Hi Jonathan,
Please, see below:
> > +static int mcp3564_update_8bits(struct mcp3564_state *adc, u8 reg,
> > u32 mask, u8 val)
> > +{
> > + u8 tmp;
> > + int ret;
> > +
> > + ret = mcp3564_read_8bits(adc, reg, &tmp);
> > + if (ret < 0)
> > + return ret;
> > +
> > + val &= mask;
> This looks wrong - would expect this to be
> val &= ~mask; // wipe out the bits in mask.
> >
Actually am doing the opperation twice (the val is already correct by
using FIELD_PREP when calling mcp3564_update_8bits). I'm making sure
that the value received has only the mask bits valid.
> > + val |= tmp & ~mask;
> and
> val |= tmp & mask; //write the bitss in mask.
>
> Is the mask the inverse ? At first glance it doesn't seem to be.
>
>
The tmp is the value that was read from the hardware (I need not to
touch/overwrite (~mask) bits). "tmp & ~mask" will clear the mask bits
from the hardware, in order to make the "|" with the val.
Actually my logic is a little bit twisted. I can rewrite it to be more
clear.
Thanks,
Marius
