On 28/03/2018 at 11:53:17 +0800, Sean Wang wrote: > On Tue, 2018-03-27 at 17:18 +0200, Alexandre Belloni wrote: > > On 25/03/2018 at 03:36:28 +0800, Sean Wang wrote: > > > just reply both replies in the same mail > > > > > > 1.) the power-off device is a part of rtc, use the same registers rtc > > > has and thus it is put as child nodes under the node rtc to reflect the > > > reality of characteristics the rtc has. > > > > > > Or am I wrong for a certain aspect in these opinions? > > > > > > > My point is that it is also part of the PMIC so it may as well be > > registers from the mfd driver which already registers a bunch of devices > > instead of doing unusual stuff from the rtc driver. > > > > mt6397_rtc->regmap is mt6397_chip->regmap anyway. You have the added > > benefit that if the RTC driver probe fails for some reason, you may > > still be able to probe the reset driver. > > > > I don't tink there is any benefit having it as a child of the rtc > > device. > > > > > really thanks! it's an optional solution I thought it 's fine and worth > doing > > but so far I cannot fully make sure of whether mfd can accept two > devices holding overlay IORESOURCE_MEM. > There is no overlay because you are using a regmap which handles concurrency for you. What your patch is doing is: struct mt6397_rtc *rtc = dev_get_drvdata(pdev->dev.parent); then you use rtc->regmap But in the rtc driver, you have: struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent); struct mt6397_rtc *rtc; rtc->regmap = mt6397_chip->regmap; So there is no benefit from being the child of the rtc, you could just do the following in your reset driver: struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent); and then use mt6397_chip->regmap. -- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com -- 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
