1*4882a593SmuzhiyunSTMicroelectronics STi family Sysconfig Peripheral Powerdown Reset Controller 2*4882a593Smuzhiyun============================================================================= 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunThis binding describes a reset controller device that is used to enable and 5*4882a593Smuzhiyundisable on-chip peripheral controllers such as USB and SATA, using 6*4882a593Smuzhiyun"powerdown" control bits found in the STi family SoC system configuration 7*4882a593Smuzhiyunregisters. These have been grouped together into a single reset controller 8*4882a593Smuzhiyundevice for convenience. 9*4882a593Smuzhiyun 10*4882a593SmuzhiyunThe actual action taken when powerdown is asserted is hardware dependent. 11*4882a593SmuzhiyunHowever, when asserted it may not be possible to access the hardware's 12*4882a593Smuzhiyunregisters and after an assert/deassert sequence the hardware's previous state 13*4882a593Smuzhiyunmay no longer be valid. 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunPlease refer to reset.txt in this directory for common reset 16*4882a593Smuzhiyuncontroller binding usage. 17*4882a593Smuzhiyun 18*4882a593SmuzhiyunRequired properties: 19*4882a593Smuzhiyun- compatible: Should be "st,stih407-powerdown" 20*4882a593Smuzhiyun- #reset-cells: 1, see below 21*4882a593Smuzhiyun 22*4882a593Smuzhiyunexample: 23*4882a593Smuzhiyun 24*4882a593Smuzhiyun powerdown: powerdown-controller { 25*4882a593Smuzhiyun compatible = "st,stih407-powerdown"; 26*4882a593Smuzhiyun #reset-cells = <1>; 27*4882a593Smuzhiyun }; 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun 30*4882a593SmuzhiyunSpecifying powerdown control of devices 31*4882a593Smuzhiyun======================================= 32*4882a593Smuzhiyun 33*4882a593SmuzhiyunDevice nodes should specify the reset channel required in their "resets" 34*4882a593Smuzhiyunproperty, containing a phandle to the powerdown device node and an 35*4882a593Smuzhiyunindex specifying which channel to use, as described in reset.txt 36*4882a593Smuzhiyun 37*4882a593Smuzhiyunexample: 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun st_dwc3: dwc3@8f94000 { 40*4882a593Smuzhiyun resets = <&powerdown STIH407_USB3_POWERDOWN>, 41*4882a593Smuzhiyun }; 42*4882a593Smuzhiyun 43*4882a593SmuzhiyunMacro definitions for the supported reset channels can be found in: 44*4882a593Smuzhiyun 45*4882a593Smuzhiyuninclude/dt-bindings/reset/stih407-resets.h 46