[PATCH 4.19 021/140] iio: imu: inv_mpu6050: fix temperature reporting using bad unit

Greg Kroah-Hartman
2019-12-16T18:02:11Z

From: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>

commit 53eaa9c27fdc01b4f4d885223e29f97393409e7e upstream.

Temperature should be reported in milli-degrees, not degrees. Fix
scale and offset values to use the correct unit.

This is a fix for an issue that has been present for a long time.
The fixes tag reflects the point at which the code last changed in a
fashion that would make this fix patch no longer apply. Backports
will be necessary to fix those elements that predate that patch.

Fixes: 1615fe41a195 ("iio: imu: mpu6050: Fix FIFO layout for ICM20602")
Cc: stable@vger.kernel.org
Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/imu/inv_mpu6050/inv_mpu_core.c | 23 ++++++++++++-----------
drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h | 16 ++++++++++++----
2 files changed, 24 insertions(+), 15 deletions(-)

--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -122,6 +122,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6050,
.config = &chip_config_6050,
.fifo_size = 1024,
+ .temp = {INV_MPU6050_TEMP_OFFSET, INV_MPU6050_TEMP_SCALE},
},
{
.whoami = INV_MPU6500_WHOAMI_VALUE,
@@ -129,6 +130,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6500,
.config = &chip_config_6050,
.fifo_size = 512,
+ .temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
},
{
.whoami = INV_MPU6515_WHOAMI_VALUE,
@@ -136,6 +138,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6500,
.config = &chip_config_6050,
.fifo_size = 512,
+ .temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
},
{
.whoami = INV_MPU6000_WHOAMI_VALUE,
@@ -143,6 +146,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6050,
.config = &chip_config_6050,
.fifo_size = 1024,
+ .temp = {INV_MPU6050_TEMP_OFFSET, INV_MPU6050_TEMP_SCALE},
},
{
.whoami = INV_MPU9150_WHOAMI_VALUE,
@@ -150,6 +154,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6050,
.config = &chip_config_6050,
.fifo_size = 1024,
+ .temp = {INV_MPU6050_TEMP_OFFSET, INV_MPU6050_TEMP_SCALE},
},
{
.whoami = INV_MPU9250_WHOAMI_VALUE,
@@ -157,6 +162,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6500,
.config = &chip_config_6050,
.fifo_size = 512,
+ .temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
},
{
.whoami = INV_MPU9255_WHOAMI_VALUE,
@@ -164,6 +170,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6500,
.config = &chip_config_6050,
.fifo_size = 512,
+ .temp = {INV_MPU6500_TEMP_OFFSET, INV_MPU6500_TEMP_SCALE},
},
{
.whoami = INV_ICM20608_WHOAMI_VALUE,
@@ -171,6 +178,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_6500,
.config = &chip_config_6050,
.fifo_size = 512,
+ .temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
},
{
.whoami = INV_ICM20602_WHOAMI_VALUE,
@@ -178,6 +186,7 @@ static const struct inv_mpu6050_hw hw_in
.reg = &reg_set_icm20602,
.config = &chip_config_6050,
.fifo_size = 1008,
+ .temp = {INV_ICM20608_TEMP_OFFSET, INV_ICM20608_TEMP_SCALE},
},
};

@@ -478,12 +487,8 @@ inv_mpu6050_read_raw(struct iio_dev *ind

return IIO_VAL_INT_PLUS_MICRO;
case IIO_TEMP:
- *val = 0;
- if (st->chip_type == INV_ICM20602)
- *val2 = INV_ICM20602_TEMP_SCALE;
- else
- *val2 = INV_MPU6050_TEMP_SCALE;
-
+ *val = st->hw->temp.scale / 1000000;
+ *val2 = st->hw->temp.scale % 1000000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
@@ -491,11 +496,7 @@ inv_mpu6050_read_raw(struct iio_dev *ind
case IIO_CHAN_INFO_OFFSET:
switch (chan->type) {
case IIO_TEMP:
- if (st->chip_type == INV_ICM20602)
- *val = INV_ICM20602_TEMP_OFFSET;
- else
- *val = INV_MPU6050_TEMP_OFFSET;
-
+ *val = st->hw->temp.offset;
return IIO_VAL_INT;
default:
return -EINVAL;
--- a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -109,6 +109,7 @@ struct inv_mpu6050_chip_config {
* @reg: register map of the chip.
* @config: configuration of the chip.
* @fifo_size: size of the FIFO in bytes.
+ * @temp: offset and scale to apply to raw temperature.
*/
struct inv_mpu6050_hw {
u8 whoami;
@@ -116,6 +117,10 @@ struct inv_mpu6050_hw {
const struct inv_mpu6050_reg_map *reg;
const struct inv_mpu6050_chip_config *config;
size_t fifo_size;
+ struct {
+ int offset;
+ int scale;
+ } temp;
};

/*
@@ -224,16 +229,19 @@ struct inv_mpu6050_state {
#define INV_MPU6050_REG_UP_TIME_MIN 5000
#define INV_MPU6050_REG_UP_TIME_MAX 10000

-#define INV_MPU6050_TEMP_OFFSET 12421
-#define INV_MPU6050_TEMP_SCALE 2941
+#define INV_MPU6050_TEMP_OFFSET 12420
+#define INV_MPU6050_TEMP_SCALE 2941176
#define INV_MPU6050_MAX_GYRO_FS_PARAM 3
#define INV_MPU6050_MAX_ACCL_FS_PARAM 3
#define INV_MPU6050_THREE_AXIS 3
#define INV_MPU6050_GYRO_CONFIG_FSR_SHIFT 3
#define INV_MPU6050_ACCL_CONFIG_FSR_SHIFT 3

-#define INV_ICM20602_TEMP_OFFSET 8170
-#define INV_ICM20602_TEMP_SCALE 3060
+#define INV_MPU6500_TEMP_OFFSET 7011
+#define INV_MPU6500_TEMP_SCALE 2995178
+
+#define INV_ICM20608_TEMP_OFFSET 8170
+#define INV_ICM20608_TEMP_SCALE 3059976

/* 6 + 6 round up and plus 8 */
#define INV_MPU6050_OUTPUT_DATA_SIZE 24