On Wed, Mar 09, 2022 at 04:28:30PM +0000, Mark Brown wrote: > On Wed, Mar 09, 2022 at 04:19:31PM +0000, John Keeping wrote: > > On Wed, Mar 09, 2022 at 03:56:12PM +0000, Mark Brown wrote: > > > > I'm still not seeing the functional change here. The actual state of > > > the GPIO is identical in both cases, all that's changing is the logical > > > view internally to the kernel. > > > Ah, sorry, I'm considering it functional since it changes the device > > tree ABI. > > > Used with the same device tree with, say, GPIO_ACTIVE_HIGH the physical > > state of the GPIO will change as a result of this patch and the device > > tree needs to be updated to use GPIO_ACTIVE_LOW. > > I think the device tree binding needs to be clarified here to be > explicit about this since there's obviously some room for user confusion > here. We can probably get away with a change at this point since it's > not hit a release but we do need to try to avoid the situation where any > other implementations use active high polarity for the bindings. Taking a quick survey of the other devices that have a pdn-gpios property: - tvp5150 is correct with the driver setting 0 to make the device active - tas571x also sets 0 to make the device active - ak4375 uses the opposite sense setting PDN = 1 to make the device active; this has no in-tree users and was merged as part of v5.17-rc1 so it's not in a released kernel yet
