Hi Javier & Mark, I am educated. Thank you all.
> -----Original Message----- > From: Javier Martinez Canillas [mailto:jav...@dowhile0.org] > Sent: 2016年1月29日 19:50 > To: Mark Brown <broo...@kernel.org> > Cc: Yang, Wenyou <wenyou.y...@atmel.com>; Liam Girdwood > <lgirdw...@gmail.com>; Rob Herring <robh...@kernel.org>; Pawel Moll > <pawel.m...@arm.com>; Ian Campbell <ijc+devicet...@hellion.org.uk>; Kumar > Gala <ga...@codeaurora.org>; Krzysztof Kozlowski > <k.kozlow...@samsung.com>; Lee Jones <lee.jo...@linaro.org>; Peter > Korsgaard <jac...@gmail.com>; Ferre, Nicolas <nicolas.fe...@atmel.com>; > linux-arm-ker...@lists.infradead.org; linux-kernel@vger.kernel.org; > devicet...@vger.kernel.org > Subject: Re: [PATCH v4 1/2] regulator: act8945a: add regulator driver for > ACT8945A > > Hello Mark, > > On Fri, Jan 29, 2016 at 8:35 AM, Mark Brown <broo...@kernel.org> wrote: > > On Fri, Jan 29, 2016 at 01:20:08AM +0000, Yang, Wenyou wrote: > > > >> > > +static const struct of_device_id act8945a_pmic_of_match[] = { { > >> > > +.compatible = "active-semi,act8945a-regulator" }, { }, }; > >> > > +MODULE_DEVICE_TABLE(of, act8945a_pmic_of_match); > > > >> > This seems mostly OK but why do we have a compatible string here - > >> > shouldn't the MFD be able to instantiate the regulator function without > needing this? > > > >> Because I got feedback from Javier for the act8945a-charger patches > >> of this MFD series, He said missing the OF match table will cause the > >> module > autoloading broken. > > > >> http://lists.infradead.org/pipermail/linux-arm-kernel/2016-January/39 > >> 8113.html > > > >> What do you think about it? > > > > If then device is not being loaded from the DT (and it shouldn't be, > > the device looks like it should be instantiated directly by the MFD as > > it can't exist separately to that MFD) an OF table will do nothing. > > Then he should remove the .of_compatible from the MFD cell definition. I tried it, But if removed this .of_compatible, and reserved the OF table. the &pdev->dev->of_node is NULL, the driver fails to get the configuration value from DT, It seems the OF table still doesn't work. Where is wrong? Could you help give some suggestion? > > Otherwise the MFD core will assign an of_node to this device in > mfd_add_device(), > making the platform core to believe the device was instantiated by OF. So an > OF > modalias uevent will be reported to load the module and the OF table should be > used for matching the device with the driver. > > IOW, the MFD and regulator driver have to agree on this. Either everything > should > have OF or platform information, both work but mixing these as it was on a > previous version doesn't. > > Best regards, > Javier Best Regards, Wenyou Yang
