* [PATCH v4 1/3] hwmon: ina2xx: make shunt resistance configurable at run-time
2014-12-03 13:06 [PATCH v4 0/3] hwmon: ina2xx: new attributes Bartosz Golaszewski
@ 2014-12-03 13:06 ` Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 2/3] hwmon: ina2xx: allow to change the averaging rate " Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 3/3] hwmon: ina2xx: documentation update for new sysfs attributes Bartosz Golaszewski
2 siblings, 0 replies; 4+ messages in thread
From: Bartosz Golaszewski @ 2014-12-03 13:06 UTC (permalink / raw)
To: Guenter Roeck
Cc: LKML, Benoit Cousson, Patrick Titiano, LM Sensors, Bartosz Golaszewski
The shunt resistance can only be set via platform_data or device tree. This
isn't suitable for devices in which the shunt resistance can change/isn't
known at boot-time.
Add a sysfs attribute that allows to read and set the shunt resistance.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/hwmon/ina2xx.c | 70 +++++++++++++++++++++++++++++++++++++++++++-------
1 file changed, 61 insertions(+), 9 deletions(-)
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index e01feba..309bfdb 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -51,7 +51,6 @@
#define INA226_ALERT_LIMIT 0x07
#define INA226_DIE_ID 0xFF
-
/* register count */
#define INA219_REGISTERS 6
#define INA226_REGISTERS 8
@@ -65,6 +64,9 @@
/* worst case is 68.10 ms (~14.6Hz, ina219) */
#define INA2XX_CONVERSION_RATE 15
+/* default shunt resistance */
+#define INA2XX_RSHUNT_DEFAULT 10000
+
enum ina2xx_ids { ina219, ina226 };
struct ina2xx_config {
@@ -87,6 +89,8 @@ struct ina2xx_data {
int kind;
u16 regs[INA2XX_MAX_REGISTERS];
+
+ long rshunt;
};
static const struct ina2xx_config ina2xx_config[] = {
@@ -110,6 +114,11 @@ static const struct ina2xx_config ina2xx_config[] = {
},
};
+static u16 ina2xx_calibration_val(const struct ina2xx_data *data)
+{
+ return data->config->calibration_factor / data->rshunt;
+}
+
static struct ina2xx_data *ina2xx_update_device(struct device *dev)
{
struct ina2xx_data *data = dev_get_drvdata(dev);
@@ -164,6 +173,9 @@ static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
/* signed register, LSB=1mA (selected), in mA */
val = (s16)data->regs[reg];
break;
+ case INA2XX_CALIBRATION:
+ val = data->config->calibration_factor / data->regs[reg];
+ break;
default:
/* programmer goofed */
WARN_ON_ONCE(1);
@@ -187,6 +199,38 @@ static ssize_t ina2xx_show_value(struct device *dev,
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 ||
+ val > LONG_MAX)
+ return -EINVAL;
+
+ mutex_lock(&data->update_lock);
+ data->rshunt = val;
+ status = i2c_smbus_write_word_swapped(data->client, INA2XX_CALIBRATION,
+ ina2xx_calibration_val(data));
+ mutex_unlock(&data->update_lock);
+ if (status < 0)
+ return status;
+
+ return count;
+}
+
/* shunt voltage */
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
INA2XX_SHUNT_VOLTAGE);
@@ -203,12 +247,18 @@ static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
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);
+
/* 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,
};
ATTRIBUTE_GROUPS(ina2xx);
@@ -221,7 +271,6 @@ static int ina2xx_probe(struct i2c_client *client,
struct device *dev = &client->dev;
struct ina2xx_data *data;
struct device *hwmon_dev;
- long shunt = 10000; /* default shunt value 10mOhms */
u32 val;
int ret;
@@ -234,19 +283,22 @@ static int ina2xx_probe(struct i2c_client *client,
if (dev_get_platdata(dev)) {
pdata = dev_get_platdata(dev);
- shunt = pdata->shunt_uohms;
+ data->rshunt = pdata->shunt_uohms;
} else if (!of_property_read_u32(dev->of_node,
"shunt-resistor", &val)) {
- shunt = val;
+ data->rshunt = val;
+ } else {
+ data->rshunt = INA2XX_RSHUNT_DEFAULT;
}
- if (shunt <= 0)
- return -ENODEV;
-
/* set the device type */
data->kind = id->driver_data;
data->config = &ina2xx_config[data->kind];
+ if (data->rshunt <= 0 ||
+ data->rshunt > data->config->calibration_factor)
+ return -ENODEV;
+
/* device configuration */
ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
data->config->config_default);
@@ -261,7 +313,7 @@ static int ina2xx_probe(struct i2c_client *client,
* (equation 13 in datasheet).
*/
ret = i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
- data->config->calibration_factor / shunt);
+ ina2xx_calibration_val(data));
if (ret < 0) {
dev_err(dev,
"error writing to the calibration register: %d", ret);
@@ -277,7 +329,7 @@ static int ina2xx_probe(struct i2c_client *client,
return PTR_ERR(hwmon_dev);
dev_info(dev, "power monitor %s (Rshunt = %li uOhm)\n",
- id->name, shunt);
+ id->name, data->rshunt);
return 0;
}
--
2.1.3
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v4 2/3] hwmon: ina2xx: allow to change the averaging rate at run-time
2014-12-03 13:06 [PATCH v4 0/3] hwmon: ina2xx: new attributes Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 1/3] hwmon: ina2xx: make shunt resistance configurable at run-time Bartosz Golaszewski
@ 2014-12-03 13:06 ` Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 3/3] hwmon: ina2xx: documentation update for new sysfs attributes Bartosz Golaszewski
2 siblings, 0 replies; 4+ messages in thread
From: Bartosz Golaszewski @ 2014-12-03 13:06 UTC (permalink / raw)
To: Guenter Roeck
Cc: LKML, Benoit Cousson, Patrick Titiano, LM Sensors, Bartosz Golaszewski
The averaging rate of ina226 is hardcoded to 16 in the driver.
Make it modifiable at run-time via a new sysfs attribute.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
drivers/hwmon/ina2xx.c | 125 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 122 insertions(+), 3 deletions(-)
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 309bfdb..9826c69 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -67,6 +67,15 @@
/* default shunt resistance */
#define INA2XX_RSHUNT_DEFAULT 10000
+/* bit masks for the averaging setting in the configuration register */
+#define INA226_AVG_RD_MASK 0x0E00
+#define INA226_AVG_WR_MASK 0xF1FF
+
+#define INA226_READ_AVG(reg) ((reg & INA226_AVG_RD_MASK) >> 9)
+
+/* common attrs, ina226 attrs and NULL */
+#define INA2XX_MAX_ATTRIBUTE_GROUPS 3
+
enum ina2xx_ids { ina219, ina226 };
struct ina2xx_config {
@@ -88,6 +97,7 @@ struct ina2xx_data {
unsigned long last_updated;
int kind;
+ const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
u16 regs[INA2XX_MAX_REGISTERS];
long rshunt;
@@ -114,11 +124,43 @@ static const struct ina2xx_config ina2xx_config[] = {
},
};
+/*
+ * 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 u16 ina2xx_calibration_val(const struct ina2xx_data *data)
{
return data->config->calibration_factor / data->rshunt;
}
+static int ina226_avg_bits(int avg)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(ina226_avg_tab); i++) {
+ if (avg == ina226_avg_tab[i])
+ return i;
+ }
+
+ return -EINVAL;
+}
+
+static int ina226_avg_val(int bits)
+{
+ /*
+ * Value read from the config register should be correct, but do check
+ * the boundary just in case.
+ */
+ if (bits >= ARRAY_SIZE(ina226_avg_tab))
+ return -ENODEV;
+
+ return ina226_avg_tab[bits];
+}
+
static struct ina2xx_data *ina2xx_update_device(struct device *dev)
{
struct ina2xx_data *data = dev_get_drvdata(dev);
@@ -231,6 +273,63 @@ static ssize_t ina2xx_set_shunt(struct device *dev,
return count;
}
+static ssize_t ina226_show_avg(struct device *dev,
+ struct device_attribute *da, char *buf)
+{
+ struct ina2xx_data *data = ina2xx_update_device(dev);
+ int avg, i, written = 0;
+ const char *fmt;
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ avg = ina226_avg_val(INA226_READ_AVG(data->regs[INA2XX_CONFIG]));
+ if (avg < 0)
+ return avg;
+
+ for (i = 0; i < ARRAY_SIZE(ina226_avg_tab); i++) {
+ if (avg == ina226_avg_tab[i])
+ fmt = "\t[%d]";
+ else
+ fmt = "\t%d";
+
+ written += snprintf(buf + written, PAGE_SIZE - written,
+ fmt, ina226_avg_tab[i]);
+ }
+ written += snprintf(buf + written, PAGE_SIZE - written, "\n");
+
+ return written;
+}
+
+static ssize_t ina226_set_avg(struct device *dev,
+ struct device_attribute *da,
+ const char *buf, size_t count)
+{
+ struct ina2xx_data *data = ina2xx_update_device(dev);
+ long val;
+ int status, avg;
+ u16 conf;
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ status = kstrtol(buf, 10, &val);
+ if (status < 0)
+ return status;
+
+ avg = ina226_avg_bits(val);
+ if (avg < 0)
+ return avg;
+
+ mutex_lock(&data->update_lock);
+ conf = (data->regs[INA2XX_CONFIG] & INA226_AVG_WR_MASK) | (avg << 9);
+ status = i2c_smbus_write_word_swapped(data->client,
+ INA2XX_CONFIG, conf);
+ mutex_unlock(&data->update_lock);
+
+ return count;
+}
+
/* shunt voltage */
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
INA2XX_SHUNT_VOLTAGE);
@@ -252,6 +351,10 @@ static SENSOR_DEVICE_ATTR(shunt_resistor, S_IRUGO | S_IWUSR,
ina2xx_show_value, ina2xx_set_shunt,
INA2XX_CALIBRATION);
+/* averaging rate */
+static SENSOR_DEVICE_ATTR(avg_rate, S_IRUGO | S_IWUSR,
+ ina226_show_avg, ina226_set_avg, 0);
+
/* pointers to created device attributes */
static struct attribute *ina2xx_attrs[] = {
&sensor_dev_attr_in0_input.dev_attr.attr,
@@ -261,7 +364,19 @@ static struct attribute *ina2xx_attrs[] = {
&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_avg_rate.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)
@@ -272,7 +387,7 @@ static int ina2xx_probe(struct i2c_client *client,
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;
@@ -323,8 +438,12 @@ static int ina2xx_probe(struct i2c_client *client,
data->client = client;
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);
--
2.1.3
^ permalink raw reply [flat|nested] 4+ messages in thread* [PATCH v4 3/3] hwmon: ina2xx: documentation update for new sysfs attributes
2014-12-03 13:06 [PATCH v4 0/3] hwmon: ina2xx: new attributes Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 1/3] hwmon: ina2xx: make shunt resistance configurable at run-time Bartosz Golaszewski
2014-12-03 13:06 ` [PATCH v4 2/3] hwmon: ina2xx: allow to change the averaging rate " Bartosz Golaszewski
@ 2014-12-03 13:06 ` Bartosz Golaszewski
2 siblings, 0 replies; 4+ messages in thread
From: Bartosz Golaszewski @ 2014-12-03 13:06 UTC (permalink / raw)
To: Guenter Roeck
Cc: LKML, Benoit Cousson, Patrick Titiano, LM Sensors, Bartosz Golaszewski
Include the rshunt and avg sysfs attributes for ina2xx in the documentation.
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
Documentation/hwmon/ina2xx | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
index 4223c2d..c100c24 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -44,6 +44,10 @@ The INA226 monitors both a shunt voltage drop and bus supply voltage.
The INA230 is a high or low side current shunt and power monitor with an I2C
interface. The INA230 monitors both a shunt voltage drop and bus supply voltage.
-The shunt value in micro-ohms can be set via platform data or device tree.
-Please refer to the Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings
-if the device tree is used.
+The shunt value in micro-ohms can be set via platform data or device tree in
+compile-time or via the shunt_resistor attribute in sysfs in run-time. Please
+refer to the Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings if
+the device tree is used.
+
+The averaging rate of INA226 and INA230 can be changed via the avg_rate sysfs
+attribute. The available rates are: 1, 4, 16, 64, 128, 256, 512 and 1024.
--
2.1.3
^ permalink raw reply [flat|nested] 4+ messages in thread