEL(1),
> + AD7605_CHANNEL(2),
> + AD7605_CHANNEL(3),
> +};
> +
> +static const struct iio_chan_spec ad7606_channels[] = {
> + IIO_CHAN_SOFT_TIMESTAMP(8),
> + AD7606_CHANNEL(0),
> + AD7606_CHANNEL(1),
> + AD7606_CHANNEL(2),
> + AD7606_CHANNEL(3),
> + AD7606_CHANNEL(4),
> + AD7606_CHANNEL(5),
> + AD7606_CHANNEL(6),
> + AD7606_CHANNEL(7),
> +};
> +
> +static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
> + /* More devices added in future */
> + [ID_AD7605_4] = {
> + .channels = ad7605_channels,
> + .num_channels = 5,
> + },
> + [ID_AD7606_8] = {
> + .channels = ad7606_channels,
> + .num_channels = 9,
> + .has_oversampling = true,
> + },
> + [ID_AD7606_6] = {
> + .channels = ad7606_channels,
> + .num_channels = 7,
> + .has_oversampling = true,
> + },
> + [ID_AD7606_4] = {
> + .channels = ad7606_channels,
> + .num_channels = 5,
> + .has_oversampling = true,
> + },
> +};
> +
> +static int ad7606_request_gpios(struct ad7606_state *st)
> +{
> + struct device *dev = st->dev;
> +
> + st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(st->gpio_convst))
> + return PTR_ERR(st->gpio_convst);
> +
> + st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(st->gpio_reset))
> + return PTR_ERR(st->gpio_reset);
> +
> + st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
> + GPIOD_OUT_LOW);
> + if (IS_ERR(st->gpio_range))
> + return PTR_ERR(st->gpio_range);
> +
> + st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
> + GPIOD_OUT_HIGH);
> + if (IS_ERR(st->gpio_standby))
> + return PTR_ERR(st->gpio_standby);
> +
> + st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
> + GPIOD_IN);
> + if (IS_ERR(st->gpio_frstdata))
> + return PTR_ERR(st->gpio_frstdata);
> +
> + if (!st->chip_info->has_oversampling)
> + return 0;
> +
> + st->gpio_os = devm_gpiod_get_array_optional(dev,
> + "adi,oversampling-ratio",
> + GPIOD_OUT_LOW);
> + return PTR_ERR_OR_ZERO(st->gpio_os);
> +}
> +
> +/*
> + * The BUSY signal indicates when conversions are in progress, so when a rising
> + * edge of CONVST is applied, BUSY goes logic high and transitions low at the
> + * end of the entire conversion process. The falling edge of the BUSY signal
> + * triggers this interrupt.
> + */
> +static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
> +{
> + struct iio_dev *indio_dev = dev_id;
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + if (iio_buffer_enabled(indio_dev)) {
> + gpiod_set_value(st->gpio_convst, 0);
> + iio_trigger_poll_chained(st->trig);
> + } else {
> + complete(&st->completion);
> + }
> +
> + return IRQ_HANDLED;
> +};
> +
> +static int ad7606_validate_trigger(struct iio_dev *indio_dev,
> + struct iio_trigger *trig)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + if (st->trig != trig)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + iio_triggered_buffer_postenable(indio_dev);
> + gpiod_set_value(st->gpio_convst, 1);
> +
> + return 0;
> +}
> +
> +static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct ad7606_state *st = iio_priv(indio_dev);
> + int ret;
> +
> + reinit_completion(&st->completion);
> + gpiod_set_value(st->gpio_convst, 1);
> + ret = wait_for_completion_timeout(&st->completion,
> + msecs_to_jiffies(1000));
> + gpiod_set_value(st->gpio_convst, 0);
> +
> + return iio_triggered_buffer_predisable(indio_dev);
> +}
> +
> +static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
> + .postenable = &ad7606_buffer_postenable,
> + .predisable = &ad7606_buffer_predisable,
> +};
> +
> +static const struct iio_info ad7606_info_no_os_or_range = {
> + .read_raw = &ad7606_read_raw,
> + .validate_trigger = &ad7606_validate_trigger,
> +};
> +
> +static const struct iio_info ad7606_info_os_and_range = {
> + .read_raw = &ad7606_read_raw,
> + .write_raw = &ad7606_write_raw,
> + .attrs = &ad7606_attribute_group_os_and_range,
> + .validate_trigger = &ad7606_validate_trigger,
> +};
> +
> +static const struct iio_info ad7606_info_os = {
> + .read_raw = &ad7606_read_raw,
> + .write_raw = &ad7606_write_raw,
> + .attrs = &ad7606_attribute_group_os,
> + .validate_trigger = &ad7606_validate_trigger,
> +};
> +
> +static const struct iio_info ad7606_info_range = {
> + .read_raw = &ad7606_read_raw,
> + .write_raw = &ad7606_write_raw,
> + .attrs = &ad7606_attribute_group_range,
> + .validate_trigger = &ad7606_validate_trigger,
> +};
> +
> +static const struct iio_trigger_ops ad7606_trigger_ops = {
> + .validate_device = iio_trigger_validate_own_device,
> +};
> +
> +static void ad7606_regulator_disable(void *data)
> +{
> + struct ad7606_state *st = data;
> +
> + regulator_disable(st->reg);
> +}
> +
> +int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> + const char *name, unsigned int id,
> + const struct ad7606_bus_ops *bops)
> +{
> + struct ad7606_state *st;
> + int ret;
> + struct iio_dev *indio_dev;
> +
> + indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + dev_set_drvdata(dev, indio_dev);
> +
> + st->dev = dev;
> + mutex_init(&st->lock);
> + st->bops = bops;
> + st->base_address = base_address;
> + st->oversampling = 1;
> +
> + st->reg = devm_regulator_get(dev, "avcc");
> + if (IS_ERR(st->reg))
> + return PTR_ERR(st->reg);
> +
> + ret = regulator_enable(st->reg);
> + if (ret) {
> + dev_err(dev, "Failed to enable specified AVcc supply\n");
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
> + if (ret)
> + return ret;
> +
> + st->chip_info = &ad7606_chip_info_tbl[id];
> +
> + ret = ad7606_request_gpios(st);
> + if (ret)
> + return ret;
> +
> + indio_dev->dev.parent = dev;
> + if (st->gpio_os) {
> + if (st->gpio_range)
> + indio_dev->info = &ad7606_info_os_and_range;
> + else
> + indio_dev->info = &ad7606_info_os;
> + } else {
> + if (st->gpio_range)
> + indio_dev->info = &ad7606_info_range;
> + else
> + indio_dev->info = &ad7606_info_no_os_or_range;
> + }
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->name = name;
> + indio_dev->channels = st->chip_info->channels;
> + indio_dev->num_channels = st->chip_info->num_channels;
> +
> + ret = ad7606_reset(st);
> + if (ret)
> + dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
> +
> + st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
> + indio_dev->name, indio_dev->id);
> + if (st->trig == NULL)
> + return -ENOMEM;
> +
> + st->trig->ops = &ad7606_trigger_ops;
> + st->trig->dev.parent = dev;
> + iio_trigger_set_drvdata(st->trig, indio_dev);
> + ret = devm_iio_trigger_register(dev, st->trig);
> + if (ret)
> + return ret;
> +
> + indio_dev->trig = iio_trigger_get(st->trig);
> +
> + init_completion(&st->completion);
> +
> + ret = devm_request_threaded_irq(dev, irq,
> + NULL,
> + &ad7606_interrupt,
> + IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> + name, indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
> + &iio_pollfunc_store_time,
> + &ad7606_trigger_handler,
> + &ad7606_buffer_ops);
> + if (ret)
> + return ret;
> +
> + return devm_iio_device_register(dev, indio_dev);
> +

Real nitpick. No point in blank line here. I'll probably take the view
this is so trivial I'll just fix it when applying (or forget about it).

> +}
> +EXPORT_SYMBOL_GPL(ad7606_probe);
> +
> +#ifdef CONFIG_PM_SLEEP
> +
> +static int ad7606_suspend(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + if (st->gpio_standby) {
> + gpiod_set_value(st->gpio_range, 1);
> + gpiod_set_value(st->gpio_standby, 0);
> + }
> +
> + return 0;
> +}
> +
> +static int ad7606_resume(struct device *dev)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + if (st->gpio_standby) {
> + gpiod_set_value(st->gpio_range, st->range);
> + gpiod_set_value(st->gpio_standby, 1);
> + ad7606_reset(st);
> + }
> +
> + return 0;
> +}
> +
> +SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
> +EXPORT_SYMBOL_GPL(ad7606_pm_ops);
> +
> +#endif
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> new file mode 100644
> index 0000000..40433af
> --- /dev/null
> +++ b/drivers/iio/adc/ad7606.h
> @@ -0,0 +1,99 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * AD7606 ADC driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + */
> +
> +#ifndef IIO_ADC_AD7606_H_
> +#define IIO_ADC_AD7606_H_
> +
> +/**
> + * struct ad7606_chip_info - chip specific information
> + * @channels: channel specification
> + * @num_channels: number of channels
> + * @has_oversampling: whether the device has oversampling support
> + */
> +struct ad7606_chip_info {
> + const struct iio_chan_spec *channels;
> + unsigned int num_channels;
> + bool has_oversampling;
> +};
> +
> +/**
> + * struct ad7606_state - driver instance specific data
> + * @dev pointer to kernel device
> + * @chip_info entry in the table of chips that describes this device
> + * @reg regulator info for the the power supply of the device
> + * @bops bus operations (SPI or parallel)
> + * @range voltage range selection, selects which scale to apply
> + * @oversampling oversampling selection
> + * @base_address address from where to read data in parallel operation
> + * @lock protect sensor state from concurrent accesses to GPIOs
> + * @gpio_convst GPIO descriptor for conversion start signal (CONVST)
> + * @gpio_reset GPIO descriptor for device hard-reset
> + * @gpio_range GPIO descriptor for range selection
> + * @gpio_standby GPIO descriptor for stand-by signal (STBY),
> + * controls power-down mode of device
> + * @gpio_frstdata GPIO descriptor for reading from device when data
> + * is being read on the first channel
> + * @gpio_os GPIO descriptors to control oversampling on the device
> + * @complete completion to indicate end of conversion
> + * @trig The IIO trigger associated with the device.
> + * @data buffer for reading data from the device
> + */
> +struct ad7606_state {
> + struct device *dev;
> + const struct ad7606_chip_info *chip_info;
> + struct regulator *reg;
> + const struct ad7606_bus_ops *bops;
> + unsigned int range;
> + unsigned int oversampling;
> + void __iomem *base_address;
> +
> + struct mutex lock; /* protect sensor state */
> + struct gpio_desc *gpio_convst;
> + struct gpio_desc *gpio_reset;
> + struct gpio_desc *gpio_range;
> + struct gpio_desc *gpio_standby;
> + struct gpio_desc *gpio_frstdata;
> + struct gpio_descs *gpio_os;
> + struct iio_trigger *trig;
> + struct completion completion;
> +
> + /*
> + * DMA (thus cache coherency maintenance) requires the
> + * transfer buffers to live in their own cache lines.
> + * 8 * 16-bit samples + 64-bit timestamp
> + */
> + unsigned short data[12] ____cacheline_aligned;
> +};
> +
> +/**
> + * struct ad7606_bus_ops - driver bus operations
> + * @read_block function pointer for reading blocks of data
> + */
> +struct ad7606_bus_ops {
> + /* more methods added in future? */
> + int (*read_block)(struct device *dev, int num, void *data);
> +};
> +
> +int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
> + const char *name, unsigned int id,
> + const struct ad7606_bus_ops *bops);
> +
> +enum ad7606_supported_device_ids {
> + ID_AD7605_4,
> + ID_AD7606_8,
> + ID_AD7606_6,
> + ID_AD7606_4
> +};
> +
> +#ifdef CONFIG_PM_SLEEP
> +extern const struct dev_pm_ops ad7606_pm_ops;
> +#define AD7606_PM_OPS (&ad7606_pm_ops)
> +#else
> +#define AD7606_PM_OPS NULL
> +#endif
> +
> +#endif /* IIO_ADC_AD7606_H_ */
> diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
> new file mode 100644
> index 0000000..32c7069
> --- /dev/null
> +++ b/drivers/iio/adc/ad7606_par.c
> @@ -0,0 +1,105 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD7606 Parallel Interface ADC driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/types.h>
> +#include <linux/err.h>
> +#include <linux/io.h>
> +
> +#include <linux/iio/iio.h>
> +#include "ad7606.h"
> +
> +static int ad7606_par16_read_block(struct device *dev,
> + int count, void *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + insw((unsigned long)st->base_address, buf, count);
> +
> + return 0;
> +}
> +
> +static const struct ad7606_bus_ops ad7606_par16_bops = {
> + .read_block = ad7606_par16_read_block,
> +};
> +
> +static int ad7606_par8_read_block(struct device *dev,
> + int count, void *buf)
> +{
> + struct iio_dev *indio_dev = dev_get_drvdata(dev);
> + struct ad7606_state *st = iio_priv(indio_dev);
> +
> + insb((unsigned long)st->base_address, buf, count * 2);
> +
> + return 0;
> +}
> +
> +static const struct ad7606_bus_ops ad7606_par8_bops = {
> + .read_block = ad7606_par8_read_block,
> +};
> +
> +static int ad7606_par_probe(struct platform_device *pdev)
> +{
> + const struct platform_device_id *id = platform_get_device_id(pdev);
> + struct resource *res;
> + void __iomem *addr;
> + resource_size_t remap_size;
> + int irq;
> +
> + irq = platform_get_irq(pdev, 0);
> + if (irq < 0) {
> + dev_err(&pdev->dev, "no irq: %d\n", irq);
> + return irq;
> + }
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + addr = devm_ioremap_resource(&pdev->dev, res);
> + if (IS_ERR(addr))
> + return PTR_ERR(addr);
> +
> + remap_size = resource_size(res);
> +
> + return ad7606_probe(&pdev->dev, irq, addr,
> + id->name, id->driver_data,
> + remap_size > 1 ? &ad7606_par16_bops :
> + &ad7606_par8_bops);
> +}
> +
> +static const struct platform_device_id ad7606_driver_ids[] = {
> + { .name = "ad7605-4", .driver_data = ID_AD7605_4, },
> + { .name = "ad7606-4", .driver_data = ID_AD7606_4, },
> + { .name = "ad7606-6", .driver_data = ID_AD7606_6, },
> + { .name = "ad7606-8", .driver_data = ID_AD7606_8, },
> + { }
> +};
> +MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
> +
> +static const struct of_device_id ad7606_of_match[] = {
> + { .compatible = "adi,ad7605-4" },
> + { .compatible = "adi,ad7606-4" },
> + { .compatible = "adi,ad7606-6" },
> + { .compatible = "adi,ad7606-8" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, ad7606_of_match);
> +
> +static struct platform_driver ad7606_driver = {
> + .probe = ad7606_par_probe,
> + .id_table = ad7606_driver_ids,
> + .driver = {
> + .name = "ad7606",
> + .pm = AD7606_PM_OPS,
> + .of_match_table = ad7606_of_match,
> + },
> +};
> +module_platform_driver(ad7606_driver);
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
> new file mode 100644
> index 0000000..6bb1867
> --- /dev/null
> +++ b/drivers/iio/adc/ad7606_spi.c
> @@ -0,0 +1,82 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD7606 SPI ADC driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/spi/spi.h>
> +#include <linux/types.h>
> +#include <linux/err.h>
> +
> +#include <linux/iio/iio.h>
> +#include "ad7606.h"
> +
> +#define MAX_SPI_FREQ_HZ 23500000 /* VDRIVE above 4.75 V */
> +
> +static int ad7606_spi_read_block(struct device *dev,
> + int count, void *buf)
> +{
> + struct spi_device *spi = to_spi_device(dev);
> + int i, ret;
> + unsigned short *data = buf;
> + __be16 *bdata = buf;
> +
> + ret = spi_read(spi, buf, count * 2);
> + if (ret < 0) {
> + dev_err(&spi->dev, "SPI read error\n");
> + return ret;
> + }
> +
> + for (i = 0; i < count; i++)
> + data[i] = be16_to_cpu(bdata[i]);
> +
> + return 0;
> +}
> +
> +static const struct ad7606_bus_ops ad7606_spi_bops = {
> + .read_block = ad7606_spi_read_block,
> +};
> +
> +static int ad7606_spi_probe(struct spi_device *spi)
> +{
> + const struct spi_device_id *id = spi_get_device_id(spi);
> +
> + return ad7606_probe(&spi->dev, spi->irq, NULL,
> + id->name, id->driver_data,
> + &ad7606_spi_bops);
> +}
> +
> +static const struct spi_device_id ad7606_id_table[] = {
> + { "ad7605-4", ID_AD7605_4 },
> + { "ad7606-4", ID_AD7606_4 },
> + { "ad7606-6", ID_AD7606_6 },
> + { "ad7606-8", ID_AD7606_8 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, ad7606_id_table);
> +
> +static const struct of_device_id ad7606_of_match[] = {
> + { .compatible = "adi,ad7605-4" },
> + { .compatible = "adi,ad7606-4" },
> + { .compatible = "adi,ad7606-6" },
> + { .compatible = "adi,ad7606-8" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, ad7606_of_match);
> +
> +static struct spi_driver ad7606_driver = {
> + .driver = {
> + .name = "ad7606",
> + .of_match_table = ad7606_of_match,
> + .pm = AD7606_PM_OPS,
> + },
> + .probe = ad7606_spi_probe,
> + .id_table = ad7606_id_table,
> +};
> +module_spi_driver(ad7606_driver);
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
> +MODULE_LICENSE("GPL v2");
...