cpm.txt (1865B)
1PPC4xx Clock Power Management (CPM) node 2 3Required properties: 4 - compatible : compatible list, currently only "ibm,cpm" 5 - dcr-access-method : "native" 6 - dcr-reg : < DCR register range > 7 8Optional properties: 9 - er-offset : All 4xx SoCs with a CPM controller have 10 one of two different order for the CPM 11 registers. Some have the CPM registers 12 in the following order (ER,FR,SR). The 13 others have them in the following order 14 (SR,ER,FR). For the second case set 15 er-offset = <1>. 16 - unused-units : specifier consist of one cell. For each 17 bit in the cell, the corresponding bit 18 in CPM will be set to turn off unused 19 devices. 20 - idle-doze : specifier consist of one cell. For each 21 bit in the cell, the corresponding bit 22 in CPM will be set to turn off unused 23 devices. This is usually just CPM[CPU]. 24 - standby : specifier consist of one cell. For each 25 bit in the cell, the corresponding bit 26 in CPM will be set on standby and 27 restored on resume. 28 - suspend : specifier consist of one cell. For each 29 bit in the cell, the corresponding bit 30 in CPM will be set on suspend (mem) and 31 restored on resume. Note, for standby 32 and suspend the corresponding bits can 33 be different or the same. Usually for 34 standby only class 2 and 3 units are set. 35 However, the interface does not care. 36 If they are the same, the additional 37 power saving will be seeing if support 38 is available to put the DDR in self 39 refresh mode and any additional power 40 saving techniques for the specific SoC. 41 42Example: 43 CPM0: cpm { 44 compatible = "ibm,cpm"; 45 dcr-access-method = "native"; 46 dcr-reg = <0x160 0x003>; 47 er-offset = <0>; 48 unused-units = <0x00000100>; 49 idle-doze = <0x02000000>; 50 standby = <0xfeff0000>; 51 suspend = <0xfeff791d>; 52};