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1Qualcomm GLINK edge binding
2
3This binding describes a Qualcomm GLINK edge, a fifo based mechanism for
4communication between subsystem-pairs on various Qualcomm platforms. Two types
5of edges can be described by the binding; the GLINK RPM edge and a SMEM based
6edge.
7
8- compatible:
9 Usage: required for glink-rpm
10 Value type: <stringlist>
11 Definition: must be "qcom,glink-rpm"
12
13- label:
14 Usage: optional
15 Value type: <string>
16 Definition: should specify the subsystem name this edge corresponds to.
17
18- interrupts:
19 Usage: required
20 Value type: <prop-encoded-array>
21 Definition: should specify the IRQ used by the remote processor to
22 signal this processor about communication related events
23
24- qcom,rpm-msg-ram:
25 Usage: required for glink-rpm
26 Value type: <prop-encoded-array>
27 Definition: handle to RPM message memory resource
28
29- mboxes:
30 Usage: required
31 Value type: <prop-encoded-array>
32 Definition: reference to the "rpm_hlos" mailbox in APCS, as described
33 in mailbox/mailbox.txt
34
35= GLINK DEVICES
36Each subnode of the GLINK node represent function tied to a virtual
37communication channel. The name of the nodes are not important. The properties
38of these nodes are defined by the individual bindings for the specific function
39- but must contain the following property:
40
41- qcom,glink-channels:
42 Usage: required
43 Value type: <stringlist>
44 Definition: a list of channels tied to this function, used for matching
45 the function to a set of virtual channels
46
47- qcom,intents:
48 Usage: optional
49 Value type: <prop-encoded-array>
50 Definition: a list of size,amount pairs describing what intents should
51 be preallocated for this virtual channel. This can be used
52 to tweak the default intents available for the channel to
53 meet expectations of the remote.
54
55= EXAMPLE
56The following example represents the GLINK RPM node on a MSM8996 device, with
57the function for the "rpm_request" channel defined, which is used for
58regualtors and root clocks.
59
60 apcs_glb: mailbox@9820000 {
61 compatible = "qcom,msm8996-apcs-hmss-global";
62 reg = <0x9820000 0x1000>;
63
64 #mbox-cells = <1>;
65 };
66
67 rpm_msg_ram: memory@68000 {
68 compatible = "qcom,rpm-msg-ram";
69 reg = <0x68000 0x6000>;
70 };
71
72 rpm-glink {
73 compatible = "qcom,glink-rpm";
74
75 interrupts = <GIC_SPI 168 IRQ_TYPE_EDGE_RISING>;
76
77 qcom,rpm-msg-ram = <&rpm_msg_ram>;
78
79 mboxes = <&apcs_glb 0>;
80
81 rpm-requests {
82 compatible = "qcom,rpm-msm8996";
83 qcom,glink-channels = "rpm_requests";
84
85 qcom,intents = <0x400 5
86 0x800 1>;
87 ...
88 };
89 };