On 06/04/17 15:20, 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 <[email protected]>
Applied to the togreg branch of iio.git and and pushed out as testing
to see if the various tests can find anything we have all missed!
Jonathan
> ---
>
> Output of iio_info on Salvator-X board for max9611 chip installed on
> VDD_0.8 lines.
> The VDD_0.8 line powers the CPU cluster and on-board RAM.
>
> iio:device0: max9611
> 5 channels found:
> voltage0: (input)
> 1 channel-specific attributes found:
> attr 0: input value: 4.085000000
> voltage1: (input)
> 3 channel-specific attributes found:
> attr 0: scale value: 14
> attr 1: offset value: 1
> attr 2: raw value: 59
> power: (input)
> 2 channel-specific attributes found:
> attr 0: shunt_resistor value: 5.000
> attr 1: input value: 663.404000000
> current: (input)
> 2 channel-specific attributes found:
> attr 0: shunt_resistor value: 5.000
> attr 1: input value: 817.000000000
> temp: (input)
> 2 channel-specific attributes found:
> attr 0: scale value: 480.076812289
> attr 1: raw value: 59
>
> The collected information represent:
>
> * voltage0 (current sense voltage) Vcsa
> voltage drop between RS+ and RS- input = 4,085 mV
> * voltage1: (common input voltage) Vcim
> voltage at RS+ input = (59 - 1) * 14 = 812 mV
> * current flowing on shunt resistor (Icsa)
> = Vcsa / Rshunt = 817 mA
> * power load on the sensed line (Pload)
> = Vcim * Icsa = 663 m
> * die temperature = (57 * 480.07) = 27360 milli Celsius
>
> ---
> drivers/iio/adc/Kconfig | 10 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/max9611.c | 585
> ++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 596 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..f0b47fa
> --- /dev/null
> +++ b/drivers/iio/adc/max9611.c
> @@ -0,0 +1,585 @@
> +/*
> + * 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>
> +#include <linux/of_device.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 GENMASK(3, 0)
> +#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 MAX9611_CSA_1X_LSB_nV 107500
> +#define MAX9611_CSA_4X_LSB_nV 26880
> +#define MAX9611_CSA_8X_LSB_nV 13440
> +
> +#define MAX9611_CSA_1X_OFFS_RAW 1
> +#define MAX9611_CSA_4X_OFFS_RAW 1
> +#define MAX9611_CSA_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 MAX9611_CIM_LSB_mV 14
> +#define MAX9611_CIM_OFFSET_RAW 1
> +
> +/*
> + * max9611 temperature reading: LSB is 480 milli degrees Celsius
> + *
> + * The complete formula to calculate temperature is:
> + * ((adc_read >> 7) * 1000) / (1 / 480 * 1000)
> + */
> +#define MAX9611_TEMP_MAX_POS 0x7f80
> +#define MAX9611_TEMP_MAX_NEG 0xff80
> +#define MAX9611_TEMP_MIN_NEG 0xd980
> +#define MAX9611_TEMP_MASK GENMASK(7, 15)
> +#define MAX9611_TEMP_SHIFT 0x07
> +#define MAX9611_TEMP_RAW(_r) ((_r) >> MAX9611_TEMP_SHIFT)
> +#define MAX9611_TEMP_SCALE_NUM 1000000
> +#define MAX9611_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 const 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 const unsigned int max9611_gain_conf[][2] = {
> + { /* [0] CSA_GAIN_1x */
> + MAX9611_CSA_1X_LSB_nV,
> + MAX9611_CSA_1X_OFFS_RAW,
> + },
> + { /* [1] CSA_GAIN_4x */
> + MAX9611_CSA_4X_LSB_nV,
> + MAX9611_CSA_4X_OFFS_RAW,
> + },
> + { /* [2] CSA_GAIN_8x */
> + MAX9611_CSA_8X_LSB_nV,
> + MAX9611_CSA_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 const 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_PROCESSED),
> + .address = MAX9611_CHAN_VOLTAGE_SENSE,
> + .indexed = 1,
> + .channel = 0,
> + },
> + {
> + .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_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 value from ADC interface
> + *
> + * 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.
> + * Data are transmitted with big-endian ordering: MSB arrives first.
> + *
> + * @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];
> +
> + /*
> + * Keep mutex lock held during read-write to avoid mux register
> + * (CTRL1) re-configuration.
> + */
> + mutex_lock(&max9611->lock);
> + 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);
> + mutex_unlock(&max9611->lock);
> + 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);
> + mutex_unlock(&max9611->lock);
> + return ret;
> + }
> +
> + *raw_val = ret;
> + mutex_unlock(&max9611->lock);
> +
> + 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;
> + const unsigned int *csa_gain;
> + u16 adc_data;
> + int ret;
> +
> + switch (mask) {
> + case IIO_CHAN_INFO_RAW:
> +
> + switch (chan->address) {
> + case MAX9611_CHAN_TEMPERATURE:
> + ret = max9611_read_single(dev, CONF_TEMP,
> + &adc_data);
> + if (ret)
> + return -EINVAL;
> +
> + *val = MAX9611_TEMP_RAW(adc_data);
> + return IIO_VAL_INT;
> +
> + case MAX9611_CHAN_VOLTAGE_INPUT:
> + ret = max9611_read_single(dev, CONF_IN_VOLT,
> + &adc_data);
> + if (ret)
> + return -EINVAL;
> +
> + *val = MAX9611_VOLTAGE_RAW(adc_data);
> + return IIO_VAL_INT;
> + }
> +
> + break;
> +
> + case IIO_CHAN_INFO_OFFSET:
> + /* MAX9611_CHAN_VOLTAGE_INPUT */
> + *val = MAX9611_CIM_OFFSET_RAW;
> +
> + return IIO_VAL_INT;
> +
> + case IIO_CHAN_INFO_SCALE:
> +
> + switch (chan->address) {
> + case MAX9611_CHAN_TEMPERATURE:
> + *val = MAX9611_TEMP_SCALE_NUM;
> + *val2 = MAX9611_TEMP_SCALE_DIV;
> +
> + return IIO_VAL_FRACTIONAL;
> +
> + case MAX9611_CHAN_VOLTAGE_INPUT:
> + *val = MAX9611_CIM_LSB_mV;
> +
> + return IIO_VAL_INT;
> + }
> +
> + break;
> +
> + case IIO_CHAN_INFO_PROCESSED:
> +
> + 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)
> + return -EINVAL;
> +
> + 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;
> +
> + 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)
> + return -EINVAL;
> +
> + 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;
> +
> + 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)
> + return -EINVAL;
> +
> + adc_data -= MAX9611_CIM_OFFSET_RAW;
> + *val = MAX9611_VOLTAGE_RAW(adc_data) *
> + MAX9611_CIM_LSB_mV;
> +
> + ret = max9611_read_csa_voltage(dev, &adc_data,
> + &gain_selector);
> + if (ret)
> + return -EINVAL;
> +
> + 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;
> +
> + return IIO_VAL_FRACTIONAL;
> + }
> +
> + break;
> + }
> +
> + return -EINVAL;
> +}
> +
> +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));
> + unsigned int i, r;
> +
> + i = max9611->shunt_resistor_uohm / 1000;
> + r = max9611->shunt_resistor_uohm % 1000;
> +
> + return sprintf(buf, "%u.%03u\n", i, r);
> +}
> +
> +static IIO_DEVICE_ATTR(in_power_shunt_resistor, 0444,
> + max9611_shunt_resistor_show, NULL, 0);
> +static IIO_DEVICE_ATTR(in_current_shunt_resistor, 0444,
> + max9611_shunt_resistor_show, NULL, 0);
> +
> +static struct attribute *max9611_attributes[] = {
> + &iio_dev_attr_in_power_shunt_resistor.dev_attr.attr,
> + &iio_dev_attr_in_current_shunt_resistor.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,
> + "I2c adapter does not support smbus write_byte or
> read_word functionalities: aborting probe.\n");
> + return -EINVAL;
> + }
> +
> + /* Make sure die temperature is in range to test communications. */
> + ret = max9611_read_single(max9611, CONF_TEMP, ®val);
> + if (ret)
> + return ret;
> +
> + regval = ret & MAX9611_TEMP_MASK;
> +
> + if ((regval > MAX9611_TEMP_MAX_POS &&
> + regval < MAX9611_TEMP_MIN_NEG) ||
> + regval > MAX9611_TEMP_MAX_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;
> + }
> +
> + 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);
> +
> + return 0;
> +}
> +
> +static const struct of_device_id max9611_of_table[] = {
> + {.compatible = "maxim,max9611", .data = "max9611"},
> + {.compatible = "maxim,max9612", .data = "max9612"},
> + { },
> +};
> +
> +MODULE_DEVICE_TABLE(of, max9611_of_table);
> +static int max9611_probe(struct i2c_client *client,
> + const struct i2c_device_id *id)
> +{
> + const char * const shunt_res_prop = "shunt-resistor-micro-ohms";
> + const struct device_node *of_node = client->dev.of_node;
> + const struct of_device_id *of_id =
> + of_match_device(max9611_of_table, &client->dev);
> + 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 = of_id->data;
> + 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 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 <[email protected]>");
> +MODULE_DESCRIPTION("Maxim max9611/12 current sense amplifier with 12bit
> ADC");
> +MODULE_LICENSE("GPL v2");
> --
> 2.7.4
>
