This adds ability to control the oversampling ratio of the temperature
and pressure measurement for both bmp180 and bmp280.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Vlad Dogaru <vlad.dogaru@xxxxxxxxx>
Cc: Christoph Mair <christoph.mair@xxxxxxxxx>
Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Cc: Hartmut Knaack <knaack.h@xxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Cc: Peter Meerwald <pmeerw@xxxxxxxxxx>
---
* v3
- fix oversampling register setting for bmp280, spotted by Vlad Dogaru
drivers/iio/pressure/bmp280.c | 203 ++++++++++++++++++++++++++++++++++++++----
1 file changed, 185 insertions(+), 18 deletions(-)
diff --git a/drivers/iio/pressure/bmp280.c b/drivers/iio/pressure/bmp280.c
index dcf3b0a..2f1498e 100644
--- a/drivers/iio/pressure/bmp280.c
+++ b/drivers/iio/pressure/bmp280.c
@@ -48,19 +48,21 @@
#define BMP280_OSRS_TEMP_MASK (BIT(7) | BIT(6) | BIT(5))
#define BMP280_OSRS_TEMP_SKIP 0
-#define BMP280_OSRS_TEMP_1X BIT(5)
-#define BMP280_OSRS_TEMP_2X BIT(6)
-#define BMP280_OSRS_TEMP_4X (BIT(6) | BIT(5))
-#define BMP280_OSRS_TEMP_8X BIT(7)
-#define BMP280_OSRS_TEMP_16X (BIT(7) | BIT(5))
+#define BMP280_OSRS_TEMP_X(osrs_t) ((osrs_t) << 5)
+#define BMP280_OSRS_TEMP_1X BMP280_OSRS_TEMP_X(1)
+#define BMP280_OSRS_TEMP_2X BMP280_OSRS_TEMP_X(2)
+#define BMP280_OSRS_TEMP_4X BMP280_OSRS_TEMP_X(3)
+#define BMP280_OSRS_TEMP_8X BMP280_OSRS_TEMP_X(4)
+#define BMP280_OSRS_TEMP_16X BMP280_OSRS_TEMP_X(5)
#define BMP280_OSRS_PRESS_MASK (BIT(4) | BIT(3) | BIT(2))
#define BMP280_OSRS_PRESS_SKIP 0
-#define BMP280_OSRS_PRESS_1X BIT(2)
-#define BMP280_OSRS_PRESS_2X BIT(3)
-#define BMP280_OSRS_PRESS_4X (BIT(3) | BIT(2))
-#define BMP280_OSRS_PRESS_8X BIT(4)
-#define BMP280_OSRS_PRESS_16X (BIT(4) | BIT(2))
+#define BMP280_OSRS_PRESS_X(osrs_p) ((osrs_p) << 2)
+#define BMP280_OSRS_PRESS_1X BMP280_OSRS_PRESS_X(1)
+#define BMP280_OSRS_PRESS_2X BMP280_OSRS_PRESS_X(2)
+#define BMP280_OSRS_PRESS_4X BMP280_OSRS_PRESS_X(3)
+#define BMP280_OSRS_PRESS_8X BMP280_OSRS_PRESS_X(4)
+#define BMP280_OSRS_PRESS_16X BMP280_OSRS_PRESS_X(5)
#define BMP280_MODE_MASK (BIT(1) | BIT(0))
#define BMP280_MODE_SLEEP 0
@@ -98,6 +100,10 @@ struct bmp280_data {
struct regmap *regmap;
const struct bmp280_chip_info *chip_info;
+ /* log of base 2 of oversampling rate */
+ u8 oversampling_press;
+ u8 oversampling_temp;
+
/*
* Carryover value from temperature conversion, used in pressure
* calculation.
@@ -108,6 +114,12 @@ struct bmp280_data {
struct bmp280_chip_info {
const struct regmap_config *regmap_config;
+ const int *oversampling_temp_avail;
+ int num_oversampling_temp_avail;
+
+ const int *oversampling_press_avail;
+ int num_oversampling_press_avail;
+
int (*chip_config)(struct bmp280_data *);
int (*read_temp)(struct bmp280_data *, int *);
int (*read_press)(struct bmp280_data *, int *, int *);
@@ -123,11 +135,13 @@ enum { P1, P2, P3, P4, P5, P6, P7, P8, P9 };
static const struct iio_chan_spec bmp280_channels[] = {
{
.type = IIO_PRESSURE,
- .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
},
{
.type = IIO_TEMP,
- .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+ BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),
},
};
@@ -333,6 +347,21 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
break;
}
break;
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ switch (chan->type) {
+ case IIO_PRESSURE:
+ *val = 1 << data->oversampling_press;
+ ret = IIO_VAL_INT;
+ break;
+ case IIO_TEMP:
+ *val = 1 << data->oversampling_temp;
+ ret = IIO_VAL_INT;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ break;
default:
ret = -EINVAL;
break;
@@ -343,22 +372,135 @@ static int bmp280_read_raw(struct iio_dev *indio_dev,
return ret;
}
+static int bmp280_write_oversampling_ratio_temp(struct bmp280_data *data,
+ int val)
+{
+ int i;
+ const int *avail = data->chip_info->oversampling_temp_avail;
+ const int n = data->chip_info->num_oversampling_temp_avail;
+
+ for (i = 0; i < n; i++) {
+ if (avail[i] == val) {
+ data->oversampling_temp = ilog2(val);
+
+ return data->chip_info->chip_config(data);
+ }
+ }
+ return -EINVAL;
+}
+
+static int bmp280_write_oversampling_ratio_press(struct bmp280_data *data,
+ int val)
+{
+ int i;
+ const int *avail = data->chip_info->oversampling_press_avail;
+ const int n = data->chip_info->num_oversampling_press_avail;
+
+ for (i = 0; i < n; i++) {
+ if (avail[i] == val) {
+ data->oversampling_press = ilog2(val);
+
+ return data->chip_info->chip_config(data);
+ }
+ }
+ return -EINVAL;
+}
+
+static int bmp280_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ int ret = 0;
+ struct bmp280_data *data = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
+ mutex_lock(&data->lock);
+ switch (chan->type) {
+ case IIO_PRESSURE:
+ ret = bmp280_write_oversampling_ratio_press(data, val);
+ break;
+ case IIO_TEMP:
+ ret = bmp280_write_oversampling_ratio_temp(data, val);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&data->lock);
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return ret;
+}
+
+static ssize_t bmp280_show_avail(char *buf, const int *vals, const int n)
+{
+ size_t len = 0;
+ int i;
+
+ for (i = 0; i < n; i++)
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", vals[i]);
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static ssize_t bmp280_show_temp_oversampling_avail(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
+
+ return bmp280_show_avail(buf, data->chip_info->oversampling_temp_avail,
+ data->chip_info->num_oversampling_temp_avail);
+}
+
+static ssize_t bmp280_show_press_oversampling_avail(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct bmp280_data *data = iio_priv(dev_to_iio_dev(dev));
+
+ return bmp280_show_avail(buf, data->chip_info->oversampling_press_avail,
+ data->chip_info->num_oversampling_press_avail);
+}
+
+static IIO_DEVICE_ATTR(in_temp_oversampling_ratio_available,
+ S_IRUGO, bmp280_show_temp_oversampling_avail, NULL, 0);
+
+static IIO_DEVICE_ATTR(in_pressure_oversampling_ratio_available,
+ S_IRUGO, bmp280_show_press_oversampling_avail, NULL, 0);
+
+static struct attribute *bmp280_attributes[] = {
+ &iio_dev_attr_in_temp_oversampling_ratio_available.dev_attr.attr,
+ &iio_dev_attr_in_pressure_oversampling_ratio_available.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group bmp280_attrs_group = {
+ .attrs = bmp280_attributes,
+};
+
static const struct iio_info bmp280_info = {
.driver_module = THIS_MODULE,
.read_raw = &bmp280_read_raw,
+ .write_raw = &bmp280_write_raw,
+ .attrs = &bmp280_attrs_group,
};
static int bmp280_chip_config(struct bmp280_data *data)
{
int ret;
+ u8 osrs = BMP280_OSRS_TEMP_X(data->oversampling_temp + 1) |
+ BMP280_OSRS_PRESS_X(data->oversampling_press + 1);
ret = regmap_update_bits(data->regmap, BMP280_REG_CTRL_MEAS,
BMP280_OSRS_TEMP_MASK |
BMP280_OSRS_PRESS_MASK |
BMP280_MODE_MASK,
- BMP280_OSRS_TEMP_2X |
- BMP280_OSRS_PRESS_16X |
- BMP280_MODE_NORMAL);
+ osrs | BMP280_MODE_NORMAL);
if (ret < 0) {
dev_err(&data->client->dev,
"failed to write ctrl_meas register\n");
@@ -377,8 +519,17 @@ static int bmp280_chip_config(struct bmp280_data *data)
return ret;
}
+static const int bmp280_oversampling_avail[] = { 1, 2, 4, 8, 16 };
+
static const struct bmp280_chip_info bmp280_chip_info = {
.regmap_config = &bmp280_regmap_config,
+
+ .oversampling_temp_avail = bmp280_oversampling_avail,
+ .num_oversampling_temp_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+
+ .oversampling_press_avail = bmp280_oversampling_avail,
+ .num_oversampling_press_avail = ARRAY_SIZE(bmp280_oversampling_avail),
+
.chip_config = bmp280_chip_config,
.read_temp = bmp280_read_temp,
.read_press = bmp280_read_press,
@@ -433,7 +584,7 @@ static int bmp180_measure(struct bmp280_data *data, u8 ctrl_meas)
if (ctrl_meas == BMP180_MEAS_TEMP)
delay_us = 4500;
else
- delay_us = conversion_time_max[ilog2(8)];
+ delay_us = conversion_time_max[data->oversampling_press];
usleep_range(delay_us, delay_us + 1000);
@@ -573,7 +724,7 @@ static int bmp180_read_adc_press(struct bmp280_data *data, int *val)
{
int ret;
__be32 tmp = 0;
- u8 oss = ilog2(8);
+ u8 oss = data->oversampling_press;
ret = bmp180_measure(data, BMP180_MEAS_PRESS_X(oss));
if (ret)
@@ -599,7 +750,7 @@ static u32 bmp180_compensate_press(struct bmp280_data *data, s32 adc_press)
s32 x1, x2, x3, p;
s32 b3, b6;
u32 b4, b7;
- s32 oss = ilog2(8);
+ s32 oss = data->oversampling_press;
struct bmp180_calib calib;
ret = bmp180_read_calib(data, &calib);
@@ -660,8 +811,20 @@ static int bmp180_chip_config(struct bmp280_data *data)
return 0;
}
+static const int bmp180_oversampling_temp_avail[] = { 1 };
+static const int bmp180_oversampling_press_avail[] = { 1, 2, 4, 8 };
+
static const struct bmp280_chip_info bmp180_chip_info = {
.regmap_config = &bmp180_regmap_config,
+
+ .oversampling_temp_avail = bmp180_oversampling_temp_avail,
+ .num_oversampling_temp_avail =
+ ARRAY_SIZE(bmp180_oversampling_temp_avail),
+
+ .oversampling_press_avail = bmp180_oversampling_press_avail,
+ .num_oversampling_press_avail =
+ ARRAY_SIZE(bmp180_oversampling_press_avail),
+
.chip_config = bmp180_chip_config,
.read_temp = bmp180_read_temp,
.read_press = bmp180_read_press,
@@ -693,9 +856,13 @@ static int bmp280_probe(struct i2c_client *client,
switch (id->driver_data) {
case BMP180_CHIP_ID:
data->chip_info = &bmp180_chip_info;
+ data->oversampling_press = ilog2(8);
+ data->oversampling_temp = ilog2(1);
break;
case BMP280_CHIP_ID:
data->chip_info = &bmp280_chip_info;
+ data->oversampling_press = ilog2(16);
+ data->oversampling_temp = ilog2(2);
break;
default:
return -EINVAL;
--
2.5.0
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