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Message-ID: <c6b2152e-7331-201d-d64a-5e5eba46e76d@metafoo.de>
Date: Mon, 22 Mar 2021 13:52:08 +0100
From: Lars-Peter Clausen <lars@...afoo.de>
To: Raviteja Narayanam <rna@...inx.com>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"jic23@...nel.org" <jic23@...nel.org>
Cc: Michal Simek <michals@...inx.com>,
"pmeerw@...erw.net" <pmeerw@...erw.net>,
"linux-iio@...r.kernel.org" <linux-iio@...r.kernel.org>,
"devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
git <git@...inx.com>, Shubhrajyoti Datta <shubhraj@...inx.com>
Subject: Re: [PATCH 2/2] iio: adc: Add support for TI INA260 power monitors
On 3/22/21 1:11 PM, Raviteja Narayanam wrote:
>
>> -----Original Message-----
>> From: Lars-Peter Clausen <lars@...afoo.de>
>> Sent: Monday, March 22, 2021 5:22 PM
>> To: Raviteja Narayanam <rna@...inx.com>; robh+dt@...nel.org;
>> jic23@...nel.org
>> Cc: Michal Simek <michals@...inx.com>; pmeerw@...erw.net; linux-
>> iio@...r.kernel.org; devicetree@...r.kernel.org; linux-
>> kernel@...r.kernel.org; git <git@...inx.com>; Shubhrajyoti Datta
>> <shubhraj@...inx.com>
>> 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@...inx.com>
>>>> Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>
>>> 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.
Can you elaborate where you see the significant difference? When I look
at the code the drivers are >90% identical.
I believe pretty much all we need to support the ina260 in the existing
driver is to add a new iio_chan_spec and ina2xx_config for it. And then
some minor tweaks to other parts of the driver, e.g. to make calibration
optional. I believe this can be done in ~50 lines of code without making
the structure of the driver more cluttered.
>
> 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@...inx.com>
>>>> +R: Shubhrajyoti Datta <shubhrajyoti.datta@...inx.com>
>>>> +R: Michal Simek <michal.simek@...inx.com>
>>>> +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@...lia.com>
>>>> M: Jens Taprogge <jens.taprogge@...rogge.org> 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, ®val);
>>>> + 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@...inx.com>");
>>>> +MODULE_DESCRIPTION("Texas Instruments INA 260 ADC driver");
>>>> +MODULE_LICENSE("GPL v2");
>>>
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