Wakeup M3 IPC Driver
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=====================
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The TI AM33xx and AM43xx family of devices use a small Cortex M3 co-processor
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(commonly referred to as Wakeup M3 or CM3) to help with various low power tasks
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that cannot be controlled from the MPU, like suspend/resume and certain deep
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C-states for CPU Idle. Once the wkup_m3_ipc driver uses the wkup_m3_rproc driver
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to boot the wkup_m3, it handles communication with the CM3 using IPC registers
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present in the SoC's control module and a mailbox. The wkup_m3_ipc exposes an
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API to allow the SoC PM code to execute specific PM tasks.
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Wkup M3 Device Node:
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====================
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A wkup_m3_ipc device node is used to represent the IPC registers within an
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SoC.
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Required properties:
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--------------------
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- compatible: Should be,
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"ti,am3352-wkup-m3-ipc" for AM33xx SoCs
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"ti,am4372-wkup-m3-ipc" for AM43xx SoCs
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- reg: Contains the IPC register address space to communicate
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with the Wakeup M3 processor
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- interrupts: Contains the interrupt information for the wkup_m3
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interrupt that signals the MPU.
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- ti,rproc: phandle to the wkup_m3 rproc node so the IPC driver
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can boot it.
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- mboxes: phandles used by IPC framework to get correct mbox
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channel for communication. Must point to appropriate
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mbox_wkupm3 child node.
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Example:
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--------
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/* AM33xx */
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l4_wkup: l4_wkup@44c00000 {
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...
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scm: scm@210000 {
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compatible = "ti,am3-scm", "simple-bus";
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reg = <0x210000 0x2000>;
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#address-cells = <1>;
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#size-cells = <1>;
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ranges = <0 0x210000 0x2000>;
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...
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wkup_m3_ipc: wkup_m3_ipc@1324 {
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compatible = "ti,am3352-wkup-m3-ipc";
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reg = <0x1324 0x24>;
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interrupts = <78>;
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ti,rproc = <&wkup_m3>;
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mboxes = <&mailbox &mbox_wkupm3>;
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};
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...
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};
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};
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