diff mbox series

[v2,2/2] iio: adc: adding support for PAC194X

Message ID 20250317090803.30003-3-marius.cristea@microchip.com (mailing list archive)
State Changes Requested
Headers show
Series adding support for Microchip PAC194X Power Monitor | expand

Commit Message

marius.cristea@microchip.com March 17, 2025, 9:08 a.m. UTC
From: Marius Cristea <marius.cristea@microchip.com>

This is the iio driver for Microchip PAC194X and PAC195X series of
Power Monitors with Accumulator.
The PAC194X family supports 9V Full-Scale Range and the PAC195X supports
32V Full-Scale Range.
There are two versions of the PAC194X/5X: the PAC194X/5X-1 devices are
for high-side current sensing and the PAC194X/5X-2 devices are for
low-side current sensing or floating VBUS applications.
The PAC194X/5X-1 is named shortly PAC194X/5X.

Signed-off-by: Marius Cristea <marius.cristea@microchip.com>
---
 .../ABI/testing/sysfs-bus-iio-adc-pac1944     |  118 +
 MAINTAINERS                                   |    7 +
 drivers/iio/adc/Kconfig                       |   12 +
 drivers/iio/adc/Makefile                      |    1 +
 drivers/iio/adc/pac1944.c                     | 3314 +++++++++++++++++
 5 files changed, 3452 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
 create mode 100644 drivers/iio/adc/pac1944.c

Comments

Jonathan Cameron March 17, 2025, 6:47 p.m. UTC | #1
On Mon, 17 Mar 2025 11:08:03 +0200
<marius.cristea@microchip.com> wrote:

> From: Marius Cristea <marius.cristea@microchip.com>
> 
> This is the iio driver for Microchip PAC194X and PAC195X series of
> Power Monitors with Accumulator.
> The PAC194X family supports 9V Full-Scale Range and the PAC195X supports
> 32V Full-Scale Range.
> There are two versions of the PAC194X/5X: the PAC194X/5X-1 devices are
> for high-side current sensing and the PAC194X/5X-2 devices are for
> low-side current sensing or floating VBUS applications.
> The PAC194X/5X-1 is named shortly PAC194X/5X.

This patch is too large. I'd suggest breaking it down into the core
driver, no events, no custom ABI etc.  Then propose the ABI stuff
on top.  That will let reviewers look at stuff that is much more
standard before moving on to looking at the new stuff.

Main feedback here is don't invent new ABI without looking very closely
at the existing ABI.  Maybe I'm missing something, but superficially it
feels like a lot of what we have here maps trivially to existing ABI.

There also seems to be quite a bit more ABI that is not in the docs
you have added.

Jonathan

> 
> Signed-off-by: Marius Cristea <marius.cristea@microchip.com>
> ---
>  .../ABI/testing/sysfs-bus-iio-adc-pac1944     |  118 +
>  MAINTAINERS                                   |    7 +
>  drivers/iio/adc/Kconfig                       |   12 +
>  drivers/iio/adc/Makefile                      |    1 +
>  drivers/iio/adc/pac1944.c                     | 3314 +++++++++++++++++
>  5 files changed, 3452 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
>  create mode 100644 drivers/iio/adc/pac1944.c
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944 b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
> new file mode 100644
> index 000000000000..e4122f58fe39
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
> @@ -0,0 +1,118 @@
> +What:		/sys/bus/iio/devices/iio:deviceX/in_currentY_shunt_resistor

This is a logical extension of in_current_shunt_resistor in the main ABI
doc. Just add this indexed variant there instead of in here (which should just
be ABI not in line with the main ABI).

> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		The value of the shunt resistor may be known only at runtime
> +		and set by a client application. This attribute allows to
> +		set its value in micro-ohms. X is the IIO index of the device.
> +		Y is the channel number. The value is used to calculate
> +		current, power and accumulated energy.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_ocY_limit_nsamples
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Number of consecutive samples exceeding the overcurrent limit
> +		that are required to trigger the ALERT function for channel Y.

Whilst it will be more complex on the driver, please map this to the main
_period event ABI that is time in seconds for which the condition should be true.
I think this device has a sequencer that runs these monitoring conditions without
us needing to trigger them individually. If so combing these with sampling_frequency
value should allow you to use period. 

Note that custom ABI is roughly speaking unused ABI, because no standard software
will have any idea what it means.  So where it is possible to map to ABI that
is in existing use, we should do so rather than defining something new.

overcurrent in general usually maps to
in_current_thresh_rising* with a specific current threshold value.



> +		Consecutive sample count to trigger could be:
> +			- 1 sample (default),
> +			- 4 samples,
> +			- 8 samples,
> +			- 16 samples.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_ucY_limit_nsamples

Undercurrent similarly normally maps to a falling threshold.

> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Number of consecutive samples exceeding the undercurrent limit
> +		that are required to trigger the ALERT function for
> +		channel Y. Consecutive sample count to trigger could be:
> +			- 1 sample (default),
> +			- 4 samples,
> +			- 8 samples,
> +			- 16 samples.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_opY_limit_nsamples
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Number of consecutive samples exceeding the overpower limit that

in_powerY_thresh_rising_period
I think maps to the equilvalent with units in seconds.


> +		are required to trigger the ALERT function for channel Y.
> +		Consecutive sample count to trigger could be:
> +			- 1 sample (default),
> +			- 4 samples,
> +			- 8 samples,
> +			- 16 samples.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_ovY_limit_nsamples
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
in_voltageY_thresh_rising_period.

> +		Number of consecutive samples exceeding the overvoltage limit
> +		that are required to trigger the ALERT function for channel Y.
> +		Consecutive sample count to trigger could be:
> +			- 1 sample (default),
> +			- 4 samples,
> +			- 8 samples,
> +			- 16 samples.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_uvY_limit_nsamples

in_voltageY_thresh_falling_period

> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		Number of consecutive samples exceeding the undervoltage limit
> +		that are required to trigger the ALERT function for channel Y.
> +		Consecutive sample count to trigger could be:
> +			- 1 sample (default),
> +			- 4 samples,
> +			- 8 samples,
> +			- 16 samples.
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/in_acc_fullness
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		A read/write property used to set a limit for how full the
> +		Accumulators and Accumulator Count registers can be before the
> +		Accumulator Full and Accumulator Count full limits are tripped.
> +		This allows an ALERT to be registered when the Accumulator and
> +		Accumulator Count are approaching 100% full.

The aim here being to handle roll over?  If so then just handle that in the
driver by accumulating into a larger store and don't use an event at all.

> +		The fullness limit could be set to:
> +			- full,
> +			- 15/16 full (default),
> +			- 7/8 full,
> +			- 3/4 full
> +
> +What:		/sys/bus/iio/devices/iio:deviceX/alert_enable
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		A read/write property used to enable/disable the limits events
> +		and also controls the signals triggered when the Accumulator for
> +		any channel overflows or exceeds its fullness or the Accumulator
> +		Count overflows or exceeds its fullness limit.

You need to wrap this up to use standard ABI as well. Will be a bunch of separate
event enables. Then probably filter in driver to only report the ones that are
enabled.

> +
> +What:		/sys/bus/iio/devices/iio:deviceX/slow_alert1
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		A read/write property used to route a specific ALERT signal to
> +		the SLOW/ALERT1 pin. The SLOW/ALERT1 pin must be configured for
> +		the ALERT function in order to control the device hardware pin
> +		(this is the default functionality of the device hardware pin).

So either:
a) This alert pin is not wired to the host. In which case this should probably be in DT.
   It reflects a signal used to cause something else to happen and those tend
   to be disabling power or something along those lines - not typically something
   we want userspace rewiring.

b) It is wired to the host, then it's not something userspace should play with.
   The driver should be able to figure out the right interrupts to map to this
   pin.

> +
> +What:		/sys/bus/iio/devices/iio:deviceX/gpio_alert2
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		A read/write property used to route a specific ALERT signal to
> +		to the GPIO/ALERT2 pin. The GPIO/ALERT2 pin must be configured
> +		for ALERT function in order to control the device hardware pin
> +		(this is the default functionality of the device hardware pin).

Similar to above.

> +
> +What:		/sys/bus/iio/devices/iio:deviceX/out_alert_status
> +KernelVersion:	6.13
> +Contact:	linux-iio@vger.kernel.org
> +Description:
> +		A read only property used to determine the cause of ALERT/events
> +		being tripped.

Why not report them via the events interface?





> diff --git a/drivers/iio/adc/pac1944.c b/drivers/iio/adc/pac1944.c
> new file mode 100644
> index 000000000000..b6f93d21b86b
> --- /dev/null
> +++ b/drivers/iio/adc/pac1944.c
> @@ -0,0 +1,3314 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * IIO driver for PAC194X and PAC195X series chips
> + *
> + * Copyright (C) 2022-2025 Microchip Technology Inc. and its subsidiaries
> + *
> + * Author: Marius Cristea marius.cristea@microchip.com
> + *
> + * Datasheet for PAC1941, PAC1942, PAC1943 and PAC1944 can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC194X-Family-Data-Sheet-DS20006543.pdf
> + * Datasheet for PAC1951, PAC1952, PAC1953 and PAC1954 can be found here:
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC195X-Family-Data-Sheet-DS20006539.pdf
> + *
No blank line here.
> + */
>
> +/*
> + * Universal Unique Identifier (UUID),
> + * 721F1534-5D27-4B60-9DF4-41A3C4B7DA3A,
> + * is reserved to Microchip for the PAC194x and PAC195x.
> + */
> +#define PAC1944_DSM_UUID	"721F1534-5D27-4B60-9DF4-41A3C4B7DA3A"

Little advantage in having this up here. I'd push it down where it is used
and put the comments there as well.


> +
> +/*
> + * [(100mV * 1000000) / (2^15)]*10^9  used to calculate the scale
> + * for accumulated current/Coulomb counter
> + */
> +#define PAC1944_MAX_VSENSE_NANO			3051757812500UL
> +
> +#define TO_PAC1944_CHIP_INFO(d) container_of(d, struct pac1944_chip_info, work_chip_rfsh)
to_pac1944_chip_info() would be more in keeping with other container_of
macros.

> +
> +static int pac1944_disable_alert_reg(struct device *dev, u32 mask, u8 *status)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct i2c_client *client = info->client;
> +	int ret;
> +	u32 val;
> +	u8 buf[PAC1944_ALERT_ENABLE_REG_LEN];
> +
> +	ret = i2c_smbus_read_i2c_block_data(client,
> +					    PAC1944_ALERT_ENABLE_REG_ADDR,
> +					    PAC1944_ALERT_ENABLE_REG_LEN,
> +					    status);
> +	if (ret < 0) {
> +		dev_err(dev, "failing %s\n", __func__);
> +		return ret;
> +	}
> +
> +	val = get_unaligned_be24(status);
> +	val = val & (~mask);
> +	put_unaligned_be24(val, &buf[0]);
> +
> +	/* disable appropriate bit from the Alert enable register */
> +	ret = i2c_smbus_write_block_data(client, PAC1944_ALERT_ENABLE_REG_ADDR,
> +					 PAC1944_ALERT_ENABLE_REG_LEN,
> +					 (u8 *)&buf[0]);
> +
> +	return ret;

	return i2c_smbus_write_block_data()

> +}

> +
> +static ssize_t pac1944_alert_status_show(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct i2c_client *client = info->client;
> +	int ret;
> +	u32 tmp;
> +	u8 status[3];
> +
> +	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_ALERT_STATUS_REG_ADDR,
> +					    ARRAY_SIZE(status), (u8 *)status);
> +	if (ret < 0) {
> +		dev_err(dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
> +			__func__, PAC1944_ALERT_STATUS_REG_ADDR);
> +		return ret;
> +	}
> +	tmp = get_unaligned_be24(&status[0]);
> +
> +	return sysfs_emit(buf, "%u\n", tmp);
	return sysfs_emit(buf, "%u\n", get_unaligned_be24(status));

> +}

> +
> +#define PAC1944_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)

I'd find it clearer if you just used the expanded form of this instead of
the macro.

> +static int pac1944_reg_snapshot(struct pac1944_chip_info *info,
> +				bool do_refresh, u8 refresh_cmd, u32 wait_time)
> +{
> +	struct i2c_client *client = info->client;
> +	u8 shift, idx;
> +	u8 *offset_reg_data_p;
> +	int cnt, ret;
> +	u32 count, inc_count;
> +	u32 fs = 0;
> +	s64 stored_value, tmp_s64;
> +	s64 inc = 0;
> +	__be16 tmp_be16;
> +	u16 smpl_mode;
> +	bool is_unipolar;
> +
> +	guard(mutex)(&info->lock);
> +
> +	if (do_refresh) {
> +		ret = pac1944_send_refresh(info, refresh_cmd, wait_time);
> +		if (ret < 0) {
> +			dev_err(&client->dev, "%s - cannot send refresh towards PAC1944\n",

Have a local struct device *dev = &client->dev;

> +				__func__);

I'd drop the __func__ bit. The message should be enough info anyway.

> +			return ret;
> +		}
> +	}

...


> +
> +		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
> +			info->chip_reg_data.vbus[cnt] =
> +			sign_extend32(info->chip_reg_data.vbus[cnt], 15);

That indent is very much not style compliant. Add another tab. Check for similar
cases (or get an editor that doesn't let you do this particular thing!)

> +
> +		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
> +	}
> +
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		info->chip_reg_data.vsense[cnt] = get_unaligned_be16(offset_reg_data_p);
> +
> +		if (info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
> +			info->chip_reg_data.vsense[cnt] =
> +			sign_extend32(info->chip_reg_data.vsense[cnt], 15);
> +
> +		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
> +	}
> +
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		info->chip_reg_data.vbus_avg[cnt] = get_unaligned_be16(offset_reg_data_p);
> +
> +		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
> +			info->chip_reg_data.vbus_avg[cnt] =
> +			sign_extend32(info->chip_reg_data.vbus_avg[cnt], 15);
> +
> +		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
> +	}
> +
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		info->chip_reg_data.vsense_avg[cnt] = get_unaligned_be16(offset_reg_data_p);
> +
> +		if (info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
> +			info->chip_reg_data.vsense_avg[cnt] =
> +			sign_extend32(info->chip_reg_data.vsense_avg[cnt], 15);
> +
> +		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
> +	}
> +
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		info->chip_reg_data.vpower[cnt] = get_unaligned_be32(offset_reg_data_p) >> 2;
> +
> +		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG ||
> +		    info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
> +			info->chip_reg_data.vpower[cnt] =
> +			sign_extend32(info->chip_reg_data.vpower[cnt], 29);
> +
> +		offset_reg_data_p += PAC1944_VPOWER_REG_LEN;
> +	}
> +
> +	return 0;
> +}

> +static ssize_t pac1944_in_power_acc_scale_show(struct device *dev,
> +					       struct device_attribute *attr,
> +					       char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +	unsigned int shunt, rem;
> +	u64 tmp, ref;
> +
> +	if (info->is_pac195x_family)
> +		ref = (u64)PAC195X_MAX_VPOWER_RSHIFTED_BY_29B;
> +	else
> +		ref = (u64)PAC194X_MAX_VPOWER_RSHIFTED_BY_29B;

why are the casts needed?

> +
> +static ssize_t pac1944_in_enable_acc_store(struct device *dev,
> +					   struct device_attribute *attr,
> +					   const char *buf, size_t count)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +	int val;
> +
> +	if (kstrtouint(buf, 10, &val)) {
> +		dev_err(dev, "Value is not valid\n");
> +		return -EINVAL;
> +	}
> +
> +	scoped_guard(mutex, &info->lock) {
> +		info->enable_acc[this_attr->address] = val ? true : false;
> +		if (!val) {
> +			info->chip_reg_data.acc_val[this_attr->address] = 0;

Comment needed for this.  Why is it reset on disable, rather just before enabling?

> +			info->chip_reg_data.total_samples_nr[this_attr->address] = 0;
> +		}
> +	}
> +
> +	return count;
> +}

> +
> +static ssize_t pac1944_in_current_acc_scale_show(struct device *dev,
> +						 struct device_attribute *attr,
> +						 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +	int shunt, rem;
> +	u64 tmp_u64, ref;
> +
> +	/*
> +	 * Currents - scale for mA - depends on the channel's shunt value
> +	 * (100mV * 1000000) / (2^16 * shunt(uOhm))
> +	 */
> +	ref = (u64)PAC1944_MAX_VSENSE_NANO;
> +
> +	switch (info->chip_reg_data.vsense_mode[this_attr->address]) {
> +	case PAC1944_UNIPOLAR_FSR_CFG:
> +	case PAC1944_BIPOLAR_HALF_FSR_CFG:
> +		shunt = info->shunts[this_attr->address];
> +		break;
> +	case PAC1944_BIPOLAR_FSR_CFG:
> +		ref = ref << 1;
> +		shunt = info->shunts[this_attr->address];
> +		break;
> +	default:
> +		return 0;

Comment needed on why this is not returning an error.

> +	}
> +
> +	/*
> +	 * Increasing precision
> +	 * (100mV * 1000000 * 1000000000) / 2^16 )
> +	 */
> +	tmp_u64 = div_u64(ref, shunt);
> +	rem = do_div(tmp_u64, 1000000000LL);
> +
> +	return sysfs_emit(buf, "%lld.%09u\n", tmp_u64, rem);
> +}


> +
> +static int pac1944_frequency_set(struct iio_dev *indio_dev,
> +				 const struct iio_chan_spec *chan,
> +				 unsigned int mode)
> +{
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct i2c_client *client = info->client;
> +	int ret;
> +	u16 tmp_u16;
> +	__be16 tmp_be16;
> +
> +	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_CTRL_ACT_REG_ADDR,
> +					    sizeof(tmp_u16), (u8 *)&tmp_be16);
> +	if (ret < 0) {
> +		dev_err(&indio_dev->dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
> +			__func__, PAC1944_CTRL_ACT_REG_ADDR);
> +		return ret;
> +	}
> +
> +	tmp_u16 = be16_to_cpu(tmp_be16);
> +	tmp_u16 &= ~PAC1944_CTRL_SAMPLE_MASK;
> +	tmp_u16 |= FIELD_PREP(PAC1944_CTRL_SAMPLE_MASK, mode);
> +	tmp_be16 = cpu_to_be16(tmp_u16);
> +
> +	scoped_guard(mutex, &info->lock) {
> +		ret = i2c_smbus_write_word_data(client, PAC1944_CTRL_REG_ADDR, tmp_be16);
> +		if (ret < 0) {
> +			dev_err(&indio_dev->dev, "Failed to configure sampling mode\n");
> +			return ret;
> +		}
> +
> +		info->sampling_mode = mode;
> +		info->chip_reg_data.ctrl_act_reg = tmp_u16
> +	}
> +
> +	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
Unless that returns positive just do return pac1944_...

> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int pac1944_frequency_get(struct iio_dev *indio_dev,
> +				 const struct iio_chan_spec *chan)
> +{
> +	struct pac1944_chip_info *info;
> +
> +	info = iio_priv(indio_dev);

	struct pac1944_chip_info *info = iio_priv(indio_dev);

> +
> +	return info->sampling_mode;
> +}

...

> +
> +static const struct iio_chan_spec_ext_info pac1944_ext_info[] = {
> +	IIO_ENUM("sampling_frequency", IIO_SHARED_BY_ALL, &sampling_mode_enum),

These are standard ABI, why are they in extinfo?

> +	{
> +		.name = "sampling_frequency_available",
> +		.shared = IIO_SHARED_BY_ALL,
> +		.read = iio_enum_available_read,
> +		.private = (uintptr_t)&sampling_mode_enum,
> +	},
> +	{}

	{ }
would be my preference.

> +};
> +


> +static int pac1944_read_thresh(struct iio_dev *indio_dev,
> +			       const struct iio_chan_spec *chan, enum iio_event_type type,
> +			       enum iio_event_direction dir, enum iio_event_info info,
> +			       int *val, int *val2)
> +{
> +	struct pac1944_chip_info *chip_info = iio_priv(indio_dev);
> +	int idx;
> +
> +	/* into the datasheet channels are noted from 1 to 4 */
> +	idx = chan->channel - 1;
> +
> +	scoped_guard(mutex, &chip_info->lock) {
As below.

> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				*val = chip_info->overvoltage[idx];
> +				return IIO_VAL_INT;
> +			case IIO_EV_DIR_FALLING:
> +				*val = chip_info->undervoltage[idx];
> +				return IIO_VAL_INT;
> +			default:
> +				return -EINVAL;
> +			}
> +		case IIO_CURRENT:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				*val = chip_info->overcurrent[idx];
> +				return IIO_VAL_INT;
> +			case IIO_EV_DIR_FALLING:
> +				*val = chip_info->undercurrent[idx];
> +				return IIO_VAL_INT;
> +			default:
> +				return -EINVAL;
> +			}
> +		case IIO_POWER:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				*val = chip_info->overpower[idx];
> +				return IIO_VAL_INT;
> +			default:
> +				return -EINVAL;
> +			}
> +		default:
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return -EINVAL;
Can't get here.

> +}
> +
> +static int pac1944_write_thresh(struct iio_dev *indio_dev,
> +				const struct iio_chan_spec *chan, enum iio_event_type type,
> +				enum iio_event_direction dir, enum iio_event_info info,
> +				int val, int val2)
> +{
> +	struct pac1944_chip_info *chip_info = iio_priv(indio_dev);
> +	int idx, ret;
> +
> +	/* into the datasheet channels are noted from 1 to 4 */
> +	idx = chan->channel - 1;
> +
> +	scoped_guard(mutex, &chip_info->lock) {
Use a guard() here

scoped_guard() and unreachable tends to have odd effects on compilers
that can get very confused.

Also, simple guard() reduces indent which is a nice to have here.

> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				ret = pac1944_update_alert_16b(&indio_dev->dev,
> +							       PAC1944_OV_LIMIT_REG_ADDR + idx,
> +							       pac1944_overvoltage_mask_tbl[idx],
> +							       val);
> +				if (!ret)
> +					chip_info->overvoltage[idx] = val;
Try to keep the error paths out of line, even if it adds a few lines to the code.

				if (ret)
					return ret;

				chip_info->overvoltage[idx] = val
				return 0;
> +			return ret;

This is indented one tab too few.

> +			case IIO_EV_DIR_FALLING:
> +				ret = pac1944_update_alert_16b(&indio_dev->dev,
> +							       PAC1944_UV_LIMIT_REG_ADDR + idx,
> +							       pac1944_undervoltage_mask_tbl[idx],
> +							       val);
> +				if (!ret)
> +					chip_info->undervoltage[idx] = val;
> +				return ret;
> +			default:
> +				return -EINVAL;
> +			}
> +		case IIO_CURRENT:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				ret = pac1944_update_alert_16b(&indio_dev->dev,
> +							       PAC1944_OC_LIMIT_REG_ADDR + idx,
> +							       pac1944_overcurrent_mask_tbl[idx],
> +							       val);
> +				if (!ret)
> +					chip_info->overcurrent[idx] = val;
> +				return ret;
> +			case IIO_EV_DIR_FALLING:
> +				ret = pac1944_update_alert_16b(&indio_dev->dev,
> +							       PAC1944_UC_LIMIT_REG_ADDR + idx,
> +							       pac1944_undercurrent_mask_tbl[idx],
> +							       val);
> +				if (!ret)
> +					chip_info->undercurrent[idx] = val;
> +				return ret;
> +			default:
> +				return -EINVAL;
> +			}
> +		case IIO_POWER:
> +			switch (dir) {
> +			case IIO_EV_DIR_RISING:
> +				ret = pac1944_update_alert_24b(&indio_dev->dev,
> +							       PAC1944_OP_LIMIT_REG_ADDR + idx,
> +							       pac1944_overpower_mask_tbl[idx],
> +							       val);
> +				if (!ret)
> +					chip_info->overpower[idx] = val;
> +				return ret;
> +			default:
> +				return -EINVAL;
> +			}
> +		default:
> +			return -EINVAL;
> +		}
> +	}
> +	unreachable();
> +}

> +static int pac1944_write_event_config(struct iio_dev *indio_dev,
> +				      const struct iio_chan_spec *chan,
> +				      enum iio_event_type type,
> +				      enum iio_event_direction dir,
> +				      bool state)
> +{
> +	struct pac1944_chip_info *info = iio_priv(indio_dev);
> +	struct i2c_client *client = info->client;
> +	int idx, val, mask, ret;
> +	bool update = false;
> +	u8 tmp[PAC1944_ALERT_ENABLE_REG_LEN];
> +
> +	/* into the datasheet channels are noted from 1 to 4 */
> +	idx = chan->channel - 1;
> +
> +	switch (chan->type) {
> +	case IIO_VOLTAGE:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			mask = pac1944_overvoltage_mask_tbl[idx];
> +			break;
> +		case IIO_EV_DIR_FALLING:
> +			mask = pac1944_undervoltage_mask_tbl[idx];
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		break;

Can't get here. So drop this break and similar ones.

> +	case IIO_CURRENT:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			mask = pac1944_overcurrent_mask_tbl[idx];
> +			break;
> +		case IIO_EV_DIR_FALLING:
> +			mask = pac1944_undercurrent_mask_tbl[idx];
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		break;
> +	case IIO_POWER:
> +		if (dir == IIO_EV_DIR_RISING)
> +			mask = pac1944_overpower_mask_tbl[idx];
> +		else
> +			return -EINVAL;
If you are going to check one specific thing, then check for error
		if (dir != IIO_EV_DIR_RISING)
			return -EINVAL;

		mask = pac1944_overpower_mask_tbl[idx];

> +		break;
> +	default:

...

> +
> +static void pac1944_work_periodic_rfsh(struct work_struct *work)
> +{
> +	struct pac1944_chip_info *info = TO_PAC1944_CHIP_INFO((struct delayed_work *)work);
Should use to_delayed_work() to get from work to delayed work.

> +	struct i2c_client *client = info->client;
> +
> +	dev_dbg(&client->dev, "%s - Periodic refresh\n", __func__);
> +
> +	pac1944_reg_snapshot(info, true, PAC1944_REFRESH_REG_ADDR,
> +			     PAC1944_MIN_UPDATE_WAIT_TIME_US);
> +
> +	schedule_delayed_work(&info->work_chip_rfsh,
> +			      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
> +}
> +
> +/*
> + * documentation related to the ACPI device definition
> + * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/UserGuides/PAC194X_5X-UEFI-BIOS-Integration-and-Microsoft-Windows-10-and-Windows-11-Energy-Meter-Interface-Device-Driver-Users-Guide-DS50003155.pdf
> + */
> +static int pac1944_acpi_parse_channel_config(struct i2c_client *client,
> +					     struct pac1944_chip_info *info)
> +{
> +	acpi_handle handle;
> +	union acpi_object *rez;
> +	struct device *dev = &client->dev;
> +	unsigned short bi_dir_mask;
> +	int i;
> +	guid_t guid;
> +	const struct acpi_device_id *id;
> +
> +	handle = ACPI_HANDLE(dev);
> +
> +	id = acpi_match_device(dev->driver->acpi_match_table, dev);
> +	if (!id)
> +		return -ENODEV;
> +
> +	guid_parse(PAC1944_DSM_UUID, &guid);
> +
> +	rez = acpi_evaluate_dsm(handle, &guid, 0, PAC1944_ACPI_GET_NAMES, NULL);
> +	if (!rez)
> +		return -EINVAL;
> +
> +	for (i = 0; i < rez->package.count; i++) {
> +		info->labels[i] = devm_kmemdup(dev, rez->package.elements[i].string.pointer,
> +					       (size_t)rez->package.elements[i].string.length + 1,
> +					       GFP_KERNEL);
> +		info->labels[i][rez->package.elements[i].string.length] = '\0';
> +	}
> +
> +	ACPI_FREE(rez);
> +
> +	rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1944_ACPI_GET_UOHMS_VALS, NULL);
> +	if (!rez)
> +		return -EINVAL;
> +
> +	for (i = 0; i < rez->package.count; i++) {
> +		info->shunts[i] = rez->package.elements[i].integer.value;
> +		info->active_channels[i] = (info->shunts[i] != 0);
> +		info->active_channels_mask |= 1 << i;

set_bit() is a little clearer.

> +
> +static int pac1944_of_parse_channel_config(struct i2c_client *client,
> +					   struct pac1944_chip_info *info)
> +{
> +	unsigned int current_channel;
> +	struct device *dev = &client->dev;
> +	int idx, ret, temp;
> +
> +	current_channel = 1;
> +
> +	device_for_each_child_node_scoped(dev, child) {
> +		ret = fwnode_property_read_u32(child, "reg", &idx);
> +		if (ret)
> +			return dev_err_probe(dev, ret, "reading invalid channel index\n");
> +
> +		/* adjust idx to match channel index (1 to 4) from the datasheet */
> +		idx--;
> +
> +		if (current_channel >= (info->phys_channels + 1) ||
> +		    idx >= info->phys_channels || idx < 0)
> +			return dev_err_probe(&client->dev, -EINVAL,
> +					     "invalid channel_index %d value\n", (idx + 1));

Those inner () aren't adding anything, so drop them.

> +
> +		/* enable channel */
>

...


> +
> +static int pac1944_prep_iio_channels(struct pac1944_chip_info *info,
> +				     struct iio_dev *indio_dev)
> +{
> +	struct device *dev = &info->client->dev;
> +	struct iio_chan_spec *ch_sp;
> +	int channel_size, attribute_count, cnt;
> +	void *dyn_ch_struct;
> +
> +	/* Finding out dynamically how many IIO channels we need */
> +	attribute_count = 0;
> +	channel_size = 0;
> +
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		/* add the size of the properties of one chip physical channel */
> +		channel_size += sizeof(pac1944_single_channel);
> +		/* count how many enabled channels we have */
> +		attribute_count += ARRAY_SIZE(pac1944_single_channel);
> +		dev_dbg(dev, ":%s: Channel %d active\n", __func__, cnt + 1);
> +	}
> +
> +	dyn_ch_struct = devm_kzalloc(dev, channel_size, GFP_KERNEL);
> +	if (!dyn_ch_struct)
> +		return -ENOMEM;
> +
> +	ch_sp = (struct iio_chan_spec *)dyn_ch_struct;
why jump through a void *?  Just assign 
	ch_sp = devm_kzalloc();
	if (!ch_sp)
		return -ENOMEM;


> +	/* Populate the dynamic channels and make all the adjustments */
> +	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
> +		memcpy(ch_sp, pac1944_single_channel, sizeof(pac1944_single_channel));
> +		/*
> +		 * Into the datasheet channels are noted from 1 to 4 so we will adjust
> +		 * the channel to match channel index (1 to 4) from the datasheet
> +		 */
> +		ch_sp[PAC1944_CH_POWER].channel = cnt + 1;
> +		ch_sp[PAC1944_CH_POWER].address = cnt + PAC1944_VPOWER_1_ADDR;
> +		ch_sp[PAC1944_CH_VOLTAGE].channel = cnt + 1;
> +		ch_sp[PAC1944_CH_VOLTAGE].address = cnt + PAC1944_VBUS_1_ADDR;
> +		ch_sp[PAC1944_CH_CURRENT].channel = cnt + 1;
> +		ch_sp[PAC1944_CH_CURRENT].address = cnt + PAC1944_VSENSE_1_ADDR;
> +		/*
> +		 * In order to be able to use labels for PAC1944_CH_VOLTAGE and
> +		 * PAC1944_CH_VOLTAGE_AVERAGE, respectively PAC1944_CH_CURRENT
> +		 * and PAC1944_CH_CURRENT_AVERAGE we need to use different channel numbers.
> +		 * We will add  +5 (+1 to maximum PAC channels).
> +		 */
> +		ch_sp[PAC1944_CH_VOLTAGE_AVERAGE].channel = cnt + PAC1944_MAX_CH + 1;
> +		ch_sp[PAC1944_CH_VOLTAGE_AVERAGE].address = cnt + PAC1944_VBUS_AVG_1_ADDR;
> +		ch_sp[PAC1944_CH_CURRENT_AVERAGE].channel = cnt + PAC1944_MAX_CH + 1;
> +		ch_sp[PAC1944_CH_CURRENT_AVERAGE].address = cnt + PAC1944_VSENSE_AVG_1_ADDR;
> +
> +		/* advance the pointer */
> +		ch_sp = (void *)ch_sp + sizeof(pac1944_single_channel);

Keep the type as that ch_spec and do 

		ch_sp += ARRAY_SIZE(pac1944_single_channel);

> +	}
> +
> +	/*
> +	 * Send the updated dynamic channel structure information towards IIO
> +	 * prepare the required field for IIO class registration
> +	 */
> +	indio_dev->num_channels = attribute_count;
> +	indio_dev->channels = (const struct iio_chan_spec *)dyn_ch_struct;

That cast isn't needed.  Not sure why there is one in the pac1921 driver in similar
place. 

> +
> +	return 0;
> +}


> +static int pac1944_probe(struct i2c_client *client)
> +{
> +	struct pac1944_chip_info *info;
> +	struct iio_dev *indio_dev;
> +	const struct pac1944_features *chip;
> +	int cnt, ret;
> +	struct device *dev = &client->dev;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	info = iio_priv(indio_dev);
> +	info->client = client;
> +
> +	ret = pac1944_chip_identify(info);
> +	if (ret < 0) {
> +		/*
> +		 * If failed to identify the hardware based on internal
> +		 * registers, try using fallback compatible in device
> +		 * tree to deal with some newer part number.
> +		 */
> +		chip = i2c_get_match_data(client);
> +		if (!chip)
> +			return -EINVAL;
> +
> +		info->chip_variant = chip->prod_id;
> +		info->phys_channels = chip->phys_channels;
> +		indio_dev->name = chip->name;
> +	} else {

If the FW disagrees with what we found it is also nice to print a message
to that effect.  Not vital, but nice to have.

> +		info->phys_channels = pac1944_chip_config[ret].phys_channels;
> +		indio_dev->name = pac1944_chip_config[ret].name;
> +	}

...

> +}
> +
> +static const struct i2c_device_id pac1944_id[] = {
> +	{ .name = "pac1941", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1941] },
> +	{ .name = "pac19412", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1941_2] },
> +	{ .name = "pac1942", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1942] },
> +	{ .name = "pac19422", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1942_2] },
> +	{ .name = "pac1943", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1943] },
> +	{ .name = "pac1944", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1944] },
> +	{ .name = "pac1951", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1951] },
> +	{ .name = "pac19512", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1951_2] },
> +	{ .name = "pac1952", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1952] },
> +	{ .name = "pac19522", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1952_2] },
> +	{ .name = "pac1953", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1953] },
> +	{ .name = "pac1954", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1954] },
> +	{}

as below.

> +};
> +MODULE_DEVICE_TABLE(i2c, pac1944_id);
> +
> +static const struct of_device_id pac1944_of_match[] = {
> +	{
> +		.compatible = "microchip,pac1941",
> +		.data = (void *)&pac1944_chip_config[PAC1941]
> +	},

...

> +	{
> +		.compatible = "microchip,pac1954",
> +		.data = (void *)&pac1944_chip_config[PAC1954]
> +	},
> +	{}
As below. Totally trivial but nice to tidy up

> +};
> +MODULE_DEVICE_TABLE(of, pac1944_of_match);
> +
> +static const struct acpi_device_id pac1944_acpi_match[] = {
> +	{ "MCHP1940", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1944] },
> +	{}
I'm slowly trying to standardize in IIO on one format for these
and the random choice I made a while back was 
	{ }

so with the space.  It isn't really better than what you have here, but
consistency is nice to have.

> +};
> +MODULE_DEVICE_TABLE(acpi, pac1944_acpi_match);
> +
> +static struct i2c_driver pac1944_driver = {
> +	.driver = {
> +		.name = "pac1944",
> +		.of_match_table = pac1944_of_match,
> +		.acpi_match_table = pac1944_acpi_match
> +	},
> +	.probe = pac1944_probe,
> +	.id_table = pac1944_id,
> +};
> +
Common practice is to tightly couple this with the struct i2c_driver
definition above by not having a blank line here. (trivial!)

> +module_i2c_driver(pac1944_driver);
kernel test robot March 18, 2025, 7:05 a.m. UTC | #2
Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 577a66e2e634f712384c57a98f504c44ea4b47da]

url:    https://github.com/intel-lab-lkp/linux/commits/marius-cristea-microchip-com/dt-bindings-iio-adc-adding-support-for-PAC194X/20250317-171150
base:   577a66e2e634f712384c57a98f504c44ea4b47da
patch link:    https://lore.kernel.org/r/20250317090803.30003-3-marius.cristea%40microchip.com
patch subject: [PATCH v2 2/2] iio: adc: adding support for PAC194X
config: sparc-randconfig-r073-20250318 (https://download.01.org/0day-ci/archive/20250318/202503181451.vybqC7U2-lkp@intel.com/config)
compiler: sparc64-linux-gcc (GCC) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250318/202503181451.vybqC7U2-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503181451.vybqC7U2-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/iio/adc/pac1944.c:614: warning: Function parameter or struct member 'active_channels_mask' not described in 'pac1944_chip_info'


vim +614 drivers/iio/adc/pac1944.c

   546	
   547	/**
   548	 * struct pac1944_chip_info - chip configuration
   549	 * @channels: array of values, true means that channel is active
   550	 * @iio_info: pointer to iio_info structure
   551	 * @client: a pointer to the i2c client associated with the device
   552	 * @lock: lock to prevent concurrent reads/writes
   553	 * @work_chip_rfsh: chip refresh workqueue implementation
   554	 * @phys_channels: number of physical channels for the device
   555	 * @active_channels: array of values, true means that channel is active
   556	 * @chip_variant: stores the type of the device
   557	 * @chip_revision: store the silicon revision version of the device
   558	 * @shunts: array of values, shunt resistor values
   559	 * @chip_reg_data: pointer to structure, containing data from the device registers
   560	 * @sample_rate_value: sampling frequency
   561	 * @labels: array of string, name of each channel
   562	 * @is_pac195x_family: true if device is part of the PAC195x family
   563	 * @sampling_mode: sampling mode used by the device
   564	 * @num_enabled_channels: count of how many chip channels are currently enabled
   565	 * @slow_alert1: snapshot of slow/alert register
   566	 * @gpio_alert2: snapshot of gpio/alert register
   567	 * @acc_fullness: snapshot of accumulator fullness limit register
   568	 * @overcurrent: array of values, overcurrent limit
   569	 * @undercurrent: array of values, undercurrent limit
   570	 * @overpower: array of values, overpower limit
   571	 * @overvoltage:  array of values, overvoltage limit
   572	 * @undervoltage: array of values, undervoltage limit
   573	 * @oc_limit_nsamples: number of consecutive samples exceeding the overcurrent limit
   574	 * @uc_limit_nsamples: number of consecutive samples exceeding the undercurrent limit
   575	 * @op_limit_nsamples: number of consecutive samples exceeding the overpower limit
   576	 * @ov_limit_nsamples: number of consecutive samples exceeding the overvoltage limit
   577	 * @uv_limit_nsamples: number of consecutive samples exceeding the undervoltage limit
   578	 * @alert_enable: snapshot of alert enable register
   579	 * @enable_acc: array of values, true means that accumulation channel is measured
   580	 */
   581	struct pac1944_chip_info {
   582		const struct iio_chan_spec  *channels;
   583		struct iio_info		iio_info;
   584		struct i2c_client	*client;
   585		struct mutex		lock; /* lock to prevent concurrent reads/writes */
   586		struct delayed_work	work_chip_rfsh;
   587		u8		phys_channels;
   588		bool		active_channels[PAC1944_MAX_CH];
   589		unsigned long	active_channels_mask;
   590		u8		chip_variant;
   591		u8		chip_revision;
   592		u32		shunts[PAC1944_MAX_CH];
   593		struct reg_data chip_reg_data;
   594		s32		sample_rate_value;
   595		char		*labels[PAC1944_MAX_CH];
   596		bool		is_pac195x_family;
   597		u8		sampling_mode;
   598		u8		num_enabled_channels;
   599		u32		slow_alert1;
   600		u32		gpio_alert2;
   601		u16		acc_fullness;
   602		u16		overcurrent[PAC1944_MAX_CH];
   603		u16		undercurrent[PAC1944_MAX_CH];
   604		u32		overpower[PAC1944_MAX_CH];
   605		u16		overvoltage[PAC1944_MAX_CH];
   606		u16		undervoltage[PAC1944_MAX_CH];
   607		u8		oc_limit_nsamples[PAC1944_MAX_CH];
   608		u8		uc_limit_nsamples[PAC1944_MAX_CH];
   609		u8		op_limit_nsamples[PAC1944_MAX_CH];
   610		u8		ov_limit_nsamples[PAC1944_MAX_CH];
   611		u8		uv_limit_nsamples[PAC1944_MAX_CH];
   612		u32		alert_enable;
   613		bool		enable_acc[PAC1944_MAX_CH];
 > 614	};
   615
kernel test robot March 18, 2025, 7:53 a.m. UTC | #3
Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 577a66e2e634f712384c57a98f504c44ea4b47da]

url:    https://github.com/intel-lab-lkp/linux/commits/marius-cristea-microchip-com/dt-bindings-iio-adc-adding-support-for-PAC194X/20250317-171150
base:   577a66e2e634f712384c57a98f504c44ea4b47da
patch link:    https://lore.kernel.org/r/20250317090803.30003-3-marius.cristea%40microchip.com
patch subject: [PATCH v2 2/2] iio: adc: adding support for PAC194X
config: riscv-randconfig-r072-20250318 (https://download.01.org/0day-ci/archive/20250318/202503181545.znULdV4G-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project 87916f8c32ebd8e284091db9b70339df57fd1e90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250318/202503181545.znULdV4G-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503181545.znULdV4G-lkp@intel.com/

All warnings (new ones prefixed by >>):

   In file included from drivers/iio/adc/pac1944.c:20:
   In file included from include/linux/i2c.h:19:
   In file included from include/linux/regulator/consumer.h:35:
   In file included from include/linux/suspend.h:5:
   In file included from include/linux/swap.h:9:
   In file included from include/linux/memcontrol.h:13:
   In file included from include/linux/cgroup.h:26:
   In file included from include/linux/kernel_stat.h:8:
   In file included from include/linux/interrupt.h:22:
   In file included from arch/riscv/include/asm/sections.h:9:
   In file included from include/linux/mm.h:2223:
   include/linux/vmstat.h:504:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     504 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     505 |                            item];
         |                            ~~~~
   include/linux/vmstat.h:511:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     511 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     512 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
   include/linux/vmstat.h:518:36: warning: arithmetic between different enumeration types ('enum node_stat_item' and 'enum lru_list') [-Wenum-enum-conversion]
     518 |         return node_stat_name(NR_LRU_BASE + lru) + 3; // skip "nr_"
         |                               ~~~~~~~~~~~ ^ ~~~
   include/linux/vmstat.h:524:43: warning: arithmetic between different enumeration types ('enum zone_stat_item' and 'enum numa_stat_item') [-Wenum-enum-conversion]
     524 |         return vmstat_text[NR_VM_ZONE_STAT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~ ^
     525 |                            NR_VM_NUMA_EVENT_ITEMS +
         |                            ~~~~~~~~~~~~~~~~~~~~~~
>> drivers/iio/adc/pac1944.c:1689:6: warning: variable 'ret' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
    1689 |         if (time_after(jiffies, info->chip_reg_data.jiffies_tstamp +
         |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    1690 |                        msecs_to_jiffies(PAC1944_MIN_POLLING_TIME_MS))) {
         |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   include/linux/jiffies.h:128:2: note: expanded from macro 'time_after'
     128 |         (typecheck(unsigned long, a) && \
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     129 |          typecheck(unsigned long, b) && \
         |          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     130 |          ((long)((b) - (a)) < 0))
         |          ~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iio/adc/pac1944.c:1707:9: note: uninitialized use occurs here
    1707 |         return ret;
         |                ^~~
   drivers/iio/adc/pac1944.c:1689:2: note: remove the 'if' if its condition is always true
    1689 |         if (time_after(jiffies, info->chip_reg_data.jiffies_tstamp +
         |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    1690 |                        msecs_to_jiffies(PAC1944_MIN_POLLING_TIME_MS))) {
         |                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/iio/adc/pac1944.c:1683:9: note: initialize the variable 'ret' to silence this warning
    1683 |         int ret;
         |                ^
         |                 = 0
   5 warnings generated.


vim +1689 drivers/iio/adc/pac1944.c

  1680	
  1681	static int pac1944_retrieve_data(struct pac1944_chip_info *info, u32 wait_time)
  1682	{
  1683		int ret;
  1684	
  1685		/*
  1686		 * Check if the minimal elapsed time has passed and if so,
  1687		 * re-read the chip, otherwise the cached info is just fine
  1688		 */
> 1689		if (time_after(jiffies, info->chip_reg_data.jiffies_tstamp +
  1690			       msecs_to_jiffies(PAC1944_MIN_POLLING_TIME_MS))) {
  1691			/*
  1692			 * We need to re-read the chip values
  1693			 * call the pac1944_reg_snapshot
  1694			 */
  1695			ret = pac1944_reg_snapshot(info, true,
  1696						   PAC1944_REFRESH_REG_ADDR,
  1697						   wait_time);
  1698			/*
  1699			 * Re-schedule the work for the read registers timeout
  1700			 * (to prevent chip regs saturation)
  1701			 */
  1702			cancel_delayed_work_sync(&info->work_chip_rfsh);
  1703			schedule_delayed_work(&info->work_chip_rfsh,
  1704					      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
  1705		}
  1706	
  1707		return ret;
  1708	}
  1709
kernel test robot March 19, 2025, 7:30 a.m. UTC | #4
Hi,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 577a66e2e634f712384c57a98f504c44ea4b47da]

url:    https://github.com/intel-lab-lkp/linux/commits/marius-cristea-microchip-com/dt-bindings-iio-adc-adding-support-for-PAC194X/20250317-171150
base:   577a66e2e634f712384c57a98f504c44ea4b47da
patch link:    https://lore.kernel.org/r/20250317090803.30003-3-marius.cristea%40microchip.com
patch subject: [PATCH v2 2/2] iio: adc: adding support for PAC194X
config: microblaze-randconfig-r131-20250319 (https://download.01.org/0day-ci/archive/20250319/202503191502.hwDCBZeN-lkp@intel.com/config)
compiler: microblaze-linux-gcc (GCC) 7.5.0
reproduce: (https://download.01.org/0day-ci/archive/20250319/202503191502.hwDCBZeN-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202503191502.hwDCBZeN-lkp@intel.com/

sparse warnings: (new ones prefixed by >>)
>> drivers/iio/adc/pac1944.c:813:55: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected unsigned short [usertype] value @@     got restricted __be16 [assigned] [usertype] tmp_be16 @@
   drivers/iio/adc/pac1944.c:813:55: sparse:     expected unsigned short [usertype] value
   drivers/iio/adc/pac1944.c:813:55: sparse:     got restricted __be16 [assigned] [usertype] tmp_be16
>> drivers/iio/adc/pac1944.c:2148:80: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected unsigned short [usertype] value @@     got restricted __be16 [addressable] [assigned] [usertype] tmp_be16 @@
   drivers/iio/adc/pac1944.c:2148:80: sparse:     expected unsigned short [usertype] value
   drivers/iio/adc/pac1944.c:2148:80: sparse:     got restricted __be16 [addressable] [assigned] [usertype] tmp_be16
>> drivers/iio/adc/pac1944.c:2936:79: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected unsigned short [usertype] value @@     got restricted __be16 [usertype] @@
   drivers/iio/adc/pac1944.c:2936:79: sparse:     expected unsigned short [usertype] value
   drivers/iio/adc/pac1944.c:2936:79: sparse:     got restricted __be16 [usertype]
   drivers/iio/adc/pac1944.c:2953:72: sparse: sparse: incorrect type in argument 3 (different base types) @@     expected unsigned short [usertype] value @@     got restricted __be16 [usertype] @@
   drivers/iio/adc/pac1944.c:2953:72: sparse:     expected unsigned short [usertype] value
   drivers/iio/adc/pac1944.c:2953:72: sparse:     got restricted __be16 [usertype]

vim +813 drivers/iio/adc/pac1944.c

   794	
   795	static int pac1944_update_alert_16b(struct device *dev, u8 addr,
   796					    u32 mask, u16 value)
   797	{
   798		struct iio_dev *indio_dev = dev_to_iio_dev(dev);
   799		struct pac1944_chip_info *info = iio_priv(indio_dev);
   800		struct i2c_client *client = info->client;
   801		int ret;
   802		__be16 tmp_be16;
   803		u8 status[PAC1944_ALERT_ENABLE_REG_LEN];
   804	
   805		ret = pac1944_disable_alert_reg(dev, mask, &status[0]);
   806		if (ret) {
   807			dev_err(dev, "failing to write %s\n", __func__);
   808			return ret;
   809		}
   810	
   811		tmp_be16 = cpu_to_be16(value);
   812	
 > 813		ret = i2c_smbus_write_word_data(client, addr, tmp_be16);
   814		if (ret) {
   815			dev_err(dev, "failing to write %s\n", __func__);
   816			return ret;
   817		}
   818	
   819		return pac1944_restore_alert_reg(indio_dev, &status[0]);
   820	}
   821
Dan Carpenter March 24, 2025, 5:57 a.m. UTC | #5
Hi,

kernel test robot noticed the following build warnings:

url:    https://github.com/intel-lab-lkp/linux/commits/marius-cristea-microchip-com/dt-bindings-iio-adc-adding-support-for-PAC194X/20250317-171150
base:   577a66e2e634f712384c57a98f504c44ea4b47da
patch link:    https://lore.kernel.org/r/20250317090803.30003-3-marius.cristea%40microchip.com
patch subject: [PATCH v2 2/2] iio: adc: adding support for PAC194X
config: arm64-randconfig-r071-20250322 (https://download.01.org/0day-ci/archive/20250323/202503230315.DVkVt7Ag-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project c2692afc0a92cd5da140dfcdfff7818a5b8ce997)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
| Closes: https://lore.kernel.org/r/202503230315.DVkVt7Ag-lkp@intel.com/

smatch warnings:
drivers/iio/adc/pac1944.c:1707 pac1944_retrieve_data() error: uninitialized symbol 'ret'.
drivers/iio/adc/pac1944.c:2463 pac1944_write_thresh() warn: inconsistent indenting

vim +/ret +1707 drivers/iio/adc/pac1944.c

e227d6e5b38646 Marius Cristea 2025-03-17  1681  static int pac1944_retrieve_data(struct pac1944_chip_info *info, u32 wait_time)
e227d6e5b38646 Marius Cristea 2025-03-17  1682  {
e227d6e5b38646 Marius Cristea 2025-03-17  1683  	int ret;
e227d6e5b38646 Marius Cristea 2025-03-17  1684  
e227d6e5b38646 Marius Cristea 2025-03-17  1685  	/*
e227d6e5b38646 Marius Cristea 2025-03-17  1686  	 * Check if the minimal elapsed time has passed and if so,
e227d6e5b38646 Marius Cristea 2025-03-17  1687  	 * re-read the chip, otherwise the cached info is just fine
e227d6e5b38646 Marius Cristea 2025-03-17  1688  	 */
e227d6e5b38646 Marius Cristea 2025-03-17  1689  	if (time_after(jiffies, info->chip_reg_data.jiffies_tstamp +
e227d6e5b38646 Marius Cristea 2025-03-17  1690  		       msecs_to_jiffies(PAC1944_MIN_POLLING_TIME_MS))) {
e227d6e5b38646 Marius Cristea 2025-03-17  1691  		/*
e227d6e5b38646 Marius Cristea 2025-03-17  1692  		 * We need to re-read the chip values
e227d6e5b38646 Marius Cristea 2025-03-17  1693  		 * call the pac1944_reg_snapshot
e227d6e5b38646 Marius Cristea 2025-03-17  1694  		 */
e227d6e5b38646 Marius Cristea 2025-03-17  1695  		ret = pac1944_reg_snapshot(info, true,
e227d6e5b38646 Marius Cristea 2025-03-17  1696  					   PAC1944_REFRESH_REG_ADDR,
e227d6e5b38646 Marius Cristea 2025-03-17  1697  					   wait_time);
e227d6e5b38646 Marius Cristea 2025-03-17  1698  		/*
e227d6e5b38646 Marius Cristea 2025-03-17  1699  		 * Re-schedule the work for the read registers timeout
e227d6e5b38646 Marius Cristea 2025-03-17  1700  		 * (to prevent chip regs saturation)
e227d6e5b38646 Marius Cristea 2025-03-17  1701  		 */
e227d6e5b38646 Marius Cristea 2025-03-17  1702  		cancel_delayed_work_sync(&info->work_chip_rfsh);
e227d6e5b38646 Marius Cristea 2025-03-17  1703  		schedule_delayed_work(&info->work_chip_rfsh,
e227d6e5b38646 Marius Cristea 2025-03-17  1704  				      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
e227d6e5b38646 Marius Cristea 2025-03-17  1705  	}

ret isn't initialized on else path.

e227d6e5b38646 Marius Cristea 2025-03-17  1706  
e227d6e5b38646 Marius Cristea 2025-03-17 @1707  	return ret;
e227d6e5b38646 Marius Cristea 2025-03-17  1708  }
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944 b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
new file mode 100644
index 000000000000..e4122f58fe39
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-pac1944
@@ -0,0 +1,118 @@ 
+What:		/sys/bus/iio/devices/iio:deviceX/in_currentY_shunt_resistor
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		The value of the shunt resistor may be known only at runtime
+		and set by a client application. This attribute allows to
+		set its value in micro-ohms. X is the IIO index of the device.
+		Y is the channel number. The value is used to calculate
+		current, power and accumulated energy.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_ocY_limit_nsamples
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Number of consecutive samples exceeding the overcurrent limit
+		that are required to trigger the ALERT function for channel Y.
+		Consecutive sample count to trigger could be:
+			- 1 sample (default),
+			- 4 samples,
+			- 8 samples,
+			- 16 samples.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_ucY_limit_nsamples
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Number of consecutive samples exceeding the undercurrent limit
+		that are required to trigger the ALERT function for
+		channel Y. Consecutive sample count to trigger could be:
+			- 1 sample (default),
+			- 4 samples,
+			- 8 samples,
+			- 16 samples.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_opY_limit_nsamples
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Number of consecutive samples exceeding the overpower limit that
+		are required to trigger the ALERT function for channel Y.
+		Consecutive sample count to trigger could be:
+			- 1 sample (default),
+			- 4 samples,
+			- 8 samples,
+			- 16 samples.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_ovY_limit_nsamples
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Number of consecutive samples exceeding the overvoltage limit
+		that are required to trigger the ALERT function for channel Y.
+		Consecutive sample count to trigger could be:
+			- 1 sample (default),
+			- 4 samples,
+			- 8 samples,
+			- 16 samples.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_uvY_limit_nsamples
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Number of consecutive samples exceeding the undervoltage limit
+		that are required to trigger the ALERT function for channel Y.
+		Consecutive sample count to trigger could be:
+			- 1 sample (default),
+			- 4 samples,
+			- 8 samples,
+			- 16 samples.
+
+What:		/sys/bus/iio/devices/iio:deviceX/in_acc_fullness
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read/write property used to set a limit for how full the
+		Accumulators and Accumulator Count registers can be before the
+		Accumulator Full and Accumulator Count full limits are tripped.
+		This allows an ALERT to be registered when the Accumulator and
+		Accumulator Count are approaching 100% full.
+		The fullness limit could be set to:
+			- full,
+			- 15/16 full (default),
+			- 7/8 full,
+			- 3/4 full
+
+What:		/sys/bus/iio/devices/iio:deviceX/alert_enable
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read/write property used to enable/disable the limits events
+		and also controls the signals triggered when the Accumulator for
+		any channel overflows or exceeds its fullness or the Accumulator
+		Count overflows or exceeds its fullness limit.
+
+What:		/sys/bus/iio/devices/iio:deviceX/slow_alert1
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read/write property used to route a specific ALERT signal to
+		the SLOW/ALERT1 pin. The SLOW/ALERT1 pin must be configured for
+		the ALERT function in order to control the device hardware pin
+		(this is the default functionality of the device hardware pin).
+
+What:		/sys/bus/iio/devices/iio:deviceX/gpio_alert2
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read/write property used to route a specific ALERT signal to
+		to the GPIO/ALERT2 pin. The GPIO/ALERT2 pin must be configured
+		for ALERT function in order to control the device hardware pin
+		(this is the default functionality of the device hardware pin).
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_alert_status
+KernelVersion:	6.13
+Contact:	linux-iio@vger.kernel.org
+Description:
+		A read only property used to determine the cause of ALERT/events
+		being tripped.
diff --git a/MAINTAINERS b/MAINTAINERS
index 98a3c1e46311..afca53b4788b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15409,6 +15409,13 @@  S:	Supported
 F:	Documentation/devicetree/bindings/iio/adc/microchip,pac1934.yaml
 F:	drivers/iio/adc/pac1934.c
 
+MICROCHIP PAC1944 ADC DRIVER
+M:	Marius Cristea <marius.cristea@microchip.com>
+L:	linux-iio@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/iio/adc/microchip,pac1944.yaml
+F:	drivers/iio/adc/pac1944.c
+
 MICROCHIP PCI1XXXX GP DRIVER
 M:	Vaibhaav Ram T.L <vaibhaavram.tl@microchip.com>
 M:	Kumaravel Thiagarajan <kumaravel.thiagarajan@microchip.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 849c90203071..66ecafa74da3 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -1082,6 +1082,18 @@  config PAC1934
 	  This driver can also be built as a module. If so, the module
 	  will be called pac1934.
 
+config PAC1944
+	tristate "Microchip Technology PAC1944/PAC1954 driver"
+	depends on I2C
+	help
+	  Say yes here to build support for Microchip Technology's PAC1941,
+	  PAC1941-2, PAC1942, PAC1942-2, PAC1943, PAC1944, PAC1951,
+	  PAC1951-2, PAC1952, PAC1952-2, PAC1953, PAC1954
+	  Single/Multi-Channel Power Monitor with Accumulator.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called pac1944.
+
 config PALMAS_GPADC
 	tristate "TI Palmas General Purpose ADC"
 	depends on MFD_PALMAS
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index ee19afba62b7..311e504103de 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -97,6 +97,7 @@  obj-$(CONFIG_NAU7802) += nau7802.o
 obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
 obj-$(CONFIG_PAC1921) += pac1921.o
 obj-$(CONFIG_PAC1934) += pac1934.o
+obj-$(CONFIG_PAC1944) += pac1944.o
 obj-$(CONFIG_PALMAS_GPADC) += palmas_gpadc.o
 obj-$(CONFIG_QCOM_PM8XXX_XOADC) += qcom-pm8xxx-xoadc.o
 obj-$(CONFIG_QCOM_SPMI_ADC5) += qcom-spmi-adc5.o
diff --git a/drivers/iio/adc/pac1944.c b/drivers/iio/adc/pac1944.c
new file mode 100644
index 000000000000..b6f93d21b86b
--- /dev/null
+++ b/drivers/iio/adc/pac1944.c
@@ -0,0 +1,3314 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * IIO driver for PAC194X and PAC195X series chips
+ *
+ * Copyright (C) 2022-2025 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Marius Cristea marius.cristea@microchip.com
+ *
+ * Datasheet for PAC1941, PAC1942, PAC1943 and PAC1944 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC194X-Family-Data-Sheet-DS20006543.pdf
+ * Datasheet for PAC1951, PAC1952, PAC1953 and PAC1954 can be found here:
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/DataSheets/PAC195X-Family-Data-Sheet-DS20006539.pdf
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/events.h>
+#include <linux/iio/sysfs.h>
+#include <linux/unaligned.h>
+
+/*
+ * Maximum (1092 * 60 * 1000), around 1092 minutes@1024 sps
+ * We will keep the refresh lower
+ */
+#define PAC1944_MAX_RFSH_LIMIT_MS		300000
+
+/* 50msec is the timeout for validity of the cached registers */
+#define PAC1944_MIN_POLLING_TIME_MS		50
+/*
+ * 1000usec is the minimum wait time for normal conversions when sample
+ * rate doesn't change
+ */
+#define PAC1944_MIN_UPDATE_WAIT_TIME_US		1000
+
+#define PAC1944_SHUNT_UOHMS_DEFAULT		100000
+
+/* 32000mV */
+#define PAC195X_VOLTAGE_MILLIVOLTS_MAX		32000
+/* 9000mV */
+#define PAC194X_VOLTAGE_MILLIVOLTS_MAX		9000
+
+/*
+ * Voltage bits resolution when set for unsigned values and
+ * HALF FSR signed values
+ */
+#define PAC1944_VOLTAGE_16B_RES			16
+/* Voltage bits resolution when set for signed values */
+#define PAC1944_VOLTAGE_15B_RES			15
+
+/* 100mV maximum voltage drop over the sense resistors */
+#define PAC1944_VSENSE_MILLIVOLTS_MAX		100
+
+/*
+ * Current bits resolution when set for unsigned values and
+ * HALF FSR signed values
+ */
+#define PAC1944_CURRENT_16B_RES			16
+
+/* Current bits resolution when set for signed values */
+#define PAC1944_CURRENT_15B_RES			15
+
+/* Power resolution is 30 bits when unsigned and HALF FSR signed values */
+#define PAC1944_POWER_30B_RES			30
+
+/* Power resolution is 29 bits when signed */
+#define PAC1944_POWER_29B_RES			29
+
+/* Accumulation register is 56 bits long for unipolar range */
+#define PAC1944_ENERGY_56B_RES			56
+
+/* Accumulation register is 56 bits long for bipolar range */
+#define PAC1944_ENERGY_55B_RES			55
+
+/* Maximum power-product value - 32 V * 0.1 V */
+#define PAC195X_PRODUCT_VOLTAGE_PV_FSR		3200000000000UL
+
+/* Maximum power-product value - 9 V * 0.1 V */
+#define PAC194X_PRODUCT_VOLTAGE_PV_FSR		900000000000UL
+
+#define PAC1944_MEAS_REG_SNAPSHOT_LEN		80
+#define PAC1944_CTRL_REG_SNAPSHOT_LEN		24
+
+#define PAC1944_DEFAULT_CHIP_SAMP_SPEED_HZ	1024
+
+/* Device register address map */
+#define PAC1944_REFRESH_REG_ADDR		0x00
+#define PAC1944_CTRL_REG_ADDR			0x01
+#define PAC1944_ACC_COUNT_REG_ADDR		0x02
+#define PAC1944_VACC_1_REG_ADDR			0x03
+#define PAC1944_VACC_2_REG_ADDR			0x04
+#define PAC1944_VACC_3_REG_ADDR			0x05
+#define PAC1944_VACC_4_REG_ADDR			0x06
+#define PAC1944_VBUS_1_ADDR			0x07
+#define PAC1944_VBUS_2_ADDR			0x08
+#define PAC1944_VBUS_3_ADDR			0x09
+#define PAC1944_VBUS_4_ADDR			0x0A
+#define PAC1944_VSENSE_1_ADDR			0x0B
+#define PAC1944_VSENSE_2_ADDR			0x0C
+#define PAC1944_VSENSE_3_ADDR			0x0D
+#define PAC1944_VSENSE_4_ADDR			0x0E
+#define PAC1944_VBUS_AVG_1_ADDR			0x0F
+#define PAC1944_VBUS_AVG_2_ADDR			0x10
+#define PAC1944_VBUS_AVG_3_ADDR			0x11
+#define PAC1944_VBUS_AVG_4_ADDR			0x12
+#define PAC1944_VSENSE_AVG_1_ADDR		0x13
+#define PAC1944_VSENSE_AVG_2_ADDR		0x14
+#define PAC1944_VSENSE_AVG_3_ADDR		0x15
+#define PAC1944_VSENSE_AVG_4_ADDR		0x16
+#define PAC1944_VPOWER_1_ADDR			0x17
+#define PAC1944_VPOWER_2_ADDR			0x18
+#define PAC1944_VPOWER_3_ADDR			0x19
+#define PAC1944_VPOWER_4_ADDR			0x1A
+
+/* Start of configurations registers */
+#define PAC1944_SMBUS_SETTINGS_REGS_ADDR	0x1C
+#define PAC1944_NEG_PWR_FSR_REG_ADDR		0x1D
+#define PAC1944_REFRESG_V_REG_ADDR		0x1E
+#define PAC1944_REFRESH_V_REG_ADDR		0x1F
+#define PAC1944_SLOW_REG_ADDR			0x20
+#define PAC1944_CTRL_ACT_REG_ADDR		0x21
+#define PAC1944_CTRL_LAT_REG_ADDR		0x23
+#define PAC1944_NEG_PWR_FSR_LAT_REG_ADDR	0x24
+#define PAC1944_ACCUM_CFG_REG_ADDR		0x25
+
+/*
+ * Registers related to alert functionality
+ */
+#define PAC1944_ALERT_STATUS_REG_ADDR		0x26
+#define PAC1944_SLOW_ALERT1_REG_ADDR		0x27
+#define PAC1944_GPIO_ALERT2_REG_ADDR		0x28
+#define PAC1944_ACC_FULLNESS_LIMITS_REG_ADDR	0x29
+#define PAC1944_OC_LIMIT_REG_ADDR		0x30
+#define PAC1944_UC_LIMIT_REG_ADDR		0x34
+#define PAC1944_OP_LIMIT_REG_ADDR		0x38
+#define PAC1944_OV_LIMIT_REG_ADDR		0x3C
+#define PAC1944_UV_LIMIT_REG_ADDR		0x40
+#define PAC1944_OC_LIMIT_NSAMPLES_REG_ADDR	0x44
+#define PAC1944_UC_LIMIT_NSAMPLES_REG_ADDR	0x45
+#define PAC1944_OP_LIMIT_NSAMPLES_REG_ADDR	0x46
+#define PAC1944_OV_LIMIT_NSAMPLES_REG_ADDR	0x47
+#define PAC1944_UV_LIMIT_NSAMPLES_REG_ADDR	0x48
+#define PAC1944_ALERT_ENABLE_REG_ADDR		0x49
+
+#define PAC1944_ALERT_ENABLE_REG_LEN		3
+#define PAC1944_ALERTS_REG_LEN			63
+
+#define PAC1944_PID_REG_ADDR			0xFD
+
+/* Alert Enable register */
+#define PAC1944_OC_MASK				GENMASK(23, 20)
+#define PAC1944_CH01OC_MASK			BIT(23)
+#define PAC1944_CH01OC_SET			BIT(23)
+#define PAC1944_CH02OC_MASK			BIT(22)
+#define PAC1944_CH02OC_SET			BIT(22)
+#define PAC1944_CH03OC_MASK			BIT(21)
+#define PAC1944_CH03OC_SET			BIT(21)
+#define PAC1944_CH04OC_MASK			BIT(20)
+#define PAC1944_CH04OC_SET			BIT(20)
+
+#define PAC1944_UC_MASK				GENMASK(19, 16)
+#define PAC1944_CH01UC_MASK			BIT(19)
+#define PAC1944_CH01UC_SET			BIT(19)
+#define PAC1944_CH02UC_MASK			BIT(18)
+#define PAC1944_CH02UC_SET			BIT(18)
+#define PAC1944_CH03UC_MASK			BIT(17)
+#define PAC1944_CH03UC_SET			BIT(17)
+#define PAC1944_CH04UC_MASK			BIT(16)
+#define PAC1944_CH04UC_SET			BIT(16)
+
+#define PAC1944_OV_MASK				GENMASK(15, 12)
+#define PAC1944_CH01OV_MASK			BIT(15)
+#define PAC1944_CH01OV_SET			BIT(15)
+#define PAC1944_CH02OV_MASK			BIT(14)
+#define PAC1944_CH02OV_SET			BIT(14)
+#define PAC1944_CH03OV_MASK			BIT(13)
+#define PAC1944_CH03OV_SET			BIT(13)
+#define PAC1944_CH04OV_MASK			BIT(12)
+#define PAC1944_CH04OV_SET			BIT(12)
+
+#define PAC1944_UV_MASK				GENMASK(11, 8)
+#define PAC1944_CH01UV_MASK			BIT(11)
+#define PAC1944_CH01UV_SET			BIT(11)
+#define PAC1944_CH02UV_MASK			BIT(10)
+#define PAC1944_CH02UV_SET			BIT(10)
+#define PAC1944_CH03UV_MASK			BIT(9)
+#define PAC1944_CH03UV_SET			BIT(9)
+#define PAC1944_CH04UV_MASK			BIT(8)
+#define PAC1944_CH04UV_SET			BIT(8)
+
+#define PAC1944_OP_MASK				GENMASK(7, 4)
+#define PAC1944_CH01OP_MASK			BIT(7)
+#define PAC1944_CH01OP_SET			BIT(7)
+#define PAC1944_CH02OP_MASK			BIT(6)
+#define PAC1944_CH02OP_SET			BIT(6)
+#define PAC1944_CH03OP_MASK			BIT(5)
+#define PAC1944_CH03OP_SET			BIT(5)
+#define PAC1944_CH04OP_MASK			BIT(4)
+#define PAC1944_CH04OP_SET			BIT(4)
+
+#define PAC1944_ACC_OVF_MASK			BIT(3)
+#define PAC1944_ACC_OVF_SET			BIT(3)
+
+#define PAC1944_ACC_COUNT_MASK			BIT(2)
+#define PAC1944_ACC_COUNT_SET			BIT(2)
+
+#define PAC1944_ALERT_CC1_MASK			BIT(1)
+#define PAC1944_ALERT_CC1_SET			BIT(1)
+
+#define PAC1944_ACC_REG_LEN			4
+#define PAC1944_VACC_REG_LEN			7
+#define PAC1944_VBUS_SENSE_REG_LEN		2
+#define PAC1944_VPOWER_REG_LEN			4
+#define PAC1944_CTRL_ACT_REG_LEN		2
+#define PAC1944_CTRL_LAT_REG_LEN		2
+#define PAC1944_MAX_REGISTER_LEN		6
+
+#define PAC1944_COMMON_DEVATTR			6
+#define PAC1944_ACC_DEVATTR			3
+#define PAC1944_SHARED_DEVATTRS_COUNT		5
+
+#define PAC1944_MID				0x5D
+#define PAC194x54_PID				0x5B
+#define PAC194x53_PID				0x5A
+#define PAC194x52_PID				0x59
+#define PAC194x51_PID				0x58
+
+#define PAC1944_MAX_CH				4
+
+/* PAC194X family */
+#define PAC_PRODUCT_ID_1941			0x68
+#define PAC_PRODUCT_ID_1942			0x69
+#define PAC_PRODUCT_ID_1943			0x6A
+#define PAC_PRODUCT_ID_1944			0x6B
+#define PAC_PRODUCT_ID_1941_2			0x6C
+#define PAC_PRODUCT_ID_1942_2			0x6D
+/* PAC195x family */
+#define PAC_PRODUCT_ID_1951			0x78
+#define PAC_PRODUCT_ID_1952			0x79
+#define PAC_PRODUCT_ID_1953			0x7A
+#define PAC_PRODUCT_ID_1954			0x7B
+#define PAC_PRODUCT_ID_1951_2			0x7C
+#define PAC_PRODUCT_ID_1952_2			0x7D
+
+#define PAC1944_ALERT				0x00
+#define PAC1944_GPIO_INPUT			0x01
+#define PAC1944_GPIO_OUTPUT			0x02
+#define PAC1944_SLOW				0x03
+
+#define PAC1944_CTRL_SAMPLE_MASK		GENMASK(15, 12)
+#define PAC1944_CTRL_GPIO_ALERT2_MASK		GENMASK(11, 10)
+#define PAC1944_CTRL_SLOW_ALERT1_MASK		GENMASK(9, 8)
+#define PAC1944_CTRL_CH_1_OFF_MASK		BIT(7)
+#define PAC1944_CTRL_CH_2_OFF_MASK		BIT(6)
+#define PAC1944_CTRL_CH_3_OFF_MASK		BIT(5)
+#define PAC1944_CTRL_CH_4_OFF_MASK		BIT(4)
+
+#define PAC1944_NEG_PWR_CFG_VS1_MASK		GENMASK(15, 14)
+#define PAC1944_NEG_PWR_CFG_VS2_MASK		GENMASK(13, 12)
+#define PAC1944_NEG_PWR_CFG_VS3_MASK		GENMASK(11, 10)
+#define PAC1944_NEG_PWR_CFG_VS4_MASK		GENMASK(9, 8)
+#define PAC1944_NEG_PWR_CFG_VB1_MASK		GENMASK(7, 6)
+#define PAC1944_NEG_PWR_CFG_VB3_MASK		GENMASK(5, 4)
+#define PAC1944_NEG_PWR_CFG_VB2_MASK		GENMASK(3, 2)
+#define PAC1944_NEG_PWR_CFG_VB4_MASK		GENMASK(1, 0)
+
+#define PAC1944_CFG_ACC4_SHIFT			0
+#define PAC1944_CFG_ACC3_SHIFT			2
+#define PAC1944_CFG_ACC2_SHIFT			4
+#define PAC1944_CFG_ACC1_SHIFT			6
+
+#define PAC1944_ACPI_GET_NAMES			1
+#define PAC1944_ACPI_GET_UOHMS_VALS		2
+#define PAC1944_ACPI_GET_BIPOLAR_SETTINGS	4
+#define PAC1944_ACPI_GET_SAMP			5
+
+/*
+ * Universal Unique Identifier (UUID),
+ * 721F1534-5D27-4B60-9DF4-41A3C4B7DA3A,
+ * is reserved to Microchip for the PAC194x and PAC195x.
+ */
+#define PAC1944_DSM_UUID	"721F1534-5D27-4B60-9DF4-41A3C4B7DA3A"
+
+#define ACCUM_REG(acc1_cfg, acc2_cfg, acc3_cfg, acc4_cfg)		   \
+			((((acc1_cfg) & 0x03) << PAC1944_CFG_ACC1_SHIFT) | \
+			 (((acc2_cfg) & 0x03) << PAC1944_CFG_ACC2_SHIFT) | \
+			 (((acc3_cfg) & 0x03) << PAC1944_CFG_ACC3_SHIFT) | \
+			 (((acc4_cfg) & 0x03) << PAC1944_CFG_ACC4_SHIFT))
+
+/*
+ * Accumulated power/energy formula (in mW-seconds):
+ * Energy = (Vacc/10^9)*[(10^9/2^30)*2^9]*3.2*10^3/Rsense
+ * Vacc - is the accumulated value per second
+ * Rsense - value of the shunt resistor in microOhms
+ *
+ * PAC195X_MAX_VPOWER_RSHIFTED_BY_29B = 3.2*((10^9)/(2^29))*10^9
+ * will be used to calculate the scale for accumulated power/energy
+ */
+#define PAC195X_MAX_VPOWER_RSHIFTED_BY_29B	5960464478UL
+
+/*
+ * PAC194X_MAX_VPOWER_RSHIFTED_BY_29B = 0.9*((10^9)/(2^29))*10^9
+ * will be used to calculate the scale for accumulated power/energy
+ */
+#define PAC194X_MAX_VPOWER_RSHIFTED_BY_29B	1676380634UL
+
+/* (100mV * 1000000) / (2^15)  used to calculate the scale for current */
+#define PAC1944_MAX_VSENSE_RSHIFTED_BY_15B	3052
+
+/*
+ * [(100mV * 1000000) / (2^15)]*10^9  used to calculate the scale
+ * for accumulated current/Coulomb counter
+ */
+#define PAC1944_MAX_VSENSE_NANO			3051757812500UL
+
+#define TO_PAC1944_CHIP_INFO(d) container_of(d, struct pac1944_chip_info, work_chip_rfsh)
+
+/*
+ * these indexes are exactly describing the element order within a single
+ * PAC1944/54 phys channel IIO channel descriptor; see the static const struct
+ * iio_chan_spec pac1944_single_channel[] declaration
+ */
+enum pac1944_ch_idx {
+	PAC1944_CH_POWER,
+	PAC1944_CH_VOLTAGE,
+	PAC1944_CH_CURRENT,
+	PAC1944_CH_VOLTAGE_AVERAGE,
+	PAC1944_CH_CURRENT_AVERAGE,
+};
+
+/* IDs ordered based on Product ID */
+enum pac1944_ids {
+	PAC1941,
+	PAC1942,
+	PAC1943,
+	PAC1944,
+	PAC1941_2,
+	PAC1942_2,
+	PAC1951,
+	PAC1952,
+	PAC1953,
+	PAC1954,
+	PAC1951_2,
+	PAC1952_2,
+};
+
+enum pac1944_acc_mode {
+	PAC1944_ACCMODE_VPOWER,
+	PAC1944_ACCMODE_VSENSE,
+	PAC1944_ACCMODE_VBUS,
+};
+
+enum pac1944_ {
+	PAC1944_UNIPOLAR_FSR_CFG,
+	PAC1944_BIPOLAR_FSR_CFG,
+	PAC1944_BIPOLAR_HALF_FSR_CFG,
+};
+
+enum pac1944_samps {
+	PAC1944_SAMP_1024SPS_ADAPT,
+	PAC1944_SAMP_256SPS_ADAPT,
+	PAC1944_SAMP_64SPS_ADAPT,
+	PAC1944_SAMP_8SPS_ADAPT,
+
+	PAC1944_SAMP_1024SPS,
+	PAC1944_SAMP_256SPS,
+	PAC1944_SAMP_64SPS,
+	PAC1944_SAMP_8SPS,
+
+	PAC1944_SAMP_SINGLE_SHOT,
+	PAC1944_SAMP_SINGLE_SHOT_8X,
+	PAC1944_SAMP_FAST_MODE,
+	PAC1944_SAMP_BURST_MODE,
+
+	PAC1944_RESERVED1,
+	PAC1944_RESERVED2,
+	PAC1944_RESERVED3,
+	PAC1944_RESERVED4,
+};
+
+enum pac1944_number_of_active_channels {
+	PAC1944_1_CHANNEL_ACTIVE,
+	PAC1944_2_CHANNELS_ACTIVE,
+	PAC1944_3_CHANNELS_ACTIVE,
+	PAC1944_4_CHANNELS_ACTIVE,
+};
+
+/*
+ * The PAC195X has a feature called Adaptive Accumulator mode (APAPT). In this
+ * mode, sampling is programmed at one of the valid sample rates and samples are
+ * accumulated. If the SLOW pin is asserted and the device begins sampling at
+ * 8 SPS, these samples are shifted by 7 bits to the left and accumulated so as
+ * to simulate sampling at the maximum sampling rate, 1024 SPS, and the
+ * accumulator count is also incremented by 128 for each sample in Slow mode
+ * (when using the Adaptive Accumulator mode) to simulate samples being
+ * accumulated at the maximum sampling rate.
+ * This offers a big reduction in host overhead and bus traffic for systems that
+ * need to use the SLOW pin for lower power operation during certain times and
+ * want to have continuous accurate energy monitoring for both the maximum
+ * sampling rate and the SLOW sampling rate.
+ */
+static const unsigned int pac1944_samp_rate_map_tbl[] = {
+	[PAC1944_SAMP_1024SPS_ADAPT] = 1024,
+	[PAC1944_SAMP_256SPS_ADAPT] = 256,
+	[PAC1944_SAMP_64SPS_ADAPT] = 64,
+	[PAC1944_SAMP_8SPS_ADAPT] = 8,
+	[PAC1944_SAMP_1024SPS] = 1024,
+	[PAC1944_SAMP_256SPS] = 256,
+	[PAC1944_SAMP_64SPS] = 64,
+	[PAC1944_SAMP_8SPS] = 8,
+	[PAC1944_SAMP_SINGLE_SHOT] = 1,
+	[PAC1944_SAMP_SINGLE_SHOT_8X] = 8,
+	[PAC1944_SAMP_FAST_MODE] = 0xff,
+	[PAC1944_SAMP_BURST_MODE] = 0xff,
+	[PAC1944_RESERVED1] = 0xff,
+	[PAC1944_RESERVED2] = 0xff,
+	[PAC1944_RESERVED3] = 0xff,
+	[PAC1944_RESERVED4] = 0xff,
+};
+
+static const unsigned int shift_map_tbl[] = {
+	[PAC1944_SAMP_1024SPS_ADAPT] = 10,
+	[PAC1944_SAMP_256SPS_ADAPT] = 10,
+	[PAC1944_SAMP_64SPS_ADAPT] = 10,
+	[PAC1944_SAMP_8SPS_ADAPT] = 10,
+	[PAC1944_SAMP_1024SPS] = 10,
+	[PAC1944_SAMP_256SPS] = 8,
+	[PAC1944_SAMP_64SPS] = 6,
+	[PAC1944_SAMP_8SPS] = 3,
+	[PAC1944_SAMP_SINGLE_SHOT] = 10,
+	[PAC1944_SAMP_SINGLE_SHOT_8X] = 8,
+	[PAC1944_SAMP_FAST_MODE] = 0xff,
+	[PAC1944_SAMP_BURST_MODE] = 0xff,
+	[PAC1944_RESERVED1] = 0xff,
+	[PAC1944_RESERVED2] = 0xff,
+	[PAC1944_RESERVED3] = 0xff,
+	[PAC1944_RESERVED4] = 0xff,
+};
+
+static const unsigned int samp_rate_burst_mode_tbl[] = {
+	[PAC1944_1_CHANNEL_ACTIVE] = 5120,
+	[PAC1944_2_CHANNELS_ACTIVE] = 2560,
+	[PAC1944_3_CHANNELS_ACTIVE] = 1706,
+	[PAC1944_4_CHANNELS_ACTIVE] = 1280,
+};
+
+static const unsigned int samp_rate_fast_mode_tbl[] = {
+	[PAC1944_1_CHANNEL_ACTIVE] = 2560,
+	[PAC1944_2_CHANNELS_ACTIVE] = 1707,
+	[PAC1944_3_CHANNELS_ACTIVE] = 1280,
+	[PAC1944_4_CHANNELS_ACTIVE] = 1024,
+};
+
+/* Available Sample Modes */
+static const char * const pac1944_frequency_avail[] = {
+	"1024_ADAP",
+	"256_ADAP",
+	"64_ADAP",
+	"8_ADAP",
+	"1024",
+	"256",
+	"64",
+	"8",
+	"single_shot_1x",
+	"single_shot_8x",
+	"fast",
+	"burst",
+};
+
+static const unsigned int pac1944_overvoltage_mask_tbl[] = {
+	PAC1944_CH01OV_MASK,
+	PAC1944_CH02OV_MASK,
+	PAC1944_CH03OV_MASK,
+	PAC1944_CH04OV_MASK,
+};
+
+static const unsigned int pac1944_undervoltage_mask_tbl[] = {
+	PAC1944_CH01UV_MASK,
+	PAC1944_CH02UV_MASK,
+	PAC1944_CH03UV_MASK,
+	PAC1944_CH04UV_MASK,
+};
+
+static const unsigned int pac1944_overcurrent_mask_tbl[] = {
+	PAC1944_CH01OC_MASK,
+	PAC1944_CH02OC_MASK,
+	PAC1944_CH03OC_MASK,
+	PAC1944_CH04OC_MASK,
+};
+
+static const unsigned int pac1944_undercurrent_mask_tbl[] = {
+	PAC1944_CH01UC_MASK,
+	PAC1944_CH02OC_MASK,
+	PAC1944_CH03OC_MASK,
+	PAC1944_CH04OC_MASK,
+};
+
+static const unsigned int pac1944_overpower_mask_tbl[] = {
+	PAC1944_CH01OP_MASK,
+	PAC1944_CH02OP_MASK,
+	PAC1944_CH03OP_MASK,
+	PAC1944_CH04OP_MASK,
+};
+
+/**
+ * struct reg_data - data from the registers
+ * @vsense_mode:array of values, Full Scale Range (FSR) mode for V Sense
+ * @vbus_mode: array of values, Full Scale Range (FSR) mode for V Bus
+ * @accumulation_mode: array of values, accumulation mode for V Acc
+ * @meas_regs: snapshot of raw measurements registers
+ * @ctrl_act_reg: snapshot of the ctrl_act register
+ * @ctrl_lat_reg: snapshot of the ctrl_lat register
+ * @acc_count: snapshot of the acc_count register
+ * @total_samples_nr: accumulated values for acc_count (total number of samples)
+ * @acc_val: accumulated values per second
+ * @vacc: accumulated vpower values
+ * @vpower: snapshot of vpower registers
+ * @vbus: snapshot of vbus registers
+ * @vbus_avg: averages of vbus registers
+ * @vsense: snapshot of vsense registers
+ * @vsense_avg: averages of vsense registers
+ * @jiffies_tstamp: chip's uptime
+ */
+struct reg_data {
+	u8	vbus_mode[PAC1944_MAX_CH];
+	u8	vsense_mode[PAC1944_MAX_CH];
+	u8	accumulation_mode[PAC1944_MAX_CH];
+	u8	meas_regs[PAC1944_MEAS_REG_SNAPSHOT_LEN];
+	u16	ctrl_act_reg;
+	u16	ctrl_lat_reg;
+	u32	acc_count;
+	u32	total_samples_nr[PAC1944_MAX_CH];
+	s64	acc_val[PAC1944_MAX_CH];
+	s64	vacc[PAC1944_MAX_CH];
+	s32	vpower[PAC1944_MAX_CH];
+	s32	vbus[PAC1944_MAX_CH];
+	s32	vbus_avg[PAC1944_MAX_CH];
+	s32	vsense[PAC1944_MAX_CH];
+	s32	vsense_avg[PAC1944_MAX_CH];
+	unsigned long jiffies_tstamp;
+};
+
+/**
+ * struct pac1944_chip_info - chip configuration
+ * @channels: array of values, true means that channel is active
+ * @iio_info: pointer to iio_info structure
+ * @client: a pointer to the i2c client associated with the device
+ * @lock: lock to prevent concurrent reads/writes
+ * @work_chip_rfsh: chip refresh workqueue implementation
+ * @phys_channels: number of physical channels for the device
+ * @active_channels: array of values, true means that channel is active
+ * @chip_variant: stores the type of the device
+ * @chip_revision: store the silicon revision version of the device
+ * @shunts: array of values, shunt resistor values
+ * @chip_reg_data: pointer to structure, containing data from the device registers
+ * @sample_rate_value: sampling frequency
+ * @labels: array of string, name of each channel
+ * @is_pac195x_family: true if device is part of the PAC195x family
+ * @sampling_mode: sampling mode used by the device
+ * @num_enabled_channels: count of how many chip channels are currently enabled
+ * @slow_alert1: snapshot of slow/alert register
+ * @gpio_alert2: snapshot of gpio/alert register
+ * @acc_fullness: snapshot of accumulator fullness limit register
+ * @overcurrent: array of values, overcurrent limit
+ * @undercurrent: array of values, undercurrent limit
+ * @overpower: array of values, overpower limit
+ * @overvoltage:  array of values, overvoltage limit
+ * @undervoltage: array of values, undervoltage limit
+ * @oc_limit_nsamples: number of consecutive samples exceeding the overcurrent limit
+ * @uc_limit_nsamples: number of consecutive samples exceeding the undercurrent limit
+ * @op_limit_nsamples: number of consecutive samples exceeding the overpower limit
+ * @ov_limit_nsamples: number of consecutive samples exceeding the overvoltage limit
+ * @uv_limit_nsamples: number of consecutive samples exceeding the undervoltage limit
+ * @alert_enable: snapshot of alert enable register
+ * @enable_acc: array of values, true means that accumulation channel is measured
+ */
+struct pac1944_chip_info {
+	const struct iio_chan_spec  *channels;
+	struct iio_info		iio_info;
+	struct i2c_client	*client;
+	struct mutex		lock; /* lock to prevent concurrent reads/writes */
+	struct delayed_work	work_chip_rfsh;
+	u8		phys_channels;
+	bool		active_channels[PAC1944_MAX_CH];
+	unsigned long	active_channels_mask;
+	u8		chip_variant;
+	u8		chip_revision;
+	u32		shunts[PAC1944_MAX_CH];
+	struct reg_data chip_reg_data;
+	s32		sample_rate_value;
+	char		*labels[PAC1944_MAX_CH];
+	bool		is_pac195x_family;
+	u8		sampling_mode;
+	u8		num_enabled_channels;
+	u32		slow_alert1;
+	u32		gpio_alert2;
+	u16		acc_fullness;
+	u16		overcurrent[PAC1944_MAX_CH];
+	u16		undercurrent[PAC1944_MAX_CH];
+	u32		overpower[PAC1944_MAX_CH];
+	u16		overvoltage[PAC1944_MAX_CH];
+	u16		undervoltage[PAC1944_MAX_CH];
+	u8		oc_limit_nsamples[PAC1944_MAX_CH];
+	u8		uc_limit_nsamples[PAC1944_MAX_CH];
+	u8		op_limit_nsamples[PAC1944_MAX_CH];
+	u8		ov_limit_nsamples[PAC1944_MAX_CH];
+	u8		uv_limit_nsamples[PAC1944_MAX_CH];
+	u32		alert_enable;
+	bool		enable_acc[PAC1944_MAX_CH];
+};
+
+/**
+ * struct pac1944_features - features of a pac194x instance
+ * @phys_channels:	number of physical channels supported by the chip
+ * @prod_id:		hardware ID
+ * @name:		chip's name
+ */
+struct pac1944_features {
+	u8 phys_channels;
+	u8 prod_id;
+	const char *name;
+};
+
+static const struct pac1944_features pac1944_chip_config[] = {
+	/* PAC194X Family */
+	[PAC1941] = {
+		.phys_channels = 1,
+		.prod_id = PAC_PRODUCT_ID_1941,
+		.name = "pac1941",
+	},
+	[PAC1942] = {
+		.phys_channels = 2,
+		.prod_id = PAC_PRODUCT_ID_1942,
+		.name = "pac1942",
+	},
+	[PAC1943] = {
+		.phys_channels = 3,
+		.prod_id = PAC_PRODUCT_ID_1943,
+		.name = "pac1943",
+	},
+	[PAC1944] = {
+		.phys_channels = 4,
+		.prod_id = PAC_PRODUCT_ID_1944,
+		.name = "pac1944",
+	},
+	[PAC1941_2] = {
+		.phys_channels = 1,
+		.prod_id = PAC_PRODUCT_ID_1941_2,
+		.name = "pac1941_2",
+	},
+	[PAC1942_2] = {
+		.phys_channels = 2,
+		.prod_id = PAC_PRODUCT_ID_1942_2,
+		.name = "pac1942_2",
+	},
+	/* PAC195X Family */
+	[PAC1951] = {
+		.phys_channels = 1,
+		.prod_id = PAC_PRODUCT_ID_1951,
+		.name = "pac1951",
+	},
+	[PAC1952] = {
+		.phys_channels = 2,
+		.prod_id = PAC_PRODUCT_ID_1952,
+		.name = "pac1952_1",
+	},
+	[PAC1953] = {
+		.phys_channels = 3,
+		.prod_id = PAC_PRODUCT_ID_1953,
+		.name = "pac1953",
+	},
+	[PAC1954] = {
+		.phys_channels = 4,
+		.prod_id = PAC_PRODUCT_ID_1954,
+		.name = "pac1954",
+	},
+	[PAC1951_2] = {
+		.phys_channels = 1,
+		.prod_id = PAC_PRODUCT_ID_1951_2,
+		.name = "pac1951_2",
+	},
+	[PAC1952_2] = {
+		.phys_channels = 2,
+		.prod_id = PAC_PRODUCT_ID_1952_2,
+		.name = "pac1952_2",
+	},
+};
+
+static inline u64 pac1944_get_unaligned_be56(const u8 *p)
+{
+	return (u64)p[0] << 48 | (u64)p[1] << 40 | (u64)p[2] << 32 |
+		(u64)p[3] << 24 | p[4] << 16 | p[5] << 8 | p[6];
+}
+
+/* Low-level I2c functions used to transfer more then 32 bytes at once */
+static int pac1944_i2c_read(struct i2c_client *client, u8 reg_addr,
+			    void *databuf, u8 len)
+{
+	struct i2c_msg msgs[2] = {
+		{ .addr = client->addr,
+		 .len = 1,
+		 .buf = (u8 *)&reg_addr,
+		 .flags = 0
+		},
+		{ .addr = client->addr,
+		 .len = len,
+		 .buf = databuf,
+		 .flags = I2C_M_RD
+		}
+	};
+
+	return i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+}
+
+static int pac1944_disable_alert_reg(struct device *dev, u32 mask, u8 *status)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u32 val;
+	u8 buf[PAC1944_ALERT_ENABLE_REG_LEN];
+
+	ret = i2c_smbus_read_i2c_block_data(client,
+					    PAC1944_ALERT_ENABLE_REG_ADDR,
+					    PAC1944_ALERT_ENABLE_REG_LEN,
+					    status);
+	if (ret < 0) {
+		dev_err(dev, "failing %s\n", __func__);
+		return ret;
+	}
+
+	val = get_unaligned_be24(status);
+	val = val & (~mask);
+	put_unaligned_be24(val, &buf[0]);
+
+	/* disable appropriate bit from the Alert enable register */
+	ret = i2c_smbus_write_block_data(client, PAC1944_ALERT_ENABLE_REG_ADDR,
+					 PAC1944_ALERT_ENABLE_REG_LEN,
+					 (u8 *)&buf[0]);
+
+	return ret;
+}
+
+static int pac1944_restore_alert_reg(struct iio_dev *indio_dev, u8 *status)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+
+	/* restoring the Alert enable register */
+	ret = i2c_smbus_write_block_data(client, PAC1944_ALERT_ENABLE_REG_ADDR,
+					 PAC1944_ALERT_ENABLE_REG_LEN, status);
+	if (ret) {
+		dev_err(&client->dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	/* Sending a REFRESH_V to the chip, so the new settings take place */
+	ret = i2c_smbus_write_byte(info->client, PAC1944_REFRESH_V_REG_ADDR);
+	if (ret)
+		dev_err(&client->dev, "cannot send REFRESH_V\n");
+
+	return ret;
+}
+
+static int pac1944_update_alert_byte_data(struct device *dev, u8 addr,
+					  u32 mask, u8 value)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u8 status[PAC1944_ALERT_ENABLE_REG_LEN];
+
+	ret = pac1944_disable_alert_reg(dev, mask, &status[0]);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, addr, value);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	return pac1944_restore_alert_reg(indio_dev, &status[0]);
+}
+
+static int pac1944_update_alert_16b(struct device *dev, u8 addr,
+				    u32 mask, u16 value)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	__be16 tmp_be16;
+	u8 status[PAC1944_ALERT_ENABLE_REG_LEN];
+
+	ret = pac1944_disable_alert_reg(dev, mask, &status[0]);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	tmp_be16 = cpu_to_be16(value);
+
+	ret = i2c_smbus_write_word_data(client, addr, tmp_be16);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	return pac1944_restore_alert_reg(indio_dev, &status[0]);
+}
+
+static int pac1944_update_alert_24b(struct device *dev, u8 addr,
+				    int mask, u32 value)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u8 status[PAC1944_ALERT_ENABLE_REG_LEN], tmp[3];
+
+	ret = pac1944_disable_alert_reg(dev, mask, &status[0]);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	put_unaligned_be24(value, &tmp[0]);
+
+	ret = i2c_smbus_write_block_data(client, addr, ARRAY_SIZE(tmp), (u8 *)&tmp[0]);
+	if (ret) {
+		dev_err(dev, "failing to write %s\n", __func__);
+		return ret;
+	}
+
+	return pac1944_restore_alert_reg(indio_dev, &status[0]);
+}
+
+/* Custom IIO Device Attributes */
+static ssize_t pac1944_shunt_value_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%u\n", info->shunts[this_attr->address]);
+}
+
+static ssize_t pac1944_shunt_value_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int sh_val;
+
+	if (kstrtouint(buf, 10, &sh_val)) {
+		dev_err(dev, "Shunt value is not valid\n");
+		return -EINVAL;
+	}
+
+	scoped_guard(mutex, &info->lock)
+		info->shunts[this_attr->address] = sh_val;
+
+	return count;
+}
+
+static ssize_t pac1944_acc_fullness_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+
+	return sysfs_emit(buf, "%u\n", info->acc_fullness);
+}
+
+static ssize_t pac1944_acc_fullness_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	int ret;
+	u16 val;
+
+	if (kstrtou16(buf, 10, &val)) {
+		dev_err(dev, "value is not valid\n");
+		return -EINVAL;
+	}
+
+	scoped_guard(mutex, &info->lock) {
+		ret = pac1944_update_alert_16b(dev, PAC1944_ACC_FULLNESS_LIMITS_REG_ADDR,
+					       (int)(0xffffff), val);
+		if (!ret)
+			info->acc_fullness = val;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_oc_limit_nsamples_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%u\n", info->oc_limit_nsamples[this_attr->address]);
+}
+
+static ssize_t pac1944_oc_limit_nsamples_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret, idx;
+	u8 val, val_tmp;
+
+	ret = kstrtou8(buf, 10, &val_tmp);
+	if (ret)
+		return ret;
+
+	if (val_tmp > 3)
+		return -EINVAL;
+
+	idx = this_attr->address;
+
+	scoped_guard(mutex, &info->lock) {
+		val = val_tmp << (6 - (idx * 2));
+		ret = pac1944_update_alert_byte_data(dev, PAC1944_OC_LIMIT_NSAMPLES_REG_ADDR,
+						     pac1944_overcurrent_mask_tbl[idx], val);
+		if (!ret)
+			info->oc_limit_nsamples[idx] = val_tmp;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_uc_limit_nsamples_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%u\n", info->uc_limit_nsamples[this_attr->address]);
+}
+
+static ssize_t pac1944_uc_limit_nsamples_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret, idx;
+	u8 val, val_tmp;
+
+	ret = kstrtou8(buf, 10, &val_tmp);
+	if (ret)
+		return ret;
+
+	if (val_tmp > 3)
+		return -EINVAL;
+
+	idx = this_attr->address;
+
+	scoped_guard(mutex, &info->lock) {
+		val = val_tmp << (6 - (idx * 2));
+		ret = pac1944_update_alert_byte_data(dev, PAC1944_UC_LIMIT_NSAMPLES_REG_ADDR,
+						     pac1944_undercurrent_mask_tbl[idx], val);
+		if (!ret)
+			info->uc_limit_nsamples[idx] = val_tmp;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_op_limit_nsamples_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%u\n", info->op_limit_nsamples[this_attr->address]);
+}
+
+static ssize_t pac1944_op_limit_nsamples_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret, idx;
+	u8 val, val_tmp;
+
+	ret = kstrtou8(buf, 10, &val_tmp);
+	if (ret)
+		return ret;
+
+	if (val_tmp > 3)
+		return -EINVAL;
+
+	idx = this_attr->address;
+
+	scoped_guard(mutex, &info->lock) {
+		val = val_tmp << (6 - (idx * 2));
+		ret = pac1944_update_alert_byte_data(dev, PAC1944_OP_LIMIT_NSAMPLES_REG_ADDR,
+						     pac1944_overpower_mask_tbl[idx], val);
+		if (ret)
+			return ret;
+
+		info->op_limit_nsamples[idx] = val_tmp;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_ov_limit_nsamples_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%u\n", info->ov_limit_nsamples[this_attr->address]);
+}
+
+static ssize_t pac1944_ov_limit_nsamples_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret, idx;
+	u8 val, val_tmp;
+
+	ret = kstrtou8(buf, 10, &val_tmp);
+	if (ret)
+		return ret;
+
+	if (val_tmp > 3)
+		return -EINVAL;
+
+	idx = this_attr->address;
+
+	scoped_guard(mutex, &info->lock) {
+		val = val_tmp << (6 - (idx * 2));
+		ret = pac1944_update_alert_byte_data(dev, PAC1944_OV_LIMIT_NSAMPLES_REG_ADDR,
+						     pac1944_overvoltage_mask_tbl[idx], val);
+		if (!ret)
+			info->ov_limit_nsamples[idx] = val_tmp;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_uv_limit_nsamples_show(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%d\n", info->uv_limit_nsamples[this_attr->address]);
+}
+
+static ssize_t pac1944_uv_limit_nsamples_store(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret, idx;
+	u8 val, val_tmp;
+
+	ret = kstrtou8(buf, 10, &val_tmp);
+	if (ret)
+		return ret;
+
+	if (val_tmp > 3)
+		return -EINVAL;
+
+	idx = this_attr->address;
+
+	scoped_guard(mutex, &info->lock) {
+		val = val_tmp << (6 - (idx * 2));
+		ret = pac1944_update_alert_byte_data(dev, PAC1944_UV_LIMIT_NSAMPLES_REG_ADDR,
+						     pac1944_undervoltage_mask_tbl[idx], val);
+		if (!ret)
+			info->uv_limit_nsamples[idx] = val_tmp;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_alert_enable_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+
+	return sysfs_emit(buf, "%u\n", info->alert_enable);
+}
+
+static ssize_t pac1944_alert_enable_store(struct device *dev,
+					  struct device_attribute *attr,
+					  const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	int ret;
+	u32 val;
+	u8 tmp[PAC1944_ALERT_ENABLE_REG_LEN];
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		return -EINVAL;
+
+	put_unaligned_be24(val, &tmp[0]);
+
+	scoped_guard(mutex, &info->lock) {
+		ret = pac1944_restore_alert_reg(indio_dev, &tmp[0]);
+		if (ret) {
+			dev_err(dev, "failing to write %s\n", __func__);
+			return ret;
+		}
+
+		info->alert_enable = val;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_slow_alert1_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u32 val;
+	u8 tmp[3];
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		return -EINVAL;
+
+	put_unaligned_be24(val, &tmp[0]);
+
+	scoped_guard(mutex, &info->lock) {
+		ret = i2c_smbus_write_block_data(client, PAC1944_SLOW_ALERT1_REG_ADDR,
+						 ARRAY_SIZE(tmp), (u8 *)&tmp[0]);
+		if (ret) {
+			dev_err(dev, "failing to write %s\n", __func__);
+			return ret;
+		}
+
+		info->slow_alert1 = val;
+	}
+
+	return count;
+}
+
+#define PAC1944_SLOW_ALERT_SHOW(alert_name) \
+static ssize_t pac1944_##alert_name##_show(struct device *dev,		\
+				       struct device_attribute *attr,	\
+				       char *buf)			\
+	{								\
+		struct iio_dev *indio_dev = dev_to_iio_dev(dev);	\
+		struct pac1944_chip_info *info = iio_priv(indio_dev);	\
+									\
+		return sysfs_emit(buf, "%u\n", info->alert_name);	\
+	}
+
+PAC1944_SLOW_ALERT_SHOW(slow_alert1)
+PAC1944_SLOW_ALERT_SHOW(gpio_alert2)
+
+static ssize_t pac1944_gpio_alert2_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u32 val;
+	u8 tmp[3];
+
+	ret = kstrtoint(buf, 10, &val);
+	if (ret)
+		return -EINVAL;
+
+	put_unaligned_be24(val, &tmp[0]);
+
+	scoped_guard(mutex, &info->lock) {
+		ret = i2c_smbus_write_block_data(client, PAC1944_GPIO_ALERT2_REG_ADDR,
+						 ARRAY_SIZE(tmp), (u8 *)&tmp[0]);
+		if (ret) {
+			dev_err(dev, "failing to write %s\n", __func__);
+			return ret;
+		}
+
+		info->gpio_alert2 = val;
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_alert_status_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u32 tmp;
+	u8 status[3];
+
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_ALERT_STATUS_REG_ADDR,
+					    ARRAY_SIZE(status), (u8 *)status);
+	if (ret < 0) {
+		dev_err(dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
+			__func__, PAC1944_ALERT_STATUS_REG_ADDR);
+		return ret;
+	}
+	tmp = get_unaligned_be24(&status[0]);
+
+	return sysfs_emit(buf, "%u\n", tmp);
+}
+
+static IIO_DEVICE_ATTR(in_current1_shunt_resistor, 0644,
+		       pac1944_shunt_value_show, pac1944_shunt_value_store, 0);
+static IIO_DEVICE_ATTR(in_oc1_limit_nsamples, 0644,
+		       pac1944_oc_limit_nsamples_show, pac1944_oc_limit_nsamples_store, 0);
+static IIO_DEVICE_ATTR(in_uc1_limit_nsamples, 0644,
+		       pac1944_uc_limit_nsamples_show, pac1944_uc_limit_nsamples_store, 0);
+static IIO_DEVICE_ATTR(in_op1_limit_nsamples, 0644,
+		       pac1944_op_limit_nsamples_show, pac1944_op_limit_nsamples_store, 0);
+static IIO_DEVICE_ATTR(in_ov1_limit_nsamples, 0644,
+		       pac1944_ov_limit_nsamples_show, pac1944_ov_limit_nsamples_store, 0);
+static IIO_DEVICE_ATTR(in_uv1_limit_nsamples, 0644,
+		       pac1944_uv_limit_nsamples_show, pac1944_uv_limit_nsamples_store, 0);
+
+static IIO_DEVICE_ATTR(in_current2_shunt_resistor, 0644,
+		       pac1944_shunt_value_show, pac1944_shunt_value_store, 1);
+static IIO_DEVICE_ATTR(in_oc2_limit_nsamples, 0644,
+		       pac1944_oc_limit_nsamples_show, pac1944_oc_limit_nsamples_store, 1);
+static IIO_DEVICE_ATTR(in_uc2_limit_nsamples, 0644,
+		       pac1944_uc_limit_nsamples_show, pac1944_uc_limit_nsamples_store, 1);
+static IIO_DEVICE_ATTR(in_op2_limit_nsamples, 0644,
+		       pac1944_op_limit_nsamples_show, pac1944_op_limit_nsamples_store, 1);
+static IIO_DEVICE_ATTR(in_ov2_limit_nsamples, 0644,
+		       pac1944_ov_limit_nsamples_show, pac1944_ov_limit_nsamples_store, 1);
+static IIO_DEVICE_ATTR(in_uv2_limit_nsamples, 0644,
+		       pac1944_uv_limit_nsamples_show, pac1944_uv_limit_nsamples_store, 1);
+
+static IIO_DEVICE_ATTR(in_current3_shunt_resistor, 0644,
+		       pac1944_shunt_value_show, pac1944_shunt_value_store, 2);
+static IIO_DEVICE_ATTR(in_oc3_limit_nsamples, 0644,
+		       pac1944_oc_limit_nsamples_show, pac1944_oc_limit_nsamples_store, 2);
+static IIO_DEVICE_ATTR(in_uc3_limit_nsamples, 0644,
+		       pac1944_uc_limit_nsamples_show, pac1944_uc_limit_nsamples_store, 2);
+static IIO_DEVICE_ATTR(in_op3_limit_nsamples, 0644,
+		       pac1944_op_limit_nsamples_show, pac1944_op_limit_nsamples_store, 2);
+static IIO_DEVICE_ATTR(in_ov3_limit_nsamples, 0644,
+		       pac1944_ov_limit_nsamples_show, pac1944_ov_limit_nsamples_store, 2);
+static IIO_DEVICE_ATTR(in_uv3_limit_nsamples, 0644,
+		       pac1944_uv_limit_nsamples_show, pac1944_uv_limit_nsamples_store, 2);
+
+static IIO_DEVICE_ATTR(in_current4_shunt_resistor, 0644,
+		       pac1944_shunt_value_show, pac1944_shunt_value_store, 3);
+static IIO_DEVICE_ATTR(in_oc4_limit_nsamples, 0644,
+		       pac1944_oc_limit_nsamples_show, pac1944_oc_limit_nsamples_store, 3);
+static IIO_DEVICE_ATTR(in_uc4_limit_nsamples, 0644,
+		       pac1944_uc_limit_nsamples_show, pac1944_uc_limit_nsamples_store, 3);
+static IIO_DEVICE_ATTR(in_op4_limit_nsamples, 0644,
+		       pac1944_op_limit_nsamples_show, pac1944_op_limit_nsamples_store, 3);
+static IIO_DEVICE_ATTR(in_ov4_limit_nsamples, 0644,
+		       pac1944_ov_limit_nsamples_show, pac1944_ov_limit_nsamples_store, 3);
+static IIO_DEVICE_ATTR(in_uv4_limit_nsamples, 0644,
+		       pac1944_uv_limit_nsamples_show, pac1944_uv_limit_nsamples_store, 3);
+
+static IIO_DEVICE_ATTR(in_acc_fullness, 0644,
+		       pac1944_acc_fullness_show, pac1944_acc_fullness_store, 0);
+
+static IIO_DEVICE_ATTR(alert_enable, 0644,
+		       pac1944_alert_enable_show, pac1944_alert_enable_store, 0);
+
+static IIO_DEVICE_ATTR(slow_alert1, 0644,
+		       pac1944_slow_alert1_show, pac1944_slow_alert1_store, 0);
+
+static IIO_DEVICE_ATTR(gpio_alert2, 0644,
+		       pac1944_gpio_alert2_show, pac1944_gpio_alert2_store, 0);
+
+static IIO_DEVICE_ATTR(alert_status, 0644,
+		       pac1944_alert_status_show, NULL, 0);
+
+#define PAC1944_DEV_ATTR(name) (&iio_dev_attr_##name.dev_attr.attr)
+
+static struct attribute *pac1944_all_attrs[] = {
+	PAC1944_DEV_ATTR(in_current1_shunt_resistor),
+	PAC1944_DEV_ATTR(in_oc1_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uc1_limit_nsamples),
+	PAC1944_DEV_ATTR(in_op1_limit_nsamples),
+	PAC1944_DEV_ATTR(in_ov1_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uv1_limit_nsamples),
+	PAC1944_DEV_ATTR(in_current2_shunt_resistor),
+	PAC1944_DEV_ATTR(in_oc2_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uc2_limit_nsamples),
+	PAC1944_DEV_ATTR(in_op2_limit_nsamples),
+	PAC1944_DEV_ATTR(in_ov2_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uv2_limit_nsamples),
+	PAC1944_DEV_ATTR(in_current3_shunt_resistor),
+	PAC1944_DEV_ATTR(in_oc3_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uc3_limit_nsamples),
+	PAC1944_DEV_ATTR(in_op3_limit_nsamples),
+	PAC1944_DEV_ATTR(in_ov3_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uv3_limit_nsamples),
+	PAC1944_DEV_ATTR(in_current4_shunt_resistor),
+	PAC1944_DEV_ATTR(in_oc4_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uc4_limit_nsamples),
+	PAC1944_DEV_ATTR(in_op4_limit_nsamples),
+	PAC1944_DEV_ATTR(in_ov4_limit_nsamples),
+	PAC1944_DEV_ATTR(in_uv4_limit_nsamples),
+	PAC1944_DEV_ATTR(in_acc_fullness),
+	PAC1944_DEV_ATTR(alert_enable),
+	PAC1944_DEV_ATTR(slow_alert1),
+	PAC1944_DEV_ATTR(gpio_alert2),
+	PAC1944_DEV_ATTR(alert_status),
+	NULL
+};
+
+static const struct iio_event_spec pac1944_events[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+			BIT(IIO_EV_INFO_ENABLE),
+	},
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+			BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+static const struct iio_event_spec pac1944_single_event[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE) |
+			BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+#define PAC1944_VBUS_CHANNEL(_index, _address, _ev_spec, _num_ev_spec) { \
+	.type = IIO_VOLTAGE,					\
+	.address = (_address),					\
+	.indexed = 1,						\
+	.channel = (_index) + 1,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.event_spec = (_ev_spec),				\
+	.num_event_specs = (_num_ev_spec),			\
+	.ext_info = pac1944_ext_info				\
+}
+
+#define PAC1944_VBUS_AVG_CHANNEL(_index, _address) {	\
+	.type = IIO_VOLTAGE,					\
+	.address = (_address),					\
+	.indexed = 1,						\
+	.channel = (_index) + 1,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_AVERAGE_RAW) |	\
+			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.ext_info = pac1944_ext_info				\
+}
+
+#define PAC1944_VSENSE_CHANNEL(_index, _address, _ev_spec, _num_ev_spec) {\
+	.type = IIO_CURRENT,					\
+	.address = (_address),					\
+	.indexed = 1,						\
+	.channel = (_index) + 1,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.event_spec = (_ev_spec),				\
+	.num_event_specs = (_num_ev_spec),			\
+	.ext_info = pac1944_ext_info				\
+}
+
+#define PAC1944_VSENSE_AVG_CHANNEL(_index, _address) {	\
+	.type = IIO_CURRENT,					\
+	.address = (_address),					\
+	.indexed = 1,						\
+	.channel = (_index) + 1,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_AVERAGE_RAW) |	\
+			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.ext_info = pac1944_ext_info				\
+}
+
+#define PAC1944_VPOWER_CHANNEL(_index, _address, _ev_spec, _num_ev_spec) {\
+	.type = IIO_POWER,					\
+	.address = (_address),					\
+	.indexed = 1,						\
+	.channel = (_index) + 1,				\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.event_spec = (_ev_spec),				\
+	.num_event_specs = (_num_ev_spec),			\
+	.ext_info = pac1944_ext_info				\
+}
+
+static int pac1944_send_refresh(struct pac1944_chip_info *info,
+				u8 refresh_cmd, u32 wait_time)
+{
+	struct i2c_client *client = info->client;
+	int ret;
+
+	/* Writing a REFRESH or a REFRESH_V command */
+	ret = i2c_smbus_write_byte(client, refresh_cmd);
+	if (ret) {
+		dev_err(&client->dev, "%s - cannot send Refresh cmd (0x%02X) to PAC1944\n",
+			__func__, refresh_cmd);
+		return ret;
+	}
+
+	/* Register data retrieval timestamp */
+	info->chip_reg_data.jiffies_tstamp = jiffies;
+	/* Wait till the data is available */
+	usleep_range(wait_time, wait_time + 100);
+
+	return 0;
+}
+
+static int pac1944_reg_snapshot(struct pac1944_chip_info *info,
+				bool do_refresh, u8 refresh_cmd, u32 wait_time)
+{
+	struct i2c_client *client = info->client;
+	u8 shift, idx;
+	u8 *offset_reg_data_p;
+	int cnt, ret;
+	u32 count, inc_count;
+	u32 fs = 0;
+	s64 stored_value, tmp_s64;
+	s64 inc = 0;
+	__be16 tmp_be16;
+	u16 smpl_mode;
+	bool is_unipolar;
+
+	guard(mutex)(&info->lock);
+
+	if (do_refresh) {
+		ret = pac1944_send_refresh(info, refresh_cmd, wait_time);
+		if (ret < 0) {
+			dev_err(&client->dev, "%s - cannot send refresh towards PAC1944\n",
+				__func__);
+			return ret;
+		}
+	}
+
+	/* Read the ctrl/status registers for this snapshot */
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_CTRL_ACT_REG_ADDR,
+					    sizeof(tmp_be16), (u8 *)&tmp_be16);
+	if (ret < 0) {
+		dev_err(&client->dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
+			__func__, PAC1944_CTRL_ACT_REG_ADDR);
+		return ret;
+	}
+
+	info->chip_reg_data.ctrl_act_reg = be16_to_cpu(tmp_be16);
+
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_CTRL_LAT_REG_ADDR,
+					    sizeof(tmp_be16), (u8 *)&tmp_be16);
+	if (ret < 0) {
+		dev_err(&client->dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
+			__func__, PAC1944_CTRL_LAT_REG_ADDR);
+		return ret;
+	}
+
+	info->chip_reg_data.ctrl_lat_reg = be16_to_cpu(tmp_be16);
+
+	/* Read the data registers */
+	ret = pac1944_i2c_read(client, PAC1944_ACC_COUNT_REG_ADDR,
+			       (u8 *)info->chip_reg_data.meas_regs,
+			       PAC1944_MEAS_REG_SNAPSHOT_LEN);
+	if (ret < 0) {
+		dev_err(&client->dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
+			__func__, PAC1944_ACC_COUNT_REG_ADDR);
+		return ret;
+	}
+
+	offset_reg_data_p = &info->chip_reg_data.meas_regs[0];
+
+	info->chip_reg_data.acc_count = get_unaligned_be32(offset_reg_data_p);
+
+	offset_reg_data_p += PAC1944_ACC_REG_LEN;
+
+	/*
+	 * Check if the channel is active(within the data read from
+	 * the chip), skip all fields if disabled
+	 */
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		/* skip if the energy accumulation is disabled */
+		if (!info->enable_acc[cnt]) {
+			offset_reg_data_p += PAC1944_VACC_REG_LEN;
+			continue;
+		}
+
+		stored_value = info->chip_reg_data.acc_val[cnt];
+
+		info->chip_reg_data.vacc[cnt] =
+		pac1944_get_unaligned_be56(offset_reg_data_p);
+		is_unipolar = true;
+
+		switch (info->chip_reg_data.accumulation_mode[cnt]) {
+		case PAC1944_ACCMODE_VPOWER:
+			if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG ||
+			    info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+				is_unipolar = false;
+			break;
+		case PAC1944_ACCMODE_VBUS:
+			if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+				is_unipolar = false;
+			break;
+		case PAC1944_ACCMODE_VSENSE:
+			if (info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+				is_unipolar = false;
+			break;
+		}
+
+		if (!is_unipolar)
+			info->chip_reg_data.vacc[cnt] =
+				sign_extend64(info->chip_reg_data.vacc[cnt], 55);
+
+		if (info->chip_reg_data.accumulation_mode[cnt] != PAC1944_ACCMODE_VBUS) {
+			/*
+			 * Integrate the accumulated power or current over
+			 * the elapsed interval.
+			 */
+			smpl_mode = info->chip_reg_data.ctrl_lat_reg >> 12;
+
+			tmp_s64 = info->chip_reg_data.vacc[cnt];
+			if (smpl_mode < PAC1944_SAMP_FAST_MODE) {
+				/*
+				 * Find how much shift is required by the sample rate
+				 * The chip's sampling rate is 2^shift samples/sec
+				 */
+				shift = shift_map_tbl[smpl_mode];
+				inc = tmp_s64 >> shift;
+			} else if (smpl_mode <= PAC1944_SAMP_BURST_MODE) {
+				idx = info->num_enabled_channels - 1;
+
+				if (smpl_mode == PAC1944_SAMP_FAST_MODE)
+					fs = samp_rate_fast_mode_tbl[idx];
+				else
+					/* smpl_mode == PAC1944_SAMP_BURST_MODE) */
+					fs = samp_rate_burst_mode_tbl[idx];
+
+				inc = div_u64(abs(tmp_s64), fs);
+				if (tmp_s64 < 0)
+					inc = -inc;
+			} else {
+				dev_err(&client->dev, "Invalid sample rate index: %d!\n",
+					smpl_mode);
+				return -EIO;
+			}
+		} else {
+			count = info->chip_reg_data.total_samples_nr[cnt];
+			inc_count = info->chip_reg_data.acc_count;
+
+			/* Check if total number of samples will overflow */
+			if (check_add_overflow(count, inc_count, &count)) {
+				dev_err(&client->dev,
+					"Number of samples on channel [%d] overflow!\n", cnt + 1);
+				info->chip_reg_data.total_samples_nr[cnt] = 0;
+				info->chip_reg_data.acc_val[cnt] = 0;
+			}
+
+			info->chip_reg_data.total_samples_nr[cnt] += inc_count;
+
+			inc = info->chip_reg_data.vacc[cnt];
+		}
+
+		if (check_add_overflow(stored_value, inc, &stored_value)) {
+			if (is_negative(stored_value))
+				info->chip_reg_data.acc_val[cnt] = S64_MIN;
+			else
+				info->chip_reg_data.acc_val[cnt] = S64_MAX;
+
+			dev_err(&client->dev, "Overflow detected on channel [%d]!\n",
+				cnt + 1);
+		} else {
+			info->chip_reg_data.acc_val[cnt] += inc;
+		}
+
+		offset_reg_data_p += PAC1944_VACC_REG_LEN;
+	}
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		info->chip_reg_data.vbus[cnt] = get_unaligned_be16(offset_reg_data_p);
+
+		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+			info->chip_reg_data.vbus[cnt] =
+			sign_extend32(info->chip_reg_data.vbus[cnt], 15);
+
+		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
+	}
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		info->chip_reg_data.vsense[cnt] = get_unaligned_be16(offset_reg_data_p);
+
+		if (info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+			info->chip_reg_data.vsense[cnt] =
+			sign_extend32(info->chip_reg_data.vsense[cnt], 15);
+
+		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
+	}
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		info->chip_reg_data.vbus_avg[cnt] = get_unaligned_be16(offset_reg_data_p);
+
+		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+			info->chip_reg_data.vbus_avg[cnt] =
+			sign_extend32(info->chip_reg_data.vbus_avg[cnt], 15);
+
+		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
+	}
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		info->chip_reg_data.vsense_avg[cnt] = get_unaligned_be16(offset_reg_data_p);
+
+		if (info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+			info->chip_reg_data.vsense_avg[cnt] =
+			sign_extend32(info->chip_reg_data.vsense_avg[cnt], 15);
+
+		offset_reg_data_p += PAC1944_VBUS_SENSE_REG_LEN;
+	}
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		info->chip_reg_data.vpower[cnt] = get_unaligned_be32(offset_reg_data_p) >> 2;
+
+		if (info->chip_reg_data.vbus_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG ||
+		    info->chip_reg_data.vsense_mode[cnt] != PAC1944_UNIPOLAR_FSR_CFG)
+			info->chip_reg_data.vpower[cnt] =
+			sign_extend32(info->chip_reg_data.vpower[cnt], 29);
+
+		offset_reg_data_p += PAC1944_VPOWER_REG_LEN;
+	}
+
+	return 0;
+}
+
+static int pac1944_retrieve_data(struct pac1944_chip_info *info, u32 wait_time)
+{
+	int ret;
+
+	/*
+	 * Check if the minimal elapsed time has passed and if so,
+	 * re-read the chip, otherwise the cached info is just fine
+	 */
+	if (time_after(jiffies, info->chip_reg_data.jiffies_tstamp +
+		       msecs_to_jiffies(PAC1944_MIN_POLLING_TIME_MS))) {
+		/*
+		 * We need to re-read the chip values
+		 * call the pac1944_reg_snapshot
+		 */
+		ret = pac1944_reg_snapshot(info, true,
+					   PAC1944_REFRESH_REG_ADDR,
+					   wait_time);
+		/*
+		 * Re-schedule the work for the read registers timeout
+		 * (to prevent chip regs saturation)
+		 */
+		cancel_delayed_work_sync(&info->work_chip_rfsh);
+		schedule_delayed_work(&info->work_chip_rfsh,
+				      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
+	}
+
+	return ret;
+}
+
+static ssize_t pac1944_in_power_acc_raw_show(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret;
+	s64 curr_energy, int_part;
+	int rem;
+
+	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return 0;
+
+	/*
+	 * Expresses the 64 bit energy value as a
+	 * 64 bit integer and a 32 bit nano value
+	 */
+	curr_energy = info->chip_reg_data.acc_val[this_attr->address];
+	int_part = div_s64_rem(curr_energy, 1000000000, &rem);
+
+	if (rem < 0)
+		return sysfs_emit(buf, "-%lld.%09u\n", abs(int_part),
+				  -rem);
+	else
+		return sysfs_emit(buf, "%lld.%09u\n", int_part, abs(rem));
+}
+
+static ssize_t pac1944_in_power_acc_scale_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	unsigned int shunt, rem;
+	u64 tmp, ref;
+
+	if (info->is_pac195x_family)
+		ref = (u64)PAC195X_MAX_VPOWER_RSHIFTED_BY_29B;
+	else
+		ref = (u64)PAC194X_MAX_VPOWER_RSHIFTED_BY_29B;
+
+	if ((info->chip_reg_data.vbus_mode[this_attr->address] == PAC1944_UNIPOLAR_FSR_CFG &&
+	     info->chip_reg_data.vsense_mode[this_attr->address] == PAC1944_UNIPOLAR_FSR_CFG) ||
+	    info->chip_reg_data.vbus_mode[this_attr->address] == PAC1944_BIPOLAR_HALF_FSR_CFG ||
+	    info->chip_reg_data.vsense_mode[this_attr->address] == PAC1944_BIPOLAR_HALF_FSR_CFG)
+		ref = ref >> 1;
+
+	shunt = info->shunts[this_attr->address];
+
+	tmp = div_u64(ref * 1000000000LL, shunt);
+	rem = do_div(tmp, 1000000000LL);
+
+	return sysfs_emit(buf, "%lld.%09u\n", tmp, rem);
+}
+
+static ssize_t pac1944_in_enable_acc_show(struct device *dev,
+					  struct device_attribute *attr,
+					  char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+
+	return sysfs_emit(buf, "%d\n", info->enable_acc[this_attr->address]);
+}
+
+static ssize_t pac1944_in_enable_acc_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int val;
+
+	if (kstrtouint(buf, 10, &val)) {
+		dev_err(dev, "Value is not valid\n");
+		return -EINVAL;
+	}
+
+	scoped_guard(mutex, &info->lock) {
+		info->enable_acc[this_attr->address] = val ? true : false;
+		if (!val) {
+			info->chip_reg_data.acc_val[this_attr->address] = 0;
+			info->chip_reg_data.total_samples_nr[this_attr->address] = 0;
+		}
+	}
+
+	return count;
+}
+
+static ssize_t pac1944_in_current_acc_raw_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret;
+
+	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return 0;
+
+	return sysfs_emit(buf, "%lld\n", info->chip_reg_data.acc_val[this_attr->address]);
+}
+
+static ssize_t pac1944_in_current_acc_scale_show(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int shunt, rem;
+	u64 tmp_u64, ref;
+
+	/*
+	 * Currents - scale for mA - depends on the channel's shunt value
+	 * (100mV * 1000000) / (2^16 * shunt(uOhm))
+	 */
+	ref = (u64)PAC1944_MAX_VSENSE_NANO;
+
+	switch (info->chip_reg_data.vsense_mode[this_attr->address]) {
+	case PAC1944_UNIPOLAR_FSR_CFG:
+	case PAC1944_BIPOLAR_HALF_FSR_CFG:
+		shunt = info->shunts[this_attr->address];
+		break;
+	case PAC1944_BIPOLAR_FSR_CFG:
+		ref = ref << 1;
+		shunt = info->shunts[this_attr->address];
+		break;
+	default:
+		return 0;
+	}
+
+	/*
+	 * Increasing precision
+	 * (100mV * 1000000 * 1000000000) / 2^16 )
+	 */
+	tmp_u64 = div_u64(ref, shunt);
+	rem = do_div(tmp_u64, 1000000000LL);
+
+	return sysfs_emit(buf, "%lld.%09u\n", tmp_u64, rem);
+}
+
+static ssize_t pac1944_in_voltage_acc_raw_show(struct device *dev,
+					       struct device_attribute *attr,
+					       char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int ret;
+	s64 acc_voltage;
+	u32 samples_count;
+	u64 tmp_u64;
+
+	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return 0;
+
+	acc_voltage = info->chip_reg_data.acc_val[this_attr->address];
+	samples_count = info->chip_reg_data.total_samples_nr[this_attr->address];
+
+	tmp_u64 = div_u64(abs(acc_voltage), samples_count);
+
+	if (is_negative(acc_voltage))
+		return sysfs_emit(buf, "-%lld\n", tmp_u64);
+	else
+		return sysfs_emit(buf, "%lld\n", tmp_u64);
+}
+
+static ssize_t pac1944_in_voltage_acc_scale_show(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	int vals[2];
+	unsigned long long tmp;
+
+	if (info->is_pac195x_family)
+		vals[0] = PAC195X_VOLTAGE_MILLIVOLTS_MAX;
+	else
+		vals[0] = PAC194X_VOLTAGE_MILLIVOLTS_MAX;
+
+	if (info->chip_reg_data.vbus_mode[this_attr->address] != PAC1944_BIPOLAR_FSR_CFG)
+		/* PAC1944_UNIPOLAR_FSR_CFG or PAC1944_BIPOLAR_HALF_FSR_CFG */
+		vals[1] = PAC1944_VOLTAGE_16B_RES;
+	else
+		vals[1] = PAC1944_VOLTAGE_15B_RES;
+
+	tmp = (s64)vals[0] * 1000000000LL >> vals[1];
+	vals[1] = do_div(tmp, 1000000000LL);
+	vals[0] = tmp;
+
+	return sysfs_emit(buf, "%d.%09u\n", vals[0], vals[1]);
+}
+
+static IIO_DEVICE_ATTR(in_energy1_raw, 0444,
+		       pac1944_in_power_acc_raw_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_energy2_raw, 0444,
+		       pac1944_in_power_acc_raw_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_energy3_raw, 0444,
+		       pac1944_in_power_acc_raw_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_energy4_raw, 0444,
+		       pac1944_in_power_acc_raw_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_energy1_scale, 0444,
+		       pac1944_in_power_acc_scale_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_energy2_scale, 0444,
+		       pac1944_in_power_acc_scale_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_energy3_scale, 0444,
+		       pac1944_in_power_acc_scale_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_energy4_scale, 0444,
+		       pac1944_in_power_acc_scale_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_energy1_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 0);
+static IIO_DEVICE_ATTR(in_energy2_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 1);
+static IIO_DEVICE_ATTR(in_energy3_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 2);
+static IIO_DEVICE_ATTR(in_energy4_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 3);
+
+static IIO_DEVICE_ATTR(in_current_acc1_raw, 0444,
+		       pac1944_in_current_acc_raw_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_current_acc2_raw, 0444,
+		       pac1944_in_current_acc_raw_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_current_acc3_raw, 0444,
+		       pac1944_in_current_acc_raw_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_current_acc4_raw, 0444,
+		       pac1944_in_current_acc_raw_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_current_acc1_scale, 0444,
+		       pac1944_in_current_acc_scale_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_current_acc2_scale, 0444,
+		       pac1944_in_current_acc_scale_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_current_acc3_scale, 0444,
+		       pac1944_in_current_acc_scale_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_current_acc4_scale, 0444,
+		       pac1944_in_current_acc_scale_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_current_acc1_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 0);
+static IIO_DEVICE_ATTR(in_current_acc2_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 1);
+static IIO_DEVICE_ATTR(in_current_acc3_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 2);
+static IIO_DEVICE_ATTR(in_current_acc4_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 3);
+
+static IIO_DEVICE_ATTR(in_voltage_acc1_raw, 0444,
+		       pac1944_in_voltage_acc_raw_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_voltage_acc2_raw, 0444,
+		      pac1944_in_voltage_acc_raw_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_voltage_acc3_raw, 0444,
+		      pac1944_in_voltage_acc_raw_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_voltage_acc4_raw, 0444,
+		      pac1944_in_voltage_acc_raw_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_voltage_acc1_scale, 0444,
+		      pac1944_in_voltage_acc_scale_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_voltage_acc2_scale, 0444,
+		      pac1944_in_voltage_acc_scale_show, NULL, 1);
+static IIO_DEVICE_ATTR(in_voltage_acc3_scale, 0444,
+		      pac1944_in_voltage_acc_scale_show, NULL, 2);
+static IIO_DEVICE_ATTR(in_voltage_acc4_scale, 0444,
+		      pac1944_in_voltage_acc_scale_show, NULL, 3);
+
+static IIO_DEVICE_ATTR(in_voltage_acc1_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 0);
+static IIO_DEVICE_ATTR(in_voltage_acc2_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 1);
+static IIO_DEVICE_ATTR(in_voltage_acc3_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 2);
+static IIO_DEVICE_ATTR(in_voltage_acc4_en, 0644,
+		       pac1944_in_enable_acc_show, pac1944_in_enable_acc_store, 3);
+
+static struct attribute *pac1944_power_acc_attr[] = {
+	PAC1944_DEV_ATTR(in_energy1_raw),
+	PAC1944_DEV_ATTR(in_energy2_raw),
+	PAC1944_DEV_ATTR(in_energy3_raw),
+	PAC1944_DEV_ATTR(in_energy4_raw),
+	PAC1944_DEV_ATTR(in_energy1_scale),
+	PAC1944_DEV_ATTR(in_energy2_scale),
+	PAC1944_DEV_ATTR(in_energy3_scale),
+	PAC1944_DEV_ATTR(in_energy4_scale),
+	PAC1944_DEV_ATTR(in_energy1_en),
+	PAC1944_DEV_ATTR(in_energy2_en),
+	PAC1944_DEV_ATTR(in_energy3_en),
+	PAC1944_DEV_ATTR(in_energy4_en),
+	NULL
+};
+
+static struct attribute *pac1944_current_acc_attr[] = {
+	PAC1944_DEV_ATTR(in_current_acc1_raw),
+	PAC1944_DEV_ATTR(in_current_acc2_raw),
+	PAC1944_DEV_ATTR(in_current_acc3_raw),
+	PAC1944_DEV_ATTR(in_current_acc4_raw),
+	PAC1944_DEV_ATTR(in_current_acc1_scale),
+	PAC1944_DEV_ATTR(in_current_acc2_scale),
+	PAC1944_DEV_ATTR(in_current_acc3_scale),
+	PAC1944_DEV_ATTR(in_current_acc4_scale),
+	PAC1944_DEV_ATTR(in_current_acc1_en),
+	PAC1944_DEV_ATTR(in_current_acc2_en),
+	PAC1944_DEV_ATTR(in_current_acc3_en),
+	PAC1944_DEV_ATTR(in_current_acc4_en),
+	NULL
+};
+
+static struct attribute *pac1944_voltage_acc_attr[] = {
+	PAC1944_DEV_ATTR(in_voltage_acc1_raw),
+	PAC1944_DEV_ATTR(in_voltage_acc2_raw),
+	PAC1944_DEV_ATTR(in_voltage_acc3_raw),
+	PAC1944_DEV_ATTR(in_voltage_acc4_raw),
+	PAC1944_DEV_ATTR(in_voltage_acc1_scale),
+	PAC1944_DEV_ATTR(in_voltage_acc2_scale),
+	PAC1944_DEV_ATTR(in_voltage_acc3_scale),
+	PAC1944_DEV_ATTR(in_voltage_acc4_scale),
+	PAC1944_DEV_ATTR(in_voltage_acc1_en),
+	PAC1944_DEV_ATTR(in_voltage_acc2_en),
+	PAC1944_DEV_ATTR(in_voltage_acc3_en),
+	PAC1944_DEV_ATTR(in_voltage_acc4_en),
+	NULL
+};
+
+static int pac1944_prep_custom_attributes(struct pac1944_chip_info *info,
+					  struct iio_dev *indio_dev)
+{
+	int ch, i, j;
+	int active_channels_count = 0;
+	struct attribute **pac1944_custom_attrs, **tmp_attr;
+	struct attribute_group *pac1944_group;
+	int custom_attr_cnt;
+	struct i2c_client *client = info->client;
+
+	active_channels_count = info->num_enabled_channels;
+
+	pac1944_group = devm_kzalloc(&client->dev, sizeof(*pac1944_group), GFP_KERNEL);
+	if (!pac1944_group)
+		return -ENOMEM;
+
+	/*
+	 * Attributes for channel X:
+	 *	- in_shunt_value_X
+	 *	- in_oc_limit_nsamples
+	 *	- in_uc_limit_nsamples
+	 *	- in_op_limit_nsamples
+	 *	- in_ov_limit_nsamples
+	 *	- in_uv_limit_nsamples
+	 *	- one of pair attributes:
+	 *		- in_power_accX_raw and in_power_accX_scale
+	 *		- in_current_accX_raw and in_current_accX_scale
+	 *		- in_voltage_accX_raw and in_voltage_accX_scale
+	 * Shared attributes:
+	 *	- in_acc_fullness
+	 *	- alert_enable
+	 *	- slow_alert1
+	 *	- gpio_alert2
+	 *	- alert_status
+	 * NULL
+	 */
+	custom_attr_cnt = PAC1944_COMMON_DEVATTR * active_channels_count;
+	custom_attr_cnt += PAC1944_ACC_DEVATTR * active_channels_count;
+	custom_attr_cnt += PAC1944_SHARED_DEVATTRS_COUNT;
+
+	pac1944_custom_attrs = devm_kzalloc(&client->dev, custom_attr_cnt *
+					    sizeof(*pac1944_group) + 1, GFP_KERNEL);
+	if (!pac1944_custom_attrs)
+		return -ENOMEM;
+
+	j = 0;
+
+	for_each_set_bit(ch, &info->active_channels_mask, info->phys_channels) {
+		for (i = 0; i < PAC1944_COMMON_DEVATTR; i++)
+			pac1944_custom_attrs[j++] =
+				pac1944_all_attrs[PAC1944_COMMON_DEVATTR * ch + i];
+
+		switch (info->chip_reg_data.accumulation_mode[ch]) {
+		case PAC1944_ACCMODE_VPOWER:
+			tmp_attr = pac1944_power_acc_attr;
+			break;
+		case PAC1944_ACCMODE_VSENSE:
+			tmp_attr = pac1944_current_acc_attr;
+			break;
+		case PAC1944_ACCMODE_VBUS:
+			tmp_attr = pac1944_voltage_acc_attr;
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		pac1944_custom_attrs[j++] = tmp_attr[ch];
+		pac1944_custom_attrs[j++] = pac1944_power_acc_attr[PAC1944_MAX_CH + ch];
+		pac1944_custom_attrs[j++] = pac1944_power_acc_attr[2 * PAC1944_MAX_CH + ch];
+	}
+
+	for (i = 0; i < PAC1944_SHARED_DEVATTRS_COUNT; i++)
+		pac1944_custom_attrs[j++] =
+			pac1944_all_attrs[PAC1944_COMMON_DEVATTR * PAC1944_MAX_CH + i];
+
+	pac1944_group->attrs = pac1944_custom_attrs;
+	info->iio_info.attrs = pac1944_group;
+
+	return 0;
+}
+
+static int pac1944_frequency_set(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan,
+				 unsigned int mode)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int ret;
+	u16 tmp_u16;
+	__be16 tmp_be16;
+
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_CTRL_ACT_REG_ADDR,
+					    sizeof(tmp_u16), (u8 *)&tmp_be16);
+	if (ret < 0) {
+		dev_err(&indio_dev->dev, "%s - cannot read PAC1944 regs from 0x%02X\n",
+			__func__, PAC1944_CTRL_ACT_REG_ADDR);
+		return ret;
+	}
+
+	tmp_u16 = be16_to_cpu(tmp_be16);
+	tmp_u16 &= ~PAC1944_CTRL_SAMPLE_MASK;
+	tmp_u16 |= FIELD_PREP(PAC1944_CTRL_SAMPLE_MASK, mode);
+	tmp_be16 = cpu_to_be16(tmp_u16);
+
+	scoped_guard(mutex, &info->lock) {
+		ret = i2c_smbus_write_word_data(client, PAC1944_CTRL_REG_ADDR, tmp_be16);
+		if (ret < 0) {
+			dev_err(&indio_dev->dev, "Failed to configure sampling mode\n");
+			return ret;
+		}
+
+		info->sampling_mode = mode;
+		info->chip_reg_data.ctrl_act_reg = tmp_u16;
+	}
+
+	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return ret;
+
+	return 0;
+}
+
+static int pac1944_frequency_get(struct iio_dev *indio_dev,
+				 const struct iio_chan_spec *chan)
+{
+	struct pac1944_chip_info *info;
+
+	info = iio_priv(indio_dev);
+
+	return info->sampling_mode;
+}
+
+static const struct iio_enum sampling_mode_enum = {
+	.items = pac1944_frequency_avail,
+	.num_items = ARRAY_SIZE(pac1944_frequency_avail),
+	.set = pac1944_frequency_set,
+	.get = pac1944_frequency_get,
+};
+
+static const struct iio_chan_spec_ext_info pac1944_ext_info[] = {
+	IIO_ENUM("sampling_frequency", IIO_SHARED_BY_ALL, &sampling_mode_enum),
+	{
+		.name = "sampling_frequency_available",
+		.shared = IIO_SHARED_BY_ALL,
+		.read = iio_enum_available_read,
+		.private = (uintptr_t)&sampling_mode_enum,
+	},
+	{}
+};
+
+static int pac1944_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
+			    int *val, int *val2, long mask)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	int ret, idx;
+	u64 tmp;
+
+	ret = pac1944_retrieve_data(info, PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return ret;
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	/*
+	 * For AVG the index should be between 5 to 8. To calculate
+	 * PAC1944_CH_VOLTAGE_AVERAGE and PAC1944_CH_CURRENT_AVERAGE real index,
+	 * we need to remove the added offset (PAC1944_MAX_CH).
+	 */
+	if (idx >= PAC1944_MAX_CH)
+		idx = idx - PAC1944_MAX_CH;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*val = info->chip_reg_data.vbus[idx];
+			return IIO_VAL_INT;
+		case IIO_CURRENT:
+			*val = info->chip_reg_data.vsense[idx];
+			return IIO_VAL_INT;
+		case IIO_POWER:
+			*val = info->chip_reg_data.vpower[idx];
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_AVERAGE_RAW:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*val = info->chip_reg_data.vbus_avg[idx];
+			return IIO_VAL_INT;
+		case IIO_CURRENT:
+			*val = info->chip_reg_data.vsense_avg[idx];
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->address) {
+		case PAC1944_VBUS_1_ADDR:
+		case PAC1944_VBUS_2_ADDR:
+		case PAC1944_VBUS_3_ADDR:
+		case PAC1944_VBUS_4_ADDR:
+		case PAC1944_VBUS_AVG_1_ADDR:
+		case PAC1944_VBUS_AVG_2_ADDR:
+		case PAC1944_VBUS_AVG_3_ADDR:
+		case PAC1944_VBUS_AVG_4_ADDR:
+			if (info->is_pac195x_family)
+				*val = PAC195X_VOLTAGE_MILLIVOLTS_MAX;
+			else
+				*val = PAC194X_VOLTAGE_MILLIVOLTS_MAX;
+
+			switch (info->chip_reg_data.vbus_mode[idx]) {
+			case PAC1944_UNIPOLAR_FSR_CFG:
+			case PAC1944_BIPOLAR_HALF_FSR_CFG:
+				*val2 = PAC1944_VOLTAGE_16B_RES;
+				break;
+			case PAC1944_BIPOLAR_FSR_CFG:
+				*val2 = PAC1944_VOLTAGE_15B_RES;
+				break;
+			default:
+				return -EINVAL;
+			}
+			return IIO_VAL_FRACTIONAL_LOG2;
+		/*
+		 * Currents - scale for mA - depends on the
+		 * channel's shunt value
+		 * (100mV * 1000000) / (2^16 * shunt(microOhm))
+		 */
+		case PAC1944_VSENSE_1_ADDR:
+		case PAC1944_VSENSE_2_ADDR:
+		case PAC1944_VSENSE_3_ADDR:
+		case PAC1944_VSENSE_4_ADDR:
+		case PAC1944_VSENSE_AVG_1_ADDR:
+		case PAC1944_VSENSE_AVG_2_ADDR:
+		case PAC1944_VSENSE_AVG_3_ADDR:
+		case PAC1944_VSENSE_AVG_4_ADDR:
+			*val = PAC1944_MAX_VSENSE_RSHIFTED_BY_15B;
+			switch (info->chip_reg_data.vsense_mode[idx]) {
+			case PAC1944_UNIPOLAR_FSR_CFG:
+			case PAC1944_BIPOLAR_HALF_FSR_CFG:
+				*val = *val >> 1;
+				*val2 = info->shunts[idx];
+				break;
+			case PAC1944_BIPOLAR_FSR_CFG:
+				*val2 = info->shunts[idx];
+				break;
+			default:
+				return -EINVAL;
+			}
+			return IIO_VAL_FRACTIONAL;
+		/*
+		 * Power - mW - it will use the combined scale
+		 * for current and voltage
+		 * current(mA) * voltage(mV) = power (uW)
+		 */
+		case PAC1944_VPOWER_1_ADDR:
+		case PAC1944_VPOWER_2_ADDR:
+		case PAC1944_VPOWER_3_ADDR:
+		case PAC1944_VPOWER_4_ADDR:
+			if (info->is_pac195x_family)
+				tmp = PAC195X_PRODUCT_VOLTAGE_PV_FSR;
+			else
+				tmp = PAC194X_PRODUCT_VOLTAGE_PV_FSR;
+
+			do_div(tmp, info->shunts[idx]);
+			*val = (int)tmp;
+			if ((info->chip_reg_data.vbus_mode[idx] == PAC1944_UNIPOLAR_FSR_CFG &&
+			     info->chip_reg_data.vsense_mode[idx] == PAC1944_UNIPOLAR_FSR_CFG) ||
+			    info->chip_reg_data.vbus_mode[idx] == PAC1944_BIPOLAR_HALF_FSR_CFG ||
+			    info->chip_reg_data.vsense_mode[idx] == PAC1944_BIPOLAR_HALF_FSR_CFG)
+				*val2 = PAC1944_POWER_30B_RES;
+			else
+				*val2 = PAC1944_POWER_29B_RES;
+
+			return IIO_VAL_FRACTIONAL_LOG2;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int pac1944_read_label(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan, char *label)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	int idx;
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	/*
+	 * For AVG the index should be between 5 to 8.
+	 * To calculate PAC1944_CH_VOLTAGE_AVERAGE and
+	 * PAC1944_CH_CURRENT_AVERAGE real index, we need
+	 * to remove the added offset (PAC1944_MAX_CH).
+	 */
+	if (idx >= PAC1944_MAX_CH)
+		idx = idx - PAC1944_MAX_CH;
+
+	switch (chan->address) {
+	case PAC1944_VBUS_1_ADDR:
+	case PAC1944_VBUS_2_ADDR:
+	case PAC1944_VBUS_3_ADDR:
+	case PAC1944_VBUS_4_ADDR:
+		if (info->labels[idx])
+			return sysfs_emit(label, "%s_VBUS_%d\n", info->labels[idx], idx + 1);
+		else
+			return sysfs_emit(label, "VBUS_%d\n", idx + 1);
+	case PAC1944_VBUS_AVG_1_ADDR:
+	case PAC1944_VBUS_AVG_2_ADDR:
+	case PAC1944_VBUS_AVG_3_ADDR:
+	case PAC1944_VBUS_AVG_4_ADDR:
+		if (info->labels[idx])
+			return sysfs_emit(label, "%s_VBUS_AVG_%d\n", info->labels[idx], idx + 1);
+		else
+			return sysfs_emit(label, "VBUS_AVG_%d\n", idx + 1);
+	case PAC1944_VSENSE_1_ADDR:
+	case PAC1944_VSENSE_2_ADDR:
+	case PAC1944_VSENSE_3_ADDR:
+	case PAC1944_VSENSE_4_ADDR:
+		if (info->labels[idx])
+			return sysfs_emit(label, "%s_IBUS_%d\n", info->labels[idx], idx + 1);
+		else
+			return sysfs_emit(label, "IBUS_%d\n", idx + 1);
+	case PAC1944_VSENSE_AVG_1_ADDR:
+	case PAC1944_VSENSE_AVG_2_ADDR:
+	case PAC1944_VSENSE_AVG_3_ADDR:
+	case PAC1944_VSENSE_AVG_4_ADDR:
+		if (info->labels[idx])
+			return sysfs_emit(label, "%s_IBUS_AVG_%d\n", info->labels[idx], idx + 1);
+		else
+			return sysfs_emit(label, "IBUS_AVG_%d\n", idx + 1);
+	case PAC1944_VPOWER_1_ADDR:
+	case PAC1944_VPOWER_2_ADDR:
+	case PAC1944_VPOWER_3_ADDR:
+	case PAC1944_VPOWER_4_ADDR:
+		if (info->labels[idx])
+			return sysfs_emit(label, "%s_POWER_%d\n", info->labels[idx], idx + 1);
+		else
+			return sysfs_emit(label, "POWER_%d\n", idx + 1);
+	}
+
+	return 0;
+}
+
+static int pac1944_read_thresh(struct iio_dev *indio_dev,
+			       const struct iio_chan_spec *chan, enum iio_event_type type,
+			       enum iio_event_direction dir, enum iio_event_info info,
+			       int *val, int *val2)
+{
+	struct pac1944_chip_info *chip_info = iio_priv(indio_dev);
+	int idx;
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	scoped_guard(mutex, &chip_info->lock) {
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				*val = chip_info->overvoltage[idx];
+				return IIO_VAL_INT;
+			case IIO_EV_DIR_FALLING:
+				*val = chip_info->undervoltage[idx];
+				return IIO_VAL_INT;
+			default:
+				return -EINVAL;
+			}
+		case IIO_CURRENT:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				*val = chip_info->overcurrent[idx];
+				return IIO_VAL_INT;
+			case IIO_EV_DIR_FALLING:
+				*val = chip_info->undercurrent[idx];
+				return IIO_VAL_INT;
+			default:
+				return -EINVAL;
+			}
+		case IIO_POWER:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				*val = chip_info->overpower[idx];
+				return IIO_VAL_INT;
+			default:
+				return -EINVAL;
+			}
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return -EINVAL;
+}
+
+static int pac1944_write_thresh(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan, enum iio_event_type type,
+				enum iio_event_direction dir, enum iio_event_info info,
+				int val, int val2)
+{
+	struct pac1944_chip_info *chip_info = iio_priv(indio_dev);
+	int idx, ret;
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	scoped_guard(mutex, &chip_info->lock) {
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				ret = pac1944_update_alert_16b(&indio_dev->dev,
+							       PAC1944_OV_LIMIT_REG_ADDR + idx,
+							       pac1944_overvoltage_mask_tbl[idx],
+							       val);
+				if (!ret)
+					chip_info->overvoltage[idx] = val;
+			return ret;
+			case IIO_EV_DIR_FALLING:
+				ret = pac1944_update_alert_16b(&indio_dev->dev,
+							       PAC1944_UV_LIMIT_REG_ADDR + idx,
+							       pac1944_undervoltage_mask_tbl[idx],
+							       val);
+				if (!ret)
+					chip_info->undervoltage[idx] = val;
+				return ret;
+			default:
+				return -EINVAL;
+			}
+		case IIO_CURRENT:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				ret = pac1944_update_alert_16b(&indio_dev->dev,
+							       PAC1944_OC_LIMIT_REG_ADDR + idx,
+							       pac1944_overcurrent_mask_tbl[idx],
+							       val);
+				if (!ret)
+					chip_info->overcurrent[idx] = val;
+				return ret;
+			case IIO_EV_DIR_FALLING:
+				ret = pac1944_update_alert_16b(&indio_dev->dev,
+							       PAC1944_UC_LIMIT_REG_ADDR + idx,
+							       pac1944_undercurrent_mask_tbl[idx],
+							       val);
+				if (!ret)
+					chip_info->undercurrent[idx] = val;
+				return ret;
+			default:
+				return -EINVAL;
+			}
+		case IIO_POWER:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				ret = pac1944_update_alert_24b(&indio_dev->dev,
+							       PAC1944_OP_LIMIT_REG_ADDR + idx,
+							       pac1944_overpower_mask_tbl[idx],
+							       val);
+				if (!ret)
+					chip_info->overpower[idx] = val;
+				return ret;
+			default:
+				return -EINVAL;
+			}
+		default:
+			return -EINVAL;
+		}
+	}
+	unreachable();
+}
+
+static int pac1944_read_event_config(struct iio_dev *indio_dev,
+				     const struct iio_chan_spec *chan,
+				     enum iio_event_type type,
+				     enum iio_event_direction dir)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	int idx;
+	u32 tmp;
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	scoped_guard(mutex, &info->lock) {
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				tmp = FIELD_GET(PAC1944_OV_MASK, info->alert_enable);
+				break;
+			case IIO_EV_DIR_FALLING:
+				tmp = FIELD_GET(PAC1944_UV_MASK, info->alert_enable);
+				break;
+			default:
+				return -EINVAL;
+			}
+			return -EINVAL;
+		case IIO_CURRENT:
+			switch (dir) {
+			case IIO_EV_DIR_RISING:
+				tmp = FIELD_GET(PAC1944_OC_MASK, info->alert_enable);
+				break;
+			case IIO_EV_DIR_FALLING:
+				tmp = FIELD_GET(PAC1944_UC_MASK, info->alert_enable);
+				break;
+			default:
+				return -EINVAL;
+			}
+			return -EINVAL;
+		case IIO_POWER:
+			if (dir == IIO_EV_DIR_RISING)
+				tmp = FIELD_GET(PAC1944_OP_MASK, info->alert_enable);
+			else
+				return -EINVAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	tmp = tmp >> (3 - idx);
+
+	return tmp & 0x01;
+}
+
+static int pac1944_write_event_config(struct iio_dev *indio_dev,
+				      const struct iio_chan_spec *chan,
+				      enum iio_event_type type,
+				      enum iio_event_direction dir,
+				      bool state)
+{
+	struct pac1944_chip_info *info = iio_priv(indio_dev);
+	struct i2c_client *client = info->client;
+	int idx, val, mask, ret;
+	bool update = false;
+	u8 tmp[PAC1944_ALERT_ENABLE_REG_LEN];
+
+	/* into the datasheet channels are noted from 1 to 4 */
+	idx = chan->channel - 1;
+
+	switch (chan->type) {
+	case IIO_VOLTAGE:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			mask = pac1944_overvoltage_mask_tbl[idx];
+			break;
+		case IIO_EV_DIR_FALLING:
+			mask = pac1944_undervoltage_mask_tbl[idx];
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_CURRENT:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			mask = pac1944_overcurrent_mask_tbl[idx];
+			break;
+		case IIO_EV_DIR_FALLING:
+			mask = pac1944_undercurrent_mask_tbl[idx];
+			break;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_POWER:
+		if (dir == IIO_EV_DIR_RISING)
+			mask = pac1944_overpower_mask_tbl[idx];
+		else
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	guard(mutex)(&info->lock);
+
+	val = info->alert_enable & mask;
+	if (state && !val) {
+		/* enable the event in hardware */
+		info->alert_enable |= mask;
+		update = true;
+	} else if (!state && val) {
+		/* disable the event in hardware */
+		info->alert_enable &= ~mask;
+		update = true;
+	}
+
+	/* do not update if not needed */
+	if (update) {
+		put_unaligned_be24(info->alert_enable, &tmp[0]);
+
+		/* update the Alert enable register */
+		ret = pac1944_restore_alert_reg(indio_dev, &tmp[0]);
+		if (ret) {
+			dev_err(&client->dev, "failing to write %s\n", __func__);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void pac1944_work_periodic_rfsh(struct work_struct *work)
+{
+	struct pac1944_chip_info *info = TO_PAC1944_CHIP_INFO((struct delayed_work *)work);
+	struct i2c_client *client = info->client;
+
+	dev_dbg(&client->dev, "%s - Periodic refresh\n", __func__);
+
+	pac1944_reg_snapshot(info, true, PAC1944_REFRESH_REG_ADDR,
+			     PAC1944_MIN_UPDATE_WAIT_TIME_US);
+
+	schedule_delayed_work(&info->work_chip_rfsh,
+			      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
+}
+
+/*
+ * documentation related to the ACPI device definition
+ * https://ww1.microchip.com/downloads/aemDocuments/documents/MSLD/ProductDocuments/UserGuides/PAC194X_5X-UEFI-BIOS-Integration-and-Microsoft-Windows-10-and-Windows-11-Energy-Meter-Interface-Device-Driver-Users-Guide-DS50003155.pdf
+ */
+static int pac1944_acpi_parse_channel_config(struct i2c_client *client,
+					     struct pac1944_chip_info *info)
+{
+	acpi_handle handle;
+	union acpi_object *rez;
+	struct device *dev = &client->dev;
+	unsigned short bi_dir_mask;
+	int i;
+	guid_t guid;
+	const struct acpi_device_id *id;
+
+	handle = ACPI_HANDLE(dev);
+
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -ENODEV;
+
+	guid_parse(PAC1944_DSM_UUID, &guid);
+
+	rez = acpi_evaluate_dsm(handle, &guid, 0, PAC1944_ACPI_GET_NAMES, NULL);
+	if (!rez)
+		return -EINVAL;
+
+	for (i = 0; i < rez->package.count; i++) {
+		info->labels[i] = devm_kmemdup(dev, rez->package.elements[i].string.pointer,
+					       (size_t)rez->package.elements[i].string.length + 1,
+					       GFP_KERNEL);
+		info->labels[i][rez->package.elements[i].string.length] = '\0';
+	}
+
+	ACPI_FREE(rez);
+
+	rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1944_ACPI_GET_UOHMS_VALS, NULL);
+	if (!rez)
+		return -EINVAL;
+
+	for (i = 0; i < rez->package.count; i++) {
+		info->shunts[i] = rez->package.elements[i].integer.value;
+		info->active_channels[i] = (info->shunts[i] != 0);
+		info->active_channels_mask |= 1 << i;
+	}
+
+	ACPI_FREE(rez);
+
+	rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1944_ACPI_GET_BIPOLAR_SETTINGS, NULL);
+	if (!rez)
+		return -EINVAL;
+
+	for_each_set_bit(i, &info->active_channels_mask, info->phys_channels) {
+		bi_dir_mask = rez->package.elements[i].integer.value;
+
+		if (bi_dir_mask == PAC1944_UNIPOLAR_FSR_CFG ||
+		    bi_dir_mask == PAC1944_BIPOLAR_FSR_CFG  ||
+		    bi_dir_mask == PAC1944_BIPOLAR_HALF_FSR_CFG) {
+			dev_dbg(dev, "VBUS{%d} mode set to: %d\n",
+				i, bi_dir_mask);
+			info->chip_reg_data.vbus_mode[i] = bi_dir_mask;
+		} else {
+			return dev_err_probe(dev, -EINVAL, "invalid vbus-mode value on %i\n", i);
+		}
+
+		bi_dir_mask = rez->package.elements[i + PAC1944_MAX_CH].integer.value;
+
+		if (bi_dir_mask == PAC1944_UNIPOLAR_FSR_CFG ||
+		    bi_dir_mask == PAC1944_BIPOLAR_FSR_CFG  ||
+		    bi_dir_mask == PAC1944_BIPOLAR_HALF_FSR_CFG) {
+			dev_dbg(dev, "VSENSE{%d} mode set to: %d\n", i, bi_dir_mask);
+			info->chip_reg_data.vsense_mode[i] = bi_dir_mask;
+		} else {
+			return dev_err_probe(dev, -EINVAL, "invalid vsense-mode value on %i\n", i);
+		}
+	}
+
+	ACPI_FREE(rez);
+
+	rez = acpi_evaluate_dsm(handle, &guid, 1, PAC1944_ACPI_GET_SAMP, NULL);
+	if (!rez)
+		return -EINVAL;
+
+	info->sample_rate_value = rez->package.elements[0].integer.value;
+
+	ACPI_FREE(rez);
+
+	return 0;
+}
+
+static int pac1944_of_parse_channel_config(struct i2c_client *client,
+					   struct pac1944_chip_info *info)
+{
+	unsigned int current_channel;
+	struct device *dev = &client->dev;
+	int idx, ret, temp;
+
+	current_channel = 1;
+
+	device_for_each_child_node_scoped(dev, child) {
+		ret = fwnode_property_read_u32(child, "reg", &idx);
+		if (ret)
+			return dev_err_probe(dev, ret, "reading invalid channel index\n");
+
+		/* adjust idx to match channel index (1 to 4) from the datasheet */
+		idx--;
+
+		if (current_channel >= (info->phys_channels + 1) ||
+		    idx >= info->phys_channels || idx < 0)
+			return dev_err_probe(&client->dev, -EINVAL,
+					     "invalid channel_index %d value\n", (idx + 1));
+
+		/* enable channel */
+		info->active_channels[idx] = true;
+		set_bit(idx, &info->active_channels_mask);
+
+		ret = fwnode_property_read_u32(child, "shunt-resistor-micro-ohms",
+					       &info->shunts[idx]);
+		if (ret)
+			return dev_err_probe(&client->dev, ret,
+					     "%s: invalid shunt-resistor value: %d\n",
+					     fwnode_get_name(child), info->shunts[idx]);
+
+		if (fwnode_property_present(child, "label")) {
+			fwnode_property_read_string(child, "label",
+						    (const char **)&info->labels[idx]);
+		}
+
+		ret = fwnode_property_read_u32(child, "microchip,vbus-mode", &temp);
+		if (ret)
+			return dev_err_probe(&client->dev, -EINVAL,
+					     "invalid vbus-mode value on %s\n",
+					     fwnode_get_name(child));
+
+		if (temp == PAC1944_UNIPOLAR_FSR_CFG ||
+		    temp == PAC1944_BIPOLAR_FSR_CFG  ||
+		    temp == PAC1944_BIPOLAR_HALF_FSR_CFG) {
+			dev_dbg(&client->dev,
+				"VBUS{%d} mode set to: %d\n",
+				idx, temp);
+			info->chip_reg_data.vbus_mode[idx] = temp;
+		} else {
+			return dev_err_probe(&client->dev, -EINVAL,
+					     "invalid vbus-mode value on %s\n",
+					     fwnode_get_name(child));
+		}
+
+		ret = fwnode_property_read_u32(child, "microchip,vsense-mode", &temp);
+		if (ret)
+			return dev_err_probe(&client->dev, ret,
+					     "invalid vsense-mode value on %s\n",
+					     fwnode_get_name(child));
+
+		if (temp == PAC1944_UNIPOLAR_FSR_CFG ||
+		    temp == PAC1944_BIPOLAR_FSR_CFG  ||
+		    temp == PAC1944_BIPOLAR_HALF_FSR_CFG) {
+			dev_dbg(&client->dev,
+				"VSENSE{%d} mode set to: %d\n",
+				idx, temp);
+			info->chip_reg_data.vsense_mode[idx] = temp;
+		} else {
+			return dev_err_probe(&client->dev, -EINVAL,
+					     "invalid vsense-mode value on %s\n",
+					     fwnode_get_name(child));
+		}
+
+		ret = fwnode_property_read_u32(child, "microchip,accumulation-mode", &temp);
+		if (ret)
+			return dev_err_probe(&client->dev, ret,
+					     "invalid accumulation-mode value on %s\n",
+					     fwnode_get_name(child));
+		if (temp == PAC1944_ACCMODE_VPOWER ||
+		    temp == PAC1944_ACCMODE_VSENSE ||
+		    temp == PAC1944_ACCMODE_VBUS) {
+			dev_dbg(&client->dev,
+				"Accumulation{%d} mode set to: %d\n",
+				idx, temp);
+			info->chip_reg_data.accumulation_mode[idx] = temp;
+		} else {
+			return dev_err_probe(&client->dev, -EINVAL,
+					     "invalid mode for accumulator value on %s\n",
+					     fwnode_get_name(child));
+		}
+		current_channel++;
+	}
+
+	return 0;
+}
+
+static void pac1944_cancel_delayed_work(void *dwork)
+{
+	cancel_delayed_work_sync(dwork);
+}
+
+static int pac1944_chip_identify(struct pac1944_chip_info *info)
+{
+	int ret = 0;
+	struct i2c_client *client = info->client;
+	u8 chip_rev_info[3];
+
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_PID_REG_ADDR,
+					    sizeof(chip_rev_info),
+					    chip_rev_info);
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret, "cannot read revision\n");
+
+	dev_info(&client->dev, "Chip revision: 0x%02X\n", chip_rev_info[2]);
+	info->chip_revision = chip_rev_info[2];
+	info->chip_variant = chip_rev_info[0];
+
+	switch (chip_rev_info[0]) {
+	case PAC_PRODUCT_ID_1941:
+	case PAC_PRODUCT_ID_1942:
+	case PAC_PRODUCT_ID_1943:
+	case PAC_PRODUCT_ID_1944:
+	case PAC_PRODUCT_ID_1941_2:
+	case PAC_PRODUCT_ID_1942_2:
+		info->is_pac195x_family = false;
+		return chip_rev_info[0] - PAC_PRODUCT_ID_1941;
+	case PAC_PRODUCT_ID_1951:
+	case PAC_PRODUCT_ID_1952:
+	case PAC_PRODUCT_ID_1953:
+	case PAC_PRODUCT_ID_1954:
+	case PAC_PRODUCT_ID_1951_2:
+	case PAC_PRODUCT_ID_1952_2:
+		info->is_pac195x_family = true;
+		return (chip_rev_info[0] - PAC_PRODUCT_ID_1951) +
+		       (PAC_PRODUCT_ID_1942_2 - PAC_PRODUCT_ID_1941) + 1;
+	default:
+		dev_err(&client->dev,
+			"product ID (0x%02X, 0x%02X, 0x%02X) for this part doesn't match\n",
+			chip_rev_info[0], chip_rev_info[1], chip_rev_info[2]);
+		return -EINVAL;
+	}
+}
+
+static int pac1944_chip_configure(struct pac1944_chip_info *info)
+{
+	int cnt, ret;
+	struct i2c_client *client = info->client;
+	u8 regs[PAC1944_ALERTS_REG_LEN];
+	u8 *offset_p;
+	u32 wait_time;
+	u8 tmp_u8;
+	__be16 tmp_be16;
+	u16 cfg;
+
+	/*
+	 * Counting how many channels are enabled and store
+	 * this information within the driver data
+	 */
+	info->num_enabled_channels = hweight_long(info->active_channels_mask);
+
+	/* get sampling rate from PAC */
+	ret = i2c_smbus_read_i2c_block_data(client, PAC1944_CTRL_REG_ADDR,
+					    sizeof(tmp_be16), (u8 *)&tmp_be16);
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret, "cannot read CTRL reg\n");
+
+	info->sampling_mode = FIELD_GET(PAC1944_CTRL_SAMPLE_MASK, be16_to_cpu(tmp_be16));
+
+	/*
+	 * The current/voltage can be measured unidirectional, bidirectional or half FSR
+	 * no SLOW triggered REFRESH, clear POR
+	 */
+	cfg = FIELD_PREP(PAC1944_NEG_PWR_CFG_VS1_MASK, info->chip_reg_data.vsense_mode[0]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VS2_MASK, info->chip_reg_data.vsense_mode[1]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VS3_MASK, info->chip_reg_data.vsense_mode[2]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VS4_MASK, info->chip_reg_data.vsense_mode[3]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VB1_MASK, info->chip_reg_data.vbus_mode[0]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VB2_MASK, info->chip_reg_data.vbus_mode[1]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VB3_MASK, info->chip_reg_data.vbus_mode[2]) |
+		FIELD_PREP(PAC1944_NEG_PWR_CFG_VB4_MASK, info->chip_reg_data.vbus_mode[3]);
+
+	ret = i2c_smbus_write_word_data(client, PAC1944_NEG_PWR_FSR_REG_ADDR, cpu_to_be16(cfg));
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "cannot write NEG_PWR_FSR reg\n");
+
+	ret = i2c_smbus_write_word_data(client, PAC1944_SLOW_REG_ADDR, 0);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "cannot write SLOW reg\n");
+
+	/* Write the CHANNEL_N_OFF from CTRL REGISTER */
+	cfg = FIELD_PREP(PAC1944_CTRL_SAMPLE_MASK, info->sampling_mode) |
+		FIELD_PREP(PAC1944_CTRL_GPIO_ALERT2_MASK, 0) |
+		FIELD_PREP(PAC1944_CTRL_SLOW_ALERT1_MASK, 0) |
+		FIELD_PREP(PAC1944_CTRL_CH_1_OFF_MASK, !(info->active_channels[0])) |
+		FIELD_PREP(PAC1944_CTRL_CH_2_OFF_MASK, !(info->active_channels[1])) |
+		FIELD_PREP(PAC1944_CTRL_CH_3_OFF_MASK, !(info->active_channels[2])) |
+		FIELD_PREP(PAC1944_CTRL_CH_4_OFF_MASK, !(info->active_channels[3]));
+
+	ret = i2c_smbus_write_word_data(client, PAC1944_CTRL_REG_ADDR, cpu_to_be16(cfg));
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "cannot write CTRL reg\n");
+
+	tmp_u8 = ACCUM_REG(info->chip_reg_data.accumulation_mode[0],
+			   info->chip_reg_data.accumulation_mode[1],
+			   info->chip_reg_data.accumulation_mode[2],
+			   info->chip_reg_data.accumulation_mode[3]);
+
+	ret = i2c_smbus_write_byte_data(client, PAC1944_ACCUM_CFG_REG_ADDR, tmp_u8);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "cannot write ACCUM_CFG reg\n");
+
+	/* reading all alerts, status and limits related registers */
+	ret = pac1944_i2c_read(client, PAC1944_ALERT_STATUS_REG_ADDR, regs, sizeof(regs));
+	if (ret < 0)
+		return dev_err_probe(&client->dev, ret, "cannot read ALERT_STATUS reg\n");
+
+	offset_p = &regs[0];
+
+	/* skip alert_status register*/
+	offset_p += 3;
+
+	info->slow_alert1 = get_unaligned_be24(offset_p);
+	offset_p += 3;
+
+	info->gpio_alert2 = get_unaligned_be24(offset_p);
+	offset_p += 3;
+
+	info->acc_fullness = get_unaligned_be16(offset_p);
+	offset_p += 2;
+
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++) {
+		info->overcurrent[cnt] = get_unaligned_be16(offset_p);
+		offset_p += 2;
+	}
+
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++) {
+		info->undercurrent[cnt] = get_unaligned_be16(offset_p);
+		offset_p += 2;
+	}
+
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++) {
+		info->overpower[cnt] = get_unaligned_be24(offset_p);
+		offset_p += 3;
+	}
+
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++) {
+		info->overvoltage[cnt] = get_unaligned_be16(offset_p);
+		offset_p += 2;
+	}
+
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++) {
+		info->undervoltage[cnt] = get_unaligned_be16(offset_p);
+		offset_p += 2;
+	}
+
+	offset_p += 1;
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++)
+		info->oc_limit_nsamples[cnt] = (*offset_p >> (2 * cnt)) & 0x03;
+
+	offset_p += 1;
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++)
+		info->uc_limit_nsamples[cnt] = (*offset_p >> (2 * cnt)) & 0x03;
+
+	offset_p += 1;
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++)
+		info->op_limit_nsamples[cnt] = (*offset_p >> (2 * cnt)) & 0x03;
+
+	offset_p += 1;
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++)
+		info->ov_limit_nsamples[cnt] = (*offset_p >> (2 * cnt)) & 0x03;
+
+	offset_p += 1;
+	for (cnt = 0; cnt < PAC1944_MAX_CH; cnt++)
+		info->uv_limit_nsamples[cnt] = (*offset_p >> (2 * cnt)) & 0x03;
+
+	offset_p += 1;
+	info->alert_enable = get_unaligned_be24(offset_p);
+
+	/*
+	 * Sending a REFRESH to the chip, so the new settings take place
+	 * as well as resetting the accumulators
+	 */
+	ret = i2c_smbus_write_byte(client, PAC1944_REFRESH_REG_ADDR);
+	if (ret)
+		return dev_err_probe(&client->dev, ret, "cannot write REFRESH reg\n");
+
+	/*
+	 * Get the current (in the chip) sampling speed and compute the
+	 * required timeout based on its value the timeout is 1/sampling_speed
+	 * wait the maximum amount of time to be on the safe side - the
+	 * maximum wait time is for 8sps
+	 */
+	wait_time = (1024 / pac1944_samp_rate_map_tbl[info->sampling_mode]) * 1000;
+	usleep_range(wait_time, wait_time + 100);
+
+	INIT_DELAYED_WORK(&info->work_chip_rfsh, pac1944_work_periodic_rfsh);
+	/* Setup the latest moment for reading the regs before saturation */
+	schedule_delayed_work(&info->work_chip_rfsh,
+			      msecs_to_jiffies(PAC1944_MAX_RFSH_LIMIT_MS));
+
+	return devm_add_action_or_reset(&client->dev, pac1944_cancel_delayed_work,
+					&info->work_chip_rfsh);
+}
+
+static const struct iio_chan_spec pac1944_single_channel[] = {
+	PAC1944_VPOWER_CHANNEL(0, PAC1944_VPOWER_1_ADDR, pac1944_single_event,
+			       ARRAY_SIZE(pac1944_single_event)),
+	PAC1944_VBUS_CHANNEL(0, PAC1944_VBUS_1_ADDR, pac1944_events,
+			     ARRAY_SIZE(pac1944_events)),
+	PAC1944_VSENSE_CHANNEL(0, PAC1944_VSENSE_1_ADDR, pac1944_events,
+			       ARRAY_SIZE(pac1944_events)),
+	PAC1944_VBUS_AVG_CHANNEL(0, PAC1944_VBUS_AVG_1_ADDR),
+	PAC1944_VSENSE_AVG_CHANNEL(0, PAC1944_VSENSE_AVG_1_ADDR),
+};
+
+static int pac1944_prep_iio_channels(struct pac1944_chip_info *info,
+				     struct iio_dev *indio_dev)
+{
+	struct device *dev = &info->client->dev;
+	struct iio_chan_spec *ch_sp;
+	int channel_size, attribute_count, cnt;
+	void *dyn_ch_struct;
+
+	/* Finding out dynamically how many IIO channels we need */
+	attribute_count = 0;
+	channel_size = 0;
+
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		/* add the size of the properties of one chip physical channel */
+		channel_size += sizeof(pac1944_single_channel);
+		/* count how many enabled channels we have */
+		attribute_count += ARRAY_SIZE(pac1944_single_channel);
+		dev_dbg(dev, ":%s: Channel %d active\n", __func__, cnt + 1);
+	}
+
+	dyn_ch_struct = devm_kzalloc(dev, channel_size, GFP_KERNEL);
+	if (!dyn_ch_struct)
+		return -ENOMEM;
+
+	ch_sp = (struct iio_chan_spec *)dyn_ch_struct;
+	/* Populate the dynamic channels and make all the adjustments */
+	for_each_set_bit(cnt, &info->active_channels_mask, info->phys_channels) {
+		memcpy(ch_sp, pac1944_single_channel, sizeof(pac1944_single_channel));
+		/*
+		 * Into the datasheet channels are noted from 1 to 4 so we will adjust
+		 * the channel to match channel index (1 to 4) from the datasheet
+		 */
+		ch_sp[PAC1944_CH_POWER].channel = cnt + 1;
+		ch_sp[PAC1944_CH_POWER].address = cnt + PAC1944_VPOWER_1_ADDR;
+		ch_sp[PAC1944_CH_VOLTAGE].channel = cnt + 1;
+		ch_sp[PAC1944_CH_VOLTAGE].address = cnt + PAC1944_VBUS_1_ADDR;
+		ch_sp[PAC1944_CH_CURRENT].channel = cnt + 1;
+		ch_sp[PAC1944_CH_CURRENT].address = cnt + PAC1944_VSENSE_1_ADDR;
+		/*
+		 * In order to be able to use labels for PAC1944_CH_VOLTAGE and
+		 * PAC1944_CH_VOLTAGE_AVERAGE, respectively PAC1944_CH_CURRENT
+		 * and PAC1944_CH_CURRENT_AVERAGE we need to use different channel numbers.
+		 * We will add  +5 (+1 to maximum PAC channels).
+		 */
+		ch_sp[PAC1944_CH_VOLTAGE_AVERAGE].channel = cnt + PAC1944_MAX_CH + 1;
+		ch_sp[PAC1944_CH_VOLTAGE_AVERAGE].address = cnt + PAC1944_VBUS_AVG_1_ADDR;
+		ch_sp[PAC1944_CH_CURRENT_AVERAGE].channel = cnt + PAC1944_MAX_CH + 1;
+		ch_sp[PAC1944_CH_CURRENT_AVERAGE].address = cnt + PAC1944_VSENSE_AVG_1_ADDR;
+
+		/* advance the pointer */
+		ch_sp = (void *)ch_sp + sizeof(pac1944_single_channel);
+	}
+
+	/*
+	 * Send the updated dynamic channel structure information towards IIO
+	 * prepare the required field for IIO class registration
+	 */
+	indio_dev->num_channels = attribute_count;
+	indio_dev->channels = (const struct iio_chan_spec *)dyn_ch_struct;
+
+	return 0;
+}
+
+static const struct iio_info pac1944_info = {
+	.read_raw = pac1944_read_raw,
+	.read_label = pac1944_read_label,
+	.read_event_value = pac1944_read_thresh,
+	.write_event_value = pac1944_write_thresh,
+	.read_event_config = pac1944_read_event_config,
+	.write_event_config = pac1944_write_event_config,
+};
+
+static int pac1944_probe(struct i2c_client *client)
+{
+	struct pac1944_chip_info *info;
+	struct iio_dev *indio_dev;
+	const struct pac1944_features *chip;
+	int cnt, ret;
+	struct device *dev = &client->dev;
+
+	indio_dev = devm_iio_device_alloc(dev, sizeof(*info));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	info = iio_priv(indio_dev);
+	info->client = client;
+
+	ret = pac1944_chip_identify(info);
+	if (ret < 0) {
+		/*
+		 * If failed to identify the hardware based on internal
+		 * registers, try using fallback compatible in device
+		 * tree to deal with some newer part number.
+		 */
+		chip = i2c_get_match_data(client);
+		if (!chip)
+			return -EINVAL;
+
+		info->chip_variant = chip->prod_id;
+		info->phys_channels = chip->phys_channels;
+		indio_dev->name = chip->name;
+	} else {
+		info->phys_channels = pac1944_chip_config[ret].phys_channels;
+		indio_dev->name = pac1944_chip_config[ret].name;
+	}
+
+	for (cnt = 0; cnt < info->phys_channels; cnt++) {
+		/* always start with accumulation channels enabled */
+		info->enable_acc[cnt] = true;
+	}
+
+	if (ACPI_HANDLE(dev))
+		ret = pac1944_acpi_parse_channel_config(client, info);
+	else
+		ret = pac1944_of_parse_channel_config(client, info);
+
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "parameter parsing returned an error\n");
+
+	ret = devm_mutex_init(dev, &info->lock);
+	if (ret < 0)
+		return ret;
+
+	ret = pac1944_chip_configure(info);
+	if (ret < 0)
+		return ret;
+
+	ret = pac1944_prep_iio_channels(info, indio_dev);
+	if (ret < 0)
+		return ret;
+
+	info->iio_info = pac1944_info;
+	indio_dev->info = &info->iio_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = pac1944_prep_custom_attributes(info, indio_dev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "Can't configure custom attributes for PAC194x/5x device\n");
+
+	ret = pac1944_reg_snapshot(info, true, false,
+				   PAC1944_MIN_UPDATE_WAIT_TIME_US);
+	if (ret < 0)
+		return ret;
+
+	ret = devm_iio_device_register(&client->dev, indio_dev);
+	if (ret < 0)
+		return dev_err_probe(dev, ret,
+				     "Can't register IIO device\n");
+
+	return 0;
+}
+
+static const struct i2c_device_id pac1944_id[] = {
+	{ .name = "pac1941", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1941] },
+	{ .name = "pac19412", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1941_2] },
+	{ .name = "pac1942", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1942] },
+	{ .name = "pac19422", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1942_2] },
+	{ .name = "pac1943", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1943] },
+	{ .name = "pac1944", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1944] },
+	{ .name = "pac1951", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1951] },
+	{ .name = "pac19512", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1951_2] },
+	{ .name = "pac1952", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1952] },
+	{ .name = "pac19522", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1952_2] },
+	{ .name = "pac1953", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1953] },
+	{ .name = "pac1954", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1954] },
+	{}
+};
+MODULE_DEVICE_TABLE(i2c, pac1944_id);
+
+static const struct of_device_id pac1944_of_match[] = {
+	{
+		.compatible = "microchip,pac1941",
+		.data = (void *)&pac1944_chip_config[PAC1941]
+	},
+	{
+		.compatible = "microchip,pac19412",
+		.data = (void *)&pac1944_chip_config[PAC1941_2]
+	},
+	{
+		.compatible = "microchip,pac1942",
+		.data = (void *)&pac1944_chip_config[PAC1942]
+	},
+	{
+		.compatible = "microchip,pac19422",
+		.data = (void *)&pac1944_chip_config[PAC1942_2]
+	},
+	{
+		.compatible = "microchip,pac1943",
+		.data = (void *)&pac1944_chip_config[PAC1943]
+	},
+	{
+		.compatible = "microchip,pac1944",
+		.data = (void *)&pac1944_chip_config[PAC1944]
+	},
+	{
+		.compatible = "microchip,pac1951",
+		.data = (void *)&pac1944_chip_config[PAC1951]
+	},
+	{
+		.compatible = "microchip,pac19512",
+		.data = (void *)&pac1944_chip_config[PAC1951_2]
+	},
+	{
+		.compatible = "microchip,pac1952",
+		.data = (void *)&pac1944_chip_config[PAC1952]
+	},
+	{
+		.compatible = "microchip,pac19522",
+		.data = (void *)&pac1944_chip_config[PAC1952_2]
+	},
+	{
+		.compatible = "microchip,pac1953",
+		.data = (void *)&pac1944_chip_config[PAC1953]
+	},
+	{
+		.compatible = "microchip,pac1954",
+		.data = (void *)&pac1944_chip_config[PAC1954]
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, pac1944_of_match);
+
+static const struct acpi_device_id pac1944_acpi_match[] = {
+	{ "MCHP1940", .driver_data = (kernel_ulong_t)&pac1944_chip_config[PAC1944] },
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, pac1944_acpi_match);
+
+static struct i2c_driver pac1944_driver = {
+	.driver = {
+		.name = "pac1944",
+		.of_match_table = pac1944_of_match,
+		.acpi_match_table = pac1944_acpi_match
+	},
+	.probe = pac1944_probe,
+	.id_table = pac1944_id,
+};
+
+module_i2c_driver(pac1944_driver);
+
+MODULE_AUTHOR("Marius Cristea <marius.cristea@microchip.com>");
+MODULE_DESCRIPTION("Microchip PAC194X and PAC195X Power Monitor");
+MODULE_LICENSE("GPL v2");