RE: [PATCH 2/2] iio: adc: Add support for TI INA260 power monitors

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> -----Original Message-----
> From: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Sent: Monday, March 22, 2021 5:22 PM
> To: Raviteja Narayanam <rna@xxxxxxxxxx>; robh+dt@xxxxxxxxxx;
> jic23@xxxxxxxxxx
> Cc: Michal Simek <michals@xxxxxxxxxx>; pmeerw@xxxxxxxxxx; linux-
> iio@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; git <git@xxxxxxxxxx>; Shubhrajyoti Datta
> <shubhraj@xxxxxxxxxx>
> Subject: Re: [PATCH 2/2] iio: adc: Add support for TI INA260 power monitors
> 
> On 3/22/21 12:43 PM, Lars-Peter Clausen wrote:
> > On 3/22/21 11:50 AM, Raviteja Narayanam wrote:
> >> This driver supports software buffer mode and raw reads of ina260 iio
> >> channels.
> >>
> >> In software buffer mode, a kthread will capture the active
> >> scan_elements periodically using a delay. This can produce a stream
> >> of up to 3 channels plus a 64 bits timestamp based on the scan_elements.
> >>
> >> Signed-off-by: Raviteja Narayanam <raviteja.narayanam@xxxxxxxxxx>
> >> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> >
> > Hi,
> >
> > Thanks for that patch, it looks really good.
> >
> > Looking at the datasheet the part seems to be very similar to the
> > ina226 from a software interface point of view. Looks like the current
> > and calibration register are missing and the scales are a bit different.
> >
> > We already have a driver for the ina226 (adc-ina2xx) and it looks like
> > your driver is also inspired by it. Have you considered adding support
> > for the ina260 to the existing driver? This will reduce the amount of
> > duplicated code.
> 
> To add to that this driver has some nice new features and bug fixes that are
> not in the ina2xx driver, like debug register access. But the ina2xx has also
> seen a fair amount of improvements since this driver was branched off of it.
> It would be nice to get the best of both in a single driver.

Thanks for the review Lars. 
Yes, using ina2xx driver was the first preference but after this discussion (https://www.spinics.net/lists/devicetree/msg354475.html ),
we have started a new driver as ina260 was considered to be sufficiently different from ina2xx.

Regards,
Raviteja N

> 
> >
> > - Lars
> >
> >> ---
> >>   MAINTAINERS                  |   8 +
> >>   drivers/iio/adc/Kconfig      |  12 +
> >>   drivers/iio/adc/Makefile     |   1 +
> >>   drivers/iio/adc/ina260-adc.c | 556
> >> +++++++++++++++++++++++++++++++++++
> >>   4 files changed, 577 insertions(+)
> >>   create mode 100644 drivers/iio/adc/ina260-adc.c
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS index
> >> aa84121c5611..768a4b148035 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -8760,6 +8760,14 @@ F:    Documentation/hwmon/ina2xx.rst
> >>   F:    drivers/hwmon/ina2xx.c
> >>   F:    include/linux/platform_data/ina2xx.h
> >>   +INA260 POWER MONITOR DRIVER
> >> +M:    Raviteja Narayanam <raviteja.narayanam@xxxxxxxxxx>
> >> +R:    Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> >> +R:    Michal Simek <michal.simek@xxxxxxxxxx>
> >> +S:    Maintained
> >> +F:    Documentation/devicetree/bindings/iio/adc/ti,ina260.yaml
> >> +F:    drivers/iio/adc/ina260-adc.c
> >> +
> >>   INDUSTRY PACK SUBSYSTEM (IPACK)
> >>   M:    Samuel Iglesias Gonsalvez <siglesias@xxxxxxxxxx>
> >>   M:    Jens Taprogge <jens.taprogge@xxxxxxxxxxxx> diff --git
> >> a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index
> >> bf7d22fa4be2..f6f8fd6bd113 100644
> >> --- a/drivers/iio/adc/Kconfig
> >> +++ b/drivers/iio/adc/Kconfig
> >> @@ -497,6 +497,18 @@ config INA2XX_ADC
> >>         Say yes here to build support for TI INA2xx family of Power
> >> Monitors.
> >>         This driver is mutually exclusive with the HWMON version.
> >>   +config INA260_ADC
> >> +    tristate "Texas Instruments INA260 Power Monitors IIO driver"
> >> +    depends on I2C
> >> +    select REGMAP_I2C
> >> +    select IIO_BUFFER
> >> +    select IIO_KFIFO_BUF
> >> +    help
> >> +      Say yes here to build support for TI INA260 power monitor.
> >> +      This driver can also be built as a module. It supports
> >> software buffer
> >> +      mode and raw reads of ina260 iio channels. Up to 4 channels
> >> +are
> >> +      supported including timestamp.
> >> +
> >>   config INGENIC_ADC
> >>       tristate "Ingenic JZ47xx SoCs ADC driver"
> >>       depends on MIPS || COMPILE_TEST diff --git
> >> a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index
> >> 5fca90ada0ec..a3bbcad64a41 100644
> >> --- a/drivers/iio/adc/Makefile
> >> +++ b/drivers/iio/adc/Makefile
> >> @@ -47,6 +47,7 @@ obj-$(CONFIG_HI8435) += hi8435.o
> >>   obj-$(CONFIG_HX711) += hx711.o
> >>   obj-$(CONFIG_IMX7D_ADC) += imx7d_adc.o
> >>   obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
> >> +obj-$(CONFIG_INA260_ADC) += ina260-adc.o
> >>   obj-$(CONFIG_INGENIC_ADC) += ingenic-adc.o
> >>   obj-$(CONFIG_INTEL_MRFLD_ADC) += intel_mrfld_adc.o
> >>   obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o diff --git
> >> a/drivers/iio/adc/ina260-adc.c b/drivers/iio/adc/ina260-adc.c new
> >> file mode 100644 index 000000000000..7f74aa94fd31
> >> --- /dev/null
> >> +++ b/drivers/iio/adc/ina260-adc.c
> >> @@ -0,0 +1,556 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * INA260 power monitor driver
> >> + * Based on drivers/iio/adc/ina2xx-adc.c
> >> + *
> >> + * Copyright (C) 2021 Xilinx, Inc.
> >> + */
> >> +
> >> +#include <linux/i2c.h>
> >> +#include <linux/iio/iio.h>
> >> +#include <linux/iio/buffer.h>
> >> +#include <linux/iio/kfifo_buf.h>
> >> +#include <linux/iio/sysfs.h>
> >> +#include <linux/kthread.h>
> >> +#include <linux/module.h>
> >> +#include <linux/of_device.h>
> >> +#include <linux/regmap.h>
> >> +#include <linux/sched/task.h>
> >> +#include <linux/util_macros.h>
> >> +
> >> +/* INA260 registers definition */
> >> +#define INA260_CONFIG        0x00
> >> +#define INA260_CURRENT        0x01
> >> +#define INA260_VOLTAGE        0x02
> >> +#define INA260_POWER        0x03
> >> +#define INA260_MASK_ENABLE    0x06
> >> +#define INA260_ALERT_LIMIT    0x07
> >> +#define INA260_MANF_ID        0xFE
> >> +#define INA260_DIE_ID        0xFF
> >> +
> >> +#define INA260_CONFIG_DEFAULT    0x6327
> >> +
> >> +#define INA260_CURRENT_LSB    1250
> >> +#define INA260_VOLTAGE_LSB    1250
> >> +#define INA260_POWER_LSB    10
> >> +
> >> +/* Bits */
> >> +#define INA260_CVRF        BIT(3)
> >> +
> >> +#define INA260_MODE_MASK    GENMASK(2, 0) #define
> INA260_VOLT_MASK
> >> +GENMASK(8, 6) #define INA260_SHIFT_VOLT(val)    ((val) << 6) #define
> >> +INA260_CURR_MASK    GENMASK(5, 3) #define
> INA260_SHIFT_CURR(val)
> >> +((val) << 3) #define INA260_AVG_MASK        GENMASK(11, 9) #define
> >> +INA260_SHIFT_AVG(val)    ((val) << 9)
> >> +
> >> +#define SAMPLING_PERIOD(x) ({        \
> >> +    typeof(x) _x = (x);        \
> >> +    (_x->config->volt_conv_time    \
> >> +    + _x->config->curr_conv_time)    \
> >> +    * _x->config->avgs; })
> >> +
> >> +static bool ina260_is_writeable_reg(struct device *dev, unsigned int
> >> reg)
> >> +{
> >> +    return (reg == INA260_CONFIG) || (reg == INA260_MASK_ENABLE) ||
> >> +        (reg == INA260_ALERT_LIMIT); }
> >> +
> >> +static bool ina260_is_volatile_reg(struct device *dev, unsigned int
> >> reg)
> >> +{
> >> +    return (reg != INA260_CONFIG);
> >> +}
> >> +
> >> +static inline bool is_signed_reg(unsigned int reg) {
> >> +    return (reg == INA260_CURRENT);
> >> +}
> >> +
> >> +static const struct regmap_config ina260_regmap_config = {
> >> +    .reg_bits = 8,
> >> +    .val_bits = 16,
> >> +    .max_register = 8,
> >> +    .writeable_reg = ina260_is_writeable_reg,
> >> +    .volatile_reg = ina260_is_volatile_reg, };
> >> +
> >> +enum ina260_ids {ina260 = 0};
> >> +
> >> +/**
> >> + * struct ina260_config - For configurable parameters
> >> + * @config_default: Default configuration
> >> + * @volt_conv_time: Bus voltage conversion time
> >> + * @curr_conv_time: Shunt current conversion time
> >> + * @avgs: Number of samples collected and averaged  */ struct
> >> +ina260_config {
> >> +    u16 config_default;
> >> +    int volt_conv_time;
> >> +    int curr_conv_time;
> >> +    int avgs;
> >> +};
> >> +
> >> +/**
> >> + * struct ina260_chip - For device specific data
> >> + * @regmap: Regmap pointer to device registers
> >> + * @task: Pointer to task created by buffer mode
> >> + * @lock: Mutex to enable use of multiple user apps
> >> + * @chip_id: Id to determine chip
> >> + * @config: Pointer to config structure  */ struct ina260_chip {
> >> +    struct regmap *regmap;
> >> +    struct task_struct *task;
> >> +    struct mutex lock; /* Lock for device writes */
> >> +    enum ina260_ids chip_id;
> >> +    struct ina260_config *config;
> >> +};
> >> +
> >> +static struct ina260_config ina260_config[] = {
> >> +    [ina260] = {
> >> +        .config_default = INA260_CONFIG_DEFAULT,
> >> +        .volt_conv_time = 1100,
> >> +        .curr_conv_time = 1100,
> >> +        .avgs = 4,
> >> +    },
> >> +};
> >> +
> >> +static int ina260_read_raw(struct iio_dev *indio_dev,
> >> +               struct iio_chan_spec const *chan,
> >> +               int *val, int *val2, long mask) {
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    unsigned int regval;
> >> +    int ret;
> >> +
> >> +    switch (mask) {
> >> +    case IIO_CHAN_INFO_RAW:
> >> +        if (iio_buffer_enabled(indio_dev))
> >> +            return -EBUSY;
> >> +
> >> +        ret = regmap_read(chip->regmap, chan->address, &regval);
> >> +        if (ret)
> >> +            return ret;
> >> +
> >> +        if (is_signed_reg(chan->address))
> >> +            *val = (s16)regval;
> >> +        else
> >> +            *val = regval;
> >> +        return IIO_VAL_INT;
> >> +
> >> +    case IIO_CHAN_INFO_SCALE:
> >> +        switch (chan->address) {
> >> +        case INA260_CURRENT:
> >> +            *val = INA260_CURRENT_LSB;
> >> +            *val2 = 1000;
> >> +            return IIO_VAL_FRACTIONAL;
> >> +
> >> +        case INA260_VOLTAGE:
> >> +            *val = INA260_VOLTAGE_LSB;
> >> +            *val2 = 1000;
> >> +            return IIO_VAL_FRACTIONAL;
> >> +
> >> +        case INA260_POWER:
> >> +            *val = INA260_POWER_LSB;
> >> +            return IIO_VAL_INT;
> >> +        }
> >> +        return -EINVAL;
> >> +
> >> +    case IIO_CHAN_INFO_INT_TIME:
> >> +        *val = 0;
> >> +        if (chan->address == INA260_VOLTAGE)
> >> +            *val2 = chip->config->volt_conv_time;
> >> +        else
> >> +            *val2 = chip->config->curr_conv_time;
> >> +
> >> +        return IIO_VAL_INT_PLUS_MICRO;
> >> +
> >> +    case IIO_CHAN_INFO_SAMP_FREQ:
> >> +        *val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
> >> +        return IIO_VAL_INT;
> >> +
> >> +    case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> >> +        *val = chip->config->avgs;
> >> +        return IIO_VAL_INT;
> >> +    }
> >> +
> >> +    return -EINVAL;
> >> +}
> >> +
> >> +static const int ina260_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512,
> >> 1024 };
> >> +
> >> +/* Conversion times in uS */
> >> +static const int ina260_conv_time_tab[] = { 140, 204, 332, 588,
> >> 1100, 2116, 4156, 8244 };
> >> +
> >> +static int ina260_write_raw(struct iio_dev *indio_dev,
> >> +                struct iio_chan_spec const *chan,
> >> +                int val, int val2, long mask) {
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    unsigned int config;
> >> +    int ret, bits;
> >> +
> >> +    if (iio_buffer_enabled(indio_dev))
> >> +        return -EBUSY;
> >> +
> >> +    mutex_lock(&chip->lock);
> >> +
> >> +    ret = regmap_read(chip->regmap, INA260_CONFIG, &config);
> >> +    if (ret)
> >> +        goto err;
> >> +
> >> +    switch (mask) {
> >> +    case IIO_CHAN_INFO_INT_TIME:
> >> +        if (val2 > 8244 || val2 < 140) {
> >> +            ret = -EINVAL;
> >> +            goto err;
> >> +        }
> >> +
> >> +        bits = find_closest(val2, ina260_conv_time_tab,
> >> +                    ARRAY_SIZE(ina260_conv_time_tab));
> >> +
> >> +        if (chan->address == INA260_VOLTAGE) {
> >> +            chip->config->volt_conv_time =
> >> +ina260_conv_time_tab[bits];
> >> +            config &= ~INA260_VOLT_MASK;
> >> +            config |= INA260_SHIFT_VOLT(bits) & INA260_VOLT_MASK;
> >> +        } else {
> >> +            chip->config->curr_conv_time =
> >> +ina260_conv_time_tab[bits];
> >> +            config &= ~INA260_CURR_MASK;
> >> +            config |= INA260_SHIFT_CURR(bits) & INA260_CURR_MASK;
> >> +        }
> >> +        break;
> >> +
> >> +    case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
> >> +        bits = find_closest(val, ina260_avg_tab,
> >> ARRAY_SIZE(ina260_avg_tab));
> >> +        chip->config->avgs = ina260_avg_tab[bits];
> >> +        config &= ~INA260_AVG_MASK;
> >> +        config |= INA260_SHIFT_AVG(bits) & INA260_AVG_MASK;
> >> +        break;
> >> +
> >> +    default:
> >> +        ret = -EINVAL;
> >> +    }
> >> +    if (!ret)
> >> +        ret = regmap_write(chip->regmap, INA260_CONFIG, config);
> >> +err:
> >> +    mutex_unlock(&chip->lock);
> >> +
> >> +    return ret;
> >> +}
> >> +
> >> +static int ina260_debug_reg(struct iio_dev *indio_dev,
> >> +                unsigned int reg, unsigned int writeval, unsigned
> >> int *readval)
> >> +{
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +
> >> +    if (!readval)
> >> +        return regmap_write(chip->regmap, reg, writeval);
> >> +
> >> +    return regmap_read(chip->regmap, reg, readval); }
> >> +
> >> +#define INA260_CHAN_VOLTAGE(_index, _address) { \
> >> +    .type = IIO_VOLTAGE, \
> >> +    .address = (_address), \
> >> +    .indexed = 1, \
> >> +    .channel = (_index), \
> >> +    .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> >> +    BIT(IIO_CHAN_INFO_SCALE) | \
> >> +    BIT(IIO_CHAN_INFO_INT_TIME), \
> >> +    .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
> >> +    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
> >> +    .scan_index = (_index), \
> >> +    .scan_type = { \
> >> +        .sign = 'u', \
> >> +        .realbits = 16, \
> >> +        .storagebits = 16, \
> >> +        .endianness = IIO_CPU, \
> >> +    } \
> >> +}
> >> +
> >> +#define INA260_CHAN_CURRENT(_index, _address) { \
> >> +    .type = IIO_CURRENT, \
> >> +    .address = (_address), \
> >> +    .indexed = 1, \
> >> +    .channel = (_index), \
> >> +    .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> >> +    BIT(IIO_CHAN_INFO_SCALE) | \
> >> +    BIT(IIO_CHAN_INFO_INT_TIME), \
> >> +    .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
> >> +    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
> >> +    .scan_index = (_index), \
> >> +    .scan_type = { \
> >> +        .sign = 's', \
> >> +        .realbits = 16, \
> >> +        .storagebits = 16, \
> >> +        .endianness = IIO_CPU, \
> >> +    } \
> >> +}
> >> +
> >> +#define INA260_CHAN_POWER(_index, _address) { \
> >> +    .type = IIO_POWER, \
> >> +    .address = (_address), \
> >> +    .indexed = 1, \
> >> +    .channel = (_index), \
> >> +    .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> >> +    BIT(IIO_CHAN_INFO_SCALE), \
> >> +    .info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
> >> +    BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
> >> +    .scan_index = (_index), \
> >> +    .scan_type = { \
> >> +        .sign = 'u', \
> >> +        .realbits = 16, \
> >> +        .storagebits = 16, \
> >> +        .endianness = IIO_CPU, \
> >> +    } \
> >> +}
> >> +
> >> +static const struct iio_chan_spec ina260_channels[] = {
> >> +    INA260_CHAN_CURRENT(0, INA260_CURRENT),
> >> +    INA260_CHAN_VOLTAGE(1, INA260_VOLTAGE),
> >> +    INA260_CHAN_POWER(2, INA260_POWER),
> >> +    IIO_CHAN_SOFT_TIMESTAMP(3),
> >> +};
> >> +
> >> +/* Possible integration times for current and voltage */ static
> >> +IIO_CONST_ATTR_NAMED(ina260_integration_time_available,
> >> +                integration_time_available,
> >> +                "0.000140 0.000204 0.000332 0.000588 0.001100
> >> 0.002116 0.004156 0.008244");
> >> +
> >> +static struct attribute *ina260_attributes[] = {
> >> +&iio_const_attr_ina260_integration_time_available.dev_attr.attr,
> >> +    NULL,
> >> +};
> >> +
> >> +static const struct attribute_group ina260_attribute_group = {
> >> +    .attrs = ina260_attributes,
> >> +};
> >> +
> >> +static const struct iio_info ina260_info = {
> >> +    .attrs = &ina260_attribute_group,
> >> +    .read_raw = ina260_read_raw,
> >> +    .write_raw = ina260_write_raw,
> >> +    .debugfs_reg_access = ina260_debug_reg, };
> >> +
> >> +static int ina260_conversion_ready(struct iio_dev *indio_dev) {
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    unsigned int alert;
> >> +    int ret;
> >> +
> >> +    ret = regmap_read(chip->regmap, INA260_MASK_ENABLE, &alert);
> >> +    if (ret < 0)
> >> +        return ret;
> >> +
> >> +    return (alert & INA260_CVRF);
> >> +}
> >> +
> >> +static int ina260_work_buffer(struct iio_dev *indio_dev) {
> >> +    /* data buffer needs space for channel data and timestap */
> >> +    unsigned short data[3 + sizeof(s64) / sizeof(short)];
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    int bit, ret, i = 0;
> >> +    s64 time;
> >> +
> >> +    time = iio_get_time_ns(indio_dev);
> >> +
> >> +    /*
> >> +     * Read current, voltage and power from device
> >> +     */
> >> +    for_each_set_bit(bit, indio_dev->active_scan_mask,
> >> +             indio_dev->masklength) {
> >> +        unsigned int val;
> >> +
> >> +        ret = regmap_read(chip->regmap, INA260_CURRENT + bit, &val);
> >> +        if (ret < 0)
> >> +            return ret;
> >> +
> >> +        data[i++] = val;
> >> +    }
> >> +
> >> +    iio_push_to_buffers_with_timestamp(indio_dev, data, time);
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static int ina260_capture_thread(void *data) {
> >> +    struct iio_dev *indio_dev = data;
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    int sampling_us = SAMPLING_PERIOD(chip);
> >> +    struct timespec64 next, now, delta;
> >> +    s64 delay_us;
> >> +    int ret;
> >> +
> >> +    ktime_get_ts64(&next);
> >> +
> >> +    do {
> >> +        while (1) {
> >> +            /* Check if conversion is ready */
> >> +            ret = ina260_conversion_ready(indio_dev);
> >> +            if (ret < 0)
> >> +                return ret;
> >> +
> >> +            /*
> >> +             * If the conversion was not yet finished,
> >> +             * reset the reference timestamp.
> >> +             */
> >> +            if (ret == 0)
> >> +                ktime_get_ts64(&next);
> >> +            else
> >> +                break;
> >> +        }
> >> +        /* Read the data from sensor and push it to buffers */
> >> +        ret = ina260_work_buffer(indio_dev);
> >> +        if (ret < 0)
> >> +            return ret;
> >> +
> >> +        ktime_get_ts64(&now);
> >> +        /*
> >> +         * Advance the timestamp for the next poll by one sampling
> >> +         * interval, and sleep for the remainder (next - now)
> >> +         * In case "next" has already passed, the interval is added
> >> +         * multiple times, i.e. samples are dropped.
> >> +         */
> >> +        do {
> >> +            timespec64_add_ns(&next, 1000 * sampling_us);
> >> +            delta = timespec64_sub(next, now);
> >> +            delay_us = div_s64(timespec64_to_ns(&delta), 1000);
> >> +        } while (delay_us <= 0);
> >> +
> >> +        usleep_range(delay_us, (delay_us * 3) >> 1);
> >> +
> >> +    } while (!kthread_should_stop());
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static int ina260_buffer_enable(struct iio_dev *indio_dev) {
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +    unsigned int sampling_us = SAMPLING_PERIOD(chip);
> >> +    struct task_struct *task;
> >> +
> >> +    task = kthread_create(ina260_capture_thread, (void *)indio_dev,
> >> +                  "%s:%d-%uus", indio_dev->name, indio_dev->id,
> >> +                  sampling_us);
> >> +
> >> +    if (IS_ERR(task))
> >> +        return PTR_ERR(task);
> >> +
> >> +    get_task_struct(task);
> >> +    wake_up_process(task);
> >> +    chip->task = task;
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static int ina260_buffer_disable(struct iio_dev *indio_dev) {
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +
> >> +    if (chip->task) {
> >> +        kthread_stop(chip->task);
> >> +        put_task_struct(chip->task);
> >> +        chip->task = NULL;
> >> +    }
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +static const struct iio_buffer_setup_ops ina260_setup_ops = {
> >> +    .postenable = &ina260_buffer_enable,
> >> +    .predisable = &ina260_buffer_disable, };
> >> +
> >> +static int ina260_probe(struct i2c_client *client, const struct
> >> i2c_device_id *id)
> >> +{
> >> +    struct iio_dev *indio_dev;
> >> +    struct iio_buffer *buffer;
> >> +    struct ina260_chip *chip;
> >> +    enum ina260_ids type = 0;
> >> +    int ret;
> >> +
> >> +    indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
> >> +    if (!indio_dev)
> >> +        return -ENOMEM;
> >> +
> >> +    chip = iio_priv(indio_dev);
> >> +    i2c_set_clientdata(client, indio_dev);
> >> +
> >> +    chip->regmap = devm_regmap_init_i2c(client,
> >> +&ina260_regmap_config);
> >> +    if (IS_ERR(chip->regmap)) {
> >> +        dev_err(&client->dev, "failed to allocate register map\n");
> >> +        return PTR_ERR(chip->regmap);
> >> +    }
> >> +
> >> +    mutex_init(&chip->lock);
> >> +
> >> +    indio_dev->modes = INDIO_DIRECT_MODE |
> INDIO_BUFFER_SOFTWARE;
> >> +    indio_dev->dev.parent = &client->dev;
> >> +    indio_dev->dev.of_node = client->dev.of_node;
> >> +
> >> +    chip->config = &ina260_config[type];
> >> +    ret = regmap_write(chip->regmap, INA260_CONFIG,
> >> +               chip->config->config_default);
> >> +    if (ret) {
> >> +        dev_err(&client->dev, "Error configuring the device\n");
> >> +        return ret;
> >> +    }
> >> +    indio_dev->channels = ina260_channels;
> >> +    indio_dev->num_channels = ARRAY_SIZE(ina260_channels);
> >> +    indio_dev->info = &ina260_info;
> >> +    indio_dev->name = id->name;
> >> +    indio_dev->setup_ops = &ina260_setup_ops;
> >> +
> >> +    buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
> >> +    if (!buffer)
> >> +        return -ENOMEM;
> >> +
> >> +    iio_device_attach_buffer(indio_dev, buffer);
> >> +
> >> +    return iio_device_register(indio_dev); }
> >> +
> >> +static int ina260_remove(struct i2c_client *client) {
> >> +    struct iio_dev *indio_dev = i2c_get_clientdata(client);
> >> +    struct ina260_chip *chip = iio_priv(indio_dev);
> >> +
> >> +    iio_device_unregister(indio_dev);
> >> +    /* Power down */
> >> +    return regmap_update_bits(chip->regmap, INA260_CONFIG,
> >> INA260_MODE_MASK, 0);
> >> +}
> >> +
> >> +static const struct i2c_device_id ina260_id[] = {
> >> +    {"ina260", ina260},
> >> +    {}
> >> +};
> >> +MODULE_DEVICE_TABLE(i2c, ina260_id);
> >> +
> >> +static const struct of_device_id ina260_of_match[] = {
> >> +    {
> >> +        .compatible = "ti,ina260",
> >> +        .data = (void *)ina260
> >> +    },
> >> +    {},
> >> +};
> >> +MODULE_DEVICE_TABLE(of, ina260_of_match);
> >> +
> >> +static struct i2c_driver ina260_driver = {
> >> +    .driver = {
> >> +        .name = "ina260-adc",
> >> +        .of_match_table = ina260_of_match,
> >> +    },
> >> +    .probe = ina260_probe,
> >> +    .remove = ina260_remove,
> >> +    .id_table = ina260_id,
> >> +};
> >> +module_i2c_driver(ina260_driver);
> >> +
> >> +MODULE_AUTHOR("Raviteja Narayanam
> <raviteja.narayanam@xxxxxxxxxx>");
> >> +MODULE_DESCRIPTION("Texas Instruments INA 260 ADC driver");
> >> +MODULE_LICENSE("GPL v2");
> >
> >





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