On Wed, 22 Dec 2010 23:58:09 -0600
Meador Inge <meador_i...@mentor.com> wrote:
> NOTE: The 'interrupt-parent' is implicit since message register nodes
> are always children of interrupt controller nodes.
>
> ** Example:
>
> mpic: p...@40000 {
> interrupt-controller;
> #address-cells = <0>;
> #interrupt-cells = <2>;
> reg = <0x40000 0x40000>;
> compatible = "chrp,open-pic";
> device_type = "open-pic";
> protected-sources = <0xb1>;
>
> m...@1400 {
> compatible = "fsl,p2020-msgr", "fsl,mpic-msgr";
> reg = <0x1400 0x200>;
> cell-index = <0>;
> interrupts = <0xb0 0x2 0xb1 0x2
> 0xb2 0x2 0xb3 0x2>;
> };
>
> m...@2400 {
> compatible = "fsl,p2020-msgr", "fsl,mpic-msgr";
> reg = <0x2400 0x200>;
> cell-index = <1>;
> interrupts = <0xb4 0x2 0xb5 0x2
> 0xb6 0x2 0xb7 0x2>;
> };
> };
These nodes cannot go under the mpic node, because interrupt
controllers need #address-cells = <0>.
It would be nice if the binding provided some way of partitioning
up individual message interrupts within a block.
Interrupt generation could be exported as a "service", similar to
(inbound) interrupts and gpios.
Perhaps a something like this, with "doorbell" being a new standard
hw-independent service with its own binding:
msg1: mpic-...@1400 {
compatible = "fsl,mpic-v3.0-msg";
reg = <0x1400 0x200>;
interrupts <176 2 178 2>;
// We have message registers 0 and 2 for sending,
// and 1 and 3 for receiving.
// If absent, we own all message registers in this block.
fsl,mpic-msg-send-mask = <0x5>;
fsl,mpic-msg-receive-mask = <0xa>;
doorbell-controller;
// split into #doorbell-send-cells and #doorbell-receive-cells?
#doorbell-cells = <1>;
};
some-amp-protocol-thingy {
send-doorbells = <&msg1 0>; // generate messages on MSGR0
receive-doorbells = <&msg1 0>; // receive messages on MSGR1
};
some-other-amp-protocol-thingy {
send-doorbells = <&msg1 1>; // generate messages on MSGR2
receive-doorbells = <&msg1 1>; // receive messages on MSGR3
};
Doorbell capabilities such as passing a 32-bit message can be negotiated
between the drivers for the doorbell controller and the doorbell client.
-Scott
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