xref: /OK3568_Linux_fs/u-boot/doc/device-tree-bindings/mailbox/nvidia,tegra186-hsp.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunNVIDIA Tegra Hardware Synchronization Primitives (HSP)
2*4882a593Smuzhiyun
3*4882a593SmuzhiyunThe HSP modules are used for the processors to share resources and communicate
4*4882a593Smuzhiyuntogether. It provides a set of hardware synchronization primitives for
5*4882a593Smuzhiyuninterprocessor communication. So the interprocessor communication (IPC)
6*4882a593Smuzhiyunprotocols can use hardware synchronization primitives, when operating between
7*4882a593Smuzhiyuntwo processors not in an SMP relationship.
8*4882a593Smuzhiyun
9*4882a593SmuzhiyunThe features that HSP supported are shared mailboxes, shared semaphores,
10*4882a593Smuzhiyunarbitrated semaphores and doorbells.
11*4882a593Smuzhiyun
12*4882a593SmuzhiyunRequired properties:
13*4882a593Smuzhiyun- name : Should be hsp
14*4882a593Smuzhiyun- compatible
15*4882a593Smuzhiyun    Array of strings.
16*4882a593Smuzhiyun    one of:
17*4882a593Smuzhiyun    - "nvidia,tegra186-hsp"
18*4882a593Smuzhiyun- reg : Offset and length of the register set for the device.
19*4882a593Smuzhiyun- interrupt-names
20*4882a593Smuzhiyun    Array of strings.
21*4882a593Smuzhiyun    Contains a list of names for the interrupts described by the interrupt
22*4882a593Smuzhiyun    property. May contain the following entries, in any order:
23*4882a593Smuzhiyun    - "doorbell"
24*4882a593Smuzhiyun    Users of this binding MUST look up entries in the interrupt property
25*4882a593Smuzhiyun    by name, using this interrupt-names property to do so.
26*4882a593Smuzhiyun- interrupts
27*4882a593Smuzhiyun    Array of interrupt specifiers.
28*4882a593Smuzhiyun    Must contain one entry per entry in the interrupt-names property,
29*4882a593Smuzhiyun    in a matching order.
30*4882a593Smuzhiyun- #mbox-cells : Should be 2.
31*4882a593Smuzhiyun
32*4882a593SmuzhiyunThe mbox specifier of the "mboxes" property in the client node should
33*4882a593Smuzhiyuncontain two data. The first one should be the HSP type and the second
34*4882a593Smuzhiyunone should be the ID that the client is going to use. Those information
35*4882a593Smuzhiyuncan be found in the following file.
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun- <dt-bindings/mailbox/tegra186-hsp.h>.
38*4882a593Smuzhiyun
39*4882a593SmuzhiyunExample:
40*4882a593Smuzhiyun
41*4882a593Smuzhiyunhsp_top0: hsp@3c00000 {
42*4882a593Smuzhiyun	compatible = "nvidia,tegra186-hsp";
43*4882a593Smuzhiyun	reg = <0x0 0x03c00000 0x0 0xa0000>;
44*4882a593Smuzhiyun	interrupts = <GIC_SPI 176 IRQ_TYPE_LEVEL_HIGH>;
45*4882a593Smuzhiyun	interrupt-names = "doorbell";
46*4882a593Smuzhiyun	#mbox-cells = <2>;
47*4882a593Smuzhiyun};
48*4882a593Smuzhiyun
49*4882a593Smuzhiyunclient {
50*4882a593Smuzhiyun	...
51*4882a593Smuzhiyun	mboxes = <&hsp_top0 HSP_MBOX_TYPE_DB HSP_DB_MASTER_XXX>;
52*4882a593Smuzhiyun};
53