xref: /OK3568_Linux_fs/kernel/Documentation/devicetree/bindings/reset/st,sti-picophyreset.txt (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunSTMicroelectronics STi family Sysconfig Picophy SoftReset Controller
2*4882a593Smuzhiyun=============================================================================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunThis binding describes a reset controller device that is used to enable and
5*4882a593Smuzhiyundisable on-chip PicoPHY USB2 phy(s) using "softreset" control bits found in
6*4882a593Smuzhiyunthe STi family SoC system configuration registers.
7*4882a593Smuzhiyun
8*4882a593SmuzhiyunThe actual action taken when softreset is asserted is hardware dependent.
9*4882a593SmuzhiyunHowever, when asserted it may not be possible to access the hardware's
10*4882a593Smuzhiyunregisters and after an assert/deassert sequence the hardware's previous state
11*4882a593Smuzhiyunmay no longer be valid.
12*4882a593Smuzhiyun
13*4882a593SmuzhiyunPlease refer to Documentation/devicetree/bindings/reset/reset.txt
14*4882a593Smuzhiyunfor common reset controller binding usage.
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunRequired properties:
17*4882a593Smuzhiyun- compatible: Should be "st,stih407-picophyreset"
18*4882a593Smuzhiyun- #reset-cells: 1, see below
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunExample:
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun	picophyreset: picophyreset-controller {
23*4882a593Smuzhiyun		compatible = "st,stih407-picophyreset";
24*4882a593Smuzhiyun		#reset-cells = <1>;
25*4882a593Smuzhiyun	};
26*4882a593Smuzhiyun
27*4882a593SmuzhiyunSpecifying picophyreset control of devices
28*4882a593Smuzhiyun=======================================
29*4882a593Smuzhiyun
30*4882a593SmuzhiyunDevice nodes should specify the reset channel required in their "resets"
31*4882a593Smuzhiyunproperty, containing a phandle to the picophyreset device node and an
32*4882a593Smuzhiyunindex specifying which channel to use, as described in
33*4882a593SmuzhiyunDocumentation/devicetree/bindings/reset/reset.txt.
34*4882a593Smuzhiyun
35*4882a593SmuzhiyunExample:
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun	usb2_picophy0: usbpicophy@0 {
38*4882a593Smuzhiyun		resets = <&picophyreset STIH407_PICOPHY0_RESET>;
39*4882a593Smuzhiyun	};
40*4882a593Smuzhiyun
41*4882a593SmuzhiyunMacro definitions for the supported reset channels can be found in:
42*4882a593Smuzhiyuninclude/dt-bindings/reset/stih407-resets.h
43