On 06/01/2016 05:55 PM, Luis de Bethencourt wrote: > Correctly handle the settling time cycles value. The else branch was an > impossible condition (> 1022 in the else branch of > 511) and the handling > of the values was dividing by 2 and 4, with a left shift, instead of > multiplying. > > Based on the Table 13 at the bottom of Page 25 of the Data Sheet: > http://www.analog.com/media/en/technical-documentation/data-sheets/AD5933.pdf > > Signed-off-by: Luis de Bethencourt <luisbg@xxxxxxxxxxxxxxx> > --- > > Hi, > > I decided to use the hexadecimal values instead of (1 << 10) and (1 << 9), for > briefness, I could resend using those instead if it is prefered. > > I also decided to use multiplications instead of right-shifts for readability. > I could use change that as well. > > Thanks, > Luis > > drivers/staging/iio/impedance-analyzer/ad5933.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/staging/iio/impedance-analyzer/ad5933.c b/drivers/staging/iio/impedance-analyzer/ad5933.c > index 9f43976..3a2cf8f3 100644 > --- a/drivers/staging/iio/impedance-analyzer/ad5933.c > +++ b/drivers/staging/iio/impedance-analyzer/ad5933.c > @@ -444,10 +444,13 @@ static ssize_t ad5933_store(struct device *dev, > st->settling_cycles = val; > > /* 2x, 4x handling, see datasheet */ > - if (val > 511) > - val = (val >> 1) | (1 << 9); > - else if (val > 1022) > - val = (val >> 2) | (3 << 9); > + if (val & 0x400 && val & 0x200) { > + val &= 0x1ff; > + val *= 4; > + } else if (val & 0x200) { > + val &= 0x1ff; > + val *= 2; > + } This does not look correct. D10 and D9 select an additional multiplier of either 1, 2 or 4. So dividing the value before writing it to the register is the right approach in that case. Just flipping the order in which the conditions are evaluated should be sufficient. > > dat = cpu_to_be16(val); > ret = ad5933_i2c_write(st->client, > _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
