xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/reserved-memory/qcom,cmd-db.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunCommand DB
2*4882a593Smuzhiyun---------
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunCommand DB is a database that provides a mapping between resource key and the
5*4882a593Smuzhiyunresource address for a system resource managed by a remote processor. The data
6*4882a593Smuzhiyunis stored in a shared memory region and is loaded by the remote processor.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunSome of the Qualcomm Technologies Inc SoC's have hardware accelerators for
9*4882a593Smuzhiyuncontrolling shared resources. Depending on the board configuration the shared
10*4882a593Smuzhiyunresource properties may change. These properties are dynamically probed by the
11*4882a593Smuzhiyunremote processor and made available in the shared memory.
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunThe bindings for Command DB is specified in the reserved-memory section in
14*4882a593Smuzhiyundevicetree. The devicetree representation of the command DB driver should be:
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunProperties:
17*4882a593Smuzhiyun- compatible:
18*4882a593Smuzhiyun	Usage: required
19*4882a593Smuzhiyun	Value type: <string>
20*4882a593Smuzhiyun	Definition: Should be "qcom,cmd-db"
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun- reg:
23*4882a593Smuzhiyun	Usage: required
24*4882a593Smuzhiyun	Value type: <prop encoded array>
25*4882a593Smuzhiyun	Definition: The register address that points to the actual location of
26*4882a593Smuzhiyun		    the Command DB in memory.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunExample:
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun	reserved-memory {
31*4882a593Smuzhiyun		[...]
32*4882a593Smuzhiyun		reserved-memory@85fe0000 {
33*4882a593Smuzhiyun			reg = <0x0 0x85fe0000 0x0 0x20000>;
34*4882a593Smuzhiyun			compatible = "qcom,cmd-db";
35*4882a593Smuzhiyun			no-map;
36*4882a593Smuzhiyun		};
37*4882a593Smuzhiyun	};
38