[PATCH v2 7/7] iio: chemical: bme680: simplify oversampling handling

David Frey
2018-08-15T23:29:25Z

Temperature, pressure and humidity all expose and oversampling setting
that works in the same way. Provide common handling for the
oversampling sysfs attributes.

Signed-off-by: David Frey <dpfrey@gmail.com>
---
drivers/iio/chemical/bme680_core.c | 99 ++++++++++++++------------------------
1 file changed, 36 insertions(+), 63 deletions(-)

diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
index c96e4a991a61..799389e8c0d9 100644
--- a/drivers/iio/chemical/bme680_core.c
+++ b/drivers/iio/chemical/bme680_core.c
@@ -91,8 +91,6 @@ static const struct iio_chan_spec bme680_channels[] = {
},
};

-static const int bme680_oversampling_avail[] = { 1, 2, 4, 8, 16 };
-
static int bme680_read_calib(struct bme680_data *data,
struct bme680_calib *calib)
{
@@ -503,12 +501,20 @@ static int bme680_set_mode(struct bme680_data *data, bool mode)
return ret;
}

+static u8 bme680_oversampling_to_reg(u8 val)
+{
+ return ilog2(val) + 1;
+}
+
static int bme680_chip_config(struct bme680_data *data)
{
struct device *dev = regmap_get_device(data->regmap);
int ret;
- u8 osrs = FIELD_PREP(BME680_OSRS_HUMIDITY_MASK,
- data->oversampling_humid + 1);
+ u8 osrs;
+
+ osrs = FIELD_PREP(
+ BME680_OSRS_HUMIDITY_MASK,
+ bme680_oversampling_to_reg(data->oversampling_humid));
/*
* Highly recommended to set oversampling of humidity before
* temperature/pressure oversampling.
@@ -529,12 +535,12 @@ static int bme680_chip_config(struct bme680_data *data)
return ret;
}

- osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK, data->oversampling_temp + 1) |
- FIELD_PREP(BME680_OSRS_PRESS_MASK, data->oversampling_press + 1);
-
+ osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK,
+ bme680_oversampling_to_reg(data->oversampling_temp)) |
+ FIELD_PREP(BME680_OSRS_PRESS_MASK,
+ bme680_oversampling_to_reg(data->oversampling_press));
ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS,
- BME680_OSRS_TEMP_MASK |
- BME680_OSRS_PRESS_MASK,
+ BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK,
osrs);
if (ret < 0)
dev_err(dev, "failed to write ctrl_meas register\n");
@@ -767,13 +773,13 @@ static int bme680_read_raw(struct iio_dev *indio_dev,
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
switch (chan->type) {
case IIO_TEMP:
- *val = 1 << data->oversampling_temp;
+ *val = data->oversampling_temp;
return IIO_VAL_INT;
case IIO_PRESSURE:
- *val = 1 << data->oversampling_press;
+ *val = data->oversampling_press;
return IIO_VAL_INT;
case IIO_HUMIDITYRELATIVE:
- *val = 1 << data->oversampling_humid;
+ *val = data->oversampling_humid;
return IIO_VAL_INT;
default:
return -EINVAL;
@@ -783,52 +789,9 @@ static int bme680_read_raw(struct iio_dev *indio_dev,
}
}

-static int bme680_write_oversampling_ratio_temp(struct bme680_data *data,
- int val)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
- if (bme680_oversampling_avail[i] == val) {
- data->oversampling_temp = ilog2(val);
-
- return bme680_chip_config(data);
- }
- }
-
- return -EINVAL;
-}
-
-static int bme680_write_oversampling_ratio_press(struct bme680_data *data,
- int val)
-{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
- if (bme680_oversampling_avail[i] == val) {
- data->oversampling_press = ilog2(val);
-
- return bme680_chip_config(data);
- }
- }
-
- return -EINVAL;
-}
-
-static int bme680_write_oversampling_ratio_humid(struct bme680_data *data,
- int val)
+static bool bme680_is_valid_oversampling(int rate)
{
- int i;
-
- for (i = 0; i < ARRAY_SIZE(bme680_oversampling_avail); i++) {
- if (bme680_oversampling_avail[i] == val) {
- data->oversampling_humid = ilog2(val);
-
- return bme680_chip_config(data);
- }
- }
-
- return -EINVAL;
+ return (rate > 0 && rate <= 16 && is_power_of_2(rate));
}

static int bme680_write_raw(struct iio_dev *indio_dev,
@@ -839,16 +802,26 @@ static int bme680_write_raw(struct iio_dev *indio_dev,

switch (mask) {
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ {
+ if (!bme680_is_valid_oversampling(val))
+ return -EINVAL;
+
switch (chan->type) {
case IIO_TEMP:
- return bme680_write_oversampling_ratio_temp(data, val);
+ data->oversampling_temp = val;
+ break;
case IIO_PRESSURE:
- return bme680_write_oversampling_ratio_press(data, val);
+ data->oversampling_press = val;
+ break;
case IIO_HUMIDITYRELATIVE:
- return bme680_write_oversampling_ratio_humid(data, val);
+ data->oversampling_humid = val;
+ break;
default:
return -EINVAL;
}
+
+ return bme680_chip_config(data);
+ }
default:
return -EINVAL;
}
@@ -910,9 +883,9 @@ int bme680_core_probe(struct device *dev, struct regmap *regmap,
indio_dev->modes = INDIO_DIRECT_MODE;

/* default values for the sensor */
- data->oversampling_humid = ilog2(2); /* 2X oversampling rate */
- data->oversampling_press = ilog2(4); /* 4X oversampling rate */
- data->oversampling_temp = ilog2(8); /* 8X oversampling rate */
+ data->oversampling_humid = 2; /* 2X oversampling rate */
+ data->oversampling_press = 4; /* 4X oversampling rate */
+ data->oversampling_temp = 8; /* 8X oversampling rate */
data->heater_temp = 320; /* degree Celsius */
data->heater_dur = 150; /* milliseconds */

--
2.11.0