On Mon, 11 Dec 2017 09:18:55 +0100 Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx> wrote: > Hi Jonathan, > > On 10/12/2017 17:36, Jonathan Cameron wrote: > > On Mon, 4 Dec 2017 15:12:48 +0100 > > Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxx> wrote: > > > >> The X-Powers AXP813 PMIC is really close to what is already done for > >> AXP20X/AXP22X. > >> > >> There are two pairs of bits to set the rate (one for Voltage and Current > >> measurements and one for TS/GPIO0 voltage measurements) instead of one. > > > > This would normally imply we need to split the device into two logical > > IIO devices. However, that only becomes relevant if we are using > > buffered output which this driver doesn't support. > > > It'll be nasty to deal with this if we add that support down the line > > though. Up to you though as it's more likely to be your problem than > > anyone else's :) > > > > I have no plans for supporting buffered output for the AXPs at the > moment. But that's an interesting (and important) limitation to raise. > Wouldn't be more of a hack to have two IIO devices representing the > actual same IP? We have thought about allowing multiple buffers from a single IIO device but that makes for some horrible changes to the ABI - so as things stand the only option is two devices for one IP. Ultimately they aren't really two devices - in the same way we have triggers separating registered on the IIO bus (often many of them). Just two different elements of the same IP. > > > For now you could elect to support the different sampling frequencies > > if you wanted to but just providing controls for each channel. > > > > I guess that you're offering to use IIO_CHAN_INFO_SAMP_FREQ in > info_mask_separate for each channel? Yes > > > Given the driver doesn't currently expose these at all (I think) > > this is all rather immaterial ;) > > I'm not giving the user the option to chose the sampling frequency for > now. I have no plans to do it either, but I think it would be rather > simple to later add support for setting frequency sampling since we only > need to add a sysfs entry (with IIO_CHAN_INFO_SAMP_FREQ) that does not > exist yet. Don't you think? Am I missing something? No should be straight forward as long as we keep clear of the buffered interfaces with their limitations. > > Thanks, > Quentin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
