On Wed, 24 May 2017, Masahiro Yamada wrote: > Hi Lee, > > 2017-05-23 16:05 GMT+09:00 Lee Jones <lee.jones@xxxxxxxxxx>: > > On Tue, 23 May 2017, Masahiro Yamada wrote: > > > >> Hi Lee, Linus, > >> > >> Thanks for your comments! > >> > >> 2017-05-22 17:43 GMT+09:00 Linus Walleij <linus.walleij@xxxxxxxxxx>: > >> > On Mon, May 22, 2017 at 3:29 AM, Masahiro Yamada > >> > <yamada.masahiro@xxxxxxxxxxxxx> wrote: > >> > > >> >> Because "simple-bus" indicates that child nodes are > >> >> simply memory mapped, but the node "register-bit-led" > >> >> can not be memory-mapped. > >> >> So, "simple-mfd" can not be replaced "simple-bus" here. > >> > > >> > Yeah... just like Lee points out, you are spot on, this is exactly > >> > the reason why we created "simple-mfd" in the first place > >> > IIRC. > >> > >> OK, Linux treats simple-bus and simple-mfd in the same way > >> as far as I see drivers/of/platform.c > > > > Correct. As I said, the functionality of the two are the same. The > > difference is their meaning. Initially we were using "simple-mfd" to This should have read "simple-bus". Sorry for any confusion this may have caused. > > achieve our aim (see below), but there was push-back due to the > > differences in what the two properties were trying to achieve. Ergo, > > we introduced a second property. > > > >> Perhaps, can we document the difference between simple-bus and > >> simple-mfd clearly? > >> For example, "Unlike simple-bus, it is legitimate that simple-mfd has > >> subnodes without reg property" > >> > >> > >> I think this is typical when "simple-mfd" is used together with "syscon". > >> The child devices will use regmap of the parent node. > >> I'd like to be sure this is valid usage. > > > > "simple-mfd" simply means "register all of my child nodes using the > > platform API without any further intervention". It's goal is to > > prevent the MFD subsystem from being stuffed full of drivers where > > their only purpose is to call of_platform_populate(). All other rules > > and policy which must be followed are generic DT ones. To that end, I > > do not believe making further statements is necessary. > > I see. Thanks for your kind explanation! No problem. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- 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
