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git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
iio: adc: Add driver support for MAX34408/9
The MAX34408/MAX34409 are two- and four-channel current monitors that are
configured and monitored with a standard I2C/SMBus serial interface. Each
unidirectional current sensor offers precision high-side operation with a
low full-scale sense voltage. The devices automatically sequence through
two or four channels and collect the current-sense samples and average them
to reduce the effect of impulse noise. The raw ADC samples are compared to
user-programmable digital thresholds to indicate overcurrent conditions.
Overcurrent conditions trigger a hardware output to provide an immediate
indication to shut down any necessary external circuitry.
Add as ADC driver which only supports current monitoring for now.
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX34408-MAX34409.pdf
Signed-off-by: Ivan Mikhaylov <fr0st61te@gmail.com>
Link: https://lore.kernel.org/r/20231014211254.16719-3-fr0st61te@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
authored by
Ivan Mikhaylov
and committed by
Jonathan Cameron
cf277758
f0d1a9b7
+288
+11
drivers/iio/adc/Kconfig
+11
drivers/iio/adc/Kconfig
···
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To compile this driver as a module, choose M here: the module will be
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called max1363.
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config MAX34408
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tristate "Maxim max34408/max344089 ADC driver"
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depends on I2C
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help
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Say yes here to build support for Maxim max34408/max34409 current sense
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monitor with 8-bits ADC interface with overcurrent delay/threshold and
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shutdown delay.
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To compile this driver as a module, choose M here: the module will be
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called max34408.
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config MAX77541_ADC
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tristate "Analog Devices MAX77541 ADC driver"
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depends on MFD_MAX77541
+1
drivers/iio/adc/Makefile
+1
drivers/iio/adc/Makefile
···
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obj-$(CONFIG_MAX11410) += max11410.o
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obj-$(CONFIG_MAX1241) += max1241.o
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obj-$(CONFIG_MAX1363) += max1363.o
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obj-$(CONFIG_MAX34408) += max34408.o
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obj-$(CONFIG_MAX77541_ADC) += max77541-adc.o
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obj-$(CONFIG_MAX9611) += max9611.o
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obj-$(CONFIG_MCP320X) += mcp320x.o
+276
drivers/iio/adc/max34408.c
+276
drivers/iio/adc/max34408.c
···
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// SPDX-License-Identifier: GPL-2.0
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/*
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* IIO driver for Maxim MAX34409/34408 ADC, 4-Channels/2-Channels, 8bits, I2C
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*
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* Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/MAX34408-MAX34409.pdf
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*
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* TODO: ALERT interrupt, Overcurrent delay, Shutdown delay
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*/
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#include <linux/bitfield.h>
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#include <linux/init.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/property.h>
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#include <linux/regmap.h>
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+
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#include <linux/iio/iio.h>
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#include <linux/iio/types.h>
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+
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#define MAX34408_STATUS_REG 0x0
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#define MAX34408_CONTROL_REG 0x1
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#define MAX34408_OCDELAY_REG 0x2
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#define MAX34408_SDDELAY_REG 0x3
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+
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#define MAX34408_ADC1_REG 0x4
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#define MAX34408_ADC2_REG 0x5
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/* ADC3 & ADC4 always returns 0x0 on 34408 */
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#define MAX34409_ADC3_REG 0x6
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#define MAX34409_ADC4_REG 0x7
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+
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#define MAX34408_OCT1_REG 0x8
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#define MAX34408_OCT2_REG 0x9
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#define MAX34409_OCT3_REG 0xA
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#define MAX34409_OCT4_REG 0xB
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+
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#define MAX34408_DID_REG 0xC
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#define MAX34408_DCYY_REG 0xD
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#define MAX34408_DCWW_REG 0xE
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+
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/* Bit masks for status register */
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#define MAX34408_STATUS_OC_MSK GENMASK(1, 0)
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#define MAX34409_STATUS_OC_MSK GENMASK(3, 0)
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#define MAX34408_STATUS_SHTDN BIT(4)
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#define MAX34408_STATUS_ENA BIT(5)
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+
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/* Bit masks for control register */
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#define MAX34408_CONTROL_AVG0 BIT(0)
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#define MAX34408_CONTROL_AVG1 BIT(1)
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#define MAX34408_CONTROL_AVG2 BIT(2)
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#define MAX34408_CONTROL_ALERT BIT(3)
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+
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#define MAX34408_DEFAULT_AVG 0x4
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+
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/* Bit masks for over current delay */
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#define MAX34408_OCDELAY_OCD_MSK GENMASK(6, 0)
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#define MAX34408_OCDELAY_RESET BIT(7)
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/* Bit masks for shutdown delay */
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#define MAX34408_SDDELAY_SHD_MSK GENMASK(6, 0)
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#define MAX34408_SDDELAY_RESET BIT(7)
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#define MAX34408_DEFAULT_RSENSE 1000
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/**
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* struct max34408_data - max34408/max34409 specific data.
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* @regmap: device register map.
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* @dev: max34408 device.
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* @lock: lock for protecting access to device hardware registers, mostly
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* for read modify write cycles for control registers.
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* @input_rsense: Rsense values in uOhm, will be overwritten by
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* values from channel nodes.
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*/
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struct max34408_data {
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struct regmap *regmap;
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struct device *dev;
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struct mutex lock;
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u32 input_rsense[4];
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};
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static const struct regmap_config max34408_regmap_config = {
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.reg_bits = 8,
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.val_bits = 8,
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.max_register = MAX34408_DCWW_REG,
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};
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struct max34408_adc_model_data {
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const char *model_name;
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const struct iio_chan_spec *channels;
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const int num_channels;
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};
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#define MAX34008_CHANNEL(_index, _address) \
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{ \
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.type = IIO_CURRENT, \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
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BIT(IIO_CHAN_INFO_SCALE) | \
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BIT(IIO_CHAN_INFO_OFFSET), \
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.channel = (_index), \
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.address = (_address), \
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.indexed = 1, \
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}
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static const struct iio_chan_spec max34408_channels[] = {
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MAX34008_CHANNEL(0, MAX34408_ADC1_REG),
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MAX34008_CHANNEL(1, MAX34408_ADC2_REG),
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};
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static const struct iio_chan_spec max34409_channels[] = {
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MAX34008_CHANNEL(0, MAX34408_ADC1_REG),
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MAX34008_CHANNEL(1, MAX34408_ADC2_REG),
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MAX34008_CHANNEL(2, MAX34409_ADC3_REG),
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MAX34008_CHANNEL(3, MAX34409_ADC4_REG),
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};
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static int max34408_read_adc_avg(struct max34408_data *max34408,
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const struct iio_chan_spec *chan, int *val)
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{
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unsigned int ctrl;
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int rc;
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guard(mutex)(&max34408->lock);
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rc = regmap_read(max34408->regmap, MAX34408_CONTROL_REG, (u32 *)&ctrl);
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if (rc)
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return rc;
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/* set averaging (0b100) default values*/
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rc = regmap_write(max34408->regmap, MAX34408_CONTROL_REG,
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MAX34408_DEFAULT_AVG);
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if (rc) {
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dev_err(max34408->dev,
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"Error (%d) writing control register\n", rc);
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return rc;
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}
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rc = regmap_read(max34408->regmap, chan->address, val);
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if (rc)
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return rc;
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/* back to old values */
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rc = regmap_write(max34408->regmap, MAX34408_CONTROL_REG, ctrl);
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if (rc)
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dev_err(max34408->dev,
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"Error (%d) writing control register\n", rc);
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return rc;
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}
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static int max34408_read_raw(struct iio_dev *indio_dev,
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struct iio_chan_spec const *chan,
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int *val, int *val2, long mask)
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{
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struct max34408_data *max34408 = iio_priv(indio_dev);
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int rc;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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rc = max34408_read_adc_avg(max34408, chan, val);
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if (rc)
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return rc;
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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/*
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* calcluate current for 8bit ADC with Rsense
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* value.
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* 10 mV * 1000 / Rsense uOhm = max current
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* (max current * adc val * 1000) / (2^8 - 1) mA
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*/
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*val = 10000 / max34408->input_rsense[chan->channel];
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*val2 = 8;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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return -EINVAL;
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}
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}
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static const struct iio_info max34408_info = {
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.read_raw = max34408_read_raw,
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};
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static const struct max34408_adc_model_data max34408_model_data = {
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.model_name = "max34408",
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.channels = max34408_channels,
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.num_channels = 2,
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};
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static const struct max34408_adc_model_data max34409_model_data = {
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.model_name = "max34409",
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.channels = max34409_channels,
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.num_channels = 4,
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};
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static int max34408_probe(struct i2c_client *client)
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{
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const struct max34408_adc_model_data *model_data;
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struct device *dev = &client->dev;
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struct max34408_data *max34408;
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struct fwnode_handle *node;
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struct iio_dev *indio_dev;
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struct regmap *regmap;
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int rc, i = 0;
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model_data = i2c_get_match_data(client);
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if (!model_data)
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return -EINVAL;
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regmap = devm_regmap_init_i2c(client, &max34408_regmap_config);
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if (IS_ERR(regmap)) {
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dev_err_probe(dev, PTR_ERR(regmap),
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"regmap_init failed\n");
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return PTR_ERR(regmap);
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}
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indio_dev = devm_iio_device_alloc(dev, sizeof(*max34408));
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if (!indio_dev)
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return -ENOMEM;
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max34408 = iio_priv(indio_dev);
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max34408->regmap = regmap;
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max34408->dev = dev;
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mutex_init(&max34408->lock);
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device_for_each_child_node(dev, node) {
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fwnode_property_read_u32(node, "maxim,rsense-val-micro-ohms",
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&max34408->input_rsense[i]);
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i++;
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}
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/* disable ALERT and averaging */
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rc = regmap_write(max34408->regmap, MAX34408_CONTROL_REG, 0x0);
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if (rc)
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return rc;
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indio_dev->channels = model_data->channels;
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indio_dev->num_channels = model_data->num_channels;
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indio_dev->name = model_data->model_name;
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indio_dev->info = &max34408_info;
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indio_dev->modes = INDIO_DIRECT_MODE;
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return devm_iio_device_register(dev, indio_dev);
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}
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static const struct of_device_id max34408_of_match[] = {
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{
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.compatible = "maxim,max34408",
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.data = &max34408_model_data,
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},
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{
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.compatible = "maxim,max34409",
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.data = &max34409_model_data,
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},
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{}
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};
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MODULE_DEVICE_TABLE(of, max34408_of_match);
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static const struct i2c_device_id max34408_id[] = {
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{ "max34408", (kernel_ulong_t)&max34408_model_data },
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{ "max34409", (kernel_ulong_t)&max34409_model_data },
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{}
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};
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MODULE_DEVICE_TABLE(i2c, max34408_id);
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static struct i2c_driver max34408_driver = {
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.driver = {
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.name = "max34408",
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.of_match_table = max34408_of_match,
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},
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.probe = max34408_probe,
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.id_table = max34408_id,
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};
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module_i2c_driver(max34408_driver);
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MODULE_AUTHOR("Ivan Mikhaylov <fr0st61te@gmail.com>");
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MODULE_DESCRIPTION("Maxim MAX34408/34409 ADC driver");
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MODULE_LICENSE("GPL");