Re: [PATCH v3 01/10] iio: adc: ad7124: Don't create more channels than the driver can handle

[David Lechner <dlechner@baylibre.com>]

On 11/22/24 9:54 AM, Uwe Kleine-König wrote:
> On Fri, Nov 22, 2024 at 09:14:18AM -0600, David Lechner wrote:
>> On 11/22/24 5:33 AM, Uwe Kleine-König wrote:
>>> The ad7124-4 and ad7124-8 both support 16 channel registers and assigns
>>> each channel defined in dt statically such a register. While the driver
>>> could be a bit more clever about this, it currently isn't and specifying
>>> more than 16 channels yields broken behaviour. So just refuse to bind in
>>> this situation.
>>
>> The ad7124-4 datasheet I am looking at says that it only has registers
>> CONFIG_0 to CONFIG_7, so do we need to limit those chips to 8 channels?
> 
> These could be reused for different channels if the settings match. I'm
> unsure what happens if the 16 channels use more than 8 different
> configs and you want to bulk read them. Single channel use should work
> fine I think. If that is a problem I might have to extend this series of
> fixes, but this is something orthogonal to this patch I think.
> 
> Best regards
> Uwe

Oh, oops, you are right. I was mixing up _channel_ registers and
_config_ registers.