On 05/05/11 11:16, Alexander Stein wrote: > Am Donnerstag, 5. Mai 2011, 12:01:25 schrieb Jonathan Cameron: >> On 05/05/11 10:44, Alexander Stein wrote: >>> Am Donnerstag, 5. Mai 2011, 11:08:18 schrieb Jonathan Cameron: >>>> On 05/05/11 09:32, Alexander Stein wrote: >>>>> Just set vref_mv in your platform config to use external vref. >>>>> Otherwise the internal one is used. >>>> >>>> Would be nicer to see this done with the regulator framework. But then >>>> if you have a use case on a board where that isn't available, then fair >>>> enough. >>> >>> Well, for the regulator framework I would redesign the driver a bit. >>> Currently the analogue inputs are displayed as mV in sysfs. If the >>> current analogue input voltage is shown via the regulator framework the >>> ads7846 driver itself can shows the actual ADC values. The latter ones >>> don't need to know the reference voltage. >>> But I think this is a different problem than choosing the reference >>> voltage for an ADC for what this patch is for. >> >> I'm somewhat confused by what you mean here. The regulator framework is >> all about power supplies. This device would merely be a consumer that >> asks for what (if anything) is being uspplied to the external vref line. >> Basically it's a more general alternative to supplying the value via >> platform data. > > Maybe I did get you wrong. I thought you meant retrieving the voltage at the > analogue input somehow using the regulator framework. > I don't know much about this framework, so how can you handle this: The > external vref is board-specific, e.g. hard-wired to 3,3V? There is no > regulator which could adjust the voltage attached to ext vref. Yup, you specify it as a fixed voltage regulator. The reason to do this is that others may well wire it up to a variable regulator (typical embedded pmic chip for example). -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
