1 TI SysCon Reset Controller 1 TI SysCon Reset Controller
2 ======================= 2 =======================
3 3
4 Almost all SoCs have hardware modules that req 4 Almost all SoCs have hardware modules that require reset control in addition
5 to clock and power control for their functiona 5 to clock and power control for their functionality. The reset control is
6 typically provided by means of memory-mapped I 6 typically provided by means of memory-mapped I/O registers. These registers are
7 sometimes a part of a larger register space re 7 sometimes a part of a larger register space region implementing various
8 functionalities. This register range is best r 8 functionalities. This register range is best represented as a syscon node to
9 allow multiple entities to access their releva 9 allow multiple entities to access their relevant registers in the common
10 register space. 10 register space.
11 11
12 A SysCon Reset Controller node defines a devic 12 A SysCon Reset Controller node defines a device that uses a syscon node
13 and provides reset management functionality fo 13 and provides reset management functionality for various hardware modules
14 present on the SoC. 14 present on the SoC.
15 15
16 SysCon Reset Controller Node 16 SysCon Reset Controller Node
17 ============================ 17 ============================
18 Each of the reset provider/controller nodes sh 18 Each of the reset provider/controller nodes should be a child of a syscon
19 node and have the following properties. 19 node and have the following properties.
20 20
21 Required properties: 21 Required properties:
22 -------------------- 22 --------------------
23 - compatible : Should be, 23 - compatible : Should be,
24 "ti,k2e-pscrst" 24 "ti,k2e-pscrst"
25 "ti,k2l-pscrst" 25 "ti,k2l-pscrst"
26 "ti,k2hk-pscrst" 26 "ti,k2hk-pscrst"
27 "ti,syscon-reset" 27 "ti,syscon-reset"
28 - #reset-cells : Should be 1. Please 28 - #reset-cells : Should be 1. Please see the reset consumer node below
29 for usage details 29 for usage details
30 - ti,reset-bits : Contains the reset c 30 - ti,reset-bits : Contains the reset control register information
31 Should contain 7 cel 31 Should contain 7 cells for each reset exposed to
32 consumers, defined a 32 consumers, defined as:
33 Cell #1 : offset o 33 Cell #1 : offset of the reset assert control
34 register 34 register from the syscon register base
35 Cell #2 : bit posi 35 Cell #2 : bit position of the reset in the reset
36 assert c 36 assert control register
37 Cell #3 : offset o 37 Cell #3 : offset of the reset deassert control
38 register 38 register from the syscon register base
39 Cell #4 : bit posi 39 Cell #4 : bit position of the reset in the reset
40 deassert 40 deassert control register
41 Cell #5 : offset o 41 Cell #5 : offset of the reset status register
42 from the 42 from the syscon register base
43 Cell #6 : bit posi 43 Cell #6 : bit position of the reset in the
44 reset st 44 reset status register
45 Cell #7 : Flags us 45 Cell #7 : Flags used to control reset behavior,
46 availabl 46 available flags defined in the DT include
47 file <dt 47 file <dt-bindings/reset/ti-syscon.h>
48 48
49 SysCon Reset Consumer Nodes 49 SysCon Reset Consumer Nodes
50 =========================== 50 ===========================
51 Each of the reset consumer nodes should have t 51 Each of the reset consumer nodes should have the following properties,
52 in addition to their own properties. 52 in addition to their own properties.
53 53
54 Required properties: 54 Required properties:
55 -------------------- 55 --------------------
56 - resets : A phandle to the reset contr 56 - resets : A phandle to the reset controller node and an index number
57 to a reset specifier as defi 57 to a reset specifier as defined above.
58 58
59 Please also refer to Documentation/devicetree/ 59 Please also refer to Documentation/devicetree/bindings/reset/reset.txt for
60 common reset controller usage by consumers. 60 common reset controller usage by consumers.
61 61
62 Example: 62 Example:
63 -------- 63 --------
64 The following example demonstrates a syscon no 64 The following example demonstrates a syscon node, the reset controller node
65 using the syscon node, and a consumer (a DSP d 65 using the syscon node, and a consumer (a DSP device) on the TI Keystone 2
66 66AK2E SoC. 66 66AK2E SoC.
67 67
68 / { 68 / {
69 soc { 69 soc {
70 psc: power-sleep-controller@23 70 psc: power-sleep-controller@2350000 {
71 compatible = "syscon", 71 compatible = "syscon", "simple-mfd";
72 reg = <0x02350000 0x10 72 reg = <0x02350000 0x1000>;
73 73
74 pscrst: reset-controll 74 pscrst: reset-controller {
75 compatible = " 75 compatible = "ti,k2e-pscrst", "ti,syscon-reset";
76 #reset-cells = 76 #reset-cells = <1>;
77 77
78 ti,reset-bits 78 ti,reset-bits = <
79 0xa3c 79 0xa3c 8 0xa3c 8 0x83c 8 (ASSERT_CLEAR | DEASSERT_SET | STATUS_CLEAR) /* 0: dsp0 */
80 0xa40 80 0xa40 5 0xa44 3 0 0 (ASSERT_SET | DEASSERT_CLEAR | STATUS_NONE) /* 1: example */
81 >; 81 >;
82 }; 82 };
83 }; 83 };
84 84
85 dsp0: dsp0 { 85 dsp0: dsp0 {
86 ... 86 ...
87 resets = <&pscrst 0>; 87 resets = <&pscrst 0>;
88 ... 88 ...
89 }; 89 };
90 }; 90 };
91 }; 91 };
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