On Wed, Apr 17, 2024 at 05:32:54PM +0200, AngeloGioacchino Del Regno wrote: > Il 17/04/24 16:54, Rob Herring ha scritto: > > On Wed, Apr 17, 2024 at 11:14:37AM +0200, AngeloGioacchino Del Regno wrote: > > > Add bindings for the MediaTek External Memory Interface Interconnect, > > > which providers support system bandwidth requirements through Dynamic > > > Voltage Frequency Scaling Resource Collector (DVFSRC) hardware. > > > > > > This adds bindings for MediaTek MT8183 and MT8195 SoCs. > > > > > > Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> > > > --- > > > .../interconnect/mediatek,mt8183-emi.yaml | 76 +++++++++++++++++++ > > > .../interconnect/mediatek,mt8183.h | 23 ++++++ > > > .../interconnect/mediatek,mt8195.h | 44 +++++++++++ > > > 3 files changed, 143 insertions(+) > > > create mode 100644 Documentation/devicetree/bindings/interconnect/mediatek,mt8183-emi.yaml > > > create mode 100644 include/dt-bindings/interconnect/mediatek,mt8183.h > > > create mode 100644 include/dt-bindings/interconnect/mediatek,mt8195.h > > > > > > diff --git a/Documentation/devicetree/bindings/interconnect/mediatek,mt8183-emi.yaml b/Documentation/devicetree/bindings/interconnect/mediatek,mt8183-emi.yaml > > > new file mode 100644 > > > index 000000000000..3ad60fd21f83 > > > --- /dev/null > > > +++ b/Documentation/devicetree/bindings/interconnect/mediatek,mt8183-emi.yaml > > > @@ -0,0 +1,76 @@ > > > +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause > > > +%YAML 1.2 > > > +--- > > > +$id: http://devicetree.org/schemas/interconnect/mediatek,mt8183-emi.yaml# > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > + > > > +title: MediaTek External Memory Interface (EMI) Interconnect > > > + > > > +maintainers: > > > + - AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> > > > + > > > +description: | > > > + EMI interconnect providers support system bandwidth requirements through > > > + Dynamic Voltage Frequency Scaling Resource Collector (DVFSRC) hardware. > > > + The provider is able to communicate with the DVFSRC through Secure Monitor > > > + Call (SMC). > > > + > > > + ICC provider ICC Nodes > > > + ---- ---- > > > + _________ |CPU | |--- |VPU | > > > + _____ | |----- ---- | ---- > > > + | |->| DRAM | ---- | ---- > > > + |DRAM |->|scheduler|----- |GPU | |--- |DISP| > > > + | |->| (EMI) | ---- | ---- > > > + |_____|->|_________|---. ----- | ---- > > > + /|\ `-|MMSYS|--|--- |VDEC| > > > + | ----- | ---- > > > + | | ---- > > > + | change DRAM freq |--- |VENC| > > > + -------- | ---- > > > + SMC --> | DVFSRC | | ---- > > > + -------- |--- |IMG | > > > + | ---- > > > + | ---- > > > + |--- |CAM | > > > + ---- > > > + > > > +properties: > > > + compatible: > > > + enum: > > > + - mediatek,mt8183-emi > > > + - mediatek,mt8195-emi > > > + > > > + reg: > > > + maxItems: 1 > > > + > > > + '#interconnect-cells': > > > + const: 1 > > > + > > > +required: > > > + - compatible > > > + - '#interconnect-cells' > > > + > > > +unevaluatedProperties: false > > > + > > > +examples: > > > + - | > > > + #include <dt-bindings/interconnect/mediatek,mt8195.h> > > > + > > > + soc { > > > + #address-cells = <2>; > > > + #size-cells = <2>; > > > + > > > + system-controller@10012000 { > > > + compatible = "mediatek,mt8195-dvfsrc"; > > > + reg = <0 0x10012000 0 0x1000>; > > > + #address-cells = <1>; > > > + #size-cells = <0>; > > > + > > > + emi_icc: interconnect@1 { > > > + compatible = "mediatek,mt8195-emi"; > > > + reg = <1>; > > > + #interconnect-cells = <1>; > > > > > > There's not really any need for this node. Just put #interconnect-cells > > in the parent. > > > > Actually, I modeled it to be a subnode of the DVFSRC for multiple reasons: > > 1. Some SoCs have more than one interconnect on the DVFSRC (two different kinds > of EMI interconnect, and then also a SMI interconnect); and > > 2. Some boards will want to not enable the interconnect driver because some of > those are not battery powered (so they just keep the knobs at full thrust > from the bootloader and never care scaling busses); and > > 3. Some DVFSRC interconnect features may depend on firmware (but I'm not > sure which ones and which SoCs, as there are lots of SMI/EMI ICC things that > are not implemented yet with this series). > > The alternative would've been to add a property to enable, or disable, the SMI ICC > (not present in this series), and/or one, or the other kind of EMI ICC (this series > implements only the simpler EMI ICC, and I keep saying "the other" because I > currently don't remember the name).... which is really ugly. > > Ideas? :-) Just provide that reasoning in the commit msg. Rob
