--- /dev/null
+/*
+ * Driver for Texas Instruments INA219, INA226 power monitor chips
+ *
+ * INA219:
+ * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina219
+ *
+ * INA220:
+ * Bi-Directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina220
+ *
+ * INA226:
+ * Bi-Directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina226
+ *
+ * INA230:
+ * Bi-directional Current/Power Monitor with I2C Interface
+ * Datasheet: http://www.ti.com/product/ina230
+ *
+ * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
+ * Thanks to Jan Volkering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/util_macros.h>
+
+#include <linux/platform_data/ina2xx.h>
+
+/* common register definitions */
+#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
+
+/* INA226 register definitions */
+#define INA226_MASK_ENABLE 0x06
+#define INA226_ALERT_LIMIT 0x07
+#define INA226_DIE_ID 0xFF
+
+/* register count */
+#define INA219_REGISTERS 6
+#define INA226_REGISTERS 8
+
+#define INA2XX_MAX_REGISTERS 8
+
+/* settings - depend on use case */
+#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
+#define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */
+
+/* worst case is 68.10 ms (~14.6Hz, ina219) */
+#define INA2XX_CONVERSION_RATE 15
+#define INA2XX_MAX_DELAY 69 /* worst case delay in ms */
+
+#define INA2XX_RSHUNT_DEFAULT 10000
+
+/* bit mask for reading the averaging setting in the configuration register */
+#define INA226_AVG_RD_MASK 0x0E00
+
+#define INA226_READ_AVG(reg) (((reg) & INA226_AVG_RD_MASK) >> 9)
+#define INA226_SHIFT_AVG(val) ((val) << 9)
+
+/* common attrs, ina226 attrs and NULL */
+#define INA2XX_MAX_ATTRIBUTE_GROUPS 3
+
+/*
+ * Both bus voltage and shunt voltage conversion times for ina226 are set
+ * to 0b0100 on POR, which translates to 2200 microseconds in total.
+ */
+#define INA226_TOTAL_CONV_TIME_DEFAULT 2200
+
+enum ina2xx_ids { ina219, ina226 };
+
+struct ina2xx_config {
+ u16 config_default;
+ int calibration_factor;
+ int registers;
+ int shunt_div;
+ int bus_voltage_shift;
+ int bus_voltage_lsb; /* uV */
+ int power_lsb; /* uW */
+};
+
+struct ina2xx_data {
+ struct i2c_client *client;
+ const struct ina2xx_config *config;
+
+ long rshunt;
+ u16 curr_config;
+
+ struct mutex update_lock;
+ bool valid;
+ unsigned long last_updated;
+ int update_interval; /* in jiffies */
+
+ int kind;
+ const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
+ u16 regs[INA2XX_MAX_REGISTERS];
+};
+
+static const struct ina2xx_config ina2xx_config[] = {
+ [ina219] = {
+ .config_default = INA219_CONFIG_DEFAULT,
+ .calibration_factor = 40960000,
+ .registers = INA219_REGISTERS,
+ .shunt_div = 100,
+ .bus_voltage_shift = 3,
+ .bus_voltage_lsb = 4000,
+ .power_lsb = 20000,
+ },
+ [ina226] = {
+ .config_default = INA226_CONFIG_DEFAULT,
+ .calibration_factor = 5120000,
+ .registers = INA226_REGISTERS,
+ .shunt_div = 400,
+ .bus_voltage_shift = 0,
+ .bus_voltage_lsb = 1250,
+ .power_lsb = 25000,
+ },
+};
+
+/*
+ * 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_reg_to_interval(u16 config)
+{
+ int avg = ina226_avg_tab[INA226_READ_AVG(config)];
+
+ /*
+ * Multiply the total conversion time by the number of averages.
+ * Return the result in milliseconds.
+ */
+ return DIV_ROUND_CLOSEST(avg * INA226_TOTAL_CONV_TIME_DEFAULT, 1000);
+}
+
+static u16 ina226_interval_to_reg(int interval, u16 config)
+{
+ int avg, avg_bits;
+
+ avg = DIV_ROUND_CLOSEST(interval * 1000,
+ INA226_TOTAL_CONV_TIME_DEFAULT);
+ avg_bits = find_closest(avg, ina226_avg_tab,
+ ARRAY_SIZE(ina226_avg_tab));
+
+ return (config & ~INA226_AVG_RD_MASK) | INA226_SHIFT_AVG(avg_bits);
+}
+
+static void ina226_set_update_interval(struct ina2xx_data *data)
+{
+ int ms;
+
+ ms = ina226_reg_to_interval(data->curr_config);
+ data->update_interval = msecs_to_jiffies(ms);
+}
+
+static int ina2xx_calibrate(struct ina2xx_data *data)
+{
+ u16 val = DIV_ROUND_CLOSEST(data->config->calibration_factor,
+ data->rshunt);
+
+ return i2c_smbus_write_word_swapped(data->client,
+ INA2XX_CALIBRATION, val);
+}
+
+/*
+ * Initialize the configuration and calibration registers.
+ */
+static int ina2xx_init(struct ina2xx_data *data)
+{
+ struct i2c_client *client = data->client;
+ int ret;
+
+ /* device configuration */
+ ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
+ data->curr_config);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * Set current LSB to 1mA, shunt is in uOhms
+ * (equation 13 in datasheet).
+ */
+ return ina2xx_calibrate(data);
+}
+
+static int ina2xx_do_update(struct device *dev)
+{
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ int i, rv, retry;
+
+ dev_dbg(&client->dev, "Starting ina2xx update\n");
+
+ for (retry = 5; retry; retry--) {
+ /* Read all registers */
+ for (i = 0; i < data->config->registers; i++) {
+ rv = i2c_smbus_read_word_swapped(client, i);
+ if (rv < 0)
+ return rv;
+ data->regs[i] = rv;
+ }
+
+ /*
+ * If the current value in the calibration register is 0, the
+ * power and current registers will also remain at 0. In case
+ * the chip has been reset let's check the calibration
+ * register and reinitialize if needed.
+ */
+ if (data->regs[INA2XX_CALIBRATION] == 0) {
+ dev_warn(dev, "chip not calibrated, reinitializing\n");
+
+ rv = ina2xx_init(data);
+ if (rv < 0)
+ return rv;
+
+ /*
+ * Let's make sure the power and current registers
+ * have been updated before trying again.
+ */
+ msleep(INA2XX_MAX_DELAY);
+ continue;
+ }
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+
+ return 0;
+ }
+
+ /*
+ * If we're here then although all write operations succeeded, the
+ * chip still returns 0 in the calibration register. Nothing more we
+ * can do here.
+ */
+ dev_err(dev, "unable to reinitialize the chip\n");
+ return -ENODEV;
+}
+
+static struct ina2xx_data *ina2xx_update_device(struct device *dev)
+{
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ struct ina2xx_data *ret = data;
+ unsigned long after;
+ int rv;
+
+ mutex_lock(&data->update_lock);
+
+ after = data->last_updated + data->update_interval;
+ if (time_after(jiffies, after) || !data->valid) {
+ rv = ina2xx_do_update(dev);
+ if (rv < 0)
+ ret = ERR_PTR(rv);
+ }
+
+ mutex_unlock(&data->update_lock);
+ return ret;
+}
+
+static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
+{
+ int val;
+
+ switch (reg) {
+ case INA2XX_SHUNT_VOLTAGE:
+ /* signed register */
+ val = DIV_ROUND_CLOSEST((s16)data->regs[reg],
+ data->config->shunt_div);
+ break;
+ case INA2XX_BUS_VOLTAGE:
+ val = (data->regs[reg] >> data->config->bus_voltage_shift)
+ * data->config->bus_voltage_lsb;
+ val = DIV_ROUND_CLOSEST(val, 1000);
+ break;
+ case INA2XX_POWER:
+ val = data->regs[reg] * data->config->power_lsb;
+ break;
+ case INA2XX_CURRENT:
+ /* signed register, LSB=1mA (selected), in mA */
+ val = (s16)data->regs[reg];
+ break;
+ case INA2XX_CALIBRATION:
+ val = DIV_ROUND_CLOSEST(data->config->calibration_factor,
+ data->regs[reg]);
+ break;
+ default:
+ /* programmer goofed */
+ WARN_ON_ONCE(1);
+ val = 0;
+ break;
+ }
+
+ return val;
+}
+
+static ssize_t ina2xx_show_value(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct ina2xx_data *data = ina2xx_update_device(dev);
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ ina2xx_get_value(data, attr->index));
+}
+
+static ssize_t ina2xx_set_shunt(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct ina2xx_data *data = ina2xx_update_device(dev);
+ unsigned long val;
+ int status;
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ status = kstrtoul(buf, 10, &val);
+ if (status < 0)
+ return status;
+
+ if (val == 0 ||
+ /* Values greater than the calibration factor make no sense. */
+ val > data->config->calibration_factor)
+ return -EINVAL;
+
+ mutex_lock(&data->update_lock);
+ data->rshunt = val;
+ status = ina2xx_calibrate(data);
+ mutex_unlock(&data->update_lock);
+ if (status < 0)
+ return status;
+
+ return count;
+}
+
+static ssize_t ina226_set_interval(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct ina2xx_data *data = dev_get_drvdata(dev);
+ unsigned long val;
+ int status;
+
+ status = kstrtoul(buf, 10, &val);
+ if (status < 0)
+ return status;
+
+ if (val > INT_MAX || val == 0)
+ return -EINVAL;
+
+ mutex_lock(&data->update_lock);
+ data->curr_config = ina226_interval_to_reg(val,
+ data->regs[INA2XX_CONFIG]);
+ status = i2c_smbus_write_word_swapped(data->client,
+ INA2XX_CONFIG,
+ data->curr_config);
+
+ ina226_set_update_interval(data);
+ /* Make sure the next access re-reads all registers. */
+ data->valid = 0;
+ mutex_unlock(&data->update_lock);
+ if (status < 0)
+ return status;
+
+ return count;
+}
+
+static ssize_t ina226_show_interval(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct ina2xx_data *data = ina2xx_update_device(dev);
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ /*
+ * We don't use data->update_interval here as we want to display
+ * the actual interval used by the chip and jiffies_to_msecs()
+ * doesn't seem to be accurate enough.
+ */
+ return snprintf(buf, PAGE_SIZE, "%d\n",
+ ina226_reg_to_interval(data->regs[INA2XX_CONFIG]));
+}
+
+/* shunt voltage */
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
+ INA2XX_SHUNT_VOLTAGE);
+
+/* bus voltage */
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
+ INA2XX_BUS_VOLTAGE);
+
+/* calculated current */
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
+ INA2XX_CURRENT);
+
+/* calculated power */
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
+ INA2XX_POWER);
+
+/* shunt resistance */
+static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR,
+ ina2xx_show_value, ina2xx_set_shunt,
+ INA2XX_CALIBRATION);
+
+/* update interval (ina226 only) */
+static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
+ ina226_show_interval, ina226_set_interval, 0);
+
+/* pointers to created device attributes */
+static struct attribute *ina2xx_attrs[] = {
+ &sensor_dev_attr_in0_input.dev_attr.attr,
+ &sensor_dev_attr_in1_input.dev_attr.attr,
+ &sensor_dev_attr_curr1_input.dev_attr.attr,
+ &sensor_dev_attr_power1_input.dev_attr.attr,
+ &sensor_dev_attr_shunt_resistor.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ina2xx_group = {
+ .attrs = ina2xx_attrs,
+};
+
+static struct attribute *ina226_attrs[] = {
+ &sensor_dev_attr_update_interval.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ina226_group = {
+ .attrs = ina226_attrs,
+};
+
+static int ina2xx_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct ina2xx_platform_data *pdata;
+ struct device *dev = &client->dev;
+ struct ina2xx_data *data;
+ struct device *hwmon_dev;
+ u32 val;
+ int ret, group = 0;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
+ return -ENODEV;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ if (dev_get_platdata(dev)) {
+ pdata = dev_get_platdata(dev);
+ data->rshunt = pdata->shunt_uohms;
+ } else if (!of_property_read_u32(dev->of_node,
+ "shunt-resistor", &val)) {
+ data->rshunt = val;
+ } else {
+ data->rshunt = INA2XX_RSHUNT_DEFAULT;
+ }
+
+ /* set the device type */
+ data->kind = id->driver_data;
+ data->config = &ina2xx_config[data->kind];
+ data->curr_config = data->config->config_default;
+ data->client = client;
+
+ /*
+ * Ina226 has a variable update_interval. For ina219 we
+ * use a constant value.
+ */
+ if (data->kind == ina226)
+ ina226_set_update_interval(data);
+ else
+ data->update_interval = HZ / INA2XX_CONVERSION_RATE;
+
+ if (data->rshunt <= 0 ||
+ data->rshunt > data->config->calibration_factor)
+ return -ENODEV;
+
+ ret = ina2xx_init(data);
+ if (ret < 0) {
+ dev_err(dev, "error configuring the device: %d\n", ret);
+ return -ENODEV;
+ }
+
+ mutex_init(&data->update_lock);
+
+ data->groups[group++] = &ina2xx_group;
+ if (data->kind == ina226)
+ data->groups[group++] = &ina226_group;
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ data, data->groups);
+ if (IS_ERR(hwmon_dev))
+ return PTR_ERR(hwmon_dev);
+
+ dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
+ id->name, data->rshunt);
+
+ return 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 = "ina2xx",
+ },
+ .probe = ina2xx_probe,
+ .id_table = ina2xx_id,
+};
+
+module_i2c_driver(ina2xx_driver);
+
+MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
+MODULE_DESCRIPTION("ina2xx driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff