Messages in this thread | | | Date | Mon, 22 Jun 2020 23:03:59 +0200 | From | Michael Walle <> | Subject | Re: [RFC] MFD's relationship with Device Tree (OF) |
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Am 2020-06-14 12:26, schrieb Michael Walle: > Hi Rob, > > Am 2020-06-10 00:03, schrieb Rob Herring: > [..] >> Yes, we should use 'reg' whenever possible. If we don't have 'reg', >> then you shouldn't have a unit-address either and you can simply match >> on the node name (standard DT driver matching is with compatible, >> device_type, and node name (w/o unit-address)). We've generally been >> doing 'classname-N' when there's no 'reg' to do 'classname@N'. >> Matching on 'classname-N' would work with node name matching as only >> unit-addresses are stripped. > > This still keeps me thinking. Shouldn't we allow the (MFD!) device > driver creator to choose between "classname@N" and "classname-N". > In most cases N might not be made up, but it is arbitrarily chosen; > for example you've chosen the bank for the ab8500 reg. It is not > a defined entity, like an I2C address if your parent is an I2C bus, > or a SPI chip select, or the memory address in case of MMIO. Instead > the device driver creator just chooses some "random" property from > the datasheet; another device creator might have chosen another > property. Wouldn't it make more sense, to just say this MFD provides > N pwm devices and the subnodes are matching based on pwm-{0,1..N-1}? > That would also be the logical consequence of the current MFD sub > device to OF node matching code, which just supports N=1. >
Rob? Lee?
-michael
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