iio: chemical: bme680: simplify oversampling handling

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>
Reviewed-by: Himanshu Jha <himanshujha199640@gmail.com>
Tested-by: Himanshu Jha <himanshujha199640@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/chemical/bme680_core.c b/drivers/iio/chemical/bme680_core.c
index ced63e3..5ddeffb 100644 (file)
--- 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 */