Hi Laurent, On Fri, Jul 24, 2020 at 02:15:49AM +0300, Laurent Pinchart wrote: > Hi Sakari, > > On Fri, Jul 24, 2020 at 01:22:59AM +0300, Sakari Ailus wrote: > > On Fri, Jul 17, 2020 at 11:57:22PM +0300, Laurent Pinchart wrote: > > > Hi Jacopo, > > > > > > (CC'ing Sakari) > > > > > > Thank you for the patch. > > > > > > On Fri, Jul 17, 2020 at 03:28:54PM +0200, Jacopo Mondi wrote: > > > > The value of the data-shift property solely depend on the selected > > > > bus width and it's not freely configurable. > > > > > > > > Remove it from the bindings document and update its users accordingly. > > > > > > Hmmmm that's an interesting one. Sakari, what do you think ? > > > > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@xxxxxxxxxx> > > > > --- > > > > Documentation/devicetree/bindings/media/i2c/ov5640.yaml | 9 --------- > > > > arch/arm/boot/dts/stm32mp157c-ev1.dts | 1 - > > > > 2 files changed, 10 deletions(-) > > > > > > > > diff --git a/Documentation/devicetree/bindings/media/i2c/ov5640.yaml b/Documentation/devicetree/bindings/media/i2c/ov5640.yaml > > > > index 5e1662e848bd..ab700a1830aa 100644 > > > > --- a/Documentation/devicetree/bindings/media/i2c/ov5640.yaml > > > > +++ b/Documentation/devicetree/bindings/media/i2c/ov5640.yaml > > > > @@ -92,12 +92,6 @@ properties: > > > > parallel bus. > > > > enum: [8, 10] > > > > > > > > - data-shift: > > > > - description: | > > > > - Shall be set to <2> for 8 bits parallel bus (lines 9:2 are used) or > > > > - <0> for 10 bits parallel bus. > > > > - enum: [0, 2] > > > > > > Should you document in the description of bus-width that data-shift is > > > implied ? > > > > The purpose of the datas-shift property is to convey how the parallel bus > > lines are connected for a given bus width for devices where it is > > configurable. As this device does not not support that, then indeed this > > property is not relevant for the device IMO. > > Could you elaborate on this ? I believe the case that Jacopo is > describing connects D[9:2] from the sensor to D[7:0] of the receiver > (Jacopo, could you confirm ?). Isn't that what data-shift is for ? Yes, it is. But in this case what data-shift configures is not configurable as such but defined by another configuration, making the data-shift property redundant. We generally haven't documented redundant things in DT bindings --- for instance data-lanes is documented in bindings only if it is configurable. That said, it'd be nice to say which pins are used on less than full width busses. -- Regards, Sakari Ailus
