Hi Jonathan,
thanks for review
On Sat, Mar 25, 2017 at 03:45:05PM +0000, Jonathan Cameron wrote:
> On 24/03/17 15:28, Jacopo Mondi wrote:
> > Add iio driver for Maxim max9611 and max9612 current-sense amplifiers
> > with 12-bits ADC interface.
> >
> > Datasheet publicly available at:
> > https://datasheets.maximintegrated.com/en/ds/MAX9611-MAX9612.pdf
> >
> > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>
> A few more little things inline. Coming together nicely.
>
> The channel set here is just odd enough that it might aid review to have
> a quick listing of the resulting sysfs entries. One or two authors do
> this an it is always useful for a quick sanity check.
>
> Perhaps even a set of typical values. Put this below the --- as we don't
> need it in the git history, only to assist lazy reviewers like me ;)
>
I included the output of iio_info in the cover letter, I can add some
more info here for sure!
> Thanks,
>
> Jonathan
> > ---
> > drivers/iio/adc/Kconfig | 10 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/max9611.c | 590 ++++++++++++++++++++++++++++++++++++++++++++++
> > 3 files changed, 601 insertions(+)
> > create mode 100644 drivers/iio/adc/max9611.c
> >
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index dedae7a..82f2e7b8 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -354,6 +354,16 @@ config MAX1363
> > To compile this driver as a module, choose M here: the module will be
> > called max1363.
> >
> > +config MAX9611
> > + tristate "Maxim max9611/max9612 ADC driver"
> > + depends on I2C
> > + help
> > + Say yes here to build support for Maxim max9611/max9612 current sense
> > + amplifier with 12-bits ADC interface.
> > +
> > + To compile this driver as a module, choose M here: the module will be
> > + called max9611.
> > +
> > config MCP320X
> > tristate "Microchip Technology MCP3x01/02/04/08"
> > depends on SPI
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index d001262..149f979 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -34,6 +34,7 @@ obj-$(CONFIG_LTC2485) += ltc2485.o
> > obj-$(CONFIG_MAX1027) += max1027.o
> > obj-$(CONFIG_MAX11100) += max11100.o
> > obj-$(CONFIG_MAX1363) += max1363.o
> > +obj-$(CONFIG_MAX9611) += max9611.o
> > obj-$(CONFIG_MCP320X) += mcp320x.o
> > obj-$(CONFIG_MCP3422) += mcp3422.o
> > obj-$(CONFIG_MEDIATEK_MT6577_AUXADC) += mt6577_auxadc.o
> > diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
> > new file mode 100644
> > index 0000000..61566ec
> > --- /dev/null
> > +++ b/drivers/iio/adc/max9611.c
> > @@ -0,0 +1,590 @@
> > +/*
> > + * iio/adc/max9611.c
> > + *
> > + * Maxim max9611/max9612 high side current sense amplifier with
> > + * 12-bit ADC interface.
> > + *
> > + * Copyright (C) 2017 Jacopo Mondi
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License version 2 as
> > + * published by the Free Software Foundation.
> > + */
> > +
> > +/*
> > + * This driver supports input common-mode voltage, current-sense
> > + * amplifier with programmable gains and die temperature reading from
> > + * Maxim max9611/max9612.
> > + *
> > + * Op-amp, analog comparator, and watchdog functionalities are not
> > + * supported by this driver.
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/i2c.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/iio/sysfs.h>
> > +#include <linux/module.h>
> > +
> > +#define DRIVER_NAME "max9611"
> > +
> > +/* max9611 register addresses */
> > +#define MAX9611_REG_CSA_DATA 0x00
> > +#define MAX9611_REG_RS_DATA 0x02
> > +#define MAX9611_REG_TEMP_DATA 0x08
> > +#define MAX9611_REG_CTRL1 0x0a
> > +#define MAX9611_REG_CTRL2 0x0b
> > +
> > +/* max9611 REG1 mux configuration options */
> > +#define MAX9611_MUX_MASK 0x07
> > +#define MAX9611_MUX_SENSE_1x 0x00
> > +#define MAX9611_MUX_SENSE_4x 0x01
> > +#define MAX9611_MUX_SENSE_8x 0x02
> > +#define MAX9611_INPUT_VOLT 0x03
> > +#define MAX9611_MUX_TEMP 0x06
> > +
> > +/* max9611 voltage (both csa and input) helper macros */
> > +#define MAX9611_VOLTAGE_SHIFT 0x04
> > +#define MAX9611_VOLTAGE_RAW(_r) ((_r) >> MAX9611_VOLTAGE_SHIFT)
> > +
> > +/*
> > + * max9611 current sense amplifier voltage output:
> > + * LSB and offset values depends on selected gain (1x, 4x, 8x)
> > + *
> > + * GAIN LSB (nV) OFFSET (LSB steps)
> > + * 1x 107500 1
> > + * 4x 26880 1
> > + * 8x 13440 3
> > + *
> > + * The complete formula to calculate current sense voltage is:
> > + * (((adc_read >> 4) - offset) / ((1 / LSB) * 10^-3)
> > + */
> > +#define CSA_VOLT_1x_LSB_nV 107500
> > +#define CSA_VOLT_4x_LSB_nV 26880
> > +#define CSA_VOLT_8x_LSB_nV 13440
> > +
> > +#define CSA_VOLT_1x_OFFS_RAW 1
> > +#define CSA_VOLT_4x_OFFS_RAW 1
> > +#define CSA_VOLT_8x_OFFS_RAW 3
> > +
> > +/*
> > + * max9611 common input mode (CIM): LSB is 14mV, with 14mV offset at 25 C
> > + *
> > + * The complete formula to calculate input common voltage is:
> > + * (((adc_read >> 4) * 1000) - offset) / (1 / 14 * 1000)
> > + */
> > +#define CIM_VOLTAGE_LSB_mV 14
> > +#define CIM_VOLTAGE_OFFSET_RAW 1
> > +
> > +/*
> > + * max9611 temperature reading: LSB is 0.48 degrees Celsius
> > + *
> > + * The complete formula to calculate temperature is:
> > + * ((adc_read >> 7) * 1000) / (1 / 0.48 * 1000)
> > + */
> I'd prefer these defines to be prefixed with MAX9611_
> Easiest to just do the lot. Some of these are 'standard' enough
> the might well clash with something that turns up in an included header
> at somepoint in the future.
>
> > +#define TEMP_SHIFT 0x07
> > +#define TEMP_MAX_RAW_POS 0x7f80
> > +#define TEMP_MAX_RAW_NEG 0xff80
> > +#define TEMP_MIN_RAW_NEG 0xd980
> > +#define TEMP_MASK ((1 << TEMP_SHIFT) - 1)
> > +#define TEMP_RAW(_r) ((_r) >> TEMP_SHIFT)
> > +#define TEMP_LSB_mC 480
> > +#define TEMP_SCALE_NUM 1000
> > +#define TEMP_SCALE_DIV 2083
> > +
> > +struct max9611_dev {
> > + struct device *dev;
> > + struct i2c_client *i2c_client;
> > + struct mutex lock;
> > + unsigned int shunt_resistor_uohm;
> > +};
> > +
> > +enum max9611_conf_ids {
> > + CONF_SENSE_1x,
> > + CONF_SENSE_4x,
> > + CONF_SENSE_8x,
> > + CONF_IN_VOLT,
> > + CONF_TEMP,
> > +};
> > +
> > +/**
> > + * max9611_mux_conf - associate ADC mux configuration with register address
> > + * where data shall be read from
> > + */
> > +static unsigned int max9611_mux_conf[][2] = {
> > + /* CONF_SENSE_1x */
> > + { MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA },
> > + /* CONF_SENSE_4x */
> > + { MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA },
> > + /* CONF_SENSE_8x */
> > + { MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA },
> > + /* CONF_IN_VOLT */
> > + { MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA },
> > + /* CONF_TEMP */
> > + { MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA },
> > +};
> > +
> > +enum max9611_csa_gain {
> > + CSA_GAIN_1x,
> > + CSA_GAIN_4x,
> > + CSA_GAIN_8x,
> > +};
> > +
> > +enum max9611_csa_gain_params {
> > + CSA_GAIN_LSB_nV,
> > + CSA_GAIN_OFFS_RAW,
> > +};
> > +
> > +/**
> > + * max9611_csa_gain_conf - associate gain multiplier with LSB and
> > + * offset values.
> > + *
> > + * Group together parameters associated with configurable gain
> > + * on current sense amplifier path to ADC interface.
> > + * Current sense read routine adjusts gain until it gets a meaningful
> > + * value; use this structure to retrieve the correct LSB and offset values.
> > + */
> > +static unsigned int max9611_gain_conf[][2] = {
> > + { /* [0] CSA_GAIN_1x */
> > + CSA_VOLT_1x_LSB_nV,
> > + CSA_VOLT_1x_OFFS_RAW,
> > + },
> > + { /* [1] CSA_GAIN_4x */
> > + CSA_VOLT_4x_LSB_nV,
> > + CSA_VOLT_4x_OFFS_RAW,
> > + },
> > + { /* [2] CSA_GAIN_8x */
> > + CSA_VOLT_8x_LSB_nV,
> > + CSA_VOLT_8x_OFFS_RAW,
> > + },
> > +};
> > +
> > +enum max9611_chan_addrs {
> > + MAX9611_CHAN_VOLTAGE_INPUT,
> > + MAX9611_CHAN_VOLTAGE_SENSE,
> > + MAX9611_CHAN_TEMPERATURE,
> > + MAX9611_CHAN_CURRENT_LOAD,
> > + MAX9611_CHAN_POWER_LOAD,
> > +};
> > +
> > +static struct iio_chan_spec max9611_channels[] = {
> > + {
> > + .type = IIO_TEMP,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> > + BIT(IIO_CHAN_INFO_SCALE),
> > + .address = MAX9611_CHAN_TEMPERATURE,
> > + },
> > + {
> > + .type = IIO_VOLTAGE,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> > + BIT(IIO_CHAN_INFO_SCALE) |
> > + BIT(IIO_CHAN_INFO_OFFSET),
> > + .address = MAX9611_CHAN_VOLTAGE_INPUT,
> > + .indexed = 1,
> > + .channel = 1,
> > + },
> > + {
> > + .type = IIO_VOLTAGE,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> > + .address = MAX9611_CHAN_VOLTAGE_SENSE,
> > + .indexed = 1,
> > + .channel = 0,
> Unusual to have the channels in here other than in channel order...
> > + },
> > + {
> > + .type = IIO_CURRENT,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> > + .address = MAX9611_CHAN_CURRENT_LOAD,
> > + },
> > + {
> > + .type = IIO_POWER,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
> > + .address = MAX9611_CHAN_POWER_LOAD
> > + },
> > +};
> > +
> > +/**
> > + * max9611_read_single() - read a single vale from ADC interface
> value
> > + *
> > + * Data registers are 16 bit long, spread between two 8 bit registers
> > + * with consecutive addresses.
> > + * Configure ADC mux first, then read register at address "reg_addr".
> > + * The smbus_read_word routine asks for 16 bits and the ADC is kind enough
> > + * to return values from "reg_addr" and "reg_addr + 1" consecutively.
> > + *
> > + * @max9611: max9611 device
> > + * @selector: index for mux and register configuration
> > + * @raw_val: the value returned from ADC
> > + */
> > +static int max9611_read_single(struct max9611_dev *max9611,
> > + enum max9611_conf_ids selector,
> > + u16 *raw_val)
> > +{
> > + int ret;
> > +
> > + u8 mux_conf = max9611_mux_conf[selector][0] & MAX9611_MUX_MASK;
> > + u8 reg_addr = max9611_mux_conf[selector][1];
> > +
> > + ret = i2c_smbus_write_byte_data(max9611->i2c_client,
> > + MAX9611_REG_CTRL1, mux_conf);
> > + if (ret) {
> > + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
> > + MAX9611_REG_CTRL1, mux_conf);
> > + return ret;
> > + }
> > +
> > + /*
> > + * need a delay here to make register configuration
> > + * stabilize. 1 msec at least, from empirical testing.
> > + */
> > + usleep_range(1000, 2000);
> > +
> > + ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr);
> > + if (ret < 0) {
> > + dev_err(max9611->dev, "i2c read word from 0x%2x failed\n",
> > + reg_addr);
> > + return ret;
> > + }
> > + *raw_val = ret;
> > +
> > + return 0;
> > +}
> > +
> > +/**
> > + * max9611_read_csa_voltage() - read current sense amplifier output voltage
> > + *
> > + * Current sense amplifier output voltage is read through a configurable
> > + * 1x, 4x or 8x gain.
> > + * Start with plain 1x gain, and adjust gain control properly until a
> > + * meaningful value is read from ADC output.
> > + *
> > + * @max9611: max9611 device
> > + * @adc_raw: raw value read from ADC output
> > + * @csa_gain: gain configuration option selector
> > + */
> > +static int max9611_read_csa_voltage(struct max9611_dev *max9611,
> > + u16 *adc_raw,
> > + enum max9611_csa_gain *csa_gain)
> > +{
> > + enum max9611_conf_ids gain_selectors[] = {
> > + CONF_SENSE_1x,
> > + CONF_SENSE_4x,
> > + CONF_SENSE_8x
> > + };
> > + unsigned int i;
> > + int ret;
> > +
> > + for (i = 0; i < ARRAY_SIZE(gain_selectors); ++i) {
> > + ret = max9611_read_single(max9611, gain_selectors[i], adc_raw);
> > + if (ret)
> > + return ret;
> > +
> > + if (*adc_raw > 0) {
> > + *csa_gain = gain_selectors[i];
> > + return 0;
> > + }
> > + }
> > +
> > + return -EIO;
> > +}
> > +
> > +static int max9611_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long mask)
> > +{
> > + struct max9611_dev *dev = iio_priv(indio_dev);
> > + enum max9611_csa_gain gain_selector;
> > + unsigned int *csa_gain;
> > + u16 adc_data;
> > + int ret;
> > +
> > + switch (mask) {
> > + case IIO_CHAN_INFO_RAW:
> > + mutex_lock(&dev->lock);
> > +
> > + switch (chan->address) {
> > + case MAX9611_CHAN_TEMPERATURE:
> > + ret = max9611_read_single(dev, CONF_TEMP,
> > + &adc_data);
> > + if (ret)
> I'm not personally keen on jumping out of deep indentations like this
> just save on repeating one line. I'd pull the unlock back here and return
> directly as I feel it'll improve readability.
I'll change it, with this and Peter's suggestion on this function in
his review.
> Actually come to think of it, why does the lock need to be held for
> the next line anyway? adc_data is on the stack so doesn't matter if we
> have concurrent readers, once the i2c transaction is finished.
> Just unlock before checking ret.
I naively overvalued 'style' (ret assignment and check in two
consecutive lines) over practicality... I'll change this
> > + goto unlock_fail;
> > +
> > + *val = TEMP_RAW(adc_data);
> > +
> > + mutex_unlock(&dev->lock);
> > + return IIO_VAL_INT;
> > +
> > + case MAX9611_CHAN_VOLTAGE_INPUT:
> > + ret = max9611_read_single(dev, CONF_IN_VOLT,
> > + &adc_data);
> > + if (ret)
> > + goto unlock_fail;
> > +
> > + *val = MAX9611_VOLTAGE_RAW(adc_data);
> > +
> > + mutex_unlock(&dev->lock);
> > + return IIO_VAL_INT;
> > + }
> > +
> > + case IIO_CHAN_INFO_OFFSET:
> > + switch (chan->address) {
> > + case MAX9611_CHAN_VOLTAGE_INPUT:
> > + *val = CIM_VOLTAGE_OFFSET_RAW;
> > +
> > + return IIO_VAL_INT;
> > + }
> > +
> > + case IIO_CHAN_INFO_SCALE:
> > + switch (chan->address) {
> > + case MAX9611_CHAN_TEMPERATURE:
> > + *val = TEMP_SCALE_NUM;
> > + *val2 = TEMP_SCALE_DIV;
> > +
> > + return IIO_VAL_FRACTIONAL;
> > +
> > + case MAX9611_CHAN_VOLTAGE_INPUT:
> > + *val = CIM_VOLTAGE_LSB_mV;
> > + return IIO_VAL_INT;
> > + }
> > +
> > + case IIO_CHAN_INFO_PROCESSED:
> > + mutex_lock(&dev->lock);
> > +
> > + switch (chan->address) {
> > + case MAX9611_CHAN_VOLTAGE_SENSE:
> > + /*
> > + * processed (mV): (raw - offset) * LSB (nV) / 10^6
> > + *
> > + * Even if max9611 can output raw csa voltage readings,
> > + * use a produced value as scale depends on gain.
> > + */
> > + ret = max9611_read_csa_voltage(dev, &adc_data,
> > + &gain_selector);
> > + if (ret)
> > + goto unlock_fail;
> > +
> > + csa_gain = max9611_gain_conf[gain_selector];
> > +
> > + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
> > + *val = MAX9611_VOLTAGE_RAW(adc_data) *
> > + csa_gain[CSA_GAIN_LSB_nV];
> > + *val2 = 1000000;
> > +
> > + mutex_unlock(&dev->lock);
> > + return IIO_VAL_FRACTIONAL;
> > +
> > + case MAX9611_CHAN_CURRENT_LOAD:
> > + /* processed (mA): Vcsa (nV) / Rshunt (uOhm) */
> > + ret = max9611_read_csa_voltage(dev, &adc_data,
> > + &gain_selector);
> > + if (ret)
> > + goto unlock_fail;
> > +
> > + csa_gain = max9611_gain_conf[gain_selector];
> > +
> > + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
> > + *val = MAX9611_VOLTAGE_RAW(adc_data) *
> > + csa_gain[CSA_GAIN_LSB_nV];
> > + *val2 = dev->shunt_resistor_uohm;
> > +
> > + mutex_unlock(&dev->lock);
> > + return IIO_VAL_FRACTIONAL;
> > +
> > + case MAX9611_CHAN_POWER_LOAD:
> > + /*
> > + * processed (mW): Vin (mV) * Vcsa (uV) /
> > + * Rshunt (uOhm)
> > + */
> > + ret = max9611_read_single(dev, CONF_IN_VOLT,
> > + &adc_data);
> > + if (ret)
> > + goto unlock_fail;
> > +
> > + adc_data -= CIM_VOLTAGE_OFFSET_RAW;
> > + *val = MAX9611_VOLTAGE_RAW(adc_data) *
> > + CIM_VOLTAGE_LSB_mV;
> > +
> > + ret = max9611_read_csa_voltage(dev, &adc_data,
> > + &gain_selector);
> > + if (ret)
> > + goto unlock_fail;
> > +
> > + csa_gain = max9611_gain_conf[gain_selector];
> > +
> > + /* divide by 10^3 here to avoid 32bit overflow */
> > + adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
> > + *val *= MAX9611_VOLTAGE_RAW(adc_data) *
> > + csa_gain[CSA_GAIN_LSB_nV] / 1000;
> > + *val2 = dev->shunt_resistor_uohm;
> > +
> > + mutex_unlock(&dev->lock);
> > + return IIO_VAL_FRACTIONAL;
> > + }
> > + }
> > +
> > + ret = -EINVAL;
> > +
> > +unlock_fail:
> > + mutex_unlock(&dev->lock);
> > + return ret;
> > +
> > +}
> > +
> > +static ssize_t max9611_shunt_resistor_show(struct device *dev,
> > + struct device_attribute *attr,
> > + char *buf)
> > +{
> > + struct max9611_dev *max9611 = iio_priv(dev_to_iio_dev(dev));
> > +
> > + return sprintf(buf, "%d\n", max9611->shunt_resistor_uohm);
> > +}
> > +
> > +static IIO_DEVICE_ATTR(in_shunt_resistor_power, 0444,
> > + max9611_shunt_resistor_show, NULL, 0);
> > +static IIO_DEVICE_ATTR(in_shunt_resistor_current, 0444,
> > + max9611_shunt_resistor_show, NULL, 0);
> > +
> > +static struct attribute *max9611_attributes[] = {
> > + &iio_dev_attr_in_shunt_resistor_power.dev_attr.attr,
> > + &iio_dev_attr_in_shunt_resistor_current.dev_attr.attr,
> > + NULL,
> > +};
> > +
> > +static const struct attribute_group max9611_attribute_group = {
> > + .attrs = max9611_attributes,
> > +};
> > +
> > +static const struct iio_info indio_info = {
> > + .driver_module = THIS_MODULE,
> > + .read_raw = max9611_read_raw,
> > + .attrs = &max9611_attribute_group,
> > +};
> > +
> > +static int max9611_init(struct max9611_dev *max9611)
> > +{
> > + struct i2c_client *client = max9611->i2c_client;
> > + u16 regval;
> > + int ret;
> > +
> > + if (!i2c_check_functionality(client->adapter,
> > + I2C_FUNC_SMBUS_WRITE_BYTE |
> > + I2C_FUNC_SMBUS_READ_WORD_DATA)) {
> > + dev_err(max9611->dev,
> > + "No smbus support in I2c adapter: aborting probe.\n");
> This isn't necessarily an accurate message. I2c adapter might support
> smbus_read_byte only rather than word reads for example.
>
> Maybe make it more explict as to what we need?
Chopped away some details to make it fit in 80 columns.. I'll make it
more verbose...
> > + return -EINVAL;
> > + }
> > +
> > + /* Configure MUX to read temperature */
> > + ret = i2c_smbus_write_byte_data(max9611->i2c_client,
> > + MAX9611_REG_CTRL1, MAX9611_MUX_TEMP);
> > + if (ret) {
> > + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
> > + MAX9611_REG_CTRL1, MAX9611_MUX_TEMP);
> > + return ret;
> > + }
> > + ret = i2c_smbus_write_byte_data(max9611->i2c_client,
> > + MAX9611_REG_CTRL2, 0);
> > + if (ret) {
> > + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
> > + MAX9611_REG_CTRL2, 0);
> > + return ret;
> > + }
> > + usleep_range(1000, 2000);
> > +
> > + /* Make sure die temperature is in range to test communications. */
> > + ret = i2c_smbus_read_word_swapped(max9611->i2c_client,
> > + MAX9611_REG_TEMP_DATA);
> > + if (ret < 0) {
> > + dev_err(max9611->dev, "i2c read word from 0x%2x failed\n",
> > + MAX9611_REG_TEMP_DATA);
> > + return ret;
> > + }
> > + regval = ret & ~TEMP_MASK;
> > +
> > + if ((regval > TEMP_MAX_RAW_POS &&
> > + regval < TEMP_MIN_RAW_NEG) ||
> > + regval > TEMP_MAX_RAW_NEG) {
> > + dev_err(max9611->dev,
> > + "Invalid value received from ADC 0x%4x: aborting\n",
> > + regval);
> > + return -EIO;
> > + }
> > +
> > + /* Mux shall be zeroed back before applying other configurations */
> > + ret = i2c_smbus_write_byte_data(max9611->i2c_client,
> > + MAX9611_REG_CTRL1, 0);
> > + if (ret) {
> > + dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
> > + MAX9611_REG_CTRL1, 0);
> > + return ret;
> > + }
> > + usleep_range(1000, 2000);
> > +
> > + return 0;
> > +}
> > +
> > +static int max9611_probe(struct i2c_client *client,
> > + const struct i2c_device_id *id)
> > +{
> > + const char * const shunt_res_prop = "shunt-resistor-uohm";
> > + struct device_node *of_node = client->dev.of_node;
> > + struct max9611_dev *max9611;
> > + struct iio_dev *indio_dev;
> > + unsigned int of_shunt;
> > + int ret;
> > +
> > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*max9611));
> > + if (IS_ERR(indio_dev))
> > + return PTR_ERR(indio_dev);
> > +
> > + i2c_set_clientdata(client, indio_dev);
> > +
> > + max9611 = iio_priv(indio_dev);
> > + max9611->dev = &client->dev;
> > + max9611->i2c_client = client;
> > + mutex_init(&max9611->lock);
> > +
> > + ret = of_property_read_u32(of_node, shunt_res_prop, &of_shunt);
> > + if (ret) {
> > + dev_err(&client->dev,
> > + "Missing %s property for %s node\n",
> > + shunt_res_prop, of_node->full_name);
> > + return ret;
> > + }
> > + max9611->shunt_resistor_uohm = of_shunt;
> > +
> > + ret = max9611_init(max9611);
> > + if (ret)
> > + return ret;
> > +
> > + indio_dev->dev.parent = &client->dev;
> > + indio_dev->dev.of_node = client->dev.of_node;
> > + indio_dev->name = client->dev.of_node->name;
> What's this going to give for the name? Name in IIO is supposed to
> be an indication of the part rather than anything more explicit.
> That's not easily obtained from device tree directly...
>
I used the one coming from device tree as otherwise device entries
have the same name, and I wanted to have it to inclued the unit
address (eg. adc@7c and not just adc)
But from you comment I guess it's fine just adc, so I'll change this
back to v1).
Thanks
j
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > + indio_dev->info = &indio_info;
> > + indio_dev->channels = max9611_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(max9611_channels);
> > +
> > + return devm_iio_device_register(&client->dev, indio_dev);
> > +}
> > +
> > +static const struct of_device_id max9611_of_table[] = {
> > + {.compatible = "maxim,max9611"},
> > + {.compatible = "maxim,max9612"},
> > + { },
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, max9611_of_table);
> > +
> > +static struct i2c_driver max9611_driver = {
> > + .driver = {
> > + .name = DRIVER_NAME,
> > + .owner = THIS_MODULE,
> > + .of_match_table = max9611_of_table,
> > + },
> > + .probe = max9611_probe,
> > +};
> > +module_i2c_driver(max9611_driver);
> > +
> > +MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@xxxxxxxxxx>");
> > +MODULE_DESCRIPTION("Maxim max9611/12 current sense amplifier with 12bit ADC");
> > +MODULE_LICENSE("GPL v2");
> >
>
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