Re: [PATCH v7 3/7] iio: adc: mcp3564: Add support for spi-device-addr

Conor Dooley <[email protected]> Wed, 22 Jul 2026 18:12:31 +0100

Newsgroups	org.kernel.vger.linux-spi,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-doc,org.kernel.vger.linux-iio,org.kernel.vger.linux-kernel
Message-ID	<20260722-trickery-unglazed-f51a23dc3842@spud>

On Wed, Jul 22, 2026 at 05:02:28PM +0000, [email protected] wrote:
> On Wed, 2026-07-22 at 17:45 +0100, Conor Dooley wrote:
> > On Wed, Jul 22, 2026 at 09:54:15AM +0200, Janani Sunil wrote:
> > > Read the generic spi-device-addr property when determining the
> > > hardware
> > > device address. Fall back to the deprecated microchip,hw-device-
> > > address
> > > property to preserve compatibility with existing device trees.
> > > 
> > > The device address remains 1 when neither property is present.
> > > 
> > > Signed-off-by: Janani Sunil <[email protected]>
> > > ---
> > >  drivers/iio/adc/mcp3564.c | 4 +++-
> > >  1 file changed, 3 insertions(+), 1 deletion(-)
> > > 
> > > diff --git a/drivers/iio/adc/mcp3564.c b/drivers/iio/adc/mcp3564.c
> > > index 36675563829e..71deb05e878e 100644
> > > --- a/drivers/iio/adc/mcp3564.c
> > > +++ b/drivers/iio/adc/mcp3564.c
> > > @@ -1122,7 +1122,9 @@ static int mcp3564_config(struct iio_dev
> > > *indio_dev, bool *use_internal_vref_att
> > >  	 * addresses are available when multiple devices are
> > > present on the same
> > >  	 * SPI bus with only one Chip Select line for all devices.
> > >  	 */
> > > -	device_property_read_u32(dev, "microchip,hw-device-
> > > address", &tmp);
> > > +	ret = device_property_read_u32(dev, "spi-device-addr",
> > > &tmp);
> > > +	if (ret)
> > > +		device_property_read_u32(dev, "microchip,hw-
> > > device-address", &tmp);
> > 
> > Same on this one, shouldn't it check the return value so that the
> > below
> > check of temp > 3 doesn't just pass with the default value of tmp?
> > 
> 
> Default hardware address is 0x01, unless a special order with custom
> hardware address is made. I think is safe to try to communicate with
> the default HW address.

Ah, sounds good so.
Reviewed-by: Conor Dooley <[email protected]>

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