xref: /kernel/linux/linux-5.10/Documentation/devicetree/bindings/soc/qcom/qcom,smem.txt

Qualcomm Shared Memory Manager binding

This binding describes the Qualcomm Shared Memory Manager, used to share data
between various subsystems and OSes in Qualcomm platforms.

- compatible:
	Usage: required
	Value type: <stringlist>
	Definition: must be:
		    "qcom,smem"

- memory-region:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: handle to memory reservation for main SMEM memory region.

- qcom,rpm-msg-ram:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: handle to RPM message memory resource

- hwlocks:
	Usage: required
	Value type: <prop-encoded-array>
	Definition: reference to a hwspinlock used to protect allocations from
		    the shared memory

= EXAMPLE
The following example shows the SMEM setup for MSM8974, with a main SMEM region
at 0xfa00000 and the RPM message ram at 0xfc428000:

	reserved-memory {
		#address-cells = <1>;
		#size-cells = <1>;
		ranges;

		smem_region: smem@fa00000 {
			reg = <0xfa00000 0x200000>;
			no-map;
		};
	};

	smem@fa00000 {
		compatible = "qcom,smem";

		memory-region = <&smem_region>;
		qcom,rpm-msg-ram = <&rpm_msg_ram>;

		hwlocks = <&tcsr_mutex 3>;
	};

	soc {
		rpm_msg_ram: memory@fc428000 {
			compatible = "qcom,rpm-msg-ram";
			reg = <0xfc428000 0x4000>;
		};
	};