On Mon, Aug 26, 2013 at 06:03:31PM +0800, Josh Wu wrote: > Hi, Ludovic and Maxime > > On 8/26/2013 4:32 PM, Ludovic Desroches wrote: > >On Fri, Aug 23, 2013 at 06:59:36PM +0200, Maxime Ripard wrote: > >>Hi Ludovic, Josh, > >> > >>On Fri, Aug 23, 2013 at 05:46:03PM +0200, Desroches, Ludovic wrote: > >>>On Thu, Aug 22, 2013 at 05:53:00PM +0800, Josh Wu wrote: > >>>>On 8/22/2013 5:51 PM, Josh Wu wrote: > >>>>>Hi, Maxime > >>>>> > >>>>>On 8/16/2013 3:20 AM, Maxime Ripard wrote: > >>>>>>Hi Josh, > >>>>>> > >>>>>>On Sun, Aug 11, 2013 at 07:04:29PM +0800, Josh Wu wrote: > >>>>>>>For at91 boards, there are different IPs for adc. Different IPs has > >>>>>>>different STARTUP & PRESCAL mask in ADC_MR. > >>>>>>> > >>>>>>>This patch introduce the multiple compatible string for those > >>>>>>>different IPs. > >>>>>>> > >>>>>>>Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx> > >>>>>>Overall it looks like the right ways, but I think we can take it a step > >>>>>>further. > >>>>>> > >>>>>>I'd drop at least the atmel,adc-drdy-mask, atmel,adc-num-channels, > >>>>>>atmel,adc-status-register, atmel,adc-trigger-register properties (and > >>>>>>probably the triggers as well description as well). > >>>>>yeah, right. Currently I want to drop following: > >>>>> > >>>>>atmel,adc-drdy-mask, atmel,adc-status-register, > >>>>>atmel,adc-trigger-register, atmel,adc-channel-base > >>>>> > >>>>>For the adc-num-channels, I'd like to leave it in dt parameters. > >>>>>It is a description for an adc capablity. > >>>About this parameter, I'll remove it too from the dt bindings. To set it you > >>>need to have a look to the datasheet and to copy a constant value into the > >>>dt. From my point of view, it means than this parameter should be managed by > >>>the driver and by the dt. > >>> > >>>On the other side since there are some dynamic allocation depending on this > >>>parameter maybe it makes sense to keep it in the dt. If the user wants to use > >>>only 2 channels why doing allocation for max channel number. By the way, this > >>>case is only valid if he uses the two first channels. > >>I don't recall it very well, is there any reason to not have it in the > >>DT? Can the ADC channels be used for something else? Or is it just some > >>IP-specific number of channels? > >> > >It is IP-specific. I don't see what benefit we could have to keep it in the DT? > >But Josh seems to have arguments to keep it. > > I'm ok to remove the channel number. What I worried is there also > has a channel-used mask in DT. > This mask should be removed too if channel number is removed. > So maybe we can also use the sysfs to set the mask. Indeed, that would make adc-channel-used irrelevant. But I'm not sure the mask is useful at all. Just enable all the channels and that's it? > >>>>>For the triggers, I am not decided. An obvious benifit to remove > >>>>>trigger in dt will save many lines of code. > >>>>> > >>>>>>Maxime > >>>>>> > >>>>>Best Regards, > >>>>>Josh Wu > >>>Since we are talking about reworking this binding I was thinking about > >>>resolution stuff. Filling atmel,adc-res is also copying constant value from > >>>the device datasheet, so if I was consistent I would say it has to be removed > >>>too. But I am not consistent! I mean by doing this the only thing the user > >>>will have to fill is the resolution value. He can't set the value he wants, > >>>there are only two choices. By keeping it into the dt then he will immediately > >>>see the choices he has. > >>But the resolution should probably be somehow user-defined, probably not > >>really related to the DT has well. I think some other IIO ADC drivers > >>are using sysfs files for this purpose, maybe that would be a better > >>fit? > >It sounds to be a good solution. > > ok, I will check the other IIO ADC driver about this point. > Maybe this sysfs replacement need a bit more time. I prefer to send > out the patches first without the sysfs implement in v3. > And the sysfs replacement patch will be send out serperately. What > do you think? Maxime. Yes, of course. The resolution rework can definitely be done later. Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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