Messages in this thread | | | Subject | Re: [PATCH 1/3] Docs: dt: add generic MSI bindings | From | David Daney <> | Date | Thu, 23 Jul 2015 11:26:11 -0700 |
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On 07/23/2015 09:52 AM, Mark Rutland wrote: [...] > +MSI clients > +=========== > + > +MSI clients are devices which generate MSIs. For each MSI they wish to > +generate, the doorbell and payload may be configured, though sideband > +information may not be configurable. > + > +Required properties: > +-------------------- > + > +- msi-parent: A list of phandle + msi-specifier pairs, one for each MSI > + controller which the device is capable of using. > +
We say here that "msi-parent" consists of pairs ...
> + This property is unordered, and MSIs may be allocated from any combination of > + MSI controllers listed in the msi-parent property. > + > + If a device has restrictions on the allocation of MSIs, these restrictions > + must be described with additional properties. > + > + When #msi-cells is non-zero, busses with an msi-parent will require > + additional properties to describe the relationship between devices on the bus > + and the set of MSIs they can potentially generate. > + > + > +Example > +======= > + > +/ { > + #address-cells = <1>; > + #size-cells = <1>; > + > + msi_a: msi-controller@a { > + reg = <0xa 0xf00>; > + compatible = "vendor-a,some-controller"; > + msi-controller; > + /* No sideband data, so #msi-cells omitted */ > + }; > + > + msi_b: msi-controller@b { > + reg = <0xb 0xf00>; > + compatible = "vendor-b,another-controller"; > + msi-controller; > + /* Each device has some unique ID */ > + #msi-cells = <1>; > + }; > + > + msi_c: msi-controller@c { > + reg = <0xb 0xf00>; > + compatible = "vendor-b,another-controller"; > + msi-controller; > + /* Each device has some unique ID */ > + #msi-cells = <1>; > + }; > + > + dev@0 { > + reg = <0x0 0xf00>; > + compatible = "vendor-c,some-device"; > + > + /* Can only generate MSIs to msi_a */ > + msi-parent = <&msi_a>;
My device-tree syntax foo is a little rusty, but doesn't "msi-parent" need a pair of elements? This has only the phandle.
> + }; > + > + dev@1 { > + reg = <0x1 0xf00>; > + compatible = "vendor-c,some-device"; > + > + /* > + * Can generate MSIs to either A or B. > + */ > + msi-parent = <&msi_a>, <&msi_b 0x17>;
... same here, ...
> + }; > + > + dev@2 { > + reg = <0x2 0xf00>; > + compatible = "vendor-c,some-device"; > + /* > + * Has different IDs at each MSI controller. > + * Can generate MSIs to all of the MSI controllers. > + */ > + msi-parent = <&msi_a>, <&msi_b 0x17>, <&msi_c 0x53>;
... and here
> + }; > +}; >
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