On Wed, 26 May 2021 14:12:02 +0200 Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > On Wed, May 26, 2021 at 11:44 AM Stephan Gerhold <stephan@xxxxxxxxxxx> wrote: > > > According to the BMA253 datasheet [1] and BMA250 datasheet [2] the > > bandwidth value for BMA25x should be set as 01xxx: > > > > "Settings 00xxx result in a bandwidth of 7.81 Hz; [...] > > It is recommended [...] to use the range from ´01000b´ to ´01111b´ > > only in order to be compatible with future products." > > > > However, at the moment the drivers sets bandwidth values from 0 to 6, > > which is not recommended and always results into 7.81 Hz bandwidth > > according to the datasheet. > > > > Fix this by introducing a bw_offset = 8 = 01000b for BMA25x, > > so the additional bit is always set for BMA25x. > > > > [1]: https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bma253-ds000.pdf > > [2]: https://datasheet.octopart.com/BMA250-Bosch-datasheet-15540103.pdf > > > > Cc: Peter Meerwald <pmeerw@xxxxxxxxxx> > > Cc: Linus Walleij <linus.walleij@xxxxxxxxxx> > > Fixes: 2017cff24cc0 ("iio:bma180: Add BMA250 chip support") > > Signed-off-by: Stephan Gerhold <stephan@xxxxxxxxxxx> > > Good catch! > Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Applied to the fixes-togreg branch of iio.git and marked for stable. I think I can probably get away with picking up patch 2 into the togreg branch without anything blowing up during the merge. Thanks, Jonathan > > > After spending some more time with the driver I noticed that BMA253/BMA254 > > would actually be better supported by the bmc150-accel driver (which > > doesn't have this problem and also supports the motion trigger/interrupt). > > > > I'm preparing a separate patch set to move BMA254 to bmc150-accel at least, > > but I'm not sure about BMA250 so this patch is relevant anyway. And I had > > it almost done already, so I thought it's better to send it. :) > > I looked at the preliminary patches and this looks really good > too. > > Yours, > Linus Walleij
