On 11/01/2016 at 18:47:34 +0530, Laxman Dewangan wrote : > > On Friday 08 January 2016 07:06 PM, Laxman Dewangan wrote: > > > >On Friday 08 January 2016 07:06 PM, Mark Brown wrote: > >>* PGP Signed by an unknown key > >> > >>On Fri, Jan 08, 2016 at 06:34:29PM +0530, Laxman Dewangan wrote: > >> > >>>If we get the parent device, regmap handle and interrupt number from > >>>mfd > >>>core independent of the PMIC (MAX77620 or MAX77686), then same driver > >>>can be > >>>used here. > >>>Two way which I can think of here: > >>Parent device is just dev->parent, you can use dev_get_regmap() to get a > >>regmap given a struct device and you can use platform resources to pass > >>the interrupts to the children from the MFD (there's some examples, > >>wm831x is one). > >> > >> > > > >I think it should work with named regmap. mfd whould init regmap with name > >and rtc driver should ask with same name. > > > >I saw three drivers which looks same: > >rtc-max77620.c (new from me) and already available rtc-max77686.c, > >rtc-max77802.c > > > >Seems I can develop IP based rtc driver as rtc-max77xxx.c > > I came with one of issue when doing this. > > The RTC driver parent is not the same parent for which i2c slave address get > registered. > There is two slave address from max77620, 0x3C (for general) and 0x68 for > RTC. > > In max77620 mfd driver, we make dummy i2c client for 0x68 and initialize > regmap with this address. > > Now on mfd_add_devices, we pass the device for 0x3c and hence the RTC driver > treat the parent as the 0x3c device but actually it should be 0x68 to get > the proper regmap. > > > Two approach: > 1. If we add the option to pass parent_dev when adding cells form > mfd_add_devices and select the parent device based on this option then it > can be easily handle. > Add parent_dev structure in struct mfd_cell and then change the parent > in mfd_add_device() if cells has parent device. > > 2. Register the RTC driver with different mfd_add_devices with dummy i2c > client device. > So two times mfd_add_devices. > > > IMO, approach 1 looks good to me. > > Any opinion? > If the RTC is not at the same address, I'd say this is not an mfd anymore, can't you probe it directly from DT? -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.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
