From 65e4345c8ef8811bbb4860fe5f2df10646b7f2e1 Mon Sep 17 00:00:00 2001 From: Linus Walleij Date: Fri, 30 Dec 2016 23:54:18 +0100 Subject: iio: accel: st_accel: fix LIS3LV02 reading and scaling The LIS3LV02 has a special bit that need to be set to get the read values left aligned. Before this patch we get gibberish like this: iio_generic_buffer -a -c10 -n lis3lv02dl_accel (...) 0.000000 -0.010042 -0.642688 19155832931907 0.000000 -0.010042 -0.642688 19155858751073 Which is because we read a raw value for 1g as 64 which is the nominal 1024 for 1g shifted 4 bits to the left by being right-aligned rather than left aligned. Since all other sensors are left aligned, add some code to set the special DAS (data alignment setting) bit to 1 so that the right value is now read like this: iio_generic_buffer -a -c10 -n lis3lv02dl_accel (...) 0.000000 -0.147095 -10.120135 24761614364956 -0.029419 -0.176514 -10.120135 24761631624540 The scaling was weird as well: we have a gain of 1000 for 1g and 3000 for 6g. I don't even remember how I came up with the old values but they are wrong. Fixes: 3acddf74f807 ("iio: st-sensors: add support for lis3lv02d accelerometer") Cc: Lorenzo Bianconi Cc: Giuseppe Barba Cc: Denis Ciocca Signed-off-by: Linus Walleij Signed-off-by: Jonathan Cameron --- include/linux/iio/common/st_sensors.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include') diff --git a/include/linux/iio/common/st_sensors.h b/include/linux/iio/common/st_sensors.h index 228bd44efa4c..497f2b3a5a62 100644 --- a/include/linux/iio/common/st_sensors.h +++ b/include/linux/iio/common/st_sensors.h @@ -115,6 +115,16 @@ struct st_sensor_bdu { u8 mask; }; +/** + * struct st_sensor_das - ST sensor device data alignment selection + * @addr: address of the register. + * @mask: mask to write the das flag for left alignment. + */ +struct st_sensor_das { + u8 addr; + u8 mask; +}; + /** * struct st_sensor_data_ready_irq - ST sensor device data-ready interrupt * @addr: address of the register. @@ -185,6 +195,7 @@ struct st_sensor_transfer_function { * @enable_axis: Enable one or more axis of the sensor. * @fs: Full scale register and full scale list available. * @bdu: Block data update register. + * @das: Data Alignment Selection register. * @drdy_irq: Data ready register of the sensor. * @multi_read_bit: Use or not particular bit for [I2C/SPI] multi-read. * @bootime: samples to discard when sensor passing from power-down to power-up. @@ -200,6 +211,7 @@ struct st_sensor_settings { struct st_sensor_axis enable_axis; struct st_sensor_fullscale fs; struct st_sensor_bdu bdu; + struct st_sensor_das das; struct st_sensor_data_ready_irq drdy_irq; bool multi_read_bit; unsigned int bootime; -- cgit v1.2.3-59-g8ed1b