Skip to content

Commit

Permalink
hwmon: (ina3221) Add averaging mode support
Browse files Browse the repository at this point in the history 
The CONFIG register has a 3-bit averaging mode field for users
to setup the number of samples that are collected and averaged
together. This is very useful to filter noise from sensor data.

This patch adds a 'samples' sysfs node using hwmon_chip_samples
of hwmon core, and updates wait time calculation by taking this
samples value into account.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
  • Loading branch information
Nicolin Chen authored and Guenter Roeck committed Apr 16, 2019
1 parent 038a9c3 commit 5c090ab
Show file tree
Hide file tree
Showing 2 changed files with 69 additions and 1 deletion.
3 changes: 3 additions & 0 deletions Documentation/hwmon/ina3221
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,3 +35,6 @@ curr[123]_max Warning alert current(mA) setting, activates the
average is above this value.
curr[123]_max_alarm Warning alert current limit exceeded
in[456]_input Shunt voltage(uV) for channels 1, 2, and 3 respectively
samples Number of samples using in the averaging mode.
Supports the list of number of samples:
1, 4, 16, 64, 128, 256, 512, 1024
67 changes: 66 additions & 1 deletion drivers/hwmon/ina3221.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -22,6 +22,7 @@
#include <linux/of.h>
#include <linux/pm_runtime.h>
#include <linux/regmap.h>
#include <linux/util_macros.h>

#define INA3221_DRIVER_NAME "ina3221"

Expand Down Expand Up @@ -51,6 +52,9 @@
#define INA3221_CONFIG_VBUS_CT_SHIFT 6
#define INA3221_CONFIG_VBUS_CT_MASK GENMASK(8, 6)
#define INA3221_CONFIG_VBUS_CT(x) (((x) & GENMASK(8, 6)) >> 6)
#define INA3221_CONFIG_AVG_SHIFT 9
#define INA3221_CONFIG_AVG_MASK GENMASK(11, 9)
#define INA3221_CONFIG_AVG(x) (((x) & GENMASK(11, 9)) >> 9)
#define INA3221_CONFIG_CHs_EN_MASK GENMASK(14, 12)
#define INA3221_CONFIG_CHx_EN(x) BIT(14 - (x))

Expand Down Expand Up @@ -135,17 +139,24 @@ static const u16 ina3221_conv_time[] = {
140, 204, 332, 588, 1100, 2116, 4156, 8244,
};

/* Lookup table for number of samples using in averaging mode */
static const int ina3221_avg_samples[] = {
1, 4, 16, 64, 128, 256, 512, 1024,
};

static inline int ina3221_wait_for_data(struct ina3221_data *ina)
{
u32 channels = hweight16(ina->reg_config & INA3221_CONFIG_CHs_EN_MASK);
u32 vbus_ct_idx = INA3221_CONFIG_VBUS_CT(ina->reg_config);
u32 vsh_ct_idx = INA3221_CONFIG_VSH_CT(ina->reg_config);
u32 samples_idx = INA3221_CONFIG_AVG(ina->reg_config);
u32 samples = ina3221_avg_samples[samples_idx];
u32 vbus_ct = ina3221_conv_time[vbus_ct_idx];
u32 vsh_ct = ina3221_conv_time[vsh_ct_idx];
u32 wait, cvrf;

/* Calculate total conversion time */
wait = channels * (vbus_ct + vsh_ct);
wait = channels * (vbus_ct + vsh_ct) * samples;

/* Polling the CVRF bit to make sure read data is ready */
return regmap_field_read_poll_timeout(ina->fields[F_CVRF],
Expand Down Expand Up @@ -176,6 +187,21 @@ static const u8 ina3221_in_reg[] = {
INA3221_SHUNT3,
};

static int ina3221_read_chip(struct device *dev, u32 attr, long *val)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int regval;

switch (attr) {
case hwmon_chip_samples:
regval = INA3221_CONFIG_AVG(ina->reg_config);
*val = ina3221_avg_samples[regval];
return 0;
default:
return -EOPNOTSUPP;
}
}

static int ina3221_read_in(struct device *dev, u32 attr, int channel, long *val)
{
const bool is_shunt = channel > INA3221_CHANNEL3;
Expand Down Expand Up @@ -279,6 +305,30 @@ static int ina3221_read_curr(struct device *dev, u32 attr,
}
}

static int ina3221_write_chip(struct device *dev, u32 attr, long val)
{
struct ina3221_data *ina = dev_get_drvdata(dev);
int ret, idx;

switch (attr) {
case hwmon_chip_samples:
idx = find_closest(val, ina3221_avg_samples,
ARRAY_SIZE(ina3221_avg_samples));

ret = regmap_update_bits(ina->regmap, INA3221_CONFIG,
INA3221_CONFIG_AVG_MASK,
idx << INA3221_CONFIG_AVG_SHIFT);
if (ret)
return ret;

/* Update reg_config accordingly */
return regmap_read(ina->regmap, INA3221_CONFIG,
&ina->reg_config);
default:
return -EOPNOTSUPP;
}
}

static int ina3221_write_curr(struct device *dev, u32 attr,
int channel, long val)
{
Expand Down Expand Up @@ -361,6 +411,9 @@ static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
mutex_lock(&ina->lock);

switch (type) {
case hwmon_chip:
ret = ina3221_read_chip(dev, attr, val);
break;
case hwmon_in:
/* 0-align channel ID */
ret = ina3221_read_in(dev, attr, channel - 1, val);
Expand All @@ -387,6 +440,9 @@ static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
mutex_lock(&ina->lock);

switch (type) {
case hwmon_chip:
ret = ina3221_write_chip(dev, attr, val);
break;
case hwmon_in:
/* 0-align channel ID */
ret = ina3221_write_enable(dev, channel - 1, val);
Expand Down Expand Up @@ -423,6 +479,13 @@ static umode_t ina3221_is_visible(const void *drvdata,
const struct ina3221_input *input = NULL;

switch (type) {
case hwmon_chip:
switch (attr) {
case hwmon_chip_samples:
return 0644;
default:
return 0;
}
case hwmon_in:
/* Ignore in0_ */
if (channel == 0)
Expand Down Expand Up @@ -463,6 +526,8 @@ static umode_t ina3221_is_visible(const void *drvdata,
HWMON_C_MAX | HWMON_C_MAX_ALARM)

static const struct hwmon_channel_info *ina3221_info[] = {
HWMON_CHANNEL_INFO(chip,
HWMON_C_SAMPLES),
HWMON_CHANNEL_INFO(in,
/* 0: dummy, skipped in is_visible */
HWMON_I_INPUT,
Expand Down

0 comments on commit 5c090ab

Please sign in to comment.