On Wed, 31 Jan 2024 at 04:39, Chen-Yu Tsai <wenst@xxxxxxxxxxxx> wrote: > > (+CC Ulf Hansson) > > On Wed, Jan 31, 2024 at 6:38 AM Rob Herring <robh@xxxxxxxxxx> wrote: > > > > On Tue, Jan 30, 2024 at 05:25:38PM +0100, Krzysztof Kozlowski wrote: > > > On 30/01/2024 08:47, Chen-Yu Tsai wrote: > > > > On Tue, Jan 30, 2024 at 3:37 PM Krzysztof Kozlowski > > > > <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > >> > > > >> On 30/01/2024 04:32, Chen-Yu Tsai wrote: > > > >>> On Mon, Jan 29, 2024 at 3:34 PM Krzysztof Kozlowski > > > >>> <krzysztof.kozlowski@xxxxxxxxxx> wrote: > > > >>>> > > > >>>> On 29/01/2024 04:38, Chen-Yu Tsai wrote: > > > >>>> > > > >>>>>>> +allOf: > > > >>>>>>> + - $ref: bluetooth-controller.yaml# > > > >>>>>>> + > > > >>>>>>> +properties: > > > >>>>>>> + compatible: > > > >>>>>>> + enum: > > > >>>>>>> + - mediatek,mt7921s-bluetooth > > > >>>>>> > > > >>>>>> Can it be also WiFi on separate bus? How many device nodes do you need > > > >>>>>> for this device? > > > >>>>> > > > >>>>> For the "S" variant, WiFi is also on SDIO. For the other two variants, > > > >>>>> "U" and "E", WiFi goes over USB and PCIe respectively. On both those > > > >>>>> variants, Bluetooth can either go over USB or UART. That is what I > > > >>>>> gathered from the pinouts. There are a dozen GPIO pins which don't > > > >>>>> have detailed descriptions though. If you want a comprehensive > > > >>>>> binding of the whole chip and all its variants, I suggest we ask > > > >>>>> MediaTek to provide it instead. My goal with the binding is to document > > > >>>>> existing usage and allow me to upstream new device trees. > > > >>>>> > > > >>>>> For now we only need the Bluetooth node. The WiFi part is perfectly > > > >>>>> detectable, and the driver doesn't seem to need the WiFi reset pin. > > > >>>>> The Bluetooth driver only uses its reset pin to reset a hung controller. > > > >>>> > > > >>>> Then suffix "bluetooth" seems redundant. > > > >>> > > > >>> I think keeping the suffix makes more sense though. The chip is a two > > > >>> function piece, and this only targets one of the functions. Also, the > > > >> > > > >> That's why I asked and you said there is only one interface: SDIO. > > > > > > > > There's only one interface, SDIO, but two SDIO functions. The two > > > > functions, if both were to be described in the device tree, would > > > > be two separate nodes. We just don't have any use for the WiFi one > > > > right now. Does that make sense to keep the suffix? > > > > > > Number of functions does not really matter. Number of interfaces on the > > > bus would matter. Why would you have two separate nodes for the same > > > SDIO interface? Or do you want to say there are two interfaces? > > There is only one external interface. I don't know how the functions > are stitched together internally. > > It could be that the separate functions have nothing in common other > than sharing a standard external SDIO interface. Each function can be > individually controlled, and operations for different functions are > directed internally to the corresponding core. > > > Right, one device at 2 addresses on a bus should be a node with 2 "reg" > > entries, not 2 nodes with 1 "reg" address each. > > AFAICU that's not what the MMC controller binding, which I quote below, > says. It implies that each SDIO function shall be a separate node under > the MMC controller node. Yes, that's what we decided to go with, a long time ago. At least in this particular case, I think it makes sense, as each function (child-node) may also describe additional resources routed to each function. A typical description could be for a WiFi-Bluetooth combo-chip, where each function may have its own clocks, irqs and regulators being routed. > > > patternProperties: > "^.*@[0-9]+$": > type: object > description: | > On embedded systems the cards connected to a host may need > additional properties. These can be specified in subnodes to the > host controller node. The subnodes are identified by the > standard \'reg\' property. Which information exactly can be > specified depends on the bindings for the SDIO function driver > for the subnode, as specified by the compatible string. > > properties: > compatible: > description: | > Name of SDIO function following generic names recommended > practice > > reg: > items: > - minimum: 0 > maximum: 7 > description: > Must contain the SDIO function number of the function this > subnode describes. A value of 0 denotes the memory SD > function, values from 1 to 7 denote the SDIO functions. > > > ChenYu Kind regards Uffe
