1TI SysCon Reset Controller
2=======================
3
4Almost all SoCs have hardware modules that require reset control in addition
5to clock and power control for their functionality. The reset control is
6typically provided by means of memory-mapped I/O registers. These registers are
7sometimes a part of a larger register space region implementing various
8functionalities. This register range is best represented as a syscon node to
9allow multiple entities to access their relevant registers in the common
10register space.
11
12A SysCon Reset Controller node defines a device that uses a syscon node
13and provides reset management functionality for various hardware modules
14present on the SoC.
15
16SysCon Reset Controller Node
17============================
18Each of the reset provider/controller nodes should be a child of a syscon
19node and have the following properties.
20
21Required properties:
22--------------------
23 - compatible		: Should be,
24			    "ti,k2e-pscrst"
25			    "ti,k2l-pscrst"
26			    "ti,k2hk-pscrst"
27			    "ti,syscon-reset"
28 - #reset-cells		: Should be 1. Please see the reset consumer node below
29			  for usage details
30 - ti,reset-bits	: Contains the reset control register information
31			  Should contain 7 cells for each reset exposed to
32			  consumers, defined as:
33			    Cell #1 : offset of the reset assert control
34			              register from the syscon register base
35			    Cell #2 : bit position of the reset in the reset
36			              assert control register
37			    Cell #3 : offset of the reset deassert control
38			              register from the syscon register base
39			    Cell #4 : bit position of the reset in the reset
40			              deassert control register
41			    Cell #5 : offset of the reset status register
42			              from the syscon register base
43			    Cell #6 : bit position of the reset in the
44			              reset status register
45			    Cell #7 : Flags used to control reset behavior,
46			              availible flags defined in the DT include
47			              file <dt-bindings/reset/ti-syscon.h>
48
49SysCon Reset Consumer Nodes
50===========================
51Each of the reset consumer nodes should have the following properties,
52in addition to their own properties.
53
54Required properties:
55--------------------
56 - resets	: A phandle to the reset controller node and an index number
57		  to a reset specifier as defined above.
58
59Please also refer to Documentation/devicetree/bindings/reset/reset.txt for
60common reset controller usage by consumers.
61
62Example:
63--------
64The following example demonstrates a syscon node, the reset controller node
65using the syscon node, and a consumer (a DSP device) on the TI Keystone 2
6666AK2E SoC.
67
68/ {
69	soc {
70		psc: power-sleep-controller@2350000 {
71			compatible = "syscon", "simple-mfd";
72			reg = <0x02350000 0x1000>;
73
74			pscrst: reset-controller {
75				compatible = "ti,k2e-pscrst", "ti,syscon-reset";
76				#reset-cells = <1>;
77
78				ti,reset-bits = <
79					0xa3c 8 0xa3c 8 0x83c 8 (ASSERT_CLEAR | DEASSERT_SET   | STATUS_CLEAR) /* 0: dsp0 */
80					0xa40 5 0xa44 3 0     0 (ASSERT_SET   | DEASSERT_CLEAR | STATUS_NONE)  /* 1: example */
81				>;
82			};
83		};
84
85		dsp0: dsp0 {
86			...
87			resets = <&pscrst 0>;
88			...
89		};
90	};
91};
92