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authorAndreas Dannenberg <dannenberg@ti.com>2018-08-27 15:57:41 +0530
committerTom Rini <trini@konsulko.com>2018-09-11 08:32:55 -0400
commit65c8a79811baa10944cebb34dcec6c0695f13197 (patch)
treefd42513d23e73a7475d6c5d826c92dffcd587f64 /doc
parentc72f9b707a3816bcb978c25e3f14ccc83906259b (diff)
reset: Introduce TI System Control Interface (TI SCI) reset driver
Some TI Keystone 2 and K3 family of SoCs contain a system controller (like the Power Management Micro Controller (PMMC) on 66AK2G SoCs and the Device Management and Security Controller on AM65x SoCs) that manage the low-level device control (like clocks, resets etc) for the various hardware modules present on the SoC. These device control operations are provided to the host processor OS through a communication protocol called the TI System Control Interface (TI SCI) protocol. This patch adds a reset driver that communicates to the system controller over the TI SCI protocol for performing reset management of various devices present on the SoC. Various reset functionalities are achieved by the means of different TI SCI device operations provided by the TI SCI framework. This code is loosely based on the drivers/reset/reset-ti-sci.c driver of the Linux kernel. Reviewed-by: Tom Rini <trini@konsulko.com> Signed-off-by: Andreas Dannenberg <dannenberg@ti.com> Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
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+Texas Instruments TI SCI Reset Controller
+=========================================
+
+Some TI SoCs contain a system controller (like the SYSFW, etc...) that is
+responsible for controlling the state of the IPs that are present.
+Communication between the host processor running an OS and the system
+controller happens through a protocol known as TI SCI [1].
+
+[1] http://processors.wiki.ti.com/index.php/TISCI
+
+Reset Controller Node
+=====================
+The reset controller node represents the resets of various hardware modules
+present on the SoC managed by the SYSFW. Because this relies on the TI SCI
+protocol to communicate with the SYSFW it must be a child of the sysfw node.
+
+Required Properties:
+--------------------
+ - compatible: Must be "ti,sci-reset"
+ - #reset-cells: Must be 2. Please see the reset consumer node below for
+ usage details.
+
+Example (AM65x):
+----------------
+ sysfw: sysfw {
+ compatible = "ti,am654-system-controller";
+ ...
+ k3_reset: reset-controller {
+ compatible = "ti,sci-reset";
+ #reset-cells = <2>;
+ };
+ };
+
+Reset Consumers
+===============
+Each of the reset consumer nodes should have the following properties,
+in addition to their own properties.
+
+Required Properties:
+--------------------
+ - resets: A phandle and reset specifier pair, one pair for each reset signal
+ that affects the device, or that the device manages. The phandle
+ should point to the TI SCI reset controller node, and the reset
+ specifier should have 2 cell-values. The first cell should contain
+ the device ID. The second cell should contain the reset mask value
+ used by system controller.
+
+Example (AM65x):
+----------------
+ uart2: serial@02800000 {
+ compatible = "ti,omap4-uart";
+ ...
+ resets = <&k3_reset 5 1>;
+ };