On Wed, Jun 19, 2024 at 12:20:54PM +0100, Jiaxun Yang wrote: > > > 在2024年6月19日六月 上午10:28，Krzysztof Kozlowski写道： > > On 18/06/2024 17:11, Jiaxun Yang wrote: > >> This compatible has been used in arch/mips/boot/dts/img/boston.dts > >> for a while but never documented properly. > >> > > > >> diff --git a/Documentation/devicetree/bindings/mfd/img,boston-platform-regs.yaml b/Documentation/devicetree/bindings/mfd/img,boston-platform-regs.yaml > >> new file mode 100644 > >> index 000000000000..79cae87c6758 > >> --- /dev/null > >> +++ b/Documentation/devicetree/bindings/mfd/img,boston-platform-regs.yaml > >> @@ -0,0 +1,74 @@ > >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > >> +%YAML 1.2 > >> +--- > >> +$id: http://devicetree.org/schemas/mfd/img,boston-platform-regs.yaml# > >> +$schema: http://devicetree.org/meta-schemas/core.yaml# > >> + > >> +title: Imagination Technologies Boston Platform Registers > >> + > >> +maintainers: > >> + - Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> > >> + > >> +properties: > >> + compatible: > >> + items: > >> + - const: img,boston-platform-regs > >> + - const: syscon > >> + - const: simple-mfd > > > > > > Fix U-boot to populate devices instead of relying on simple-mfd. > > Hi Krzysztof, > > I believe U-Boot's implementation is correct. As per simple-mfd binding: > > ``` > simple-mfd" - this signifies that the operating system should > consider all subnodes of the MFD device as separate devices akin to how > "simple-bus" indicates when to see subnodes as children for a simple > memory-mapped bus. > ``` > > This reads to me as "if you want sub nodes to be populated as devices > you need this." > > In our case there are "clock" and "reset" node sub nodes which should be > probed as regular device, so it's true for us. > > Linux managed to work without "simple-mfd" only because clock subsystem > is bypassing regular OF population process. Semantically we need this. I'm confused. Neither u-boot nor linux .dts files have 'simple-mfd' for this binding. So why do you need it? Why are we changing a platform that's had 1 dts change since 2018? If anything, add it in a separate patch and we can discuss it there instead of a conversion. > Besides Linux as upstream of devicetree source had accepted U-Boot > only stuff here, such as "bootph-all" property. Yes, and there are things we've rejected. See Arm FFA threads if you want to waste a few hours reading. Rob
