1*c66ec88fSEmmanuel VadotSTMicroelectronics STi family Sysconfig Peripheral Powerdown Reset Controller 2*c66ec88fSEmmanuel Vadot============================================================================= 3*c66ec88fSEmmanuel Vadot 4*c66ec88fSEmmanuel VadotThis binding describes a reset controller device that is used to enable and 5*c66ec88fSEmmanuel Vadotdisable on-chip peripheral controllers such as USB and SATA, using 6*c66ec88fSEmmanuel Vadot"powerdown" control bits found in the STi family SoC system configuration 7*c66ec88fSEmmanuel Vadotregisters. These have been grouped together into a single reset controller 8*c66ec88fSEmmanuel Vadotdevice for convenience. 9*c66ec88fSEmmanuel Vadot 10*c66ec88fSEmmanuel VadotThe actual action taken when powerdown is asserted is hardware dependent. 11*c66ec88fSEmmanuel VadotHowever, when asserted it may not be possible to access the hardware's 12*c66ec88fSEmmanuel Vadotregisters and after an assert/deassert sequence the hardware's previous state 13*c66ec88fSEmmanuel Vadotmay no longer be valid. 14*c66ec88fSEmmanuel Vadot 15*c66ec88fSEmmanuel VadotPlease refer to reset.txt in this directory for common reset 16*c66ec88fSEmmanuel Vadotcontroller binding usage. 17*c66ec88fSEmmanuel Vadot 18*c66ec88fSEmmanuel VadotRequired properties: 19*c66ec88fSEmmanuel Vadot- compatible: Should be "st,stih407-powerdown" 20*c66ec88fSEmmanuel Vadot- #reset-cells: 1, see below 21*c66ec88fSEmmanuel Vadot 22*c66ec88fSEmmanuel Vadotexample: 23*c66ec88fSEmmanuel Vadot 24*c66ec88fSEmmanuel Vadot powerdown: powerdown-controller { 25*c66ec88fSEmmanuel Vadot compatible = "st,stih407-powerdown"; 26*c66ec88fSEmmanuel Vadot #reset-cells = <1>; 27*c66ec88fSEmmanuel Vadot }; 28*c66ec88fSEmmanuel Vadot 29*c66ec88fSEmmanuel Vadot 30*c66ec88fSEmmanuel VadotSpecifying powerdown control of devices 31*c66ec88fSEmmanuel Vadot======================================= 32*c66ec88fSEmmanuel Vadot 33*c66ec88fSEmmanuel VadotDevice nodes should specify the reset channel required in their "resets" 34*c66ec88fSEmmanuel Vadotproperty, containing a phandle to the powerdown device node and an 35*c66ec88fSEmmanuel Vadotindex specifying which channel to use, as described in reset.txt 36*c66ec88fSEmmanuel Vadot 37*c66ec88fSEmmanuel Vadotexample: 38*c66ec88fSEmmanuel Vadot 39*c66ec88fSEmmanuel Vadot st_dwc3: dwc3@8f94000 { 40*c66ec88fSEmmanuel Vadot resets = <&powerdown STIH407_USB3_POWERDOWN>, 41*c66ec88fSEmmanuel Vadot }; 42*c66ec88fSEmmanuel Vadot 43*c66ec88fSEmmanuel VadotMacro definitions for the supported reset channels can be found in: 44*c66ec88fSEmmanuel Vadot 45*c66ec88fSEmmanuel Vadotinclude/dt-bindings/reset/stih407-resets.h 46