#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 {
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];
};
},
};
+/*
+ * 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_avg_bits(int avg)
+{
+ int i;
+
+ /* Get the closest average from the tab. */
+ for (i = 0; i < ARRAY_SIZE(ina226_avg_tab) - 1; i++) {
+ if (avg <= (ina226_avg_tab[i] + ina226_avg_tab[i + 1]) / 2)
+ break;
+ }
+
+ return i; /* Return 0b0111 for values greater than 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 = ina226_avg_bits(avg);
+
+ 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)
{
return i2c_smbus_write_word_swapped(data->client, INA2XX_CALIBRATION,
/* device configuration */
ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
- data->config->config_default);
+ data->curr_config);
if (ret < 0)
return ret;
{
struct ina2xx_data *data = dev_get_drvdata(dev);
struct ina2xx_data *ret = data;
+ unsigned long after;
int rv;
mutex_lock(&data->update_lock);
- if (time_after(jiffies, data->last_updated +
- HZ / INA2XX_CONVERSION_RATE) || !data->valid) {
+ 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);
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;
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ 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);
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_shunt_resistor.dev_attr.attr,
NULL,
};
-ATTRIBUTE_GROUPS(ina2xx);
+
+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 ina2xx_data *data;
struct device *hwmon_dev;
u32 val;
- int ret;
+ int ret, group = 0;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
/* 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;
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, ina2xx_groups);
+ data, data->groups);
if (IS_ERR(hwmon_dev))
return PTR_ERR(hwmon_dev);