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/ina226 Signed-off-by: Marc Titinger <mtitinger@xxxxxxxxxxxx> --- drivers/iio/adc/Kconfig | 10 + drivers/iio/adc/Makefile | 1 + drivers/iio/adc/ina2xx-adc.c | 670 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 681 insertions(+) create mode 100644 drivers/iio/adc/ina2xx-adc.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index eb0cd89..e5fdc7d 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -170,6 +170,16 @@ config EXYNOS_ADC of SoCs for drivers such as the touchscreen and hwmon to use to share this resource. +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 diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index a096210..2869b0ef 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_BERLIN2_ADC) += berlin2-adc.o obj-$(CONFIG_DA9150_GPADC) += da9150-gpadc.o obj-$(CONFIG_CC10001_ADC) += cc10001_adc.o obj-$(CONFIG_EXYNOS_ADC) += exynos_adc.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 diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c new file mode 100644 index 0000000..0e7c474 --- /dev/null +++ b/drivers/iio/adc/ina2xx-adc.c @@ -0,0 +1,670 @@ +/* + * 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@xxxxxx> + * + * 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 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_get_value(struct ina2xx_chip_info *chip, u8 reg, + unsigned int regval, int *val, int *uval) +{ + *val = 0; + + switch (reg) { + case INA2XX_SHUNT_VOLTAGE: + /* signed register */ + *uval = DIV_ROUND_CLOSEST((s16) regval, + chip->config->shunt_div); + return IIO_VAL_INT_PLUS_MICRO; + + case INA2XX_BUS_VOLTAGE: + *uval = (regval >> chip->config->bus_voltage_shift) + * chip->config->bus_voltage_lsb; + *val = *uval / 1000000; + *uval = *uval % 1000000; + return IIO_VAL_INT_PLUS_MICRO; + + case INA2XX_POWER: + *uval = regval * chip->config->power_lsb; + *val = *uval / 1000000; + *uval = *uval % 1000000; + return IIO_VAL_INT_PLUS_MICRO; + + case INA2XX_CURRENT: + /* signed register, LSB=1mA (selected), in mA */ + *uval = (s16) regval * 1000; + return IIO_VAL_INT_PLUS_MICRO; + + default: + /* programmer goofed */ + WARN_ON_ONCE(1); + } + return -EINVAL; +} + +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, ®val); + if (ret < 0) + return ret; + + return ina2xx_get_value(chip, chan->address, regval, val, val2); + + 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; + + default: + return -EINVAL; + } + + return 0; +} + +/* + * 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), \ + .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_BE, \ + } \ +} + +/* + * 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_INT_TIME), \ + .scan_index = (_index), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = 16, \ + .storagebits = 16, \ + .endianness = IIO_BE, \ + } \ +} + +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; +} + +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); +} + +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, + .postdisable = &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@xxxxxxxxxxxx>"); +MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver"); +MODULE_LICENSE("GPL v2"); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
