Re: [PATCH v7 3/5] iio: adc: max77541: Add ADI MAX77541 ADC Support

[Andy Shevchenko]

On Wed, Apr 12, 2023 at 02:12:44PM +0300, Okan Sahin wrote:
> The MAX77541 has an 8-bit Successive Approximation Register (SAR) ADC
> with four multiplexers for supporting the telemetry feature.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

> Signed-off-by: Okan Sahin <okan.sahin@xxxxxxxxxx>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
> ---
>  drivers/iio/adc/Kconfig        |  11 ++
>  drivers/iio/adc/Makefile       |   1 +
>  drivers/iio/adc/max77541-adc.c | 194 +++++++++++++++++++++++++++++++++
>  3 files changed, 206 insertions(+)
>  create mode 100644 drivers/iio/adc/max77541-adc.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 45af2302be53..518e7bd453aa 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -735,6 +735,17 @@ config MAX1363
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called max1363.
>  
> +config MAX77541_ADC
> +	tristate "Analog Devices MAX77541 ADC driver"
> +	depends on MFD_MAX77541
> +	help
> +	  This driver controls a Analog Devices MAX77541 ADC
> +	  via I2C bus. This device has one adc. Say yes here to build
> +	  support for Analog Devices MAX77541 ADC interface.
> +
> +	  To compile this driver as a module, choose M here:
> +	  the module will be called max77541-adc.
> +
>  config MAX9611
>  	tristate "Maxim max9611/max9612 ADC driver"
>  	depends on I2C
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 36c18177322a..f8433b560c3b 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -67,6 +67,7 @@ obj-$(CONFIG_MAX11205) += max11205.o
>  obj-$(CONFIG_MAX11410) += max11410.o
>  obj-$(CONFIG_MAX1241) += max1241.o
>  obj-$(CONFIG_MAX1363) += max1363.o
> +obj-$(CONFIG_MAX77541_ADC) += max77541-adc.o
>  obj-$(CONFIG_MAX9611) += max9611.o
>  obj-$(CONFIG_MCP320X) += mcp320x.o
>  obj-$(CONFIG_MCP3422) += mcp3422.o
> diff --git a/drivers/iio/adc/max77541-adc.c b/drivers/iio/adc/max77541-adc.c
> new file mode 100644
> index 000000000000..21d024bde16b
> --- /dev/null
> +++ b/drivers/iio/adc/max77541-adc.c
> @@ -0,0 +1,194 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2022 Analog Devices, Inc.
> + * ADI MAX77541 ADC Driver with IIO interface
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/iio/iio.h>
> +#include <linux/mod_devicetable.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/units.h>
> +
> +#include <linux/mfd/max77541.h>
> +
> +enum max77541_adc_range {
> +	LOW_RANGE,
> +	MID_RANGE,
> +	HIGH_RANGE,
> +};
> +
> +enum max77541_adc_channel {
> +	MAX77541_ADC_VSYS_V,
> +	MAX77541_ADC_VOUT1_V,
> +	MAX77541_ADC_VOUT2_V,
> +	MAX77541_ADC_TEMP,
> +};
> +
> +static int max77541_adc_offset(struct iio_dev *indio_dev,
> +			       struct iio_chan_spec const *chan,
> +			       int *val, int *val2)
> +{
> +	switch (chan->channel) {
> +	case MAX77541_ADC_TEMP:
> +		*val = DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 1725);
> +		return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int max77541_adc_scale(struct iio_dev *indio_dev,
> +			      struct iio_chan_spec const *chan,
> +			      int *val, int *val2)
> +{
> +	struct regmap **regmap = iio_priv(indio_dev);
> +	unsigned int reg_val;
> +	int ret;
> +
> +	switch (chan->channel) {
> +	case MAX77541_ADC_VSYS_V:
> +		*val = 25;
> +		return IIO_VAL_INT;
> +	case MAX77541_ADC_VOUT1_V:
> +	case MAX77541_ADC_VOUT2_V:
> +		ret = regmap_read(*regmap, MAX77541_REG_M2_CFG1, &reg_val);
> +		if (ret)
> +			return ret;
> +
> +		reg_val = FIELD_GET(MAX77541_BITS_MX_CFG1_RNG, reg_val);
> +		switch (reg_val) {
> +		case LOW_RANGE:
> +			*val = 6;
> +			*val2 = 250000;
> +			break;
> +		case MID_RANGE:
> +			*val = 12;
> +			*val2 = 500000;
> +			break;
> +		case HIGH_RANGE:
> +			*val = 25;
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	case MAX77541_ADC_TEMP:
> +		*val = 1725;
> +		return IIO_VAL_INT;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int max77541_adc_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int *val)
> +{
> +	struct regmap **regmap = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = regmap_read(*regmap, chan->address, val);
> +	if (ret)
> +		return ret;
> +
> +	return IIO_VAL_INT;
> +}
> +
> +#define MAX77541_ADC_CHANNEL_V(_channel, _name, _type, _reg) \
> +	{							\
> +		.type = _type,					\
> +		.indexed = 1,					\
> +		.channel = _channel,				\
> +		.address = _reg,				\
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
> +				      BIT(IIO_CHAN_INFO_SCALE), \
> +		.datasheet_name = _name,			\
> +	}
> +
> +#define MAX77541_ADC_CHANNEL_TEMP(_channel, _name, _type, _reg) \
> +	{							\
> +		.type = _type,					\
> +		.indexed = 1,					\
> +		.channel = _channel,				\
> +		.address = _reg,				\
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
> +				      BIT(IIO_CHAN_INFO_SCALE) |\
> +				      BIT(IIO_CHAN_INFO_OFFSET),\
> +		.datasheet_name = _name,			\
> +	}
> +
> +static const struct iio_chan_spec max77541_adc_channels[] = {
> +	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VSYS_V, "vsys_v", IIO_VOLTAGE,
> +			       MAX77541_REG_ADC_DATA_CH1),
> +	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT1_V, "vout1_v", IIO_VOLTAGE,
> +			       MAX77541_REG_ADC_DATA_CH2),
> +	MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT2_V, "vout2_v", IIO_VOLTAGE,
> +			       MAX77541_REG_ADC_DATA_CH3),
> +	MAX77541_ADC_CHANNEL_TEMP(MAX77541_ADC_TEMP, "temp", IIO_TEMP,
> +				  MAX77541_REG_ADC_DATA_CH6),
> +};
> +
> +static int max77541_adc_read_raw(struct iio_dev *indio_dev,
> +				 struct iio_chan_spec const *chan,
> +				 int *val, int *val2, long mask)
> +{
> +	switch (mask) {
> +	case IIO_CHAN_INFO_OFFSET:
> +		return max77541_adc_offset(indio_dev, chan, val, val2);
> +	case IIO_CHAN_INFO_SCALE:
> +		return max77541_adc_scale(indio_dev, chan, val, val2);
> +	case IIO_CHAN_INFO_RAW:
> +		return max77541_adc_raw(indio_dev, chan, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct iio_info max77541_adc_info = {
> +	.read_raw = max77541_adc_read_raw,
> +};
> +
> +static int max77541_adc_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct iio_dev *indio_dev;
> +	struct regmap **regmap;
> +
> +	indio_dev = devm_iio_device_alloc(dev, sizeof(*regmap));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	regmap = iio_priv(indio_dev);
> +
> +	*regmap = dev_get_regmap(dev->parent, NULL);
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	indio_dev->name = "max77541";
> +	indio_dev->info = &max77541_adc_info;
> +	indio_dev->channels = max77541_adc_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(max77541_adc_channels);
> +
> +	return devm_iio_device_register(dev, indio_dev);
> +}
> +
> +static const struct platform_device_id max77541_adc_platform_id[] = {
> +	{ "max77541-adc" },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(platform, max77541_adc_platform_id);
> +
> +static struct platform_driver max77541_adc_driver = {
> +	.driver = {
> +		.name = "max77541-adc",
> +	},
> +	.probe = max77541_adc_probe,
> +	.id_table = max77541_adc_platform_id,
> +};
> +module_platform_driver(max77541_adc_driver);
> +
> +MODULE_AUTHOR("Okan Sahin <Okan.Sahin@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("MAX77541 ADC driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.30.2
> 

-- 
With Best Regards,
Andy Shevchenko