[PATCH v8 5/5] hwmon: ina2xx: allow to change the averaging rate at run-time
The averaging rate of ina226 is hardcoded to 16 in the driver. Make it
modifiable at run-time via a new sysfs attribute.
While we're at it - add an additional variable to ina2xx_data, which holds
the current configuration settings - this way we'll be able to restore the
configuration in case of an unexpected chip reset.
Signed-off-by: Bartosz Golaszewski
---
Documentation/hwmon/ina2xx | 3 ++
drivers/hwmon/ina2xx.c | 129 +++--
2 files changed, 128 insertions(+), 4 deletions(-)
diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
index 320dd69..a11256d 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -48,3 +48,6 @@ The shunt value in micro-ohms can be set via platform data or
device tree at
compile-time or via the shunt_resistor attribute in sysfs at 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.
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 49537ea..6f6aebd 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -68,6 +68,15 @@
#define INA2XX_RSHUNT_DEFAULT 1
+/* 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_GROUPS3
+
enum ina2xx_ids { ina219, ina226 };
struct ina2xx_config {
@@ -85,12 +94,14 @@ struct ina2xx_data {
const struct ina2xx_config *config;
long rshunt;
+ u16 curr_config;
struct mutex update_lock;
bool valid;
unsigned long last_updated;
int kind;
+ const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
u16 regs[INA2XX_MAX_REGISTERS];
};
@@ -115,6 +126,39 @@ 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 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)
+ return i;
+ }
+
+ return i; /* Return 0b0111 for other values. */
+}
+
+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 int ina2xx_calibrate(struct ina2xx_data *data)
{
return i2c_smbus_write_word_swapped(data->client, INA2XX_CALIBRATION,
@@ -131,7 +175,7 @@ static int ina2xx_init(struct ina2xx_data *data)
/* device configuration */
ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
- data->config->config_default);
+ data->curr_config);
if (ret < 0)
return ret;
@@ -292,6 +336,62 @@ 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;
+
+ 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])
+ break;
+ }
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", ina226_avg_tab[i]);
+}
+
+static ssize_t ina226_set_avg(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, avg;
+
+ if (IS_ERR(data))
+ return PTR_ERR(data);
+
+ status = kstrtoul(buf, 10, );
+ if (status < 0)
+ return status;
+
+ if (val > INT_MAX || val == 0)
+ return -EINVAL;
+
+ avg = ina226_avg_bits(val);
+
+ mutex_lock(>update_lock);
+
[PATCH v8 5/5] hwmon: ina2xx: allow to change the averaging rate at run-time
The averaging rate of ina226 is hardcoded to 16 in the driver. Make it
modifiable at run-time via a new sysfs attribute.
While we're at it - add an additional variable to ina2xx_data, which holds
the current configuration settings - this way we'll be able to restore the
configuration in case of an unexpected chip reset.
Signed-off-by: Bartosz Golaszewski bgolaszew...@baylibre.com
---
Documentation/hwmon/ina2xx | 3 ++
drivers/hwmon/ina2xx.c | 129 +++--
2 files changed, 128 insertions(+), 4 deletions(-)
diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
index 320dd69..a11256d 100644
--- a/Documentation/hwmon/ina2xx
+++ b/Documentation/hwmon/ina2xx
@@ -48,3 +48,6 @@ The shunt value in micro-ohms can be set via platform data or
device tree at
compile-time or via the shunt_resistor attribute in sysfs at 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.
diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index 49537ea..6f6aebd 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -68,6 +68,15 @@
#define INA2XX_RSHUNT_DEFAULT 1
+/* 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_GROUPS3
+
enum ina2xx_ids { ina219, ina226 };
struct ina2xx_config {
@@ -85,12 +94,14 @@ struct ina2xx_data {
const struct ina2xx_config *config;
long rshunt;
+ u16 curr_config;
struct mutex update_lock;
bool valid;
unsigned long last_updated;
int kind;
+ const struct attribute_group *groups[INA2XX_MAX_ATTRIBUTE_GROUPS];
u16 regs[INA2XX_MAX_REGISTERS];
};
@@ -115,6 +126,39 @@ 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 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)
+ return i;
+ }
+
+ return i; /* Return 0b0111 for other values. */
+}
+
+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 int ina2xx_calibrate(struct ina2xx_data *data)
{
return i2c_smbus_write_word_swapped(data-client, INA2XX_CALIBRATION,
@@ -131,7 +175,7 @@ static int ina2xx_init(struct ina2xx_data *data)
/* device configuration */
ret = i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
- data-config-config_default);
+ data-curr_config);
if (ret 0)
return ret;
@@ -292,6 +336,62 @@ 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;
+
+ 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])
+ break;
+ }
+
+ return snprintf(buf, PAGE_SIZE, %d\n, ina226_avg_tab[i]);
+}
+
+static ssize_t ina226_set_avg(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, avg;
+
+ 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;
+
+ avg = ina226_avg_bits(val);
+
+ mutex_lock(data-update_lock);
