Commit c43a102e authored by Marc Titinger's avatar Marc Titinger Committed by Jonathan Cameron

iio: ina2xx: add support for TI INA2xx Power Monitors

in SOFTWARE buffer mode, a kthread will capture the active scan_elements
into a kfifo, then compute the remaining time until the next capture tick
and do an active wait (udelay).

This will produce a stream of up to fours channels plus a 64bits
timestamps (ns).

Tested with ina226, on BeagleBoneBlack.

Datasheet: http://www.ti.com/lit/gpn/ina226Signed-off-by: default avatarMarc Titinger <mtitinger@baylibre.com>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 466df4d0
......@@ -194,6 +194,16 @@ config HI8435
This driver can also be built as a module. If so, the module will be
called hi8435.
config INA2XX_ADC
tristate "Texas Instruments INA2xx Power Monitors IIO driver"
depends on I2C && !SENSORS_INA2XX
select REGMAP_I2C
select IIO_BUFFER
select IIO_KFIFO_BUF
help
Say yes here to build support for TI INA2xx family of Power Monitors.
This driver is mutually exclusive with the HWMON version.
config LP8788_ADC
tristate "LP8788 ADC driver"
depends on MFD_LP8788
......
......@@ -20,6 +20,7 @@ obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o
obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o
obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.o
obj-$(CONFIG_HI8435) += hi8435.o
obj-$(CONFIG_INA2XX_ADC) += ina2xx-adc.o
obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o
obj-$(CONFIG_MAX1027) += max1027.o
obj-$(CONFIG_MAX1363) += max1363.o
......
/*
* INA2XX Current and Power Monitors
*
* Copyright 2015 Baylibre SAS.
*
* 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.
*
* Based on linux/drivers/iio/adc/ad7291.c
* Copyright 2010-2011 Analog Devices Inc.
*
* Based on linux/drivers/hwmon/ina2xx.c
* Copyright 2012 Lothar Felten <l-felten@ti.com>
*
* Licensed under the GPL-2 or later.
*
* IIO driver for INA219-220-226-230-231
*
* Configurable 7-bit I2C slave address from 0x40 to 0x4F
*/
#include <linux/module.h>
#include <linux/kthread.h>
#include <linux/delay.h>
#include <linux/iio/kfifo_buf.h>
#include <linux/iio/sysfs.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/platform_data/ina2xx.h>
#include <linux/util_macros.h>
/* INA2XX registers definition */
#define INA2XX_CONFIG 0x00
#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
#define INA2XX_POWER 0x03 /* readonly */
#define INA2XX_CURRENT 0x04 /* readonly */
#define INA2XX_CALIBRATION 0x05
#define INA226_ALERT_MASK 0x06
#define INA266_CVRF BIT(3)
#define INA2XX_MAX_REGISTERS 8
/* settings - depend on use case */
#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
#define INA226_CONFIG_DEFAULT 0x4327
#define INA226_DEFAULT_AVG 4
#define INA226_DEFAULT_IT 1110
#define INA2XX_RSHUNT_DEFAULT 10000
/*
* bit mask for reading the averaging setting in the configuration register
* FIXME: use regmap_fields.
*/
#define INA2XX_MODE_MASK GENMASK(3, 0)
#define INA226_AVG_MASK GENMASK(11, 9)
#define INA226_SHIFT_AVG(val) ((val) << 9)
/* Integration time for VBus */
#define INA226_ITB_MASK GENMASK(8, 6)
#define INA226_SHIFT_ITB(val) ((val) << 6)
/* Integration time for VShunt */
#define INA226_ITS_MASK GENMASK(5, 3)
#define INA226_SHIFT_ITS(val) ((val) << 3)
/* Cosmetic macro giving the sampling period for a full P=UxI cycle */
#define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \
* c->avg)
static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
{
return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
}
static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
{
return (reg != INA2XX_CONFIG);
}
static inline bool is_signed_reg(unsigned int reg)
{
return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
}
static const struct regmap_config ina2xx_regmap_config = {
.reg_bits = 8,
.val_bits = 16,
.max_register = INA2XX_MAX_REGISTERS,
.writeable_reg = ina2xx_is_writeable_reg,
.volatile_reg = ina2xx_is_volatile_reg,
};
enum ina2xx_ids { ina219, ina226 };
struct ina2xx_config {
u16 config_default;
int calibration_factor;
int shunt_div;
int bus_voltage_shift;
int bus_voltage_lsb; /* uV */
int power_lsb; /* uW */
};
struct ina2xx_chip_info {
struct regmap *regmap;
struct task_struct *task;
const struct ina2xx_config *config;
struct mutex state_lock;
long rshunt;
int avg;
s64 prev_ns; /* track buffer capture time, check for underruns*/
int int_time_vbus; /* Bus voltage integration time uS */
int int_time_vshunt; /* Shunt voltage integration time uS */
};
static const struct ina2xx_config ina2xx_config[] = {
[ina219] = {
.config_default = INA219_CONFIG_DEFAULT,
.calibration_factor = 40960000,
.shunt_div = 100,
.bus_voltage_shift = 3,
.bus_voltage_lsb = 4000,
.power_lsb = 20000,
},
[ina226] = {
.config_default = INA226_CONFIG_DEFAULT,
.calibration_factor = 5120000,
.shunt_div = 400,
.bus_voltage_shift = 0,
.bus_voltage_lsb = 1250,
.power_lsb = 25000,
},
};
static int ina2xx_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret;
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
unsigned int regval;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = regmap_read(chip->regmap, chan->address, &regval);
if (ret < 0)
return ret;
if (is_signed_reg(chan->address))
*val = (s16) regval;
else
*val = regval;
return IIO_VAL_INT;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = chip->avg;
return IIO_VAL_INT;
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
if (chan->address == INA2XX_SHUNT_VOLTAGE)
*val2 = chip->int_time_vshunt;
else
*val2 = chip->int_time_vbus;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
/*
* Sample freq is read only, it is a consequence of
* 1/AVG*(CT_bus+CT_shunt).
*/
*val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
switch (chan->address) {
case INA2XX_SHUNT_VOLTAGE:
/* processed (mV) = raw*1000/shunt_div */
*val2 = chip->config->shunt_div;
*val = 1000;
return IIO_VAL_FRACTIONAL;
case INA2XX_BUS_VOLTAGE:
/* processed (mV) = raw*lsb (uV) / (1000 << shift) */
*val = chip->config->bus_voltage_lsb;
*val2 = 1000 << chip->config->bus_voltage_shift;
return IIO_VAL_FRACTIONAL;
case INA2XX_POWER:
/* processed (mW) = raw*lsb (uW) / 1000 */
*val = chip->config->power_lsb;
*val2 = 1000;
return IIO_VAL_FRACTIONAL;
case INA2XX_CURRENT:
/* processed (mA) = raw (mA) */
*val = 1;
return IIO_VAL_INT;
}
}
return -EINVAL;
}
/*
* Available averaging rates for ina226. The indices correspond with
* the bit values expected by the chip (according to the ina226 datasheet,
* table 3 AVG bit settings, found at
* http://www.ti.com/lit/ds/symlink/ina226.pdf.
*/
static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };
static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
unsigned int *config)
{
int bits;
if (val > 1024 || val < 1)
return -EINVAL;
bits = find_closest(val, ina226_avg_tab,
ARRAY_SIZE(ina226_avg_tab));
chip->avg = ina226_avg_tab[bits];
*config &= ~INA226_AVG_MASK;
*config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;
return 0;
}
/* Conversion times in uS */
static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
2116, 4156, 8244 };
static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
unsigned int val_us, unsigned int *config)
{
int bits;
if (val_us > 8244 || val_us < 140)
return -EINVAL;
bits = find_closest(val_us, ina226_conv_time_tab,
ARRAY_SIZE(ina226_conv_time_tab));
chip->int_time_vbus = ina226_conv_time_tab[bits];
*config &= ~INA226_ITB_MASK;
*config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;
return 0;
}
static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
unsigned int val_us, unsigned int *config)
{
int bits;
if (val_us > 8244 || val_us < 140)
return -EINVAL;
bits = find_closest(val_us, ina226_conv_time_tab,
ARRAY_SIZE(ina226_conv_time_tab));
chip->int_time_vshunt = ina226_conv_time_tab[bits];
*config &= ~INA226_ITS_MASK;
*config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;
return 0;
}
static int ina2xx_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
int ret;
unsigned int config, tmp;
if (iio_buffer_enabled(indio_dev))
return -EBUSY;
mutex_lock(&chip->state_lock);
ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
if (ret < 0)
goto _err;
tmp = config;
switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
ret = ina226_set_average(chip, val, &tmp);
break;
case IIO_CHAN_INFO_INT_TIME:
if (chan->address == INA2XX_SHUNT_VOLTAGE)
ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
else
ret = ina226_set_int_time_vbus(chip, val2, &tmp);
break;
default:
ret = -EINVAL;
}
if (!ret && (tmp != config))
ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
_err:
mutex_unlock(&chip->state_lock);
return ret;
}
#define INA2XX_CHAN(_type, _index, _address) { \
.type = (_type), \
.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_LE, \
} \
}
/*
* Sampling Freq is a consequence of the integration times of
* the Voltage channels.
*/
#define INA2XX_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), \
.scan_index = (_index), \
.scan_type = { \
.sign = 'u', \
.realbits = 16, \
.storagebits = 16, \
.endianness = IIO_LE, \
} \
}
static const struct iio_chan_spec ina2xx_channels[] = {
INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
INA2XX_CHAN(IIO_CURRENT, 2, INA2XX_CURRENT),
INA2XX_CHAN(IIO_POWER, 3, INA2XX_POWER),
IIO_CHAN_SOFT_TIMESTAMP(4),
};
static int ina2xx_work_buffer(struct iio_dev *indio_dev)
{
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
unsigned short data[8];
int bit, ret, i = 0;
unsigned long buffer_us, elapsed_us;
s64 time_a, time_b;
unsigned int alert;
time_a = iio_get_time_ns();
/*
* Because the timer thread and the chip conversion clock
* are asynchronous, the period difference will eventually
* result in reading V[k-1] again, or skip V[k] at time Tk.
* In order to resync the timer with the conversion process
* we check the ConVersionReadyFlag.
* On hardware that supports using the ALERT pin to toggle a
* GPIO a triggered buffer could be used instead.
* For now, we pay for that extra read of the ALERT register
*/
do {
ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
&alert);
if (ret < 0)
return ret;
alert &= INA266_CVRF;
trace_printk("Conversion ready: %d\n", !!alert);
} while (!alert);
/*
* Single register reads: bulk_read will not work with ina226
* as there is no auto-increment of the address register for
* data length longer than 16bits.
*/
for_each_set_bit(bit, indio_dev->active_scan_mask,
indio_dev->masklength) {
unsigned int val;
ret = regmap_read(chip->regmap,
INA2XX_SHUNT_VOLTAGE + bit, &val);
if (ret < 0)
return ret;
data[i++] = val;
}
time_b = iio_get_time_ns();
iio_push_to_buffers_with_timestamp(indio_dev,
(unsigned int *)data, time_a);
buffer_us = (unsigned long)(time_b - time_a) / 1000;
elapsed_us = (unsigned long)(time_a - chip->prev_ns) / 1000;
trace_printk("uS: elapsed: %lu, buf: %lu\n", elapsed_us, buffer_us);
chip->prev_ns = time_a;
return buffer_us;
};
static int ina2xx_capture_thread(void *data)
{
struct iio_dev *indio_dev = (struct iio_dev *)data;
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
unsigned int sampling_us = SAMPLING_PERIOD(chip);
int buffer_us;
/*
* Poll a bit faster than the chip internal Fs, in case
* we wish to sync with the conversion ready flag.
*/
sampling_us -= 200;
do {
buffer_us = ina2xx_work_buffer(indio_dev);
if (buffer_us < 0)
return buffer_us;
if (sampling_us > buffer_us)
udelay(sampling_us - buffer_us);
} while (!kthread_should_stop());
return 0;
}
static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
{
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
unsigned int sampling_us = SAMPLING_PERIOD(chip);
trace_printk("Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
(unsigned int)(*indio_dev->active_scan_mask),
1000000/sampling_us, chip->avg);
trace_printk("Expected work period: %u us\n", sampling_us);
chip->prev_ns = iio_get_time_ns();
chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
"ina2xx-%uus", sampling_us);
return PTR_ERR_OR_ZERO(chip->task);
}
static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
{
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
if (chip->task) {
kthread_stop(chip->task);
chip->task = NULL;
}
return 0;
}
static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
.postenable = &ina2xx_buffer_enable,
.predisable = &ina2xx_buffer_disable,
};
static int ina2xx_debug_reg(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval, unsigned *readval)
{
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
if (!readval)
return regmap_write(chip->regmap, reg, writeval);
return regmap_read(chip->regmap, reg, readval);
}
/* Possible integration times for vshunt and vbus */
static IIO_CONST_ATTR_INT_TIME_AVAIL \
("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");
static struct attribute *ina2xx_attributes[] = {
&iio_const_attr_integration_time_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ina2xx_attribute_group = {
.attrs = ina2xx_attributes,
};
static const struct iio_info ina2xx_info = {
.debugfs_reg_access = &ina2xx_debug_reg,
.read_raw = &ina2xx_read_raw,
.write_raw = &ina2xx_write_raw,
.attrs = &ina2xx_attribute_group,
.driver_module = THIS_MODULE,
};
/* Initialize the configuration and calibration registers. */
static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
{
u16 regval;
int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
if (ret < 0)
return ret;
/*
* Set current LSB to 1mA, shunt is in uOhms
* (equation 13 in datasheet). We hardcode a Current_LSB
* of 1.0 x10-6. The only remaining parameter is RShunt.
* There is no need to expose the CALIBRATION register
* to the user for now.
*/
regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
chip->rshunt);
return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
}
static int ina2xx_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ina2xx_chip_info *chip;
struct iio_dev *indio_dev;
struct iio_buffer *buffer;
int ret;
unsigned int val;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
if (!indio_dev)
return -ENOMEM;
chip = iio_priv(indio_dev);
chip->config = &ina2xx_config[id->driver_data];
if (of_property_read_u32(client->dev.of_node,
"shunt-resistor", &val) < 0) {
struct ina2xx_platform_data *pdata =
dev_get_platdata(&client->dev);
if (pdata)
val = pdata->shunt_uohms;
else
val = INA2XX_RSHUNT_DEFAULT;
}
if (val <= 0 || val > chip->config->calibration_factor)
return -ENODEV;
chip->rshunt = val;
mutex_init(&chip->state_lock);
/* This is only used for device removal purposes. */
i2c_set_clientdata(client, indio_dev);
indio_dev->name = id->name;
indio_dev->channels = ina2xx_channels;
indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &ina2xx_info;
indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
if (IS_ERR(chip->regmap)) {
dev_err(&client->dev, "failed to allocate register map\n");
return PTR_ERR(chip->regmap);
}
/* Patch the current config register with default. */
val = chip->config->config_default;
if (id->driver_data == ina226) {
ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
}
ret = ina2xx_init(chip, val);
if (ret < 0) {
dev_err(&client->dev, "error configuring the device: %d\n",
ret);
return -ENODEV;
}
buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
if (!buffer)
return -ENOMEM;
indio_dev->setup_ops = &ina2xx_setup_ops;
iio_device_attach_buffer(indio_dev, buffer);
return iio_device_register(indio_dev);
}
static int ina2xx_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
struct ina2xx_chip_info *chip = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
/* Powerdown */
return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
INA2XX_MODE_MASK, 0);
}
static const struct i2c_device_id ina2xx_id[] = {
{"ina219", ina219},
{"ina220", ina219},
{"ina226", ina226},
{"ina230", ina226},
{"ina231", ina226},
{}
};
MODULE_DEVICE_TABLE(i2c, ina2xx_id);
static struct i2c_driver ina2xx_driver = {
.driver = {
.name = KBUILD_MODNAME,
},
.probe = ina2xx_probe,
.remove = ina2xx_remove,
.id_table = ina2xx_id,
};
module_i2c_driver(ina2xx_driver);
MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
MODULE_LICENSE("GPL v2");
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment