The BMI270 IMU includes a temperature sensor. Add a channel for reading
the temperature.
Signed-off-by: Gustavo Silva <gustavograzs@xxxxxxxxx>
---
drivers/iio/imu/bmi270/bmi270_core.c | 49 ++++++++++++++++++++++++++++++++----
1 file changed, 44 insertions(+), 5 deletions(-)
diff --git a/drivers/iio/imu/bmi270/bmi270_core.c b/drivers/iio/imu/bmi270/bmi270_core.c
index 7fec52e0b48624f07031b63a9caf6c318f33f5dc..c7853923aa69f83a829a71979135f1f7a7ef29ec 100644
--- a/drivers/iio/imu/bmi270/bmi270_core.c
+++ b/drivers/iio/imu/bmi270/bmi270_core.c
@@ -5,6 +5,7 @@
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/regmap.h>
+#include <linux/units.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -28,10 +29,11 @@
#define BMI270_INTERNAL_STATUS_REG 0x21
#define BMI270_INTERNAL_STATUS_MSG_MSK GENMASK(3, 0)
#define BMI270_INTERNAL_STATUS_MSG_INIT_OK 0x01
-
#define BMI270_INTERNAL_STATUS_AXES_REMAP_ERR_MSK BIT(5)
#define BMI270_INTERNAL_STATUS_ODR_50HZ_ERR_MSK BIT(6)
+#define BMI270_TEMPERATURE_0_REG 0x22
+
#define BMI270_ACC_CONF_REG 0x40
#define BMI270_ACC_CONF_ODR_MSK GENMASK(3, 0)
#define BMI270_ACC_CONF_ODR_100HZ 0x08
@@ -69,6 +71,10 @@
#define BMI270_PWR_CTRL_ACCEL_EN_MSK BIT(2)
#define BMI270_PWR_CTRL_TEMP_EN_MSK BIT(3)
+/* See datasheet section 4.6.14, Temperature Sensor */
+#define BMI270_TEMP_OFFSET 11776
+#define BMI270_TEMP_SCALE 1953125
+
#define BMI260_INIT_DATA_FILE "bmi260-init-data.fw"
#define BMI270_INIT_DATA_FILE "bmi270-init-data.fw"
@@ -109,6 +115,7 @@ EXPORT_SYMBOL_NS_GPL(bmi270_chip_info, "IIO_BMI270");
enum bmi270_sensor_type {
BMI270_ACCEL = 0,
BMI270_GYRO,
+ BMI270_TEMP,
};
struct bmi270_scale {
@@ -136,6 +143,10 @@ static const struct bmi270_scale bmi270_gyro_scale[] = {
{ 0, 66 },
};
+static const struct bmi270_scale bmi270_temp_scale[] = {
+ {BMI270_TEMP_SCALE / MEGA, BMI270_TEMP_SCALE % MEGA},
+};
+
struct bmi270_scale_item {
const struct bmi270_scale *tbl;
int num;
@@ -150,6 +161,10 @@ static const struct bmi270_scale_item bmi270_scale_table[] = {
.tbl = bmi270_gyro_scale,
.num = ARRAY_SIZE(bmi270_gyro_scale),
},
+ [BMI270_TEMP] = {
+ .tbl = bmi270_temp_scale,
+ .num = ARRAY_SIZE(bmi270_temp_scale),
+ },
};
static const struct bmi270_odr bmi270_accel_odr[] = {
@@ -255,7 +270,7 @@ static int bmi270_set_scale(struct bmi270_data *data, int chan_type, int uscale)
}
static int bmi270_get_scale(struct bmi270_data *bmi270_device, int chan_type,
- int *uscale)
+ int *scale, int *uscale)
{
int ret;
unsigned int val;
@@ -280,6 +295,10 @@ static int bmi270_get_scale(struct bmi270_data *bmi270_device, int chan_type,
val = FIELD_GET(BMI270_GYR_CONF_RANGE_MSK, val);
bmi270_scale_item = bmi270_scale_table[BMI270_GYRO];
break;
+ case IIO_TEMP:
+ val = 0;
+ bmi270_scale_item = bmi270_scale_table[BMI270_TEMP];
+ break;
default:
return -EINVAL;
}
@@ -287,6 +306,7 @@ static int bmi270_get_scale(struct bmi270_data *bmi270_device, int chan_type,
if (val >= bmi270_scale_item.num)
return -EINVAL;
+ *scale = bmi270_scale_item.tbl[val].scale;
*uscale = bmi270_scale_item.tbl[val].uscale;
return 0;
}
@@ -399,6 +419,9 @@ static int bmi270_get_data(struct bmi270_data *bmi270_device,
case IIO_ANGL_VEL:
reg = BMI270_ANG_VEL_X_REG + (axis - IIO_MOD_X) * 2;
break;
+ case IIO_TEMP:
+ reg = BMI270_TEMPERATURE_0_REG;
+ break;
default:
return -EINVAL;
}
@@ -427,12 +450,20 @@ static int bmi270_read_raw(struct iio_dev *indio_dev,
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- *val = 0;
- ret = bmi270_get_scale(bmi270_device, chan->type, val2);
+ ret = bmi270_get_scale(bmi270_device, chan->type, val, val2);
return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
+ case IIO_CHAN_INFO_OFFSET:
+ switch (chan->type) {
+ case IIO_TEMP:
+ *val = BMI270_TEMP_OFFSET;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
case IIO_CHAN_INFO_SAMP_FREQ:
ret = bmi270_get_odr(bmi270_device, chan->type, val, val2);
return ret ? ret : IIO_VAL_INT_PLUS_MICRO;
+
default:
return -EINVAL;
}
@@ -544,6 +575,13 @@ static const struct iio_chan_spec bmi270_channels[] = {
BMI270_ANG_VEL_CHANNEL(X),
BMI270_ANG_VEL_CHANNEL(Y),
BMI270_ANG_VEL_CHANNEL(Z),
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = -1, /* No buffer support */
+ },
IIO_CHAN_SOFT_TIMESTAMP(BMI270_SCAN_TIMESTAMP),
};
@@ -646,7 +684,8 @@ static int bmi270_configure_imu(struct bmi270_data *bmi270_device)
ret = regmap_set_bits(regmap, BMI270_PWR_CTRL_REG,
BMI270_PWR_CTRL_AUX_EN_MSK |
BMI270_PWR_CTRL_GYR_EN_MSK |
- BMI270_PWR_CTRL_ACCEL_EN_MSK);
+ BMI270_PWR_CTRL_ACCEL_EN_MSK |
+ BMI270_PWR_CTRL_TEMP_EN_MSK);
if (ret)
return dev_err_probe(dev, ret, "Failed to enable accelerometer and gyroscope");
---
base-commit: 577a66e2e634f712384c57a98f504c44ea4b47da
change-id: 20250111-bmi270-temp-e9d253619180
Best regards,
--
Gustavo Silva <gustavograzs@xxxxxxxxx>
