1ARM MHU Mailbox Driver 2====================== 3 4The ARM's Message-Handling-Unit (MHU) is a mailbox controller that has 53 independent channels/links to communicate with remote processor(s). 6 MHU links are hardwired on a platform. A link raises interrupt for any 7received data. However, there is no specified way of knowing if the sent 8data has been read by the remote. This driver assumes the sender polls 9STAT register and the remote clears it after having read the data. 10The last channel is specified to be a 'Secure' resource, hence can't be 11used by Linux running NS. 12 13Mailbox Device Node: 14==================== 15 16Required properties: 17-------------------- 18- compatible: Shall be "arm,mhu" & "arm,primecell" 19- reg: Contains the mailbox register address range (base 20 address and length) 21- #mbox-cells Shall be 1 - the index of the channel needed. 22- interrupts: Contains the interrupt information corresponding to 23 each of the 3 links of MHU. 24 25Example: 26-------- 27 28 mhu: mailbox@2b1f0000 { 29 #mbox-cells = <1>; 30 compatible = "arm,mhu", "arm,primecell"; 31 reg = <0 0x2b1f0000 0x1000>; 32 interrupts = <0 36 4>, /* LP-NonSecure */ 33 <0 35 4>, /* HP-NonSecure */ 34 <0 37 4>; /* Secure */ 35 clocks = <&clock 0 2 1>; 36 clock-names = "apb_pclk"; 37 }; 38 39 mhu_client: scb@2e000000 { 40 compatible = "fujitsu,mb86s70-scb-1.0"; 41 reg = <0 0x2e000000 0x4000>; 42 mboxes = <&mhu 1>; /* HP-NonSecure */ 43 }; 44