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