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path: root/drivers/iio/adc/ina2xx-adc.c
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Diffstat (limited to 'drivers/iio/adc/ina2xx-adc.c')
-rw-r--r--drivers/iio/adc/ina2xx-adc.c668
1 files changed, 668 insertions, 0 deletions
diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
new file mode 100644
index 000000000000..707bd69a7353
--- /dev/null
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -0,0 +1,668 @@
+/*
+ * 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");
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-13 02:41:17 +0300