On 11/11/24 6:08 AM, Uwe Kleine-König wrote: > [dropped Mircea Caprioru from Cc: as their address bounces.] > > Hello David, > > On Fri, Nov 08, 2024 at 12:52:35PM -0600, David Lechner wrote: >> On 11/8/24 12:18 PM, Uwe Kleine-König wrote: >>> The ad7124-4 and ad7124-8 both support 16 channel registers. Don't >>> accept more (logical) channels from dt than that. >> >> Why should the devicetree be limited by the number of channel >> registers? Channel registers are a resource than can be >> dynamically assigned, so it doesn't seem like the devicetree >> should be specifying that assignment. > > Note the device tree isn't limited as I didn't adapt the binding. It's > just that the driver doesn't bind if too many channels are specified. > And while your statement about the channels being a dynamic resource is > right, currently the driver doesn't cope and allocates resources > statically, and happily assumes there is a CHANNEL_16 register if the > device tree specifies 17 (or more) logical channels and writes to > CONFIG_0 then which very likely results in strange effects. > > So as long as the driver doesn't implement this (possible) dynamic > mapping to the CHANNEL registers, it's IMHO right to refuse to bind (or > alternatively only use the 16 first logical channels). > > Best regards > Uwe Understood. It would be nice to implement such dynamic allocation in the future but as a fix to backport to stable kernels, this makes sense.
