Documentation/devicetree/bindings/soc/ti/wkup_m3_ipc.txt

   1 Wakeup M3 IPC Driver
   2 =====================
   3
   4 The TI AM33xx and AM43xx family of devices use a small Cortex M3 co-processor
   5 (commonly referred to as Wakeup M3 or CM3) to help with various low power tasks
   6 that cannot be controlled from the MPU, like suspend/resume and certain deep
   7 C-states for CPU Idle. Once the wkup_m3_ipc driver uses the wkup_m3_rproc driver
   8 to boot the wkup_m3, it handles communication with the CM3 using IPC registers
   9 present in the SoC's control module and a mailbox. The wkup_m3_ipc exposes an
  10 API to allow the SoC PM code to execute specific PM tasks.
  11
  12 Wkup M3 Device Node:
  13 ====================
  14 A wkup_m3_ipc device node is used to represent the IPC registers within an
  15 SoC.
  16
  17 Required properties:
  18 --------------------
  19 - compatible:           Should be,
  20                                 "ti,am3352-wkup-m3-ipc" for AM33xx SoCs
  21                                 "ti,am4372-wkup-m3-ipc" for AM43xx SoCs
  22 - reg:                  Contains the IPC register address space to communicate
  23                         with the Wakeup M3 processor
  24 - interrupts:           Contains the interrupt information for the wkup_m3
  25                         interrupt that signals the MPU.
  26 - ti,rproc:             phandle to the wkup_m3 rproc node so the IPC driver
  27                         can boot it.
  28 - mboxes:               phandles used by IPC framework to get correct mbox
  29                         channel for communication. Must point to appropriate
  30                         mbox_wkupm3 child node.
  31
  32 Example:
  33 --------
  34 /* AM33xx */
  35         l4_wkup: l4_wkup@44c00000 {
  36                 ...
  37
  38                 scm: scm@210000 {
  39                         compatible = "ti,am3-scm", "simple-bus";
  40                         reg = <0x210000 0x2000>;
  41                         #address-cells = <1>;
  42                         #size-cells = <1>;
  43                         ranges = <0 0x210000 0x2000>;
  44
  45                         ...
  46
  47                         wkup_m3_ipc: wkup_m3_ipc@1324 {
  48                                 compatible = "ti,am3352-wkup-m3-ipc";
  49                                 reg = <0x1324 0x24>;
  50                                 interrupts = <78>;
  51                                 ti,rproc = <&wkup_m3>;
  52                                 mboxes = <&mailbox &mbox_wkupm3>;
  53                         };
  54
  55                         ...
  56                 };
  57         };