Re: [PATCH 0/5] iio: dac: ad5758: fix DMA alignment, raw range, offset and 4-20 mA

[Jonathan Cameron <jic23@kernel.org>]

On Sun, 20 Sep 2026 19:41:07 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Fri, 18 Sep 2026 16:22:27 +0100
> Nuno Sá <noname.nuno@gmail.com> wrote:
> 
> > On Fri, 2026-09-18 at 21:20 +0900, Arka Mondal wrote:  
> > > The first attempt to send this series on 2026-09-18 was rejected by
> > > the kernel.org mail servers, so it did not reach the lists. The patches
> > > are unchanged.
> > > 
> > > This series fixes four bugs in the AD5758 driver, all present since
> > > commit 28d1a7ac2a0d ("iio: dac: Add AD5758 support"). The last bug
> > > takes two patches, one for the binding and one for the driver.
> > > 
> > > Patch 1 marks the SPI receive buffer __aligned(IIO_DMA_MINALIGN), so
> > > it no longer shares a cacheline with other driver state. The 2022
> > > conversion of IIO drivers to IIO_DMA_MINALIGN only changed existing
> > > ____cacheline_aligned markings, and this driver had none.
> > > 
> > > Patch 2 rejects raw values outside 0 to U16_MAX. Writing -1 currently
> > > gives full-scale output.
> > > 
> > > Patch 3 fixes the offset for every range that does not start at 0.
> > > The +-20 mA range reports -32 instead of -32768.
> > > 
> > > Patches 4 and 5 fix the 4 mA to 20 mA range. The binding and the
> > > driver give it as <4 24000>, which is 4 uA to 24 mA. The data sheet
> > > (Rev. B, Table 32) and the original text binding say range code 1010
> > > is 4 mA to 20 mA. The old value is still accepted: the binding marks
> > > it deprecated and the driver maps it to the corrected range, so
> > > existing device trees keep working.
> > > 
> > > Compile tested only; no relevant hardware available. The binding was
> > > checked with make dt_binding_check and with test device trees:
> > > <4000 20000> and <4 24000> are accepted; <4 20000> is rejected.
> > > 
> > > Arka Mondal (5):
> > >   iio: dac: ad5758: Fix alignment for DMA safety
> > >   iio: dac: ad5758: Reject out-of-range raw values
> > >   iio: dac: ad5758: Fix the offset calculation
> > >   dt-bindings: iio: dac: adi,ad5758: Fix the 4 mA to 20 mA current range
> > >   iio: dac: ad5758: Fix the 4 mA to 20 mA current range
> > > 
> > >  .../bindings/iio/dac/adi,ad5758.yaml           |  4 ++++
> > >  drivers/iio/dac/ad5758.c                       | 18 ++++++++++++++----
> > >  2 files changed, 18 insertions(+), 4 deletions(-)
> > > 
> > > 
> > > base-commit: 08df884136f1c1197bab2a27814404fd329d9aac    
> > 
> > LGTM,
> > 
> > Reviewed-by: Nuno Sá <nuno.sa@analog.com>  
> Other than the one thing on the dt-binding that is more policy than anything
> else these all look good to me.  I'll wait for that to resolve though before
> picking these up.
> 
Occurred to me that I might as well queue up patches 1-3 whilst we
wait for dt review.  So done that.
Thanks,

Jonathan

> Thanks,
> 
> Jonathan
> 
>