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| author |   Linus Walleij <linus.walleij@linaro.org> | 2021-03-22 14:24:08 +0100 |
|---|---|---|
| committer |   Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2021-03-29 11:18:45 +0100 |
| commit | 454c219f5d8452eff87b701735ae1224f4410356 (patch) | |
| tree | 698575f10c71504d15a7cc88459ac6715aa7ae81 /drivers/iio/imu | |
| parent | iio:accel:adis16201: Fix wrong axis assignment that prevents loading (diff) | |
| download | linux-dev-454c219f5d8452eff87b701735ae1224f4410356.tar.xz linux-dev-454c219f5d8452eff87b701735ae1224f4410356.zip | |
iio: imu: inv_mpu6050: Use as standalone trigger
It may happen that the MPU6050 is the only hardware
trigger available on your system such as this:
> lsiio
Device 003: hscdtd008a
Device 001: mpu6050
Device 002: gp2ap002
Device 000: ab8500-gpadc
Trigger 000: mpu6050-dev1
And when you want to use it to read periodically from
your magnetometer like this:
> iio_generic_buffer -a -c 100 -n hscdtd008a -t mpu6050-dev1
Then the following happens:
[ 209.951334] Internal error: Oops: 5 [#1] SMP ARM
(...)
[ 209.981969] Hardware name: ST-Ericsson Ux5x0 platform (Device Tree Support)
[ 209.988925] PC is at inv_scan_query_mpu6050+0x8/0xb8
[ 209.993914] LR is at inv_mpu6050_set_enable+0x40/0x194
This is because since we are not using any channels from the
same device, the indio_dev->active_scan_mask is NULL.
Just checking for that and bailing out is however not enough:
we have to enable some kind of FIFO for the readout to work.
So enable the temperature as a dummy FIFO and all works
fine.
Not suitable for backporting to stable. It is an odd corner case
and does not represent a regression.
Fixes: 09a642b78523 ("Invensense MPU6050 Device Driver.")
Cc: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com>
Link: https://lore.kernel.org/r/20210322132408.1003443-1-linus.walleij@linaro.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/imu')
| -rw-r--r-- | drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c index f7b5a70be30f..de8ed1446d60 100644 --- a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c +++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c @@ -11,6 +11,16 @@ static unsigned int inv_scan_query_mpu6050(struct iio_dev *indio_dev) struct inv_mpu6050_state *st = iio_priv(indio_dev); unsigned int mask; + /* + * If the MPU6050 is just used as a trigger, then the scan mask + * is not allocated so we simply enable the temperature channel + * as a dummy and bail out. + */ + if (!indio_dev->active_scan_mask) { + st->chip_config.temp_fifo_enable = true; + return INV_MPU6050_SENSOR_TEMP; + } + st->chip_config.gyro_fifo_enable = test_bit(INV_MPU6050_SCAN_GYRO_X, indio_dev->active_scan_mask) || |